U.S. patent application number 16/738662 was filed with the patent office on 2020-06-25 for hollow motor apparatuses and associated systems and methods.
This patent application is currently assigned to SZ DJI TECHNOLOGY CO., LTD.. The applicant listed for this patent is SZ DJI TECHNOLOGY CO., LTD. Invention is credited to Xiaoping HONG, Huai HUANG, Peng WANG, Jin ZHAO, Zhenhao ZHOU.
Application Number | 20200204038 16/738662 |
Document ID | / |
Family ID | 63669994 |
Filed Date | 2020-06-25 |
View All Diagrams
United States Patent
Application |
20200204038 |
Kind Code |
A1 |
HUANG; Huai ; et
al. |
June 25, 2020 |
HOLLOW MOTOR APPARATUSES AND ASSOCIATED SYSTEMS AND METHODS
Abstract
Hollow motor apparatuses and associated systems and methods for
manufacturing hollow motor apparatuses may be provided. In one
implementation, a hollow motor apparatus may include a rotor
assembly rotatable about a rotation axis, a stator assembly
positioned adjacent to, and coaxially with, the rotor assembly, and
a bearing assembly configured to maintain a position of the rotor
assembly relative to the stator assembly. The rotor assembly may
include an inner portion disposed around an opening configured to
receive and to rotate at least a portion of a payload. The bearing
assembly may be disposed outside of the inner portion of the rotor
assembly.
Inventors: |
HUANG; Huai; (Shenzhen,
CN) ; ZHAO; Jin; (Shenzhen, CN) ; WANG;
Peng; (Shenzhen, CN) ; HONG; Xiaoping;
(Shenzhen, CN) ; ZHOU; Zhenhao; (Shenzhen,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SZ DJI TECHNOLOGY CO., LTD |
Shenzhen City |
|
CN |
|
|
Assignee: |
SZ DJI TECHNOLOGY CO., LTD.
Shenzhen City
CN
|
Family ID: |
63669994 |
Appl. No.: |
16/738662 |
Filed: |
January 9, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15729518 |
Oct 10, 2017 |
10554097 |
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16738662 |
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PCT/CN2017/078678 |
Mar 29, 2017 |
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15729518 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 26/0875 20130101;
B64C 2201/042 20130101; H02K 7/14 20130101; H02K 7/088 20130101;
H02K 1/2706 20130101; H02K 1/148 20130101; H02K 7/116 20130101;
G02B 26/0883 20130101; B64C 39/024 20130101; H02K 1/27 20130101;
G02B 26/108 20130101; B64C 2201/108 20130101; H02K 15/165 20130101;
H02K 7/085 20130101 |
International
Class: |
H02K 7/14 20060101
H02K007/14; G02B 26/10 20060101 G02B026/10; H02K 1/27 20060101
H02K001/27; H02K 1/14 20060101 H02K001/14; H02K 7/08 20060101
H02K007/08; B64C 39/02 20060101 B64C039/02; G02B 26/08 20060101
G02B026/08 |
Claims
1. A hollow motor apparatus, comprising: a rotor assembly
configured for rotation about a rotation axis, the rotor assembly
having an inner portion disposed around an opening that is
configured to receive at least a portion of a payload and to rotate
the payload; a stator assembly positioned adjacent to the rotor
assembly and coaxially with the rotor assembly relative to the
rotation axis; and a bearing assembly disposed outside of the inner
portion of the rotor assembly and operably coupled to the rotor
assembly, the bearing assembly configured to maintain a position of
the rotor assembly relative to the stator assembly.
2. The apparatus of claim 1, wherein the payload comprises an
optical component configured for rotation with the rotor assembly
about the rotation axis, the optical component comprising at least
one of a prism or a reflector.
3-31. (canceled)
32. The apparatus of claim 1, wherein the stator assembly is
arranged within a first plane that is substantially perpendicular
to the rotation axis, and wherein the bearing assembly is arranged
within a second plane that is substantially perpendicular to the
rotation axis, the second plane being different from the first
plane.
33. (canceled)
34. The apparatus of claim 32, wherein the rotor assembly
comprises: a magnet yoke and a magnet coupled to the magnet yoke,
wherein the magnet yoke comprises a portion in contact with the
bearing assembly, and wherein the magnet is positioned either
radially internal to the stator assembly, external to the magnet
yoke, between the stator assembly and the bearing assembly, or
between the magnet yoke and the bearing assembly.
35-61. (canceled)
62. The apparatus of claim 1, wherein the bearing assembly
comprises: an inner portion coupled to the rotor assembly and
surrounding the inner portion of the rotor assembly; an outer
portion positioned radially external to the inner portion of the
bearing assembly; and at least one rolling component rotatably
positioned between the inner portion of the bearing assembly and
the outer portion of the bearing assembly.
63-82. (canceled)
83. A system, comprising: the hollow motor apparatus of claim 1;
and a second hollow motor apparatus comprising: a second rotor
assembly configured for rotation about a second rotation axis, the
second rotor assembly having an inner portion disposed around an
opening that is configured to receive at least a portion of a
payload; a second stator assembly positioned adjacent to the second
rotor assembly and coaxially with the second rotor assembly
relative to the second rotation axis; and a second bearing assembly
disposed outside of the inner portion of the second rotor assembly
and operably coupled to the second rotor assembly, the second
bearing assembly configured to maintain a position of the second
rotor assembly relative to the second stator assembly, wherein the
hollow motor apparatus and the second hollow motor apparatus are
positioned adjacent to one another.
84. The system of claim 83, wherein the hollow motor apparatus and
the second hollow motor apparatus have a common rotation axis.
85-113. (canceled)
114. A method for positioning a bearing assembly in a hollow motor
apparatus, the hollow motor apparatus comprising: a rotor assembly
configured for rotation about a rotation axis, and a stator
assembly positioned adjacent to the rotor assembly and coaxially
with the rotor assembly relative to the rotation axis, the bearing
assembly comprising: an inner portion coupled to the rotor
assembly, an outer portion positioned radially external to the
inner portion of the bearing assembly, and at least one rolling
component rotatably positioned between the inner portion of the
bearing assembly and the outer portion of the bearing assembly,
wherein the method comprises: attaching the outer portion of the
bearing assembly to a support; and applying a force to the inner
portion of the bearing assembly along a direction parallel to the
rotation.
115-118. (canceled)
119. The apparatus of claim 1, wherein the bearing assembly
comprises: an inner portion; an outer portion positioned radially
external to the inner portion of the bearing assembly; and at least
one rolling component rotatably positioned between the inner
portion of the bearing assembly and the outer portion of the
bearing assembly, wherein the inner portion of the bearing assembly
and the outer portion of the bearing assembly are configured to
move in opposite directions when electrical current flows in the
stator assembly.
120. The apparatus of claim 119, wherein the rotor assembly
comprises a magnet, at least one of the inner portion of the
bearing assembly or the outer portion of the bearing assembly being
coupled to the rotor assembly, and wherein when the electrical
current flows in the stator assembly: the inner portion of the
bearing assembly and the outer portion of the bearing assembly are
configured to be driven in the opposite directions, and the magnet
is configured to move toward the stator assembly along the rotation
axis.
121. The apparatus of claim 1, wherein the stator assembly and the
bearing assembly are configured to surround the rotor assembly when
the stator assembly and bearing assembly are arranged side by
side.
122. The apparatus of claim 2, further comprising: a second optical
component configured to rotate about the rotation axis, wherein the
optical component is configured to rotate about the rotation axis
at a first rotational speed and the second optical component is
configured to rotate about the rotation axis at a second rotational
speed that is different from the first rotational speed.
123. The apparatus of claim 62, further comprising: a chassis
coupled to the outer portion of the bearing assembly, wherein the
stator assembly is fixedly coupled to a housing and the chassis is
fixedly coupled to the housing
124. The apparatus of claim 123, wherein the inner portion of the
bearing assembly is configured to be driven into a predetermined
position by a force along the rotation axis.
125. The apparatus of claim 123, further comprising: a first magnet
coupled to the inner portion of the bearing assembly; and a second
magnet facing the first magnet, wherein the bearing assembly is
configured to be driven into a predetermined position by a magnetic
force generated between the first magnet and the second magnet.
126. The system of claim 83, further comprising: a first magnet
coupled with the rotor assembly of the hollow motor apparatus; and
a second magnet coupled with the second rotor assembly of the
second hollow motor apparatus, the second magnet facing the first
magnet, wherein the first magnet and second magnet are configured
to position the bearing assembly of the hollow motor apparatus and
the second bearing assembly of the second hollow motor apparatus in
a predetermined configuration.
127. The system of claim 126, wherein the first magnet and the
second magnet are configured to respectively apply opposing forces
on the inner portion of the hollow motor apparatus and the inner
portion of the second hollow motor apparatus.
128. The apparatus of claim 83, wherein the rotor assembly and the
second rotor assembly are configured to rotate at one or more of
different speed or different directions.
129. The apparatus of claim 83, wherein the rotor assembly is
configured to rotate a first light bending element, and wherein the
second rotor assembly is configured to rotate a second light
bending element.
130. The apparatus of claim 129, wherein the first light bending
element is a first prism, and the second light bending element is a
second prism or a reflector.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The present application is a continuation application of
U.S. application Ser. No. 15/729,518, filed Oct. 10, 2017, which is
a continuation application of International Application No.
PCT/CN2017/078678, filed Mar. 29, 2017, both of which are herein
incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] The present technology is directed generally to hollow motor
apparatuses, associated systems, and methods for manufacturing the
same. More particularly, embodiments of the present technology
relate to a hollow motor that can accommodate a component (e.g., a
light source, a lens, and/or other suitable components)
therein.
BACKGROUND
[0003] Traditionally, an electrical motor includes a stator and a
rotor rotatable relative to the stator. The rotor includes a magnet
and the stator includes a set of winding wires. When an electrical
current passes through the winding wires, a magnetic field is
formed which then rotates the rotor relative to the stator. There
are various structural designs for the electrical motor. For
example, an "inner-rotor" type electrical motor has a rotor
positioned generally internal to the stator. On the contrary, an
"outer-rotor" type electrical motor has a rotor positioned
generally external to the stator. In general, traditional
electrical motors are not suitable for positioning additional
rotatable components/elements therein at least because they do not
have sufficient space to accommodate such components/elements. Due
to a need for driving a rotatable component positioned in an
electrical motor, it is beneficial to have an improved apparatus or
system to address this need.
SUMMARY
[0004] The following summary is provided for the convenience of the
reader and identifies several representative embodiments of the
disclosed technology. Generally speaking, the present technology
provides an improved hollow motor apparatus that enables a user to
position a component (an element, a module, and/or other suitable
devices) therein such that the component can rotate with a rotor
assembly of the hollow motor apparatus. For example, embodiments of
the present technology include a hollow electrical motor that has
an interior space (or an opening) to accommodate one or more
optical components (e.g., lenses, prisms, and/or other suitable
optical devices) and/or a light source (e.g., a light source
emitting visible or non-visible radiation, a laser emitter, and/or
other suitable light sources).
[0005] In some embodiments, the optical component rotates with the
rotor assembly and the light source does not rotate with the rotor
assembly (e.g., the light source is fixedly coupled to a stator
assembly of the hollow electrical motor). In some embodiments, both
the optical component and the light source can rotate with the
rotor assembly. In such embodiments, various aspects of the light
emitted from the light source (e.g., by changing an emitting angle,
a color, a brightness, and/or other suitable parameters) can be
configured or adjusted so as to perform scanning, ranging,
signifying different statuses of the UAV and/or performing other
functions.
[0006] By rotating the optical component, the user can direct the
light emitted from the light source in desirable directions. For
example, the present technology enables the user to generate a set
of focused light rays (or a set of parallel light rays, in other
embodiments). The focused light rays (e.g., laser rays) can be used
to transmit information to the user of a moveable apparatus (e.g.,
a vehicle or a UAV) coupled to the hollow electrical motor. In some
embodiments, the focused light rays can be used for ranging and
scanning objects or obstacles in a surrounding environment of the
moveable apparatus. The hollow electrical motor can also be used to
drive the moveable apparatus (e.g., by coupling to and rotating a
propeller). Accordingly, embodiments of the present technology
provide an improved hollow electrical motor that can (1) rotate
optical components positioned in a compact hollow structure (e.g.,
a range finder or a Lidar system); and (2) drive a UAV and signify
a status of the UAV.
[0007] Representative embodiments of the present technology include
a hollow motor apparatus having a rotor assembly, a stator
assembly, and a positioning component (e.g., a bearing assembly)
positioned to maintain a location of the rotor assembly relative to
the stator assembly. The rotor assembly is positioned to be
rotatable about a rotation axis (e.g., an axis passing through the
rotation center of the rotor assembly when it is rotating). The
rotor assembly has an inner portion and an outer portion. The inner
portion circumferentially faces the rotation axis and bounds, at
least in part, an interior chamber for accommodating a component to
be positioned inside the hollow motor apparatus. The bearing
assembly is positioned external to the inner portion of the rotor
assembly (e.g., farther away from the rotation axis). In some
embodiments, the bearing assembly is operably (e.g., rotatably)
coupled to the rotor assembly and the stator assembly. The bearing
assembly can rotate relative to the rotor assembly and/or the
stator assembly while maintaining the relative locations of the
rotor/stator assemblies. The bearing assembly can include a
bearing, a rolling ball, a rolling pin, and/or other suitable
devices. In some embodiments, additional components, such as a set
of lens or prisms, can be positioned in the interior space and
coupled to the rotor assembly.
[0008] Some embodiments of the present technology provide a hollow
apparatus having an annular structure, an optical component, and a
driving assembly. The annular structure (which can include, for
example, a hollow cylinder, a pipe-shaped structure, and/or other
suitable hollow structures) is positioned to be rotatable about a
rotation axis. The annular structure has an inner portion, which
circumferentially faces the rotation axis and bounds (or defines),
at least in part, an interior chamber (or an opening). The interior
chamber is used to accommodate the optical component, which is
carried by the annular structure. The driving assembly is
configured to rotate the annular structure (with the optical
component) so as to position the optical component at a particular
(angular) location (e.g., such that the optical component can
direct light from a light source to a desirable target area). In
some embodiments, the driving assembly can be a stator assembly and
the annular structure can be a rotor assembly. In some embodiments,
the driving assembly can include a driving component (e.g., a motor
or a means that can rotate other components). In some embodiments,
the driving component can be coupled to the rotor assembly via a
positioning component (e.g., a belt, a gear, a pulley and/or other
suitable devices) that is positioned/configured to maintain a
location of the annular structure relative to the driving
assembly.
[0009] Some embodiments of the present technology can be
implemented as methods for manufacturing and/or using a hollow
motor apparatus. A representative method can include, inter alia,
(1) performing a rotation-balance analysis on an optical component
to generate an analysis result; (2) at least partially based on the
analysis result, weight-balancing the optical component; (3)
positioning the optical component in an interior chamber defined at
least in part by an inner portion of a rotor assembly; (4) coupling
the optical component to the rotor assembly; (5) coupling the rotor
assembly to a bearing assembly; and (6) coupling the bearing
assembly to a stator assembly. The bearing assembly is positioned
external to the inner portion of the rotor assembly so as to
maintain a location (e.g., a radial location relative to a rotation
axis of the rotor assembly) of the rotor assembly relative to the
stator assembly. Methods and systems in accordance with embodiments
of the present technology can include any one or a combination of
any of the foregoing elements described above.
[0010] The present technology also includes a method for balancing
a rotatable component to be positioned inside the hollow motor
apparatus. The method includes, for example, (1) determining the
shape and the density of the rotatable component; (2) performing a
weight-balance test at multiple planes (which are generally
perpendicular to a rotation axis about which the rotatable
component rotates); (3) consolidating the results of the
weight-balance test for the multiple planes; (4) determining a
counterweight (or a portion of the rotatable component that needs
to be removed) to be coupled to the rotatable component (or to a
rotor assembly coupled to the rotatable component) and an expected
location of the counterweight; and (5) positioning the
counterweight at the expected location. In some embodiments, the
method can be used to balance multiple rotatable components. In
such embodiments, the multiple rotatable components can rotate at
different rotational speeds (e.g., driven by different motors or
driven by different gears coupled to one motor).
[0011] In some embodiments, the present technology enables a user
to determine a combination of rotatable components to be installed
in a hollow motor apparatus so as to perform desirable functions
described above. For example, a user can select a combination of a
focusing lens, a coloring lens, and a point light source. In this
embodiment, the selected combination can generate a focused light
beam with a specific color. As another example, the user can select
two asymmetrical lenses and a laser light source. In this
embodiment, the selected combination can generate multiple laser
rays that can be properly distributed in a target area (e.g., the
two asymmetrical lenses can rotate at different rotational speeds
and directions, so as to achieve this goal). In such embodiments,
the reflected laser rays can be received and then be used to
measure the distance between the target area and the laser light
source (or a surface feature, contour, terrain, and/or other
suitable parameters of the target area). Having a proper
distribution of laser rays in the target area can be beneficial at
because this can effectively increase the accuracy of the related
measurement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a schematic diagram illustrating a UAV having a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0013] FIG. 1B is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0014] FIG. 1C is a partially schematic cross-sectional view
illustrating a propeller and a hollow motor assembly configured in
accordance with representative embodiments of the present
technology.
[0015] FIG. 1D is a partially schematic cross-sectional view
illustrating two hollow motor assemblies in a Lidar system
configured in accordance with representative embodiments of the
present technology.
[0016] FIG. 2 is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0017] FIG. 3A is a cross sectional view illustrating components of
a hollow motor assembly configured in accordance with
representative embodiments of the present technology.
[0018] FIG. 3B is a cross-sectional view taken along line A-A of
FIG. 3A illustrating components of a hollow motor assembly
configured in accordance with representative embodiments of the
present technology.
[0019] FIG. 4A is a top view illustrating components of a hollow
motor assembly configured in accordance with representative
embodiments of the present technology.
[0020] FIG. 4B is a cross-sectional view taken along line B-B of
FIG. 4A illustrating components of a hollow motor assembly
configured in accordance with representative embodiments of the
present technology.
[0021] FIG. 4C is a cross-sectional view taken along line B-B of
FIG. 4A illustrating components of another hollow motor assembly
configured in accordance with representative embodiments of the
present technology.
[0022] FIG. 4D is an isometric, schematic view illustrating
components of a hollow motor assembly configured in accordance with
representative embodiments of the present technology.
[0023] FIG. 5A is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0024] FIG. 5B is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0025] FIG. 5C is an isometric view illustrating components of
another hollow motor assembly configured in accordance with
representative embodiments of the present technology.
[0026] FIG. 5D includes an end view illustrating components of yet
another hollow motor assembly configured in accordance with
representative embodiments of the present technology.
[0027] FIG. 5E is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0028] FIGS. 5F, 5G, and 5H are schematic diagrams illustrating
methods for pre-positioning or pre-tightening in accordance with
representative embodiments of the present technology.
[0029] FIG. 6A is an isometric view illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0030] FIG. 6B is an isometric view illustrating a stator assembly
configured in accordance with representative embodiments of the
present technology.
[0031] FIG. 6C is an isometric view illustrating another stator
assembly configured in accordance with representative embodiments
of the present technology.
[0032] FIG. 6D is an isometric view illustrating a stator segment
configured in accordance with representative embodiments of the
present technology.
[0033] FIG. 7A is a top view illustrating components of a hollow
assembly configured in accordance with representative embodiments
of the present technology.
[0034] FIG. 7B is an isometric view illustrating components of a
hollow assembly configured in accordance with representative
embodiments of the present technology.
[0035] FIG. 7C is an isometric view illustrating components of
another hollow assembly configured in accordance with
representative embodiments of the present technology.
[0036] FIG. 8 is a top view illustrating components of yet another
hollow assembly configured in accordance with representative
embodiments of the present technology.
[0037] FIG. 9A is a schematic diagram illustrating components of a
hollow motor assembly configured in accordance with representative
embodiments of the present technology.
[0038] FIGS. 9B and 9C are isometric views illustrating multiple
optical components configured in accordance with embodiments of the
present technology.
[0039] FIG. 10 is a schematic diagram illustrating multiple optical
components configured in accordance with embodiments of the present
technology.
[0040] FIGS. 11A and 11B are schematic diagrams illustrating a
counterweight configured in accordance with representative
embodiments of the present technology.
[0041] FIG. 12 is a schematic diagram illustrating a
rotation-balance analysis for an optical component configured in
accordance with representative embodiments of the present
technology.
[0042] FIG. 13 is a flowchart illustrating a method in accordance
with representative embodiments of the present technology.
[0043] FIG. 14 is a flowchart illustrating a method in accordance
with representative embodiments of the present technology.
DETAILED DESCRIPTION
1. Overview
[0044] The present technology is directed generally to hollow motor
apparatuses and associated systems and methods. A representative
hollow motor apparatus in accordance with the present technology
can be used to (1) provide power to move a moveable device (e.g., a
UAV); (2) visually present indications or signals that relate to a
status of the moveable device (e.g., an indication that the UAV is
low on battery power) or other information that an operator of the
moveable device wants to convey; and/or (3) detect the status of an
object outside the moveable device. For example, the operator can
use a laser light source positioned in the hollow apparatus to
detect the existence of (or the distance to) an obstacle outside
the moveable device. A representative hollow motor apparatus in
accordance with the present technology includes a hollow structure
that can be used to accommodate a component or payload (e.g., a
lens, a prism, a light source, and/or other suitable devices) that
(1) is positioned inside the hollow motor apparatus, and (2) is
rotatable with a rotor assembly (or an annular structure) of the
hollow motor apparatus. Via this arrangement, the moveable device
can have additional functions (e.g., visually presenting
information and/or detecting an object) without requiring extra
space for installing additional parts/components. In other words,
the present technology efficiently utilizes the interior space
inside the hollow motor apparatus to make additional functions
possible.
[0045] Several details describing structures or processes that are
well-known and often associated with electrical motors and
corresponding systems and subsystems, but that may unnecessarily
obscure some significant aspects of the disclosed technology, are
not set forth in the following description for purposes of clarity.
Moreover, although the following disclosure sets forth several
embodiments of different aspects of the technology, several other
embodiments can have different configurations and/or different
components than those described in this section. Accordingly, the
technology may have other embodiments with additional elements
and/or without several of the elements described below with
reference to FIGS. 1-13.
[0046] FIGS. 1-13 are provided to illustrate representative
embodiments of the disclosed technology. Unless provided for
otherwise, the drawings are not intended to limit the scope of the
claims in the present application. Many embodiments of the
technology described below may take the form of computer- or
controller-executable instructions, including routines executed by
a programmable computer or controller. Those skilled in the
relevant art will appreciate that the technology can be practiced
on computer or controller systems other than those shown and
described below. The technology can be embodied in a
special-purpose computer or data processor that is specifically
programmed, configured or constructed to perform one or more of the
computer-executable instructions described below. Accordingly, the
terms "computer" and "controller" as generally used herein refer to
any suitable data processor and can include Internet appliances and
handheld devices (including palm-top computers, wearable computers,
cellular or mobile phones, multi-processor systems, processor-based
or programmable consumer electronics, network computers, mini
computers, a programmed computer chip, and the like).
[0047] Information handled by these computers and controllers can
be presented at any suitable display medium, including a CRT
display or an LCD. Instructions for performing computer- or
controller-executable tasks can be stored in or on any suitable
computer-readable medium, including hardware, firmware or a
combination of hardware and firmware. Instructions can be contained
in any suitable memory device, including, for example, a flash
drive, USB device, or other suitable medium. In particular
embodiments, the term "component" can include hardware, firmware,
or a set of instructions stored in a computer-readable medium.
2. Representative Embodiments
[0048] FIG. 1A is a schematic diagram illustrating a UAV 100 having
a hollow motor assembly 101 configured in accordance with
representative embodiments of the present technology. As shown in
FIG. 1A, the UAV 100 includes an airframe (or a main body) 106, a
UAV controller 102 carried by the UAV 100 and configured to control
the UAV 100, a gimbal 103 coupled to the airframe 106, and a UAV
payload 104 coupled to and carried by the gimbal 103. In some
embodiments, the UAV payload 104 can include an imaging device. In
particular embodiments, the imaging device can include an image
camera (e.g., a camera that is configured to capture video data,
still data, or both). The camera can be sensitive to wavelengths in
any of a variety of suitable wavelength bands, including visual,
ultraviolet, infrared or combinations thereof. In still further
embodiments, the UAV payload 104 can include other types of
sensors, other types of cargo (e.g., packages or other
deliverables), or both. In many of these embodiments, the gimbal
103 supports the UAV payload 104 in a way that allows the UAV
payload 104 to be independently positioned relative to the airframe
106. Accordingly, for example, when the UAV payload 104 includes an
imaging device, the imaging device can be moved relative to the
airframe 106 to track a target.
[0049] The airframe 106 can include a central portion 106a and one
or more outer portions 106b. In particular embodiments, the
airframe 106 can include four outer portions 106b (e.g., arms) that
are spaced apart from each other as they extend away from the
central portion 106a. In other embodiments, the airframe 106 can
include other numbers of outer portions 106b. In any of these
embodiments, individual outer portions 106b can support one or more
components of a propulsion system that drives the UAV 100. For
example, individual arms can support corresponding individual
motors 101a that drive corresponding propellers 105. The UAV
controller 102 is configured to control the UAV 100. In some
embodiments, the UAV controller 102 can include a processor coupled
and configured to control the other components of the UAV 100. In
some embodiments, the UAV controller 102 can be coupled to a
storage component that is configured to, permanently or
temporarily, store information associated with or generated by the
UAV 100. In particular embodiments, the storage component can
include a disk drive, a hard disk, a flash drive, a memory, or the
like. As shown in FIG. 1A, the UAV 100 can also include a hollow
motor assembly 101b configured to rotate a rotatable lens/prism of
a range finding device/component (or a range scanning device or a
Lidar system). In some embodiments, the hollow motor assembly 101b
can be carried by a vehicle (e.g., a self-driving car).
[0050] FIG. 1B is an isometric view illustrating components of a
hollow motor assembly 101 configured in accordance with
representative embodiments of the present technology. As shown in
FIG. 1B, the hollow motor assembly 101 includes a rotor assembly
107, a stator assembly 108, and a positioning component (e.g., a
bearing assembly) 109. In some embodiments, the rotor assembly 107
includes a magnet 107a and a magnet yoke 107b coupled to the magnet
107a. The rotor assembly 107 is positioned/configured to rotate
about a rotation axis R. The rotor assembly 107 includes an inner
surface 116 that circumferentially faces or bounds an opening or an
interior chamber 117. As noted in FIG. 1B, a radial direction and
an angular direction can be defined at least partially based on the
rotation axis R.
[0051] The stator assembly 108 can include a first stator portion
108a and a second stator portion 108b positioned opposite to the
first stator portion 108a. The stator assembly 108 is not rotatable
and is fixedly attached to other components of the UAV 100 (e.g., a
housing). When an electrical current passes through a winding
component (discussed in further detail below with reference to FIG.
6E) of the stator assembly 108, a magnetic field is formed, which
moves the magnet 107a. By controlling the electrical current and
the generated magnetic field, the rotor assembly 107 can be rotated
at various rotational speeds. In some embodiments, the stator
assembly 108 can have any number of stator portions (such as
illustrated in FIG. 1B), or can have a full annular structure (such
as discussed elsewhere herein).
[0052] The bearing assembly 109 is positioned adjacent to the rotor
assembly 107 and configured to maintain the (radial) location of
the rotor assembly 107 relative to the stator assembly 108. In the
illustrated embodiments, the bearing assembly 109 includes a
bearing that can rotate about a rotation axis A. Because the
bearing assembly 109 can rotate relative to the rotor assembly 107,
it can effectively position the rotor assembly 107 without unduly
interfering with the rotation of the rotor assembly 107. In the
illustrated embodiment, the hollow motor assembly 101 further
includes a guide rail (or protrusion) 115 positioned adjacent to or
as a part of the rotor assembly 107. In the illustrated embodiment,
the guide rail 115 is positioned to facilitate maintaining the
location of the bearing assembly 109 relative to the rotor assembly
107. In other embodiments, the guide rail 115 can implemented as a
protrusion extending from the bearing assembly 109. In some
embodiments, the guide rail 115 can also facilitate maintaining the
location of the bearing assembly 109 relative to the stator
assembly 108.
[0053] FIG. 1C is a partially schematic cross-sectional view
illustrating a propeller 105 and a hollow motor assembly 101
configured in accordance with representative embodiments of the
present technology. The propeller 105 includes a first blade 110, a
second blade 111 opposite to the first blade 110, and a hub 112.
When the propeller 105 is rotating, the outer edges of the
first/second blades 110, 111 can together define a rotational disk.
The hollow motor assembly 101 includes a rotor assembly 107 and a
stator assembly 108 positioned external to the rotor assembly 107.
In this arrangement, the hollow motor assembly 101 is referred to
as an "inner-rotor" motor. In other embodiments, however, the
hollow motor assembly 101 can be an "outer-rotor" motor (as
discussed below with reference to FIG. 5E). In some embodiments,
the stator assembly 108 can be fixedly attached to other components
(e.g., a housing) of the UAV 100. The rotor assembly 107 can rotate
relative to the stator assembly 108. As shown, the rotor assembly
107 has an inner surface 116 that circumferentially faces or bounds
an interior chamber (or interior space) 117. The interior chamber
117 is at least partially defined by the inner surface 116 of the
rotor assembly 107. The interior chamber 117 can be used to
accommodate one or more rotatable or non-rotatable components.
[0054] As shown in FIG. 1C, an optical component, a transparent
component or other suitable component 114 can be positioned in the
interior chamber 117 and coupled to the rotor assembly 107. When
the rotor assembly 107 rotates, the optical component 114 can
rotate with the rotor assembly 107. In some embodiments, the
optical component 114 can include a lens, a prism, or a combination
thereof. In the illustrated embodiment of FIG. 1C, a light source
113 is positioned in the interior chamber 117 and coupled to a
non-rotatable component (e.g., a housing or the stator component
108 of the UAV 100). The light source 113 is configured to emit
light rays to the propeller 105 through the optical component 114.
The optical component 114 can change the direction of the light
rays and then further direct them to the propeller 105. The light
rays can then be emitted out of the propeller 105 to form a visual
indication or signal that can convey information (e.g., a status of
the UAV 100) to an operator or a bystander. In some embodiments,
the optical component 114 can change a parameter of the light rays.
For example, the optical component 114 can include a color filter
that can change the color of the incoming light rays. In some
embodiments, the light source 113 can be non-rotatable (as
discussed above) and in other embodiments, the light source 113 can
be rotatable (e.g., can be coupled to the rotor assembly 107).
[0055] In some embodiments, the hollow motor assembly 101 can be
used in a range finding/scanning system (or a Lidar system). For
example, FIG. 1D is a partially schematic cross-sectional view
illustrating first and second hollow motor assemblies 101a, 101b in
a Lidar system 145 configured in accordance with representative
embodiments of the present technology. The first hollow motor
assembly 101a and the second hollow motor assembly 101b are
positioned axially adjacent to each other (e.g., along a rotation
axis R). The first hollow motor assembly 101a includes a first
stator assembly 108a positioned radially external to a first rotor
assembly 107a. The second hollow motor assembly 101b includes a
second stator assembly 108b positioned radially external to a
second rotor assembly 107b. In the illustrated embodiment, the
first/second hollow motor assemblies 101a, 101b are "inner-rotor"
type electrical motors. In other embodiments, one (or both) of the
first/second hollow motor assemblies 101a, 101b can be an
"outer-rotor" type electrical motor. As shown, the Lidar system 145
includes a Risley prism pair, which further includes a first prism
114a and a second prism 114b. The first prism 114a is positioned in
a first opening 117a of the first hollow motor assembly 101a. The
second prism 114b is positioned in a second opening 117b of the
second hollow motor assembly 101b. The first prism 114a is coupled
to and rotates with the first rotor assembly 107a. The second prism
114b is coupled to and rotates with the second rotor assembly 107b.
By rotating the first and second prisms 114a, 114b, the Lidar
system 145 can perform various range finding/scanning tasks.
Embodiments of rotating multiple optical components are further
discussed in detail with reference to FIG. 10.
[0056] FIG. 2 is an isometric view illustrating components of a
hollow motor assembly 201 configured in accordance with
representative embodiments of the present technology. As shown, the
hollow motor assembly 201 includes a rotor assembly 207 having an
annular structure. The rotor assembly 207 is positioned to rotate
about a rotation axis R. The hollow motor assembly 201 also
includes a stator assembly 208 positioned external to the rotor
assembly 207. As shown, the stator assembly 208 includes three
stator portions 208a, 208b, and 208c. The stator assembly 208
remains stationary as the rotor assembly 207 rotates. The hollow
motor assembly 201 includes three bearing assemblies 109a, 109b,
and 109c. In the illustrated embodiment, the stator portions 208a,
208b, and 208c and the bearing assemblies 109a, 109b, and 109c are
positioned along a circumference C (of the rotor assembly 207) in a
plane P that is generally perpendicular to the rotation axis R. In
FIG. 2, each of the bearing assemblies 109a-c is positioned between
two of the stator portions 208a-c. In some embodiments, the hollow
motor assembly 201 can include different numbers of bearing
assemblies and stator portions than illustrated.
[0057] FIG. 3A is a cross sectional view illustrating components of
a hollow motor assembly 301 configured in accordance with
representative embodiments of the present technology. FIG. 3B is a
cross-sectional view along line A-A of FIG. 3A illustrating
components of the hollow motor assembly 301. As shown, the hollow
motor assembly 301 includes a rotor assembly 307 having an annular
structure (and an annular magnet 320). The rotor assembly 307 is
positioned to rotate about a rotation axis R. The hollow motor
assembly 301 includes a stator assembly 308 positioned radially
external to the rotor assembly 307. As shown, the stator assembly
308 includes two stator portions 308a and 308b positioned opposite
to each other. The stator assembly 208 remains stationary when the
rotor assembly 307 rotates. The hollow motor assembly 301 includes
four bearing assemblies 109a, 109b, 109c, and 109d. In the
illustrated embodiment, the stator portions 308a and 308b and the
bearing assemblies 109a, 109b, 109c, and 109d are positioned around
a circumference of the rotor assembly 307 in a plane that is
generally perpendicular to the rotation axis R. As shown in FIG.
3A, each of the stator portions 208a, 208b is positioned between
two of the positioning components 109a-d. In other embodiments, the
hollow motor assembly 301 can include different numbers of bearing
assemblies and stator portions.
[0058] As shown in FIG. 3B, the hollow motor assembly 301 includes
a guide rail (or protrusion) 315 extending radially outwardly from
the rotor assembly 307. The guide rail 315 is positioned to
facilitate maintaining the location (e.g., the axial location) of
the bearing assemblies 109a-d relative to the rotor assembly
107.
[0059] FIG. 4A is a top view illustrating components of a hollow
motor 401 assembly configured in accordance with representative
embodiments of the present technology. FIG. 4B is a cross-sectional
view along line B-B of FIG. 4A illustrating components of the
hollow motor assembly 401. As shown, the hollow motor assembly 401
includes a rotor assembly 407, a stator assembly 408, and a
positioning component 409 positioned between the rotor assembly 407
and the stator assembly 408. The rotor assembly 407 is positioned
to rotate about a rotation axis R. The stator assembly 408 is
positioned external to the rotor assembly 407 and does not rotate.
As shown, the rotor assembly 407 is positioned adjacent to but is
rotatable relative to the stator assembly 408. In the illustrated
embodiments shown in FIGS. 4A and 4B, the positioning component 409
includes multiple rolling balls positioned around a circumference
of the rotor assembly 407 in a plane generally perpendicular to the
rotation axis R. The positioning component 409 is positioned in the
integral housing that is formed by the rotor assembly 407 and the
stator assembly 408. As shown, both the rotor assembly 407 and the
stator assembly 408 have an annular structure. In some embodiments,
the positioning component 409 can include an annular structure.
[0060] FIG. 4C is a cross-sectional view along line B-B of FIG. 4A
illustrating another embodiment of the hollow motor assembly 401a.
In this embodiment, the hollow motor assembly 401a includes a
positioning component 409a which further includes multiple rolling
pins positioned around a circumference of the rotor assembly 407 in
a plane generally perpendicular to the rotation axis R.
[0061] FIG. 4D is an isometric, schematic view illustrating
components of a hollow motor assembly 401b configured in accordance
with representative embodiments of the present technology. The
hollow motor assembly 401b includes a rotor assembly 407 and a
stator assembly 408 positioned external to the rotor assembly 407.
The rotor assembly 407 is positioned to rotate about a rotation
axis R relative to the stator assembly 408 (which does not rotate).
In this embodiment, the hollow motor assembly 401b includes a
positioning component 409b which further includes multiple rolling
balls. As shown, each of the rolling balls is positioned in a space
defined by a support component 417 positioned between the rotor
assembly 407 and the stator assembly 408. The support component 417
is configured to maintain the location of the positioning component
409b relative to the stator assembly 408 and/or the rotor assembly
407.
[0062] FIG. 5A is an isometric view illustrating components of a
hollow motor assembly 501a configured in accordance with
representative embodiments of the present technology. As shown, the
hollow motor assembly 501a includes a rotor assembly 507 having an
annular structure. The rotor assembly 507 is positioned to rotate
about a rotation axis R. The hollow motor assembly 501a includes a
stator assembly 508 positioned external to the rotor assembly 507.
As shown, the stator assembly 508 includes two stator portions 508a
and 508b positioned opposite to each other. The stator assembly 508
remains stationary when the rotor assembly 507 rotates. The hollow
motor assembly 501a includes four bearing assemblies 509a, 509b,
509c, and 509d (note that the bearing assembly 509d is not visible
in FIG. 5A). In the illustrated embodiment, the stator portions
508a and 508b are positioned along a circumference of the rotor
assembly 507 in a plane that is generally perpendicular to the
rotation axis R. The bearing assemblies 509a, 509b, 509c, and 509d
are positioned along another circumference of the rotor assembly
507 in another plane that is generally perpendicular to the
rotation axis R. In other embodiments, the hollow motor assembly
501a can include different numbers of bearing assemblies and/or
stator portions than are shown in FIG. 5A. In some embodiments, at
least one of the stator portions 508a and 508b can be positioned
axially in alignment with a least one of the bearing assemblies
509a-d. In other embodiments, none of the stator portions 508a and
508b is positioned axially in alignment with any one of the bearing
assemblies 509a-d.
[0063] FIG. 5B is an isometric view illustrating components of a
hollow motor assembly 501b configured in accordance with
representative embodiments of the present technology. As shown, the
hollow motor assembly 501b includes a rotor assembly 507 positioned
to rotate about a rotation axis R. As shown, the rotor assembly 507
includes a magnet 520 and a magnet yoke 522. The magnet yoke 522
includes an outer portion 507a and an inner portion 507b. The inner
portion 507b includes an inner surface 516 that circumferentially
faces or bounds an interior chamber (or interior space) 517. The
interior chamber or space 517 can be used to accommodate an optical
component (e.g., a lens, a prism, and/or other suitable devices)
and/or a light source. The outer portion 507a is formed with a
recess 518 configured to accommodate the magnet 520 which has a
flat structure. In some embodiments, the inner portion 507b is
positioned generally parallel to the rotation axis R, and the outer
portion 507a is portioned generally perpendicular to the rotation
axis R.
[0064] As shown in FIG. 5B, the hollow motor assembly 501b includes
a stator assembly 508 positioned external to at least a portion
(e.g., the inner portion 507b) of the rotor assembly 507. As shown,
the stator assembly 508 includes two stator portions 508a and 508b
positioned opposite to each other. The stator assembly 508 remains
stationary as the rotor assembly 507 rotates. The hollow motor
assembly 501b includes four bearing assemblies 509a, 509b, 509c,
and 509d (note that the bearing assembly 509d is not visible in
FIG. 5B). In the illustrated embodiment, the stator portions 508a
and 508b are positioned along a first circumference of the rotor
assembly 507 in a plane that is generally perpendicular to the
rotation axis R. The bearing assemblies 509a, 509b, 509c, and 509d
are positioned along a second circumference of the rotor assembly
507 in another plane that is generally perpendicular to the
rotation axis R. In some embodiments, the radius of the first
circumference can be generally the same as the radius of the second
circumference.
[0065] FIG. 5C is an isometric view illustrating components of a
hollow motor assembly 501c configured in accordance with
representative embodiments of the present technology. The hollow
motor assembly 501c includes a rotor assembly 507 positioned to
rotate about a rotation axis R. As shown, the rotor assembly 507
includes a magnet 520 and a magnet yoke 522. The magnet yoke 522
includes an outer portion 507a and an inner portion 507b. The inner
portion 507b includes an inner surface 516 circumferentially faces
or bounds an interior chamber 517, which can be used to accommodate
a rotatable component (e.g., coupled to the rotor assembly 507) or
non-rotatable component (e.g., coupled to a non-rotatable component
such as a housing or a chassis). As shown, the outer portion 507a
is formed in flush with the magnet 520 such that the rotor assembly
507 has a smooth outer surface 524. In the illustrated embodiment,
the magnet 520 is axially positioned between the stator assembly
508 and the outer portion 507a of the stator assembly 507. In other
embodiments, the magnet 520 can be radially positioned between the
stator assembly 508 and the inner portion 507b of the stator
assembly 507.
[0066] As shown in FIG. 5C, the hollow motor assembly 501c includes
a stator assembly 508 positioned external to at least a portion
(e.g., the inner portion 507b) of the rotor assembly 507. As shown,
the stator assembly 508 includes two stator portions 508a and 508b
positioned opposite each other. The stator assembly 508 remains
stationary as the rotor assembly 507 rotates. The hollow motor
assembly 501c includes four bearing assemblies 509a, 509b, 509c,
and 509d (note that the bearing assembly 509d is not visible in
FIG. 5B). In the illustrated embodiment, the stator portions 508a
and 508b and the bearing assemblies 509a, 509b, 509c, and 509d are
positioned along a circumference of the rotor assembly 507 in a
plane that is generally perpendicular to the rotation axis R.
[0067] FIG. 5D includes an end view illustrating components of a
hollow motor assembly 501d configured in accordance with
representative embodiments of the present technology. The hollow
motor assembly 501d includes a rotor assembly 507 positioned to
rotate about a rotation axis R (e.g., extending perpendicular to
the plane in which FIG. 5D is located). The stator assembly 508
remains stationary as the rotor assembly 507 rotates. As shown, the
rotor assembly 507 includes an annular structure. The hollow motor
assembly 501d includes a stator assembly 508 positioned external to
the rotor assembly 507. As shown, the stator assembly 508 includes
two sector-stator portions (or arcuate-stator portions) 519a and
519b positioned opposite each other. Each of the sector-stator
portions 519a-b includes a stator core portion 526, a winding
portion (or winding protrusion) 528 extending form the stator core
portion 526, and a connecting component 530 configured to be
coupled to a chassis 523 of the hollow motor assembly 501d. The
chassis 523 can be further coupled to other components (e.g., a
housing) of the hollow motor assembly 501d. The winding portions
528 can be used to position a wire winding component thereon (e.g.,
by wrapping a wire on the winding portion 528). In some
embodiments, the hollow motor assembly 501d can include multiple
bearing assemblies (not shown in FIG. 5D) positioned to maintain
the location of the rotor assembly 507 relative to the stator
assembly 508.
[0068] FIG. 5E is an isometric view illustrating components of a
hollow motor assembly 501e configured in accordance with
representative embodiments of the present technology. The hollow
motor assembly 501e includes a first (or lower) rotor/stator set
531, a second (or upper) rotor/stator set 532, and a chassis 533
positioned to couple the first rotor/stator set 531 to the second
rotor/stator set 532. The first and second rotor/stator sets 531,
532 have similar structures and are positioned on opposite sides of
the chassis 533. In other embodiments, the first and second
rotor/stator sets 531, 532 can be coupled by other suitable
structures or means.
[0069] As shown in FIG. 5E, each of the first rotor/stator sets
531, 532 includes a rotor assembly 507 positioned to rotate about a
rotation axis R. As shown, the rotor assembly 507 includes a magnet
520 and a magnet yoke 522 coupled to the magnet 520. The magnet
yoke 522 includes an outer portion 507a and an inner portion 507b.
The inner portion 507b includes an inner surface 516 that
circumferentially faces or bounds the interior chamber 517. As
shown, the outer portion 507a is formed with a recess 518
configured to accommodate the magnet 520 which has a flat
structure.
[0070] As shown in FIG. 5E, each of the first rotor/stator sets
531, 532 includes a stator assembly 508 positioned external to at
least a portion (e.g., the inner portion 507b) of the rotor
assembly 507. As shown, the stator assembly 508 includes an annular
structure. Embodiments of the annular stator assembly are discussed
in further detail below with reference to FIGS. 6A-6C. Each of the
first rotor/stator sets 531, 532 includes an "annular" bearing
assembly 509 (e.g., a set of bearings, rolling balls, rolling pins,
and/or other suitable rolling components) that are annularly
positioned to maintain the location of the rotor assembly 507
relative to the stator assembly 508. The hollow motor assembly 501e
can be described as an "outer-rotor" type because the magnet 520 is
positioned external to the stator assembly 508, even though a
portion (e.g., the inner portion 507b) of the rotor assembly 507 is
positioned internal to the stator assembly 508.
[0071] As shown in FIG. 5E, the magnet yoke 522 (e.g., as an
integral part of the rotor assembly 507) has a structure that can
generally cover the magnet 520, the stator assembly 508, and the
bearing assembly 509 (e.g., the structure generally covers the top
side, the inner side, and the outer side of these components). In
such embodiments, the magnet yoke 522 can function as a housing to
protect the magnet 520, the stator assembly 508, and the bearing
assembly 509. In some embodiments, the magnet yoke 522 can have
different structures (e.g., it can cover a portion of other sides
of these components).
[0072] The first/second rotor/stator sets 531, 532 can be
separately controlled such that the rotor assemblies 507 of the
first/second rotor/stator sets 531, 532 can rotate at different
rotational speeds. In some embodiments, the rotor assembly 507 of
the first rotor/stator set 531 can be coupled to a first optical
component (e.g., a first lens or prism), and the rotor assembly 507
of the second rotor/stator set 532 can be coupled to a second
optical component (e.g., a second lens or prism). The hollow motor
assembly 501e can further include a light source positioned
therein. By separately controlling the rotor assemblies 507 of the
first and second rotor/stator sets 531, 532 (e.g., at different
rotational speeds and/or directions, to different angles), the
hollow motor assembly 501e can precisely control the light rays
emitted from the light source that pass through the first/second
optical components (e.g., passing through an interior chamber 517
inside the hollow motor assembly 501e). Embodiments of techniques
and devices for controlling the emitted light rays are discussed
below with reference to FIGS. 9A-10.
[0073] FIGS. 5F, 5G and 5H are schematic diagrams illustrating
methods for "pre-positioning" or "pre-tightening" in accordance
with representative embodiments of the present technology. The
methods for "pre-positioning" or "pre-tightening" are further
discussed in detail below with reference to FIG. 14. In FIGS. 5F
and 5G, hollow motor assemblies 501f, 501g each include a rotor
assembly 507 positioned to rotate about a rotation axis R, a stator
assembly 508 positioned external to the rotor assembly 507, and a
bearing assembly 509 positioned to maintain the location of the
rotor assembly 507 relative to the stator assembly 508. The rotor
assembly 507 includes a magnet 520 and a magnet yoke 522 coupled to
the magnet 520. The bearing assembly 509 further includes (1) an
inner portion 5091 (closer to the rotation axis R) coupled to and
configured to rotate with the rotor assembly 507; (2) an outer
portion 5092 (farther away from the rotation axis R) positioned
radially external to the inner portion 5091; and (3) a rolling
component 5093 rotatably positioned between the inner portion 5091
and the outer portion 5092. In some embodiments, the inner portion
5091 and/or the outer portion 5092 may be annular or partially
annular in shape.
[0074] When the bearing assembly 509 is manufactured and before it
is installed, bearing clearance is typically provided such that
components of the bearing assembly (e.g., the rolling component
5093) can move axially (e.g., with axial clearance) and/or radially
(e.g., with radial clearance). However, such clearance can cause
movement of the bearing assembly during operation, which in turn
can lead to noise, vibration, heat, and other undesirable effects.
Such effects can be mitigated by a "pre-positioning" or
"pre-tightening" process, in which such bearing clearance can be
reduced by causing opposing forces to act upon the bearing
assembly.
[0075] In FIG. 5F, the magnet 520 is positioned along a direction
generally parallel to the rotation axis R. When an electrical
current flows in the stator assembly 508, a magnetic force is
created between the magnet 520 and the stator component 508. The
magnetic force can move the magnet 520 toward alignment with the
stator component 508 (e.g., as indicated by arrow A1 in FIG. 5F, an
edge of the magnet 520 is generally or substantially flush with an
edge of the stator assembly 508). When the magnet 520 is moved, the
coupled magnet yoke 522 is also moved in the same direction (e.g.,
as indicated by arrow A2 in FIG. 5F). The magnet yoke 522 is
coupled to the inner portion 5091. Accordingly, when the magnet
yoke 522 is moved, the inner portion 5091 is also moved (e.g., as
indicated by arrow A3 in FIG. 5F). In some embodiments, the inner
portion 5091 may be coupled with and hence move with the magnet
yoke 522, while the outer portion 5092 may not move with the magnet
yoke 522 (e.g., the outer portion 5092 may be fixedly coupled to
the housing or a similar structure). Thus, when the inner portion
5091 is moved relative to the outer portion 5092, opposing forces
A3 and A4 act upon the bearing assembly 509 along the axial
direction, thereby reducing an internal axial clearance of the
rolling component 5093. In other words, the relative movement
between the inner portion 5091 and the outer portion 5092 can
facilitate positioning the rolling component 5093 at its proper
working location (e.g., to reduce an axial clearance of the bearing
assembly 509). Accordingly, the rolling component 5093 can be
better positioned between the inner portion 5091 and the outer
portion 5092, which can effectively reduce noise or vibration.
[0076] In FIG. 5G, the magnet 520 is positioned between the stator
assembly 508 and the bearing assembly 509, but can still be used to
orient the bearing assembly 509. When an electrical current flows
in the stator assembly 508, it creates a magnetic force between the
magnet 520 and the stator component 508 that can move the magnet
520 toward the stator component 508 (e.g., as indicated by arrow B1
in FIG. 5G, the size of a gap G between the between the magnet 520
and the stator component 508 is decreased). When the magnet 520 is
moved, the coupled magnet yoke 522 is also moved in the same
direction (e.g., as indicated by arrow B2 in FIG. 5G). The magnet
yoke 522 is coupled to the inner portion 5091. Accordingly, when
the magnet yoke 522 is moved, the inner portion 5091 is also moved
(e.g., as indicated by arrow B3 in FIG. 5G). In some embodiments,
the inner portion 5091 may be coupled with and hence move with the
magnet yoke 522, while the outer portion 5092 may not move with the
magnet yoke 522 (e.g., the outer portion 5092 may be fixedly
coupled to the housing or a similar structure). Thus, when the
inner portion 5091 is moved relative to the outer portion 5092,
opposing forces B3 and B4 act upon the bearing assembly 509 along
the axial direction, thereby reducing an internal axial clearance
of the rolling component 5093. In other words, the relative
movement between the inner portion 5091 and the outer portion 5092
can facilitate positioning the rolling component 5093 at its proper
working location (e.g., to reduce an axial clearance of the bearing
assembly 509). Accordingly, the rolling component 5093 can be
better positioned between the inner portion 5091 and the outer
portion 5092, which can effectively reduce noise or vibration. The
"pre-positioning" or "pre-tightening" process described herein can
be applied to other types of bearing assemblies (e.g., the
positioning component 109).
[0077] In some embodiments, the "pre-positioning" or
"pre-tightening" process can be done by adding two or more
additional magnets to a hollow motor assembly. For example, FIG. 5H
illustrates methods for "pre-positioning" or "pre-tightening" by
additional magnets in accordance with representative embodiments of
the present technology. A hollow motor assembly 501h in FIG. 5H
includes first and second rotor/stator sets 531,532 (e.g., similar
to the motor structure discussed in FIG. 5E).
[0078] The first rotor/stator set 531 includes a first connecting
member 550X configured to couple with a second connecting member
550Y of the second rotor/stator set 532. The first rotor/stator set
531 includes a first rotor assembly 507X coupled to an optical
component 514, a first stator assembly 508X positioned radially
external to the first rotor assembly 507X, a first bearing assembly
509X positioned to maintain the location of the first rotor
assembly 507X relative to the first stator assembly 508X, and a
first magnet 551X positioned adjacent to the first connecting
member 550X. The second rotor/stator set 532 includes a second
rotor assembly 507Y, a second stator assembly 508Y positioned
radially external to the second rotor assembly 507Y, a second
bearing assembly 509Y positioned to maintain the location of the
second rotor assembly 507Y relative to the second stator assembly
508Y, and a second magnet 551Y positioned adjacent to the second
connecting member 550Y. In some embodiments, the second
rotor/stator set 532 can also couple to an optical component. In
the illustrated embodiment in FIG. 5 H, the first and second
bearing assemblies 509X, 509Y both have an annular structure.
[0079] The first bearing assembly 509X includes an inner portion
509X1 (rotatable; coupled to the first rotor assembly 507X) and an
outer portion 509X2 (non-rotatable; coupled to the housing 537).
The first bearing assembly 509X can include one or more rolling
component (not shown in FIG. 5H) between the outer portion 509X2
and the inner portion 509X1, so as to facilitate the relative
rotation between these two components. Similarly, the second
bearing assembly 509Y can include an outer portion 509Y2
(non-rotatable; coupled to the housing 537) and an inner portion
509Y1 (rotatable; coupled to the second rotor assembly 507Y).
[0080] As shown in FIG. 5H, the first and second magnets 551X, 551Y
are configured to generate a repulsive magnetic force. When the
first rotor assembly 507X rotates to a location where the first and
second magnet 551X, 551Y are axially aligned (as shown in FIG. 5H),
the repulsive magnetic force moves the first magnet 551X and the
first connecting member 550X in direction D1 and moves the second
magnet 551Y and the second connecting member 551Y in opposite
direction D2. As a result, the inner portions 509X2, 509Y2 can be
moved by the repulsive magnetic force (e.g., via the first and
second rotor assemblies 507X, 507Y and the first and second
connecting members 550X, 550Y). More particularly, the inner
portion 509X1 moves in direction D1, and the inner portion 509Y1
moves in direction D2. Opposing forces (in the directions D1 and
D2) act upon the first bearing assembly 509X. Similarly, opposing
forces (in the directions D1 and D2) act upon the second bearing
assembly 509Y. Accordingly, the first and second bearing assemblies
509X, 509Y can be "pre-positioned" or "pre-tightened" in the ways
similar to those described above with reference to FIGS. 5F and 5G.
In some embodiments, the "pre-positioning" or "pre-tightening"
methods described above with reference to FIG. 5H can be applied to
a hollow motor assembly with a single rotor/stator set (e.g., the
first rotor/stator set 531). For example, in such embodiments, the
first magnet 551X can be attached to the first rotor assembly 507X,
and the second magnet 551Y can be attached to housing 537 or a
chassis attached to the housing 537. When the first magnet 551X and
the second magnet 551Y are positioned to generate a repulsive
magnetic force, the bearing assembly 509X can be "pre-positioned"
or "pre-tightened" in the ways similar to those described
above.
[0081] FIG. 6A is an isometric view illustrating components of a
hollow motor assembly 601 configured in accordance with
representative embodiments of the present technology. The hollow
motor assembly 601 includes a rotor assembly 507 having an annular
structure. The rotor assembly 507 is positioned to rotate about a
rotation axis R. The hollow motor assembly 601 includes an annular
stator assembly 608 positioned external to the rotor assembly 507.
The annular stator assembly 608 includes a continuous annular
structure. The hollow motor assembly 601 includes four bearing
assemblies 509a, 509b, 509c, and 509d (note that the bearing
assembly 509d is not visible in FIG. 6A). In the illustrated
embodiment, the stator assembly 608 is positioned along a first
circumference of the rotor assembly 507 in a plane that is
generally perpendicular to the rotation axis R. The bearing
assemblies 509a, 509b, 509c, and 509d are positioned along a second
circumference of the rotor assembly 507 in another plane that is
generally perpendicular to the rotation axis R. In the illustrated
embodiment in FIG. 6A, the radius of the first circumference is
generally the same as the radius of the second circumference. In
some embodiments, the hollow motor assembly 601 can have a
positioning assembly having an annular structure.
[0082] FIGS. 6B and 6C are isometric views illustrating annular
stator assemblies 608a, 608b configured in accordance with
representative embodiments of the present technology. As shown in
FIG. 6B, the annular stator assembly 608a includes (1) an annular
stator core portion 626, and (2) multiple winding portions (or
winding protrusions) 628 positioned along and extending inwardly
from the stator assembly 608a. The winding portions 628 can be used
to position a wire winding component thereon (e.g., by winding a
wire on the winding portion 628). In FIG. 6B, the winding portions
628 are radially positioned (e.g., toward a rotation axis R). In
FIG. 6C, the annular stator assembly 608b can include a plurality
of (e.g., six) stator segments 634a-f that are positioned adjacent
to one another in a circumferential direction. In FIG. 6C, the
winding portions 628 are axially positioned (e.g., generally
parallel to a rotation axis R).
[0083] FIG. 6D is an isometric view illustrating one stator segment
634 configured in accordance with representative embodiments of the
present technology. As shown, the stator segment 634 can include a
main body 635 and one or more (e.g., four) protrusions 636
extending from the main body 635. In some embodiments, the
protrusions 636 can be used to position winding components thereon.
The stator segment 634 can include a hexagonal recess 646 and a
hexagonal protrusion 647 on one side (e.g., the inner side of the
stator segment 634). The hexagonal recess 646 is configured to
fittingly accommodate another hexagonal protrusion 647 (of another
stator segment 634 positioned next thereto). By this arrangement,
the six stator segments 634a-f can together form the stator
assembly 608b shown in FIG. 6C. In other embodiments, at least two
of the six stator segments 634a-f can be coupled by glue or other
suitable means. In some embodiments, the stator segment 634 can be
made by winding components (e.g., wire windings).
[0084] FIG. 7A is a top view illustrating components of a hollow
assembly 701a configured in accordance with representative
embodiments of the present technology. The hollow assembly 701a
includes a housing 737 and a rotor assembly 707 positioned in the
housing 737. The rotor assembly 707 is positioned to rotate about a
rotation axis R. The hollow assembly 701a further includes four
positioning components 709a-d positioned at the four corners of the
housing 737 and external to the rotor assembly 707. The positioning
components 709a-d can rotate relative to the rotor assembly 707 and
maintain the (radial) location of the rotor assembly 707. At least
one of the positioning components 709a-d can be coupled to a
driving assembly (e.g., an electrical motor). The driving assembly
provides torque to rotate the positioning components 709a-d and the
rotator assembly 707.
[0085] FIG. 7B is an isometric view illustrating components of a
hollow assembly 701b configured in accordance with representative
embodiments of the present technology. The hollow assembly 701b
includes a first rotor assembly 707a, a second rotor assembly 707b,
a first positioning component 709a, a second positioning component
709b, and a driving assembly 708 (e.g., an electrical motor). The
first/second rotor assemblies 707a, 707b are both positioned to
rotate about a common rotation axis R. The first positioning
component 709a is rotatably coupled to and positioned external to
the first rotor assembly 707a. The first positioning component 709a
can rotate relative to the first rotor assembly 707a and maintain
the location thereof. The second positioning component 709b is
rotatably coupled to and positioned external to the second rotor
assembly 707b. The second positioning component 709b can rotate
relative to the second rotor assembly 707b and maintain the
location thereof. As shown, both the first/second positioning
components 709a, 709b are coupled to and driven by the driving
assembly 708 (e.g., the first and second positioning components
709a, 709b are positioned coaxially along an axial direction A). In
other embodiments, the first and second positioning components
709a, 709b can be driven by separate driving assemblies. In some
embodiments, the first and second positioning components 709a, 709b
can be positioned differently (e.g., non-coaxially). In the
illustrated embodiment, the first positioning component 709a is a
first gear (e.g., having a first number of gear teeth) and the
second positioning component 709b is a second gear (e.g., having a
second number of gear teeth) different than the first gear. Because
the first gear may have a configuration different than the second
gear (e.g., a different number of teeth), the driving assembly 708
can rotate the first/second rotor assemblies 707a, 707b at
different rotational speeds. In some embodiments, a first optical
component can be positioned inside and fixedly coupled to the first
rotor assembly 707a and a second optical component can be
positioned inside and fixedly coupled to the second rotor assembly
707b. In such embodiments, the driving assembly 708 can rotate the
first/second optical components at different rotational speeds.
[0086] FIG. 7C is an isometric view illustrating components of
another hollow assembly 701c configured in accordance with
representative embodiments of the present technology. The hollow
assembly 701c includes a first rotor assembly 707a, a second rotor
assembly 707b, a first positioning component 709a, a second
positioning component 709b, and a driving assembly 708. The
first/second rotor assemblies 707a, 707b are both positioned to
rotate about a rotation axis R. The first positioning component
709a is positioned external to and coupled with the first rotor
assembly 707a via a first belt 738a. The first positioning
component 709a can rotate with the first rotor assembly 707a and
maintain the location thereof. The second positioning component
709b is positioned external to and coupled with the second rotor
assembly 707b via a second belt 738b. The second positioning
component 709b can rotate with the second rotor assembly 707b and
maintain the location thereof. As shown, both the first/second
positioning components 709a, 709b are coupled to and driven by the
driving assembly 708. In the illustrated embodiment, the first
positioning component 709a and the second positioning component
709b have a similar size/shape. Therefore, the driving assembly 708
can rotate the first/second rotor assemblies 707a, 707b at the same
rotational speed. In other embodiments, the first positioning
component 709a and the second positioning component 709b can have
different sizes/shapes such that the driving assembly 708 can
rotate the first/second rotor assemblies 707a, 707b at different
rotational speeds. In some embodiments, a first optical component
can be positioned inside and fixedly coupled to the first rotor
assembly 707a and a second optical component can be positioned
inside and fixedly coupled to the second rotor assembly 707b. In
such embodiments, the driving assembly 708 can also rotate the
first/second optical components.
[0087] FIG. 8 is a top view illustrating components of a hollow
assembly 801 configured in accordance with representative
embodiments of the present technology. The hollow assembly 801
includes a housing (or a ring gear) 837, a rotor assembly (or a sun
gear) 807, a chassis (or a planetary carrier) 840, and four
positioning components (or planetary pinions) 809a-d rotatably
coupled to the chassis 840. The chassis 840 can be fixed and not
rotatable. The rotor assembly 807 is positioned internal to the
positioning components 809a-d, the chassis 840, and the housing
837. The rotor assembly 807 can rotate with respect to a rotation
axis R. At least one of the positioning components 809a-d can be
coupled to a driving assembly (e.g., an electrical motor). The
driving assembly provides torque to rotate the positioning
components 809a-d. When the positioning components 809a-d are
rotated, the rotor assembly 807 and the housing 837 are also
rotated. The positioning components 809a-d can maintain the
relative locations of the rotor assembly 807 and the housing 837
when they are rotated. In some embodiments, a first optical
component can be coupled to and rotate with the rotor assembly 807,
and a second optical component can be coupled to and rotate with
the housing 837.
[0088] FIG. 9A is a schematic diagram illustrating components of a
hollow motor assembly 901 configured in accordance with
representative embodiments of the present technology. In the
illustrated embodiments, the hollow motor assembly 901 is
configured to drive an optical component 914 positioned therein. As
shown, the hollow motor assembly 901 further includes a housing
937, a rotor assembly 907, a stator assembly 908 positioned
external to the rotor assembly 907, a positioning component 909,
and a light source 913 (e.g., a range finding/scanning
component/sensor or a light source for a Lidar system). The
positioning component 909 is positioned between the stator assembly
908 and the rotor assembly 907 to maintain a location of the rotor
assembly 907 relative to the stator assembly 908. As shown, the
stator assembly 908 is fixedly attached to the housing 937. The
stator assembly 908 is positioned radially external to and
coaxially with the rotor assembly 907 (relative to a rotation axis
R). The rotor assembly 907 can rotate relative to the stator
assembly 908. In the illustrated embodiment, the optical component
914 is coupled to and rotates with the rotor assembly 907. By this
arrangement, the optical component 914 can corporate with the light
source 913 to adjust the directions of the light rays (as indicated
by arrows in FIG. 9A) from the light source 913 (so as to perform a
scanning or range-finding task).
[0089] For example, at a first time point, the light ray from the
light source 913 passes through the optical component 914 and the
optical component 914 changes its direction from arrow T to arrow
T1 (e.g., the optical component 914 has an asymmetric shape so it
can change the direction of incoming light rays). From the first
time point to a second time point, the optical component 914 has
been rotated. At the second time point, the light ray from the
light source 913 passes through the optical component 914 and the
optical component 914 changes its direction from arrow T to arrow
T2. As a result, the optical component 914 can adjust the
directions of the light rays from the light source 913.
[0090] In some embodiments, the hollow motor assembly 901 can also
be configured to drive a propeller 105 (of a UAV). As indicated by
dashed lines, the hollow motor assembly 901 can be coupled to the
propeller 105, which includes a first blade 110, a second blade 111
opposite to the first blade 110, and a hub 112. When the rotor
assembly 907 rotates, the propeller 105 rotates with it.
[0091] As shown, the rotor assembly 907 has an inner surface 916
that circumferentially faces or bounds an interior chamber (or
interior space) 917. The interior chamber 917 can be used to
accommodate the optical component 914. The optical component 914 is
fixedly coupled to the rotor assembly 907. In some embodiments, the
optical component 914 and the rotor assembly 907 can be coupled by
a mechanical mechanism (e.g., a connecting component, a screw, a
bolt, a nail, a paired recess and protrusion, a wedge, and/or other
suitable mechanisms). In some embodiments, the optical component
914 and the rotor assembly 907 can be coupled with/using glue. When
the rotor assembly 907 rotates, the optical component 914 rotates
with it. Examples of the optical component 914 include a lens, a
prism, or a combination thereof.
[0092] As shown in FIG. 9A, the light source 913 can be positioned
at the center of the hollow motor assembly 901 (e.g., on the
rotation axis R). In some embodiments, the light source 913 can be
positioned at other locations in the housing 937 (e.g., off the
rotation axis R). In other embodiments, the light source 913 can be
fixedly attached to (an inner surface of) the housing 937. In some
embodiment, the light emitted from the light source can be
collimated or adjusted before it reaches the optical component
914.
[0093] In the embodiments where the hollow motor assembly 901 is
coupled to the propeller 105, the light source 913 can emit light
rays to the propeller 105 through the optical component 914. The
optical component 914 can change the directions of the light rays
(as indicated by arrows in FIG. 9A) and then further direct them to
the propeller 105. By rotating the optical component 914 and the
rotor assembly 907, the directions of the light rays can be
controlled. Accordingly, the incoming angles of the light rays can
be controlled when the light rays enter into the propeller 105. By
so doing, the light rays emitted from the propeller 105 can
accordingly be controlled.
[0094] For example, in response to receiving the incoming light
rays with different incoming angles, the propeller 105 can
accordingly generate various visual indications (e.g., by
redirecting/reflecting the light rays with different incoming
angles). In some embodiments, the propeller 105 can include a light
guide structure, which further includes: (1) a light entrance
portion configured/positioned to receive a light ray from the
hollow motor assembly 901; (2) a light transmission portion
configured/positioned to transmit the light ray; and (3) a light
exit portion configured/positioned to direct the light ray toward a
target (e.g., an operator, a bystander, and/or a target surface) in
one or more directions. In some embodiments, the visual indication
can include an outer contour of the propeller 105 or a UAV. In some
embodiments, the visual indication can be indicative of a location
of a UAV (or the location of a UAV component). In some embodiments,
the visual indication can be indicative of a status/parameter of a
UAV (e.g., travel direction, orientation, and/or flight
status).
[0095] FIGS. 9B and 9C are isometric views illustrating optical
component 914a, 914b configured in accordance with multiple
embodiments of the present technology. As shown in FIG. 9B, one
optical component 914a can have an elliptical-cylinder shape. As
shown in FIG. 9C, another optical component 914b can have an
elliptical-wedge shape. In other embodiments, the optical
components can be formed as a cylinder or can have other suitable
shapes. Both the optical components 914a, 914b can have a first
surface 941 and a second surface 942 opposite to the first surface
941. In the illustrated embodiment, the first surface 941 and the
second surface 942 are not generally parallel to each other. In
other embodiments, the first surface 941 and the second surface 942
can be generally parallel to each other. In the illustrated
embodiment, the first surface 941 and the second surface 942 are
both flat surfaces. In other embodiments, however, one or both of
the first/second surfaces 941, 942 can be a curved surface (e.g.,
as the dashed lines shown in FIG. 10), a rough surface, a teethed
surface, or a combination thereof. For example, when a user wants
to focus light rays, the user can choose a convex optical component
with one or two curved surfaces. As another example, when a user
needs to diffuse light rays, the user can select an optical
component with one or two teethed/rough surfaces.
[0096] FIG. 10 is a schematic diagram illustrating the use of
multiple optical components in accordance with embodiments of the
present technology. The present technology can be used to
change/control the light pathways of multiple light rays that pass
through the multiple optical components. The ability to control the
light pathways is important in certain technical fields such as
distance measurement by emitting/receiving laser beams. As shown in
FIG. 10, a light source 913, a first optical component 914c and a
second optical component 914d are positioned along a rotation axis
R. The first optical component 914c and the second optical
component 914d can rotate at different rotational speeds and/or
directions. For example, the first optical component 914c can be
fixedly coupled to a first rotor assembly, and the second optical
component 914d can be fixedly coupled to a second rotor assembly.
The first/second rotor assemblies can be independently
controlled/rotated. The light source 913 can direct a light ray to
the first optical component 914c along the rotation axis R
(indicated as D1 in FIG. 10). The first optical component 914c then
changes the direction of the incoming light ray from D1 to D2. The
second optical component 914d then further changes the direction of
the incoming light ray from D2 to D3. By rotating the first optical
component 914c and the second optical component 914d, a user can
precisely control the direction of the light ray emitted from the
light source 913. (To clarify, in such embodiments, the
first/second rotor assemblies are only used to rotate the
first/second optical components 914c, 914d, and are not used to
rotate a propeller.)
[0097] The optical components described above may have asymmetric
shapes. When rotated, these components may be unbalanced.
Particular embodiments of the present technology can address this
potential issue. For example, FIGS. 11A and 11B are schematic
diagrams illustrating counterweights 1143, 1144 configured in
accordance with representative embodiments of the present
technology. In FIGS. 11A and 11B, an optical component 1114 is
fixedly coupled to a rotor assembly 1107. The optical component
1114 and the rotor assembly 1107 are positioned to rotate together
about a rotation axis R. As shown, the optical component 1114 has
an asymmetric shape. After a rotation-balance analysis (discussed
below with reference to FIG. 12), the shapes, materials, and/or
weights of the counterweights 1143, 1144 can be determined. The
locations to position or install the counterweights 1143, 1144 can
also be determined. As shown in FIG. 11A, the counterweight 1143
can be a counterweight block fixedly attached to the inner surface
of the rotor assembly 1107. In FIG. 11B, the counterweight 1144 can
be glue attached to the inner surface of the rotor assembly 1107.
The optical component 1114 in FIG. 11B can have a better light
transmission rate than the optical component 1114 in FIG. 11A, at
least because the counterweight 1144 blocks less light passage than
does the counterweight 1143. In some embodiments, the
counterweights 1143, 1144 can be made of materials with different
densities. In some embodiments, to enhance the light transmission
rate of the optical component 1114, the shapes, transparency, or
other suitable parameters of the counterweights 1143, 1144 can also
be considered. In other embodiments, the counterweights 1143, 1144
can be positioned in other locations such as an edge or a
peripheral portion of the rotor component 1107. In some
embodiments, the numbers of the counterweights 1143, 1144 can
vary.
[0098] In some embodiments, instead of adding a counterweight, the
optical component 1114 can be balanced by removing a portion
thereof. In some embodiments, the optical component 1114 can be
reshaped so as to balance its rotation. In some embodiments, the
rotor assembly 1107 can be balanced in similar ways, alone or in
conjunction with balancing the optical component 1114.
[0099] FIG. 12 is a schematic diagram illustrating a
rotation-balance analysis for an optical component 1214 configured
in accordance with representative embodiments of the present
technology. As shown, the optical component 1214 has an asymmetric
shape and therefore it may not rotate in a balanced manner about a
rotation axis Z. The present technology provides a method for
effectively and efficiently determining how to balance an optical
component having an asymmetric shape. The method is based in part
on the mass and the density of the optical component.
[0100] First, the method includes calculating the product of the
mass (in) and a radius vector (r) for each layer of the optical
component, based on the integral Equation (A) below:
P.sub.Z=.intg..intg..sub.s.rho.{right arrow over (r)}dS (A)
[0101] In Equation (A) above, "P.sub.Z" represents the "unbalance"
value at level Z, "S" represents the cross-sectional area of level
Z, ".rho." represents the density of the optical component at level
Z, and "{right arrow over (r)}" represents radius vector.
[0102] The method then decomposes the calculated product value to
two or more levels. For example, as shown in FIG. 12, the
calculated product value can be decomposed to level Z.sub.1 and
Z.sub.2, according to Equations (B) and (C) below.
P 1 = .intg. .intg. .intg. v Z - Z 2 Z 1 - Z 2 .rho. r .fwdarw. dV
( B ) P 2 = .intg. .intg. .intg. v Z 1 - Z Z 1 - Z 2 .rho. r
.fwdarw. dV ( C ) ##EQU00001##
[0103] In Equations (B) and (C) above, "P.sub.1" represents the
"unbalance" value at level Z.sub.1, "P.sub.2" represents the
"unbalance" value at level Z.sub.2, "V" represents the volume of
the optical component, "Z" is the height variable, ".rho."
represents the density of the optical component at level Z, and
"{right arrow over (r)}" represents the radius vector. Based on
Equations (A), (B) and (C) above, a user can determine the
"unbalance" amount (e.g., how much weight to be added) to be added
(or removed, in some embodiments) at specific levels (e.g., levels
Z.sub.1 and Z.sub.2).
[0104] Below is an example showing how the "unbalance" value can be
calculated for a prism having a right-triangle cross-section.
Assume that the height of the prism is "H" and the radius of the
prism is "r," and then the "unbalance" value "P.sub.Z0" at level
Z.sub.0 can be calculated as follows:
dP.sub.Z0=.intg..intg..sub.S{right arrow over
(r.sub.xy)}dm=.intg..intg..sub.s(x{right arrow over (l)}+y{right
arrow over (j)})dm=0{right arrow over
(l)}+.intg..intg..sub.sy.rho.dxdydz.sub.0{right arrow over (j)}
(D)
[0105] In Equation (D) above, "S" represents the (cross-sectional)
area of level Z.sub.0, which can be defined by the circle
"x.sup.2+y.sup.2=R.sup.2" and the line "y=y.sub.0." "{right arrow
over (r.sub.xy)}" represents the radius vector from point (x, y) to
the rotation axis of the prism. ".rho." represents the density of
the prism. The "unbalance" value at level Z.sub.0 can be further
calculated based on Equations (E), (F), and (G) below.
d P z 0 = .intg. - R 2 - y 2 R 2 - y 2 d x .intg. - R y 0 .rho. y d
y d z 0 = .rho. 2 3 ( R 2 - y 0 2 ) 3 2 d z 0 ( E ) y 0 = - 2 R H z
0 ( F ) d P z 0 = .rho. 2 3 ( R 2 - 4 R 2 z 0 2 H 2 ) 3 2 d z 0 ( G
) ##EQU00002##
[0106] The method can further decompose the "unbalance" value to
two levels, "Z=H/2" and "Z=-H2." The method can then integrally
calculate the "unbalance" values for all levels "Z=Z.sub.0" As a
result, the "unbalance" values at these two levels (P.sub.1 and
P.sub.11) can be calculated based on Equations (H), (I), (J), and
(K) below.
dP 1 = H 2 + z 0 H dP z 0 ( H ) dP 11 = H 2 - z 0 H dP z 0 ( I ) P
1 = .intg. - H 2 H 2 dP 1 = .pi. .rho. 16 HR 3 ( J ) P 11 = .intg.
- H 2 H 2 dP 11 = .pi. .rho. 16 HR 3 ( K ) ##EQU00003##
[0107] FIG. 13 is a flowchart illustrating embodiments of a method
1300 for manufacturing (or assembling) a hollow motor apparatus in
accordance with representative embodiments of the present
technology. At block 1301, the method 1300 includes performing a
rotation-balance analysis on an optical component to generate an
analysis result. Embodiments of the rotation-balance analysis can
be found in the descriptions above with reference to FIG. 12. The
analysis result shows a user whether the optical component needs to
be balanced. At block 1303, the method 1300 can include
weight-balancing the optical component at least partially based on
the result of the analysis. In some embodiments, a counterweight
(e.g., a weight block, glue, and/or other suitable weights) can be
coupled to the optical component to balance the optical component.
In some embodiments, a portion of the optical component can be
removed so as to balance the optical component. In some
embodiments, the optical component can be reshaped to be balanced.
Embodiments of the balance process can be found in the descriptions
above with reference to FIG. 11.
[0108] At block 1305, the method 1300 includes positioning the
optical component in an interior chamber defined at least in part
by an inner portion of a rotor assembly. Embodiments of the
interior chamber include interior chambers 117, 517, and 917
discussed above. At block 1307, the method 1300 includes coupling
the optical component to the rotor assembly. At block 1309, the
rotor assembly is rotatably coupled to a positioning component. In
some embodiments, the positioning component can be a bearing
assembling. In some embodiments, the positioning component can be a
bearing, gear, puller, a roller, and/or other suitable components.
At block 1311, the positioning component is rotatably coupled to a
stator assembly. The positioning component is positioned external
to the inner portion of the rotor assembly to maintain a location
of the rotor assembly relative to the stator assembly.
[0109] FIG. 14 is a flowchart illustrating embodiments of a method
1400 for pre-positioning a bearing assembly in a hollow motor
apparatus in accordance with representative embodiments of the
present technology. The hollow motor apparatus includes a rotor
assembly having a rotation axis and a stator assembly coaxially
positioned adjacent to the rotor assembly. The bearing assembly is
configured to maintain the location of the rotor assembly relative
to the stator assembly. The bearing assembly includes (1) an inner
portion coupled to the rotor assembly, (2) an outer portion
positioned axially external to the inner portion, and (3) more than
one rolling component rotatably positioned between the inner
portion and the outer portion. Embodiments of the inner portion,
the outer portion, and the rolling component are discussed in
detail with reference to FIGS. 5F and 5G. At block 1401, the method
1400 includes causing generation of a magnetic force between the
stator assembly and the rotor assembly. At block 1403, the method
includes causing relative movement between the inner portion of the
bearing assembly and the outer portion of the bearing assembly, via
the magnetic force, to reduce a bearing clearance of the bearing
assembly.
[0110] As discussed above, aspects of the present technology
provide an improved hollow motor assembly that enables a user to
position an optical component therein such that the component can
rotate with a rotor assembly of the hollow motor assembly. The
rotor assembly can be coupled to and rotate a propeller of a UAV.
In addition to driving the propeller, the hollow motor assembly can
also illuminate the propeller by having a light source positioned
therein. The propeller can receive light from the light source (the
light passes through the rotatable optical component), and then
generate a visual indication to convey information (e.g., a status)
associated with the UAV to an operator. Accordingly, the operator
can effectively learn the information (e.g., orientation, location,
flight status, and/or other suitable status) of the UAV in a
straight-forward manner. It is especially helpful for
unsophisticated or relatively new UAV operators, at least because
the discussed technology can help them properly control the UAV.
Another advantage includes that the hollow motor assembly can have
a compact design. Accordingly, it can be implemented in a
traditional UAV by simply replacing a traditional motor assembly by
the hollow motor assembly of the present technology, without
requiring extra space for installation.
[0111] The present technology also provides a hollow apparatus that
can include multiple hollow, annular structures that can
independently rotate. Each annular structure can be coupled to a
corresponding optical component and rotate the same. In particular
embodiment, the hollow apparatus can be implemented as a laser
distance-measuring device. That device can include a laser light
source positioned therein and configured to emit laser rays,
through the optical components, to a target surface. By (1)
directing the laser rays to pass the optical components and (2)
controlling the rotation of the optical components, the device can
generate various desirable laser rays (e.g., focused, parallel, in
a particular direction, and/or other suitable characteristics) that
can be used to measure different types of target surfaces (e.g.,
rough, smooth, teethed, angled or a combination thereof). It is
also advantageous that the device can have a compact design, such
that a user can carry it or it can be easily installed in other
devices (e.g. a vehicle or UAV).
[0112] From the foregoing, it will be appreciated that specific
embodiments of the technology have been described herein for
purposes of illustration, but that various modifications may be
made without deviating from the technology. For example, particular
embodiments were described above in the context of a hollow motor
apparatus. In other embodiments, the present technology can be
implemented by other suitable rotatable hollow annular structure
(e.g., a laser emitter with a hollow annular structure). The hollow
motor assemblies can include different numbers of stator portions,
bearing assemblies, and/or other elements that are specifically
illustrated herein.
[0113] Further, while advantages associated with certain
embodiments of the technology have been described in the context of
those embodiments, other embodiments may also exhibit such
advantages, and not all embodiments need necessarily exhibit such
advantages to fall with within the scope of the present technology.
Accordingly, the present disclosure and associated technology can
encompass other embodiments not expressly shown or described
herein.
[0114] At least a portion of the disclosure of this patent document
contains material which is subject to copyright protection. The
copyright owner has no objection to the facsimile reproduction by
anyone of the patent document or the patent disclosure, as it
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