U.S. patent application number 15/165604 was filed with the patent office on 2017-11-30 for rotatable assembly including a coupling interface.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC. The applicant listed for this patent is GM GLOBAL TECHNOLOGY OPERATIONS LLC. Invention is credited to Ronald B. Beals, Chris D. Hosler, Scott A. Hucker.
Application Number | 20170343096 15/165604 |
Document ID | / |
Family ID | 60269410 |
Filed Date | 2017-11-30 |
United States Patent
Application |
20170343096 |
Kind Code |
A1 |
Hucker; Scott A. ; et
al. |
November 30, 2017 |
ROTATABLE ASSEMBLY INCLUDING A COUPLING INTERFACE
Abstract
A rotatable assembly, such as a crankshaft or camshaft assembly,
includes a first rotatable component and a second rotatable
component coupled to the first rotatable component. The first
rotatable component includes a first body and defines a plurality
of recesses extending into the first body. The second rotatable
component includes a second body and defines a plurality of
protrusions extending from the second body. The protrusions are
disposed inside the respective recesses to allow the second
rotatable component to rotate in unison with the first rotatable
component.
Inventors: |
Hucker; Scott A.;
(Ortonville, MI) ; Hosler; Chris D.; (Dryden,
MI) ; Beals; Ronald B.; (South Lyon, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM GLOBAL TECHNOLOGY OPERATIONS LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS
LLC
Detroit
MI
|
Family ID: |
60269410 |
Appl. No.: |
15/165604 |
Filed: |
May 26, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 57/12 20130101;
F16C 3/06 20130101; F16H 2055/306 20130101; F16H 57/0025 20130101;
F16H 55/30 20130101; F16H 55/566 20130101 |
International
Class: |
F16H 57/00 20120101
F16H057/00; F16C 3/06 20060101 F16C003/06; F16H 55/30 20060101
F16H055/30 |
Claims
1. (canceled)
2. The rotatable assembly of claim 11, wherein the plurality of
protrusions defines a coupling interface, and the coupling
interface does not allow relative rotation between the first
rotatable component and the second rotatable component across the
coupling interface.
3. The rotatable assembly of claim 11, wherein each of the
plurality of protrusions is in tapered, conformal contact with the
plurality of recesses to create a joint with minimized runout of
the second rotatable component from the first rotatable
component.
4. The rotatable assembly of claim 3, wherein the tapered,
conformal contact creates a unique lateral final resting position
when the second rotatable component is slid onto the first
rotatable component.
5. The rotatable assembly of claim 11, wherein the recesses and
protrusions define a coupling interface to allow torque
transmission between the first rotatable component and the second
rotatable component.
6. The rotatable assembly of claim 5, wherein the torque
transmission does not require a clamp load.
7. The rotatable assembly of claim 11, wherein a radius and form of
the protrusions and recesses are configured to limit contact
stress.
8. (canceled)
9. (canceled)
10. The rotatable assembly of claim 11, wherein each of the
protrusions mates with each of the recesses such that first
rotatable component is prevented from rotating relative to the
second rotatable component while allowing the second rotatable
component to be slid over the first rotatable component.
11. A rotatable assembly, comprising: a first rotatable component
including a first body and defining a plurality of recesses
extending into the first body; a second rotatable component
including a second body and defining a plurality of protrusions
extending from the second body, wherein the protrusions are
disposed inside the recesses such as to allow the second rotatable
component to rotate in unison with the first rotatable component
and wherein the recesses are not equally spaced from one another,
and the protrusions not equally spaced from one another such that
the first rotatable component and the second rotatable component
are configured to be assembled together in only a single
orientation relative to each other, the recesses include a first
recess, a second recess, and a third recess, and the protrusions
include a first protrusion, a second protrusion, and a third
protrusion, a first angle is defined from the first recess to the
second recess, a second angle is defined from the second recess to
third recess, a third angle is defined from the third recess to the
first recess, the first angle, the second angle, and the third
angle are all be different from each other, the first rotatable
component extends along a longitudinal axis, and each of the
recesses has a recess width and a tapered configuration such that
the recess width of each of the recesses continuously decreases in
an axial direction, the recess width of each of the recesses
decreases exponentially in the axial direction, each of the
recesses has a recess height, and the recess height of each of the
recesses decreases exponentially in the axial direction, each of
the protrusions has a protrusion width and a tapered configuration
such that the protrusion width continuously decreases in the axial
direction, the protrusion width of each of the protrusions
decreases exponentially in the axial direction, and each of the
protrusions has a protrusion height that decreases exponentially in
the axial direction.
12-20. (canceled)
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a rotatable assembly, such
as a crankshaft assembly, including a coupling interface.
BACKGROUND
[0002] Mechanical devices, such as internal combustion engines,
include rotatable components for different purposes. For instance,
internal combustion engines include at least one crankshaft. A
crankshaft converts reciprocating linear movement of a piston into
rotational movement about an axis to provide torque to propel a
vehicle, such as but not limited to a train, a boat, a plane, or an
automobile, or to drive any other apparatus powered by the
engine.
SUMMARY
[0003] The present disclosure relates to a rotatable assembly, such
as a crankshaft assembly, including a coupling interface. The
presently disclosed coupling interface can be mass-produced and
manufactured in a cost-effective manner. This coupling interface
may be incorporated into automobiles, agricultural equipment, home
appliance, etc. In certain embodiments, the coupling interface
includes recesses and protrusions configured to mate with each
other in order to couple different components of the rotatable
assembly. As a non-limiting example, a first rotatable component of
a rotatable assembly includes a first body and defines a plurality
of recesses extending into the first body. A second rotatable
component of the rotatable assembly includes a second body and
defines a plurality of protrusions extending from the second body.
The protrusions are disposed inside the recesses to allow the
second rotatable component to rotate in unison with the first
rotatable component. The recesses can be formed using a machining
or forming process, and the protrusions can be formed by using
powder metal manufacturing processes, by attaching metal dowels to
the second body, or by directly machining the second rotatable
component.
[0004] The above features and advantages and other features and
advantages of the present teachings are readily apparent from the
following detailed description of the best modes for carrying out
the teachings when taken in connection with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic perspective, fragmentary view of a
rotatable assembly including a post with circumferentially spaced
recesses.
[0006] FIG. 2 is a schematic perspective, fragmentary view of the
rotatable assembly shown in FIG. 1, illustrating a sprocket
disposed over the post.
[0007] FIG. 3 is a schematic, cross-sectional front view of the
rotatable assembly shown in FIG. 2.
[0008] FIG. 4 is a schematic perspective, fragmentary view of the
sprocket, illustrating an inner sprocket surface and protrusions of
the sprocket.
[0009] FIG. 5 is a schematic, fragmentary front view of a recess of
the rotatable assembly shown in FIG. 1.
[0010] FIG. 6 is a schematic, fragmentary side view of a recess of
the rotatable assembly shown in FIG. 1.
[0011] FIG. 7 is a schematic, fragmentary front view of a
protrusion of the sprocket shown in FIG. 4.
[0012] FIG. 8 is a schematic, fragmentary side view of a protrusion
of the sprocket shown in FIG. 4;
[0013] FIG. 9 is a schematic, fragmentary top view of inner view of
the sprocket shown in FIG. 4, illustrating the protrusions; and
[0014] FIG. 10 is a schematic, fragmentary view of the sprocket,
illustrating an inner sprocket surface and curved protrusions of
the sprocket.
[0015] FIG. 11 is a schematic, enlarged fragmentary view of the
rotatable assembly shown in FIG. 2, taken around area 11 in FIG.
3.
DETAILED DESCRIPTION
[0016] Referring to the drawings, wherein like reference numbers
correspond to like or similar components throughout the several
figures, and beginning with FIGS. 1-4, a rotatable assembly 100 is
configured to rotate about a longitudinal axis X. In the depicted
embodiment, the rotatable assembly 100 includes a coupling
interface 101 for connecting a first rotatable component 102 to a
second rotatable component 104. The coupling interface 101 allows
the first rotatable component 102 and the second rotatable
component 104 to rotate in unison about the longitudinal axis X.
However, the coupling interface 101 does not allow relative
rotation between the first rotatable component 102 and the second
rotatable 104 component across the coupling interface 101. The
coupling interface 101 allows torque transmission between the first
rotatable component 102 and the second rotatable component 104. In
other words, due to the coupling interface 101, torque can be
transmitted between the first rotatable component 102 and the
second rotatable component 104. This torque transmission does not
require a clamp load.
[0017] The rotatable assembly 100 may be, for example, configured
as a crankshaft assembly 106. In such a case, the first rotatable
component 102 is configured as a shaft 108 (FIG. 1), and the second
rotatable component 104 is configured as a sprocket 110 (FIG. 2).
In addition to the sprocket 110 and the shaft 108, the crankshaft
assembly 106 includes a plurality of counterweights 112 coupled to
the shaft 108. Regardless of their respective configuration, the
first rotatable component 102 and the second rotatable component
104 both extend along the longitudinal axis X. Accordingly, the
first rotatable component 102 and the second rotatable component
104 can rotate about the longitudinal axis X and are coaxial with
respect to each other.
[0018] The first rotatable component 102 includes a first body 114,
and the second rotatable component 104 includes a second body 118.
In the crankshaft assembly 106, the first body 114 is configured as
a post 116, and the second body 118 is configured as a ring 120. In
addition to the ring 120, the sprocket 110 includes a plurality of
teeth 122 coupled to the ring 120. Specifically, the teeth 122 are
annularly arranged about the ring 120.
[0019] The first rotatable component 102 defines a plurality of
recesses 124 extending into the first body 114. The recesses 124
are part of the coupling interface and can be manufactured using
grinding processes or any other suitable machining process.
Specifically, the first body 114 defines circumferential outer body
surface 126 and a plurality of concave surfaces 128 each defining
one of the recesses 124. The concave surfaces 128 may have a
substantially semi-elliptical cross-sectional shape in order to
facilitate the connection between the first rotatable component 102
and the second rotatable component 104. As such, the recesses 124
may have a substantially scalloped shaped configuration. The
substantially scalloped shaped configuration of the recesses 124
enhances the connection between the first rotatable component 102
and the second rotatable component 104 while allowing the second
rotatable component 104 to easily slide over the first rotatable
component 102 for assembly. As a non-limiting example, the first
body 114 defines three concave surfaces 128 circumferentially
spaced apart from one another. However, it is contemplated that the
first body 114 may define any plurality of concave surfaces 128 and
recesses 124. In the depicted non-limiting example, the first
rotatable component 102 defines three recesses 124
circumferentially spaced apart from one another in order to ensure
a proper alignment and connection with the second rotatable
component 104 especially when the rotatable assembly 100 rotates
about the longitudinal axis X.
[0020] The second rotatable component 104 defines an inner body
opening 130 extending through the second body 118. The body opening
130 is configured, shaped, and sized to receive the first body 114.
In particular, the second body 118 has a circumferential inner
surface 132 defining the body opening 130. In the example, the
second body 118 includes three protrusions 134 extending from the
circumferential inner surface 132 toward a center C of the body
opening 130. The protrusions 134 may be formed by machining (e.g.,
grinding) the second rotatable component 104. Alternatively, the
protrusions 134 may be formed in powdered metal in order to
minimize cost. Irrespective of the manufacturing process employed,
each protrusion 134 is configured, shaped, and sized to mate with
one of the recesses 124 of the first rotatable component 102. In
other words, each of the protrusions 134 mates with one of the
recesses 124, such that the first rotatable component 102 is
prevented from rotating relative to the second rotatable component
104 while allowing the second rotatable component 104 to be slid
over the first rotatable component 102. The recess 124 and the
protrusion 134 jointly define the coupling interface 101. The
tapered, conformal contact between the protrusion 134 and the
recess 124 creates a unique lateral final resting position when the
second rotatable component 104 is slide onto the first rotatable
component 102. Thus, when the first rotatable component 102 and the
second rotatable component 104 are combined, the lateral
relationship between the first rotatable component 102 and the
second rotatable component 104 fixed and defined by their geometry.
When used provide defined lateral alignment without requiring
limited radial alignment or torque transmission, the rotatable
assembly 100 may include one or more protrusions 134 and one or
more recesses 124.
[0021] Accordingly, when the protrusions 134 are disposed inside of
the recesses 124, the first rotatable component 102 is coupled to
the second rotatable component 104, thereby allowing the second
rotatable component 104 to rotate in unison with the first
rotatable component 102. The second body 118 includes convex
surfaces 136 extending from the circumferential inner surface 132.
The convex surfaces 136 may also be referred as raised surfaces and
can be formed by using powder metal manufacturing processes, by
attaching dowels to the second body, or by directly machining the
second rotatable component 104. Moreover, the convex surfaces 136
at least partially define the protrusions 134 and are therefore
circumferentially spaced apart from one another. The convex
surfaces 136 may have a substantially semi-elliptical
cross-sectional shape in order to facilitate the connection between
the first rotatable component 102 and the second rotatable
component 104 when the protrusions 134 are disposed inside the
recesses 124. As such, the protrusions 134 may have a substantially
scalloped shaped configuration in order to mate with the recesses
124 having the substantially scalloped shaped configuration. The
substantially scalloped shaped configuration of the recesses 124
and the protrusions 134 allows the second body 118 to be slid over
the first body 114 during assembly while rotatably coupling the
first rotatable component 102 to the second rotatable component
104. It is contemplated that the convex surfaces 136 may have other
suitable shapes. As non-limiting examples, the convex surfaces 136
and the concave surfaces 128 may have variable radius. The
particular radius of the convex surfaces 136 and the concave
surfaces 128 may be determined based on the maximum allowable
stress and the accuracy required. In summary, the radius and form
of the protrusion 134 and recess 124 can be adjusted as desired to
limit the contact stresses appropriate for the materials being
considered. Regardless of its particular shape, the convex surfaces
136 are in direct contact with the concave surfaces 128 when the
protrusions 134 are disposed inside of the recesses 124, thereby
enhancing the connection between the first rotatable component 102
and the second rotatable component 104. The second rotatable
component 104 surrounds the first rotatable component 102, such
that the protrusions 134 are in direct contact with the concave
surfaces 128. As a non-limiting example, the second rotatable
component 104 includes three protrusions 134 circumferentially
spaced apart from one another in order to ensure a proper alignment
and connection with the first rotatable component 102 especially
when the rotatable assembly 100 rotates about the longitudinal axis
X. However, it is contemplated that the second rotatable component
104 may include any plurality of protrusions 134.
[0022] With specific reference to FIG. 3, the recesses 124 are not
equally spaced from one another, and the corresponding protrusions
134 are not equally spaced from one another such that the first
rotatable component 102 and the second rotatable component 104 can
be assembled only a single orientation for error proofing. If error
proofing orientation is not required, then the spacing may be
equal. In the depicted embodiment, for example, the recesses 124
include a first recess 124a, a second recess 124b, and a third
recess 124c, and the protrusions 134 include a first protrusion
134a, a second protrusion 134b, and a third protrusion 134c. The
angle between the first recess 124a and the second recess 124b is
defined by a first angle .alpha.. The first angle .alpha. also
represents the angle between the first protrusion 134a and the
second protrusion 134b. The angle between the second recess 124b
and the third recess 124c is defined by a second angle .beta.. The
second angle .beta. also represents the angle between the second
protrusion 134b and the third protrusion 134c. The angle between
the third recess 124c and the first recess 124a is defined by a
third angle .gamma.. The third angle .gamma. also represents the
angle between the third protrusion 134c and the first protrusion
134a. At least two of the first angle .alpha., the second angle
.beta., and the third angle .gamma. are different to ensure that
the first rotatable component 102 is properly aligned with the
second rotatable component 104 during assembly. For example, the
first angle .alpha. and the second angle .beta. may be equal to
each other but each may be different from the third angle .gamma..
It is contemplated, the first angle .alpha., the second angle
.beta., and the third angle .gamma. may all be different from each
other in order to further minimize the risk of misalignment between
the first rotatable component 102 and the second rotatable
component 104.
[0023] As shown in FIG. 11, the radius of the protrusion 134 is
slightly smaller than the radius of the recess 124. As such, the
protrusion 134 is in conformal contact with the recess 124 to allow
the coupling interface 101 to carry torque through the rotatable
assembly 100. The protrusion 134 is in tapered, conformal contact
with the recess 124 to create a joint with minimized runout of the
second rotatable component 104 from the first rotatable component
102. Additional protrusions 134 and recesses 124 decrease the
runout. The tapered, conformal contact between the protrusion 134
and the recess 124 creates a unique lateral final resting position
when the second rotatable component 104 is slide onto the first
rotatable component 102.
[0024] With reference to FIGS. 1, 5, and 6, each recess 124 has a
recess height RH that is defined as the maximum distance from the
concave surfaces 128 to the circumferential inner surface 132.
Further, each protrusion 134 may have a tapered configuration in
order to facilitate sliding the second rotatable component 104 over
the first rotatable component 102. In particular, the protrusion
height PH continuously decreases in an axial direction A, which is
a direction from the outer post end 138 toward the inner post end
140. As a non-limiting example, the recess height RH of each recess
124 decreases exponentially in the axial direction A in order to
facilitate sliding the second rotatable component 104 over the
first rotatable component 102. In the present disclosure, the term
"exponentially" means that the rate of change must be expressed
using exponents. Each recess 124 is also tapered such that the
recess width RW (FIG. 1) continuously decreases in the axial
direction A. The recess width RW may decrease exponentially in the
axial direction in order to facilitate sliding the second rotatable
component 104 over the first rotatable component 102. In other
non-limiting examples, the recess height RH of each recess 124 may
experience a quadratic or cubic spline decrease in the axial
direction A.
[0025] With reference to FIGS. 4, 7, 8, and 9, each protrusion 134
has a protrusion height PH that is defined as the distance from the
convex surface 136 to a circumference CR (FIG. 7) of the
circumferential inner surface 132. Further, each protrusion 134 may
have a tapered configuration in order to facilitate sliding the
second rotatable component 104 over the first rotatable component
102. In particular, the protrusion height PH continuously decreases
in the axial direction A. In the depicted embodiment, the
protrusion height PH of each protrusion 134 decreases exponentially
in the axial direction A in order to facilitate sliding the second
rotatable component 104 over the first rotatable component 102.
Each protrusion 134 is also tapered such that the protrusion width
PW (FIG. 9) continuously decreases in the axial direction A. As a
non-limiting example, the protrusion width PW may decrease
exponentially in the axial direction A in order to facilitate
sliding the second rotatable component 104 over the first rotatable
component 102. In other non-limiting examples, the protrusion width
PW may experience a quadratic or cubic spline decrease in the axial
direction A.
[0026] With reference to FIG. 10, the protrusions 134 may have a
curved configuration about the longitudinal axis X (FIG. 1) instead
of being linear. In this embodiment, the recesses 124 also have a
curved configuration in order to mate with the protrusions 134,
thereby enhancing the connection between the first rotatable
component 102 and the second rotatable component 104. The spiral
can be oriented to provide a self-tightening impact as a result of
the direction of rotation of the part while in service.
[0027] While the best modes for carrying out the teachings have
been described in detail, those familiar with the art to which this
disclosure relates will recognize various alternative designs and
embodiments for practicing the teachings within the scope of the
appended claims. The rotatable assembly illustratively disclosed
herein may be suitably practiced in the absence of any element
which is not specifically disclosed herein.
* * * * *