EPS coupling and electric power steering gear

Abstract

The invention provides an EPS coupling and an electric power steering gear, the EPS coupling comprises a first coupling part, a second coupling part and a buffer material layer used for eliminating a gap between the first coupling part and the second coupling part, the first coupling part is uniformly provided with a plurality of first convex claws, and a first clamping groove is formed between every two adjacent first convex claws; the second coupling part is evenly provided with a plurality of second protruding claws matched with the first clamping grooves, a second clamping groove matched with the first protruding claws is formed between every two adjacent second protruding claws, the buffer material layers are bonded to the surfaces of the first protruding claws and the surfaces of the second protruding claws in a vulcanized mode respectively, and the thickness of the buffer material layers is smaller than or equal to 1 mm. A layer of buffer pad with the thickness smaller than or equal to 1 mm is directly vulcanized on the surface of the first convex claw and the surface of the second convex claw to eliminate a gap between the first coupling part and the second coupling part, so that the purchase and installation cost of the buffer pad is saved, the thickness of the buffer pad is small, the permanent deformation of rubber after durability is extremely small, and the situation that the coupler generates abnormal sound is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of automobile steering, and in particular to an EPS coupling and an electric power steering gear. Background Art

[0002] Most cars now use electric power steering systems. This electric power steering system is based on the ECU controller, which controls the rotation of the EPS motor according to the changes in the collected sensor torque signal and angle signal. The EPS motor drives the worm gear and worm reduction mechanism to provide the power assistance required for vehicle steering, thereby improving the vehicle's steering performance and allowing the driver to more easily control the direction of the vehicle.

[0003] The automotive EPS coupling is a device that transmits the rotational torque of the motor to the worm. The existing automotive EPS coupling mainly has the following three structural forms: (1) It consists of three parts: the motor claw, the buffer pad, and the worm claw; (2) It consists of the internal and external splines; (3) It consists of three parts: the motor special-shaped claw, the buffer sleeve, and the worm special-shaped claw. In the spline transmission mode, collision and wear between the spline and the spline groove are inevitable, which greatly shortens the life of the worm gear or the motor, and produces abnormal noise as the spline wears; the staggered connection transmission mode of the claws with rubber pads between the pairs of claws of (1) and (3), the thickness of the existing buffer pads is mostly above 3mm, and the permanent deformation of the rubber after durability is large. After the car has been used for a period of time, the buffer pad is permanently deformed, and the coupling has a gap, which causes abnormal noise when the car is driving on uneven roads, causing user complaints. Summary of the invention

[0004] In view of the deficiencies in the prior art, an object of the present invention is to provide an EPS coupling and an electric power steering gear, which can effectively solve the problems in the background technology.

[0005] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: an EPS coupling, comprising a first coupling part, a second coupling part and a buffer material layer for eliminating the gap between the first coupling part and the second coupling part, the first coupling part is evenly provided with a plurality of first protruding claws, and a first groove is formed between every two adjacent first protruding claws, the second coupling part is evenly provided with a plurality of second protruding claws matching the first groove, and a second groove matching the first protruding claw is formed between every two adjacent second protruding claws, the buffer material layer is vulcanized and bonded to the surfaces of the first protruding claw and the second protruding claw, respectively, the thickness of the buffer material layer is T, and the value range of T is: T≤1mm.

[0006] The second protruding claw and the first clamping groove, as well as the first protruding claw and the second clamping groove are interference fit.

[0007] The thickness of the buffer material layer is 0.5 mm.

[0008] The number of the first protruding claws is equal to the number of the second locking grooves.

[0009] The number of the first protruding claws and the number of the second protruding claws are both four.

[0010] The buffer material layer is formed by vulcanizing a rubber material.

[0011] The side walls of the first protruding claw and the second protruding claw are inclined surfaces.

[0012] The side walls of the first protruding claw and the second protruding claw have an inclination angle A, and the angle A is 5°.

[0013] The present invention also provides an electric power steering device, comprising a motor, a reduction mechanism and the EPS coupling described above, wherein the EPS coupling comprises a first coupling part, a second coupling part and a buffer material layer for eliminating the gap between the first coupling part and the second coupling part, wherein the first coupling part is evenly provided with a plurality of first protruding claws, and a first groove is formed between every two adjacent first protruding claws, and the second coupling part is evenly provided with a plurality of second protruding claws matching the first groove, and a second groove matching the first protruding claw is formed between every two adjacent second protruding claws, and the buffer material layer is vulcanized and bonded to the surfaces of the first protruding claw and the second protruding claw, respectively, and the thickness of the buffer material layer is ≤1mm, and the reduction mechanism comprises a worm, the first coupling part is arranged at the end of the motor output shaft, and the second coupling part is arranged on the worm.

[0014] Compared with the prior art, the above technical solution brings the following technical effects:

[0015] The present invention adopts a coupling with a staggered connection structure of a pair of claws to transmit the rotational torque of the motor. A buffer material layer with a thickness of ≤1mm is directly vulcanized on the first claw of the first coupling part and the surface of the second claw of the second coupling part. The gap between the first coupling part and the second coupling part is eliminated by this thin buffer material layer. Since the buffer material layer is directly vulcanized and bonded to the surfaces of the first claw and the second claw, the purchase and installation costs of the buffer pad are saved. In addition, the thickness of the buffer material layer is very small, and the permanent deformation of the rubber after durability is extremely small (negligible). Therefore, it can be avoided that a gap is generated between the first coupling part and the second coupling part, which causes abnormal noise in the coupling.

[0016] The side walls of the first cam and the second cam of the present invention are both inclined surfaces, which facilitates the first cam to be quickly inserted into the second slot to form an interference fit during assembly, and facilitates the second cam to be quickly inserted into the first slot to form an interference fit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a schematic diagram after the first coupling part and the second coupling part are installed;

[0019] Figure 2 is a schematic diagram of the first coupling portion;

[0020] Figure 3 yes Figure 2 Sectional view along AA direction;

[0021] Figure 4 is a schematic diagram of the second coupling portion;

[0022] Figure 5 yes Figure 4 Middle section view along BB direction;

[0023] Figure 6 It is a schematic diagram of the connection structure between the motor and the reduction mechanism of the electric power steering;

[0024] Description of main component symbols:

[0025] 1. First coupling part; 101. First cam; 102. First slot; 2. Second coupling part; 201. Second cam; 202. Second slot; 3. Buffer material layer; 4. Motor; 5. Speed ​​reduction mechanism. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] like Figures 1 to 6As shown, the EPS coupling of this embodiment includes a first coupling part 1, a second coupling part 2 and a buffer material layer 3 for eliminating the gap between the first coupling part 1 and the second coupling part 2. The first coupling part 1 is evenly provided with a plurality of first protruding claws 101, and a first groove 102 is formed between every two adjacent first protruding claws 101. The second coupling part 2 is evenly provided with a plurality of second protruding claws 201 matching the first groove 102, and a second groove 202 matching the first protruding claw 101 is formed between every two adjacent second protruding claws 201. The buffer material layer 3 is vulcanized and bonded to the surfaces of the first protruding claw 101 and the second protruding claw 201, respectively. The thickness of the buffer material layer 3 is T, and the value range of T is: T≤1mm. The second protruding claw 201 and the first groove 102, as well as the first protruding claw 101 and the second groove 202 are both interference fit.

[0032] The coupling is a device that connects the motor output shaft and the worm together. The motor's rotational torque is transmitted to the worm through the coupling. Since the motor output shaft and the worm are both made of rigid materials, there will be an assembly gap at the connection between the two (this assembly gap is usually 0.05mm-0.2mm). The existence of the gap causes abnormal noise when the car is driving on uneven roads. The existing coupling is achieved by installing a buffer pad between the motor claw and the worm claw, but the buffer pad is an independent component that needs to be purchased and installed, and the thickness of the buffer pad is relatively large (generally 3mm-5mm, a buffer pad with a smaller thickness greatly increases the difficulty of installation, and is prone to misalignment during installation). According to the permanent deformation percentage of the rubber, the permanent deformation of the rubber after durability is large, which causes abnormal noise from the coupling. The present invention adopts a coupling with a staggered connection structure of a pair of cams to transmit the rotational torque of the motor. During installation, the first cam 101 is inserted into the second slot 202 to form an interference fit, and the second cam 201 is inserted into the first slot 102 to form an interference fit. A layer of buffer material layer 3 with a thickness of ≤1mm is directly vulcanized on the first cam 101 of the first coupling part 1 and the surface of the second cam 201 of the second coupling part 2. During the staggered embedding process of the first cam 101 and the second cam 201, the buffer material layer 3 is deformed. This thin buffer material layer 3 can eliminate the gap between the first coupling part 1 and the second coupling part 2. Since the buffer material layer 3 is directly vulcanized and bonded to the surface of the first claw 101 and the second claw 201, the purchase and installation costs of the buffer pad are saved. In addition, the thickness of the buffer material layer 3 is small, and the permanent deformation percentage of the rubber is fixed. Therefore, the permanent deformation of the rubber after durability is extremely small (negligible), which can avoid the gap between the first coupling part 1 and the second coupling part 2, resulting in abnormal noise of the coupling.

[0033] In this embodiment, the thickness of the buffer material layer 3 is 0.5 mm.

[0034] The thickness of the buffer material layer 3 is 0.5 mm, which can eliminate the gap between the first coupling part 1 and the second coupling part 2 and reduce the permanent deformation of the rubber.

[0035] In this embodiment, the number of the first protruding claws 101 is equal to the number of the second locking grooves 202 .

[0036] In this embodiment, there are four first protruding claws 101 and four second protruding claws 201. The four first protruding claws 101 are evenly distributed on the first coupling part 1 to form four first clamping grooves 102, and the four second protruding claws 201 are evenly distributed on the second coupling part 2 to form four second clamping grooves 202. When installing, the four first protruding claws 101 are inserted into the four second clamping grooves 202, and the four second protruding claws 201 are inserted into the four first clamping grooves 102.

[0037] In this embodiment, the number of the first protruding claws 101 evenly arranged around the circumference of the first coupling part 1 and the number of the second protruding claws 201 evenly arranged around the circumference of the second coupling part 2 are not limited to four.

[0038] In this embodiment, the buffer material layer 3 is made of vulcanized rubber material. The specific model of the rubber material is M4BC814_HG / T2196. When making the buffer material layer 3, a vulcanization mold is used to place rubber powder and the first protruding claw 101 and the second protruding claw 201 in the mold and heat until the rubber powder melts and adheres to the side walls of the first protruding claw 101 and the second protruding claw 201.

[0039] In this embodiment, the side walls of the first protruding claw 101 and the second protruding claw 201 are inclined surfaces.

[0040] like Figure 2 and Figure 4 As shown, the first cam 101 and the second cam 201 have two side walls that are arc-shaped surfaces, and the other two side walls are designed to be inclined surfaces. The size of the insertion end (free end) of the first cam 101 is smaller than the size of the fixed end, and the size of the insertion end (free end) of the second cam 201 is smaller than the size of the fixed end. During assembly, the insertion end of the first cam 101 can be quickly inserted into the second slot 202 to form an interference fit, and the insertion end of the second cam 201 can be quickly inserted into the first slot 102 to form an interference fit.

[0041] like Figure 3 and Figure 5 As shown, the side walls of the first protruding claw 101 and the second protruding claw 201 have an inclination angle A, and the angle A is 5°.

[0042] The present embodiment also discloses an electric power steering device, comprising a motor 4, a reduction mechanism 5 and the above-mentioned EPS coupling, the EPS coupling comprising a first coupling part 1, a second coupling part 2 and a buffer material layer 3 for eliminating the gap between the first coupling part 1 and the second coupling part 2, the first coupling part 1 is evenly provided with a plurality of first protruding claws 101, a first groove 102 is formed between every two adjacent first protruding claws 101, the second coupling part 2 is evenly provided with a plurality of second protruding claws 201 matching the first groove 102, a second groove 202 matching the first protruding claw 101 is formed between every two adjacent second protruding claws 201, the buffer material layer 3 is vulcanized and bonded to the surfaces of the first protruding claw 101 and the second protruding claw 201, respectively, the thickness of the buffer material layer 3 is ≤1 mm, the reduction mechanism 5 comprises a worm, the first coupling part 1 is arranged at the end of the output shaft of the motor 4, and the second coupling part 2 is arranged on the worm.

[0043] The motor 4 has an output shaft. When the first coupling part 1 is arranged at the end of the output shaft, the second coupling part 2 is arranged at the end of the worm, and the first coupling part 1 is integrally formed with the output shaft, and the second coupling part 2 is integrally formed with the end of the worm. When the motor 4 is running, the first coupling part 1 is driven to rotate by the output shaft of the motor 4, and the first cam 101 of the first coupling part 1 transmits the torque to the second cam 201, and the second cam 201 drives the worm to rotate, and then transmits it to the worm wheel through the worm. The transmission of the worm wheel and worm realizes the effect of speed reduction and torque increase, and the rack shaft is driven to move axially to the left and right through the gear shaft fixed on the worm wheel, and the tire is driven to rotate through the inner tie rod combination and the outer tie rod combination to realize the left and right steering function of the vehicle.

[0044] After the zero-kilometer and road durability tests, the present invention has no abnormal noise, meeting the performance requirements of the main engine manufacturer. The specific test environment is: cobblestone road surface, European brick road surface, rope, pothole road surface and empty brick road surface.

[0045] Except for the technical features described in the specification, the other technical features are known to those skilled in the art.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0047] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments. As long as they conform to the purpose of the present invention, they shall be within the scope of protection required by the present invention, such as different combinations of specific embodiments and different combinations of distinguishing technical features.

Claims

1. An EPS coupling, It is characterized in that The invention comprises a first coupling part (1), a second coupling part (2) and a buffer material layer (3) for eliminating the gap between the first coupling part (1) and the second coupling part (2); the first coupling part (1) is evenly provided with a plurality of first protruding claws (101), and a first clamping groove (102) is formed between every two adjacent first protruding claws (101); the second coupling part (2) is evenly provided with a plurality of second protruding claws (201) matching the first clamping groove (102), and a second clamping groove (202) matching the first protruding claw (101) is formed between every two adjacent second protruding claws (201); the buffer material layer (3) is vulcanized and bonded to the surfaces of the first protruding claw (101) and the second protruding claw (201), respectively; the thickness of the buffer material layer (3) is T, and the value range of T is: T≤1mm.

2. The EPS coupling according to claim 1, It is characterized in that The second protruding claw (201) and the first clamping groove (102), as well as the first protruding claw (101) and the second clamping groove (202) are both interference fit.

3. The EPS coupling according to claim 1, It is characterized in that The buffer material layer (3) has a thickness of 0.5 mm.

4. The EPS coupling according to claim 1, It is characterized in that The number of the first protruding claws (101) is equal to the number of the second locking grooves (202).

5. The EPS coupling according to claim 1, It is characterized in that The number of the first protruding claws (101) and the number of the second protruding claws (201) are both four.

6. The EPS coupling according to claim 1, It is characterized in that The buffer material layer (3) is made of vulcanized rubber material.

7. The EPS coupling according to claim 1, It is characterized in that The side walls of the first protruding claw (101) and the second protruding claw (201) are inclined surfaces.

8. The EPS coupling according to claim 7, It is characterized in that The side walls of the first protruding claw (101) and the second protruding claw (201) have an inclination angle A, and the angle A is 5°.

9. An electric power steering device, It is characterized in that The invention comprises a motor (4), a speed reduction mechanism (5) and the EPS coupling according to any one of claims 1 to 8, wherein the EPS coupling comprises a first coupling part (1), a second coupling part (2) and a buffer material layer (3) for eliminating the gap between the first coupling part (1) and the second coupling part (2), wherein the first coupling part (1) is evenly provided with a plurality of first protruding claws (101), and a first slot (102) is formed between every two adjacent first protruding claws (101); and the second coupling part (2) is evenly provided with a plurality of first protruding claws (101) and a first slot (102) is formed between every two adjacent first protruding claws (101). A second cam (201) matches the first groove (102), and a second groove (202) matching the first cam (101) is formed between every two adjacent second cams (201). The buffer material layer (3) is vulcanized and bonded to the surfaces of the first cam (101) and the second cam (201), respectively. The buffer material layer (3) has a thickness of ≤1 mm. The speed reduction mechanism (5) comprises a worm. The first coupling portion (1) is arranged at the end of the output shaft of the motor (4), and the second coupling portion (2) is arranged on the worm.

Images