Flexible motor mount

Abstract

A power assist assembly includes an assist housing and a motor housing. The assist housing includes a motor portion defining an assist edge, and the motor housing defines a motor edge for mounting to the assist edge. A mounting pad is defined by one of the motor portion and the motor housing, and a shoulder surface is defined by the other of the motor portion and the motor housing. The mounting portion defines a hole. The mounting fixture defines a hole and includes a body portion and a clamping portion extending laterally from the body portion. A fastener extends through the hole of the mounting portion and the hole of the mounting fixture, and the clamping portion presses against the shoulder surface to hold the motor housing against the mounting portion.

Description

Technical Field

[0001] Embodiments described herein relate to flexible motor mounts, and more particularly, to flexible motor mounts that include a mounting fixture. Background Art

[0002] Vehicles (such as cars, trucks, sport utility vehicles, crossovers, minivans, boats, aircraft, all-terrain vehicles, recreational vehicles or other suitable vehicles) include various steering system systems, such as Steer-by-Wire (SbW) and driver interface steering. Typically, these different steering systems include Electric Power Steering (EPS) systems, which include components such as steering wheels, columns, rack-pinion gears, motor actuators, etc. EPS helps the operator steer the vehicle by providing the necessary assist torque. The assist torque is based on the torque applied by the operator. In a steady-state sense, the operator torque and the assist torque counteract the rack force generated due to tire-road interaction.

[0003] A typical EPS system includes an auxiliary housing with fixed mounting pads and a motor assembly attached to the mounting pads. The exact orientation and location of the mounting pads are specific to the vehicle and program to meet specific packaging requirements and often vary from program to program. This requires the development of program-specific auxiliary housings, which is cost-prohibitive for low-volume programs.

[0004] Therefore, an EPS system including adjustable motor orientation would provide a cost-effective design solution for low-volume programs and facilitate the installation and testing of EPS components in new vehicles. Summary of the invention

[0005] In order to better understand the following detailed description of the invention, the features and technical advantages of the present invention have been summarized quite broadly above. The following will describe additional features and advantages of the present invention that constitute the subject matter of the claims of the present invention. It should be recognized by those skilled in the art that the disclosed concepts and specific embodiments can be easily used as the basis for modifying or designing other embodiments for achieving the same purpose of the present invention. It should also be appreciated by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the present invention as set forth in the appended claims. This section provides a general overview of the present disclosure and should not be interpreted as a complete and comprehensive listing of all objects, schemes, features and advantages associated with the present disclosure.

[0006] According to one aspect of the present invention, a power assist assembly is provided. The power assist assembly includes an auxiliary housing and a motor housing. The auxiliary housing includes a motor portion defining an auxiliary edge, and the motor housing defines a motor edge for mounting to the auxiliary edge. The mounting pad is defined by one of the motor portion and the motor housing, and the shoulder surface is defined by the other of the motor portion and the motor housing. The mounting portion defines a hole. The mounting fixture defines a hole and includes a body portion and a clamping portion extending laterally from the body portion. The fastener extends through the hole of the mounting portion and the hole of the mounting fixture, and the clamping portion presses against the shoulder surface to hold the motor housing against the mounting portion.

[0007] According to another aspect, a mounting fixture for mounting a motor housing to an assembly is provided. The mounting fixture includes a body portion and a clamping portion extending laterally from the body portion. A hole extends through the mounting fixture to receive a fastener. The body portion includes a bottom surface that is spaced apart from the clamping portion by an outer body side surface and an inner body side surface. The clamping portion includes a bottom clamping surface that extends laterally from the body portion, wherein the bottom clamping surface is spaced apart from the top clamping surface by an outer clamping side surface and an inner clamping side surface.

[0008] These and other advantages and features will become more apparent from the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of this specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 A power steering system including a power assist assembly according to the principles of the present disclosure is schematically illustrated;

[0011] Figure 2 is a perspective view of a prior art power assist assembly including a pair of static mounting pads;

[0012] Figure 3 is a perspective view of a power assist assembly configured as a rack assist system and including a mounting fixture in accordance with the principles of the present disclosure;

[0013] Figure 4 is a perspective view of a motor mounting portion clamped to a motor housing according to the principles of the present disclosure;

[0014] Figure 5 is an upper perspective view of a mounting fixture according to the principles of the present disclosure;

[0015] Figure 6 is a lower perspective view of a mounting fixture according to the principles of the present disclosure; and

[0016] Figure 7 is a perspective view of a second embodiment of a power assist assembly according to the principles of the present disclosure. DETAILED DESCRIPTION

[0017] The following discussion is directed to various embodiments of the present disclosure. The embodiments disclosed herein should not be interpreted or otherwise used as limiting the scope of the present disclosure (including the claims). In addition, it will be understood by those skilled in the art that the following description has a wide range of applications, and the discussion of any embodiment is intended only as an example of that embodiment, and is not intended to imply that the scope of the present disclosure (including the claims) is limited to that embodiment.

[0018] The invention described herein may be incorporated into any suitable vehicle, such as a car, truck, sport utility vehicle, minivan, crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. In addition, the principles of the present disclosure may be applied to other vehicles, such as airplanes, boats, trains, drones, or other suitable vehicles. In addition, the present invention may be incorporated into various steering system architectures and electric power steering (EPS) systems.

[0019] Referring now to the drawings, in which various embodiments are shown and described herein, but not limited thereto, Figure 1 and Figure 2 shows the background and environment of the present invention, and Figures 3 to 7 Embodiments of a power assist assembly are shown that include a flexible motor mount, resulting in an adaptable and cost-effective solution.

[0020] First reference Figure 1 , generally showing a power steering system 20. The power steering system 20 may be configured as a driver interface steering system, an automated driving system, or a system that allows driver interface and automated steering. The steering system may include an input device 22 (such as a steering wheel or other HWA), wherein a driver may mechanically provide steering input by turning the steering wheel. An airbag device 24 may be located on or near the input device 22. A steering column 26 extends along an axis from the input device 22 to an output assembly 28. The steering column 26 may include at least two axially adjustable components, such as a first portion 30 and a second portion 32 that are axially adjustable relative to each other. The output assembly 28 may include a pinion shaft assembly, an I-shaft, a universal joint, a steer-by-wire component, or any other feature that is conventionally positioned relative to the input device 22. The output assembly 28 may be connected to a power assist assembly 34 (RWA) via a connector 36. The connector 36 may be one of a steering device input shaft, a continuation of a pinion shaft assembly, or a wired or wireless digital communication protocol.

[0021] The power assist assembly 34 may include a steering assembly 38, such as a rack and pinion, a recirculating ball steering assembly, or any other type of steering assembly associated with an automated steering system, a driver interface steering system, or a combination thereof. The power assist assembly 34 may then be operably connected to a drive shaft assembly 40 via the steering assembly 38. In operation, actuation of the driver input device 22 causes a responsive movement of the power assist assembly 34 and causes the drive shaft assembly 40 to rotate a drive wheel 42 of an associated vehicle. The power assist assembly 34 may be part of a single pinion electric power steering (SPEPS) system, a dual pinion electric power steering (DPEPS) system, a column electric power steering (CEPS) system, or a recirculating ball rack electric power steering (REPS) system.

[0022] Reference now Figure 2 , generally showing a prior art power assist assembly 34'. The prior art power assist assembly 34' includes a housing 44'. The housing 44' includes a motor portion 46' that defines an edge 48' for attachment to a motor housing (not shown). The conventional motor portion 46' includes a mounting pad 50' statically positioned about the edge 48' that is connected to a corresponding connection feature on the motor housing that is also secured by a fastener that extends through both the mounting pad 50' and the connection feature of the motor housing. The exact orientation and location of the mounting pad 50' is specific to the vehicle program to meet packaging requirements and therefore must be rebuilt for different programs.

[0023] Figure 3 and Figure 4 A first embodiment of a power assist assembly 34 according to the principles of the present disclosure is shown. In some embodiments, the power assist assembly 34 can be configured as a rack assist system 52, which includes an auxiliary housing 44, which defines an input gear portion 54 and a steering rack portion 56. In some embodiments, the auxiliary housing 44 (e.g., a rack housing) can be a die cast housing. The auxiliary housing 44 also includes a motor portion 46 for mounting a motor housing 58. The motor housing 58 contains motor components. The motor portion 46 includes an auxiliary edge 48. The motor housing 58 defines a motor housing edge 60 that aligns with the auxiliary edge 48 during connection.

[0024] The motor housing 58 is connected to the auxiliary edge 48 by at least one mounting clamp 62. In some embodiments, the housing 58 is connected to the auxiliary edge 48 by at least two mounting clamps 62. More specifically, each mounting clamp 62 defines a body portion 64 and a clamping portion 66 ( Figure 5 and Figure 6 The mounting fixture 62 defines a hole 68 ( Figure 5 and Figure 6 ) to receive a fastener 70, the hole extending through the body portion 64 and the clamping portion 66. During assembly, one of the motor housing 58 and the auxiliary housing 44 defines a hole 72 for receiving the fastener 70, and the other of the motor housing 58 and the auxiliary housing 44 defines at least one shoulder surface 74 for engaging with the clamping portion 66. In some embodiments, the hole 68 in the mounting fixture is threaded. In some embodiments, the fastener 70 includes a nut. Therefore, when the fastener is tightened into the hole 72 through the threaded interior, the nut, or a combination thereof, the clamping portion 66 abuts against the shoulder surface 74 to lock the motor housing 58 to the auxiliary housing 44.

[0025] exist Figure 3 and Figure 4 In an exemplary configuration of , the axial housing 44 defines at least one mounting pad 50 on or near the auxiliary edge 48. The at least one mounting pad 50 defines a hole 72 for receiving a fastener 70. The motor housing 58 defines the at least one shoulder surface 74. The at least one shoulder surface 74 is disposed on a flange 76 extending around the motor housing edge 60, the flange laterally facing or opposite the motor housing edge 60. The motor housing 58 includes an annular protrusion 77 extending around the motor housing 58 adjacent to the flange 76. In some embodiments, the flange 76 includes a flange radius Rf, the annular protrusion 77 includes a protrusion radius Rp, and the motor housing 58 includes a motor radius Rm. In some embodiments, the flange radius Rf is greater than the protrusion radius Rp and the motor radius Rm, and the protrusion radius Rp is greater than the motor radius Rm.

[0026] Figure 5 is an upper perspective view of a mounting fixture 62 according to the principles of the present disclosure, Figure 6 6 is a lower perspective view of a mounting fixture 62 according to the principles of the present disclosure. The mounting fixture 62 defines a body portion 64 and a clamping portion 66 extending laterally (greater than, less than, or equal to 90°) from the body portion 64, and the body portion 64 defines a hole 68. The body portion 64 includes a bottom surface 80, which is separated from the clamping portion 66 by an outer body side surface 82 and an inner body side surface 84. In some embodiments, the inner body side surface 84 can be concave, for example, defining an inward body radius RI. In some embodiments, the outer body side surface 82 can be convex, for example, defining a first body retaining surface 86 and a second body retaining surface 88 that merge at a body vertex 90, which can be rounded.

[0027] The clamping portion 66 includes a bottom clamping surface 91 extending laterally (greater than, less than, or equal to 90°) from the body portion 64. The bottom clamping surface 91 is spaced apart from the top clamping surface 92 by an outer clamping side surface 94 and an inner clamping side surface 96. In some embodiments, the inner clamping side surface 96 can be concave, for example, defining an inward clamping radius Ri. In some embodiments, the outer clamping side surface 94 can be convex, for example, defining a first clamping retention surface 98 and a second clamping retention surface 100 that merge at a body vertex 102, and the body vertex 102 can be rounded. In some embodiments, the outer body side surface 82 is flush with the outer clamping side surface 94, and the inner body side surface 84 is spaced apart from the inner clamping side surface 96 by the bottom clamping surface 91. In some embodiments, the inward body radius RI is greater than the inward clamping radius Ri. In some embodiments, the mounting fixture 62 is a one-piece structure formed of steel. In some embodiments, at least one of the clamping side surface 94 , the inner body side surface 84 , and the bottom clamping surface 91 includes a non-smooth configuration (eg, knurling) to enhance clamping force and prevent any radial sliding between the motor housing 58 and the motor portion 46 of the auxiliary housing 44 .

[0028] In some embodiments, the flange radius Rf is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the protrusion radius Rp or otherwise matches the protrusion radius Rp. In some embodiments, the flange radius Rf is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the motor radius Rm or otherwise matches the motor radius Rm. In some embodiments, the protrusion radius Rp is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the motor radius Rm or otherwise matches the motor radius Rm. Therefore, when the power assist assembly 34 is assembled, the radial width of the bottom clamping surface 91 of the clamping portion 66 is equal to or substantially equal to the difference between the flange radius Rf and one of the protrusion radius Rp and the motor radius Rm. However, in some embodiments, the radial width of the bottom clamping surface 91 of the clamping portion 66 is equal to or substantially equal to the difference between the protrusion radius Rp and the motor radius Rm. In some embodiments, at least one of the flange 76 , the annular protrusion 77 , and the motor housing 58 includes a non-smooth configuration (eg, knurling) to further enhance the clamping force and prevent any radial sliding between the motor housing 58 and the motor portion 46 of the auxiliary housing 44 .

[0029] Figure 7 A second embodiment of a power assist assembly 134 according to the principles of the present disclosure is shown. Unless otherwise specified, the second embodiment may be used in conjunction with Figure 3 and Figure 4The first embodiment shown in the drawings shares all the same features, elements, materials. For example, the mounting fixture 62 can be used in either embodiment. However, in the second embodiment, the motor housing 158 defines at least one mounting pad 150, which defines a hole 172. In some embodiments, the hole 172 is threaded. In some embodiments, the fastener 70 includes a nut. Therefore, when the fastener 70 is tightened into the hole 172 through the threaded interior, the nut, or a combination thereof, the clamping portion 66 abuts against the shoulder surface 174 to lock the motor housing 158 to the auxiliary housing 144.

[0030] In addition, at least one shoulder surface 174 is located on the motor portion 146 of the auxiliary housing 144. More specifically, the shoulder surface 174 can be provided on a flange 176 extending around the motor portion 146, which flange laterally faces the auxiliary edge 148 or is opposite to the auxiliary edge 148. The motor portion 146 includes an annular protrusion 177 extending around the motor portion 146 adjacent to the flange 176. In some embodiments, the flange 176 includes a flange radius rf, the annular protrusion 177 includes a protrusion radius rp, and the motor portion 146 includes a motor portion radius rm. In some embodiments, the flange radius rf is greater than the protrusion radius rp, and the protrusion radius rp is greater than the motor portion radius rm. In some embodiments, the motor portion radius rm is discontinuous (e.g., circular or conical) in a direction opposite to the auxiliary edge 148.

[0031] In some embodiments, the flange radius rf is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the protrusion radius rp or otherwise matches the protrusion radius rp. In some embodiments, the flange radius rf is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the motor portion radius rm or otherwise matches the motor portion radius rm. In some embodiments, the protrusion radius rp is equal to the inward body radius RI or otherwise matches the inward body radius RI, and the inward clamping radius Ri is equal to the motor portion radius rm or otherwise matches the motor portion radius rm. Therefore, when the power assist assembly 134 is assembled, the radial width of the bottom clamping surface 91 of the clamping portion 66 is equal to or substantially equal to the difference between the flange radius rf and one of the protrusion radius rp and the motor portion radius rm. However, in some embodiments, the radial width of the bottom clamping surface 91 of the clamping portion 66 is equal to or substantially equal to the difference between the protrusion radius rp and the motor portion radius rm. In some embodiments, at least one of the flange 176 , the annular protrusion 177 , and the motor portion 146 includes a non-smooth configuration (eg, knurling) to further enhance the clamping force and prevent any radial sliding between the motor housing 158 and the motor portion 146 of the auxiliary housing 144 .

[0032] It should be understood that, unless otherwise specified, the mounting portion described herein may also be a part of a component other than a power assist component, such as a mounting portion on a steering system or other parts and / or components of other automotive systems.

[0033] Although the present invention has been described in detail in conjunction with only a limited number of embodiments, it should be readily understood that the present invention is not limited to these disclosed embodiments. On the contrary, the present invention may be modified to include any number of variations, changes, substitutions, or equivalent arrangements that have not been described so far but are commensurate with the concept and scope of the present invention. In addition, although various embodiments of the present invention have been described, it should be understood that the scheme of the present invention may include only some of the described embodiments. In addition, any feature, element, component, or advantage of any one embodiment may be used in any other embodiment. Therefore, the present invention should not be considered to be limited by the above description.

Claims

1. A power assist component, include: Auxiliary housing and motor housing; The auxiliary housing includes a motor portion defining an auxiliary edge, and the motor housing defines a motor edge for mounting to the auxiliary edge; wherein one of the motor housing and the motor portion of the auxiliary housing defines a flange having a flange radius and an annular protrusion having a protrusion radius adjacent to the flange; a mounting pad and a shoulder surface, the mounting pad being defined by one of the motor portion and the motor housing, the shoulder surface being defined by the other of the motor portion and the motor housing; wherein the mounting pad defines a first aperture; a mounting fixture defining a second hole and comprising a body portion and a clamping portion extending laterally from the body portion, the second hole extending through the body portion and the clamping portion; wherein the body portion comprises a first concave curved surface having a first radius, the clamping portion comprises a second concave curved surface having a second radius, the first radius matches the flange radius, and the second radius matches the protrusion radius; and A fastener extends through the first and second holes to press the clamp portion against the shoulder surface and the body portion against the mounting pad to lock the auxiliary housing and the motor housing.

2. The power assist assembly according to claim 1, in, The shoulder surface and the clamping portion include non-smooth surfaces.

3. The power assist assembly according to claim 1, in, The shoulder surface is defined by a flange extending around one of the motor portion and the motor housing.

4. The power assist assembly according to claim 3, in, The body portion includes a bottom surface that is spaced apart from the clamping portion by an outer body side surface and an inner body side surface.

5. The power assist assembly according to claim 4, in, The clamping portion includes a bottom clamping surface engaged with the shoulder surface and extending laterally from the body portion, wherein the bottom clamping surface is spaced apart from the top clamping surface by an outer clamping side surface and an inner clamping side surface.

6. The power assist assembly according to claim 5, in, The bottom clamping surface includes a non-smooth surface.

7. The power assist assembly according to claim 5, in, The inner body side surface is concave.

8. The power assist assembly according to claim 7, in, The inner clamping side surface is concave.

9. The power assist assembly according to claim 8, in, The protrusion radius is smaller than the flange radius.

10. The power assist assembly according to claim 9, in, The inner body side surface contacts the flange along the flange radius, and wherein the inner clamp side surface contacts the annular protrusion along the protrusion radius.

11. A mounting fixture for mounting a motor housing to an assembly, in, One of the motor housing and the assembly defines a flange having a flange radius and an annular protrusion adjacent the flange having a protrusion radius; The mounting fixture comprises: a body portion and a clamping portion extending laterally from the body portion; a second aperture extending through the body portion and the clamp portion to receive a fastener; The body portion includes a bottom surface that is spaced apart from the clamping portion by an outer body side surface and an inner body side surface; the inner body side surface is a first concave curved surface having a first radius; and The clamping portion includes a bottom clamping surface extending laterally from the body portion, wherein the bottom clamping surface is separated from the top clamping surface by an outer clamping side surface and an inner clamping side surface; the inner clamping side surface is a second concave curved surface having a second radius; wherein the first radius matches the flange radius and the second radius matches the protrusion radius; wherein one of the motor housing and the assembly defines a mounting pad, the other of the motor housing and the assembly defines a shoulder surface, the mounting pad defines a first hole, the fastener extends through the first hole and the second hole such that the bottom clamping surface is pressed against the shoulder surface and the bottom surface abuts against the mounting pad.

12. The mounting fixture according to claim 11, in, At least one of the bottom clamping surface, the inner clamping side surface, and the inner body side surface of the clamping portion defines a non-smooth configuration.

13. The mounting fixture according to claim 11, in, The mounting fixture is integrally formed.

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