U.S. patent application number 15/985376 was filed with the patent office on 2018-09-20 for deformation motion mechanism.
This patent application is currently assigned to NEC Corporation. The applicant listed for this patent is NEC Corporation. Invention is credited to Kazuo HAMADA, Tsui HAPPY, Yoshihiko KATSUYAMA, Takuro KOBAYASHI, Minoru KUROSE, Naoto TANIMICHI.
Application Number | 20180266528 15/985376 |
Document ID | / |
Family ID | 59960359 |
Filed Date | 2018-09-20 |
United States Patent
Application |
20180266528 |
Kind Code |
A1 |
KUROSE; Minoru ; et
al. |
September 20, 2018 |
DEFORMATION MOTION MECHANISM
Abstract
A novel deformation motion mechanism with precise motion precise
motion and structural robustness is achieved. A deformation motion
mechanism includes: an elastic ring member shaped symmetrically
with respect to a center line, wherein one end of the elastic ring
member is fixed and the other end is movable along the center line;
a drive unit which is placed within the elastic ring member and is
arranged to rotate a feed screw engaged with both ends of the
elastic ring member along an operating line orthogonal to the
center line, to press or stretch the elastic ring member along the
center line; and a plurality of flexible arms which connects the
drive unit to the elastic member in at least a direction of the
center line.
Inventors: |
KUROSE; Minoru; (Tokyo,
JP) ; KATSUYAMA; Yoshihiko; (Tokyo, JP) ;
HAMADA; Kazuo; (Tokyo, JP) ; KOBAYASHI; Takuro;
(Tokyo, JP) ; TANIMICHI; Naoto; (Tokyo, JP)
; HAPPY; Tsui; (Castaic, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NEC Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
NEC Corporation
Tokyo
JP
|
Family ID: |
59960359 |
Appl. No.: |
15/985376 |
Filed: |
May 21, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15089866 |
Apr 4, 2016 |
|
|
|
15985376 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B25J 7/00 20130101; F16H
25/20 20130101; F16H 2025/2059 20130101; F16H 37/122 20130101; F16H
19/001 20130101 |
International
Class: |
F16H 25/20 20060101
F16H025/20; B25J 7/00 20060101 B25J007/00 |
Claims
1.-4. (Canceled)
5. A deformation motion method comprising: preparing an elastic
ring member shaped symmetrically with respect to a center line,
wherein one end of the elastic ring member is fixed and the other
end is movable along the center line wherein a drive unit is placed
within the elastic ring member and is arranged to rotate a feed
screw engaged with both ends of the elastic member along an
operating line orthogonal to the center line; connecting the drive
unit to the elastic ring member through a plurality of flexible
arms in at least a direction of the center line; and by the drive
unit, rotating the feed screw to press or stretch the elastic ring
member along the operating line.
6. The deformation motion method according to claim 5, wherein the
plurality of flexible arms are arranged symmetrically about a point
at which the center line and the operating line intersect.
7. The deformation motion method according to claim 5, wherein each
of the plurality of flexible arms is flexible in the direction of
the center line but rigid in a direction orthogonal to a ring plane
of the elastic ring member.
8. The deformation motion method according to claim 5, wherein each
of the plurality of flexible arms is formed from an elastic plate
of a predetermined width, wherein the flexible arm is installed
such that a width direction of the elastic plate is the same as a
direction orthogonal to a ring plane of the elastic ring member.
Description
BACKGROUND
[0001] The present invention relates to a mechanism which produces
predetermined motion by a predetermined deformation.
[0002] With the increasing market demand for precision technology,
a linear motion actuator providing high precision has become
important for machinery requiring precise displacement such as
multiple-degree-of-freedom displacement mechanism,
micro-manipulator or the like. In most cases, such a fine linear
motion actuator employs reduction gearing mechanism, which requires
not only a plurality of parts such as different gears but also
backlash adjustment of gears and other alignments during its
assembly.
[0003] In order to eliminate the need of backlash adjustment and
other alignments, there has been proposed a simplified linear
motion mechanism using a combination of elastic plates to allow
fine linear displacement (see Japanese Patent Unexamined
Publication No. JP2003-075572). More specifically, two elastic
plates are fixed to a fixed block at one ends and to a movable
block at the other ends. The two elastic plates placed in parallel
are connected by a curve elastic plate in the approximate shape of
a letter H. The movable block is supported by an elastic plate
orthogonal to a plane formed by the H-shaped elastic plates. The
curve elastic plate is connected to the slider of a micrometer at
the center thereof. Accordingly, extension or contraction of the
slider causes the curve elastic plate to push or pull the parallel
elastic plates in widening or narrowing directions, which linearly
moves the movable block in the retracting or extending
direction.
SUMMARY
[0004] However, the above-mentioned linear motion actuator using
reduction gearing mechanism requires a plurality of parts,
complicated assembly process and complicated adjustment operations.
The above-mentioned linear motion mechanism using the elasticity of
combined elastic plates has the spatial arrangement of a plurality
of elastic plates, resulting in weakness in structural strength,
which makes it difficult to achieve precise displacements.
Accordingly, the existing techniques cannot achieve a light-weight,
miniaturized and simply-manufactured linear motion mechanism
providing high precision.
[0005] An object of the present invention is to provide a novel
deformation motion mechanism with precise motion and structural
robustness.
[0006] According to the present invention, a deformation motion
mechanism includes: an elastic ring member shaped symmetrically
with respect to a center line, wherein one end of the elastic ring
member is fixed and the other end is movable along the center line;
a drive unit which is placed within the elastic ring member and is
arranged to rotate a feed screw engaged with both ends of the
elastic ring member along an operating line orthogonal to the
center line, to press or stretch the elastic ring member along the
center line; and a plurality of flexible arms which connects the
drive unit to the elastic member in at least a direction of the
center line.
[0007] According to the present invention, a deformation motion
method includes: preparing an elastic ring member shaped
symmetrically with respect to a center line, wherein one end of the
elastic ring member is fixed and the other end is movable along the
center line wherein a drive unit is placed within the elastic ring
member and is arranged to rotate a feed screw engaged with both
ends of the elastic member along an operating line orthogonal to
the center line; connecting the drive unit to the elastic ring
member through a plurality of flexible arms in at least a direction
of the center line; and by the drive unit, rotating the feed screw
to press or stretch the elastic ring member along the operating
line.
[0008] As described above, according to the present invention, the
drive unit is placed within the elastic ring member and is flexibly
connected to the elastic ring member through the flexible arms in
at least a direction of the center line. Accordingly, the drive
unit is placed at the center of the elastic ring member
irrespective of the presence or absence of elongated deformation of
the elastic ring member. Further, the flexible arms are flexible in
the center line direction but rigid in the operating line
direction. Accordingly, the flexible arms prevents the drive unit
from rotating when the drive unit rotates the feed screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a plan view illustrating a deformation motion
mechanism according to an exemplary embodiment of the present
invention.
[0010] FIG. 2 is a sectional view taken along lines A-A of FIG.
1.
[0011] FIG. 3 is a diagram showing a typical operation of the
deformation motion mechanism shown in FIG. 1.
[0012] FIG. 4 is a diagram showing an analytical example of the
operation of the deformation motion mechanism as shown in FIG.
1.
[0013] FIG. 5 is a diagram showing another analytical example of
the operation of the deformation motion mechanism as shown in FIG.
1.
DETAILED DESCRIPTION
1. Outline of Embodiment
[0014] According to an exemplary embodiment of the present
invention, a deformation motion mechanism is arranged to use a
pressure mechanism to deform a symmetrically shaped elastic ring
member along a center line of the symmetrically shaped elastic
member to produce a linear motion. More specifically, the pressure
mechanism is composed of a feed screw and a drive unit which are
provided within the elastic ring member. The feed screw is screwed
into a pair of nuts provided at the respective ends of the elastic
ring member. The feed screw may have left-handed and right-handed
screw sections which are screwed in the pair of nuts, respectively.
The drive unit is arranged to rotate the feed screw to press or
stretch the hard spring in the minor-axis direction to produce a
linear motion in a direction of the major axis of the hard
spring.
[0015] In the above-mentioned structure, since the drive unit
rotates the feed screw, the drive unit has to be fixed to something
secured so as not to rotate itself. However, the drive unit cannot
be fixed rigidly because the drive unit joined to the feed screw
moves in the major-axis direction of the hard spring when pressing
or stretching the hard spring in the minor-axis direction. For
instance, if the drive unit is fixed rigidly to the hard spring,
the drive unit causes hard deformation of the hard spring,
resulting the linear motion with a low degree of accuracy. If the
drive unit is fixed rigidly to the base plate of the deformation
motion mechanism, the drive unit cannot be moved, which may cause
unexpected deformation of the hard spring.
[0016] Accordingly, it is important to fix the drive unit flexibly
to the hard spring. Preferably, the drive unit is fixed to the hard
spring through symmetrically arranged flexible arms so as to place
the drive unit at the center of the elliptical ring of the hard
spring before or after deformed. Further preferably, the flexible
arms are flexible in the major-axis direction of the hard spring
but rigid in a direction orthogonal to the plane including the
elliptical ring of the hard spring. As an example, each of the
flexible arms may be formed using an elastic plate or a leaf
spring. Hereinafter, an exemplary embodiment of the present
invention will be describe with references to figures.
2. Exemplary Embodiment
[0017] 2.1) Arrangement
[0018] Referring to FIGS. 1 and 2, a deformation motion mechanism
10 includes a hard spring 101 shaped like an elliptical ring
symmetrically with respect to a center line L1 and an operating
line L2 orthogonal to the center line L1. The hard spring 101 is
connected to a fixed section 102 and a movable section 103 at both
ends of the major axis of the hard spring 101. The hard spring 101
is joined to a pressure mechanism composed of a pair of nuts 104
and 105, a feed screw 106 and an input mechanism 107.
[0019] The feed screw 106 may have left-handed and right-handed
screw sections which are screwed into the nuts 104 and 105,
respectively. The nuts 104 and 105 are fixed respectively to both
sides of the hard spring 101 in the direction of the minor axis so
that the hard spring 101 is sandwiched between the nuts 104 and
105. The input mechanism 107 rotates the feed screw 106 to press or
stretch the hard spring 101 depending on rotation direction. In
FIG. 1, when rotating the feed screw in a direction 108, the hard
spring 101 is pressed in the operating direction 109 to move the
movable section 103 in the linear motion direction 110.
[0020] The input mechanism 107 is a drive unit for rotating the
feed screw 106 which rotatably passes through the drive unit as
shown in FIG. 2. The input mechanism 107 is placed within the
elliptical ring of the hard spring 101 and is flexibly joined to
the hard spring 101 through an even number of elastic arms (here,
four elastic arms S1-S4). The elastic arms S1-S4 having the same
elasticity are placed symmetrically with respect to a center point
O, the line (or plane) L1, and/or the line (or plane) L2 so as to
keep the input mechanism 107 at the center of the elliptical ring
of the hard spring 101 irrespective of the presence or absence of
the deformation.
[0021] Preferably, the elastic arms S1-S4 are placed in parallel
along their retracting or extending direction which is the same
direction as the major axis of the hard spring 101. In this
example, the elastic arms S1-S4 are formed using an elastic plate
or a leaf spring and are shaped like an accordion to be made
flexible in the major-axis direction of the hard spring 101.
However, as shown in FIG. 2, the elastic arms S1-S4 are installed
vertically, that is, in a direction L3 orthogonal to the plane L1,
causing them to be hardly bent in the direction L3. Accordingly,
the elastic arms S1-S4 prevents the input mechanism 107 from
rotating when the input mechanism 107 rotates the feed screw
106.
[0022] 2.2) Operation
[0023] Referring to FIG. 3, when the input mechanism 107 rotates
the feed screw in the direction 108, the nuts 104 and 105 presses
and deforms the hard spring 101 in the direction 109. More
specifically, pressure in the direction 109 causes the elliptical
ring of the hard spring 101 to be elongated in the direction of its
major axis, thereby extending the elastic arms S1-S4 and shifting
the feed screw 106 and the input mechanism 107 by a displacement
201 while shifting the movable section 103 by a displacement
202.
[0024] As shown in FIG. 4, the respective elastic arms S1-S4 are
fixed to the input mechanism 107 at points P1-P4, which are
symmetric about the center point O of the elliptic ring of the hard
spring 101. Accordingly, even when the hard spring 101 is
elongated, the input mechanism 107 is kept at the center position
of the elongated elliptic ring of the hard spring 101.
[0025] Similarly, as shown in FIG. 5, the respective elastic arms
S1-S4 connecting between the hard spring 101 and the input
mechanism 107 are placed symmetrically with respect to the center
point O of the elliptic ring of the hard spring 101.
[0026] Accordingly, even when the hard spring 101 is elongated, the
input mechanism 107 is kept at the center position of the elongated
elliptic ring of the hard spring 101.
[0027] 2.3) Advantageous effects
[0028] According to the exemplary embodiment of the present
invention, the input mechanism 107 which is arranged to rotate the
feed screw 106 to deform the hard spring 101 is placed within the
elliptic ring of the hard spring 101 and is flexibly connected to
the hard spring through elastic arms S1-S4 which are symmetrically
arranged along the major axis of the elliptic ring of the hard
spring 101. Accordingly, the input mechanism 107 is placed at the
center of the elliptical ring of the hard spring 101 irrespective
of the presence or absence of elongated deformation of the elliptic
ring.
[0029] Further, the elastic arms S1-S4 are flexible in the
major-axis direction of the hard spring but rigid in a direction
orthogonal to the plane including the elliptical ring. Accordingly,
the elastic arms S1-S4 prevents the input mechanism 107 from
rotating when the input mechanism 107 rotates the feed screw
106.
3. Other Exemplary Embodiment
[0030] The present invention is not limited to the above-mentioned
embodiment as shown FIGS. 1 and 2. Any symmetric arrangement of
elastic arms supporting the input mechanism or the drive unit
within the elliptic ring can be employed, provided that the
symmetrically arranged elastic arms allow the input mechanism or
the drive unit to be placed at the center of the elliptical ring
irrespective of the presence or absence of deformation of the
elliptic ring.
[0031] The present invention may be embodied in other specific
forms without departing from the spirit or essential
characteristics thereof. The above-described exemplary embodiment
and examples are therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention being
indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *