CN114131311B

CN114131311B - Axiality adjusting device, worm gear steering gear and assembly quality

Info

Publication number: CN114131311B
Application number: CN202111444166.9A
Authority: CN
Inventors: 邓念
Original assignee: China Automotive Innovation Co Ltd
Current assignee: China Automotive Innovation Co Ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-10-10
Anticipated expiration: 2041-11-30
Also published as: CN114131311A

Abstract

The invention relates to the technical field of steering, and discloses a coaxiality adjusting device, a worm gear steering machine and an assembling device. The elastic tolerance ring can also reduce vibration and noise when the worm gear steering machine works, even if the vibration during working causes looseness between the hole parts and the shaft parts or circumferential relative sliding between the hole parts and the shaft parts under the limiting working condition, the torque transmission between the hole parts and the shaft parts can not be damaged, the elastic tolerance ring still can continue to provide stable friction torque, and normal torque transmission can be ensured.

Description

Axiality adjusting device, worm gear steering gear and assembly quality

Technical Field

The invention relates to the technical field of steering, in particular to a coaxiality adjusting device, a worm gear steering machine and an assembling device.

Background

The double-pinion electric power-assisted steering system adopts a worm and gear steering machine to carry out power transmission, a worm is connected with a motor spindle to receive the torque of the motor, and the motor transmits power to a driving gear shaft through a worm and gear mechanism, so that the driving gear shaft drives a rack meshed with the driving gear shaft to reciprocate in a steering machine shell, and the steering function of an automobile is realized. The worm and gear mechanism has the functions of reducing speed and increasing torque, and can amplify the torque of the motor to more than 20 times.

When the worm gear mechanism is connected with the driving gear shaft, the worm gear and the driving gear shaft are assembled in a press fit mode. The following technical problems exist in the rigid connection of the worm wheel and the driving gear shaft in a press-fit manner:

(1) When the worm wheel and the driving gear shaft are pressed, an inner hole of the worm wheel is usually set as a unthreaded hole, one end of the driving gear shaft is set as an optical axis or a spline shaft, if the driving gear shaft adopts an optical axis design, the size of the optical axis is very sensitive to the pressing force when the worm wheel and the driving gear shaft are pressed, and therefore, higher processing requirements are provided for the precision and the surface roughness of the optical axis; if the driving gear shaft adopts a spline shaft design, the processing cost of parts can be increased.

(2) When the worm wheel is rigidly connected with the driving gear shaft in a press-fit mode, vibration noise is easy to be generated when the worm wheel and the driving gear shaft work.

(3) In the direct press-fitting process of the worm wheel and the driving gear shaft, the phenomenon of worm wheel bias is extremely easy to occur, so that the meshing state of the worm wheel and the worm is influenced, and a series of consequences such as noise, vibration, sound vibration roughness, torque fluctuation and the like can also be generated; even the press fitting failure of the worm wheel and the driving gear shaft can be caused in severe cases.

In the prior art, when the worm and gear mechanism is connected with the motor main shaft, the motor main shaft and the coupling connected with the motor main shaft are also pressed, the connection mode of the worm and the coupling is the same as the connection mode of the worm wheel and the driving gear shaft, and the connection between the worm and the coupling also has the problems.

Disclosure of Invention

The invention aims to provide a coaxiality adjusting device, a worm gear steering machine and an assembling device, which can correct deviation during press fitting, improve the assembling precision of two press fitting components, reduce torque fluctuation during power transmission of two connected press fitting components, reduce vibration and noise during operation of the worm gear steering machine, and also play a role in protecting rigid connection of hole components and shaft components.

To achieve the purpose, the invention adopts the following technical scheme:

the coaxiality adjusting device is connected to two press-fitting parts, wherein the two press-fitting parts are a hole part and a shaft part respectively, and the hole part is sleeved outside the shaft part; the coaxiality adjusting device comprises:

an elastic tolerance ring interposed between an inner peripheral surface of the hole-like member and an outer peripheral surface of the shaft-like member;

the resilient tolerance ring is configured to be resiliently deformable in a radial direction during press fitting to allow movement of one of the press fitting components and up to coaxial with the other of the press fitting components.

As an optional technical scheme of the coaxiality adjusting device, the elastic tolerance ring is provided with a deformation space, and the deformation space is used for providing space for elastic deformation of the elastic tolerance ring in the press fitting process.

As an alternative to the above coaxiality adjusting device, the elastic tolerance ring includes:

the correcting body is a C-shaped ring, and the deformation space is an axial opening on the periphery of the C-shaped ring.

As an alternative to the above coaxiality adjusting device, the elastic tolerance ring further includes:

The deformation convex parts are convexly arranged on the outer circumferential surface of the deviation correcting body at intervals and are abutted against the hole parts; and/or the interval is convexly arranged on the inner circumferential surface of the deviation rectifying body and is in butt joint with the shaft part.

As an optional technical solution of the coaxiality adjusting device, the deformation convex portion includes a protrusion protruding from an inner peripheral surface to an outer peripheral surface of the deviation rectifying body;

and/or the number of the groups of groups,

and a protrusion protruding from the outer circumferential surface to the inner circumferential surface of the deviation rectifying body.

As an alternative technical scheme of the coaxiality adjusting device, the radial thickness of the elastic tolerance ring is 2% -5% of the inner diameter of the elastic tolerance ring.

As an alternative technical scheme of the coaxiality adjusting device, a deformation groove is formed at the bottom of the deformation convex part, and the cross section of the deformation groove is in a sector shape, a rectangle shape or a trapezoid shape.

As an optional technical scheme of the coaxiality adjusting device, the cross section of the deformation groove is fan-shaped, the axial length of the deformation convex part is 1.2 mm-3.0 mm, and the circumferential arc length of the deformation convex part is 0.8 mm-2.0 mm.

As an alternative to the above-mentioned coaxiality adjusting device, the deformation protrusion is at least partially embedded in the press-fitting member.

As an alternative to the above-mentioned coaxiality adjusting device, the press-fit member in which the deformation protrusion is embedded has a hardness smaller than that of the elastic tolerance ring.

As an alternative technical scheme of the coaxiality adjusting device, the deformation convex part is arranged on the inner peripheral surface of the elastic tolerance ring, and the occupied area of the deformation convex part is 33% -55% of the surface area of the inner peripheral surface of the elastic tolerance ring;

or alternatively, the process may be performed,

the deformation convex part is arranged on the outer circumferential surface of the elastic tolerance ring, and the area of the set area is 33% -55% of the surface area of the outer circumferential surface of the elastic tolerance ring.

As an alternative to the coaxiality adjusting device, the yield strength of the material for manufacturing the elastic tolerance ring is more than 450MPa.

The invention also provides a worm gear steering machine, which comprises:

a driving unit;

the input end of the worm is connected with the output shaft of the driving unit through a coupler, and the driving unit is used for driving the worm to rotate;

the worm wheel is meshed with the worm, and the worm wheel is connected with a driving gear shaft;

the coaxiality adjusting device is characterized by further comprising the coaxiality adjusting device according to any scheme;

The elastic tolerance ring is arranged between the input end of the worm and the driven end of the coupler;

and/or the elastic tolerance ring is arranged between the driving gear shaft and the worm wheel;

and/or the elastic tolerance ring is arranged between the output shaft of the driving unit and the driving end of the coupler.

The invention also provides a worm gear steering machine, which comprises:

a driving unit;

the input end of the worm is connected with the output shaft of the driving unit, and the driving unit is used for driving the worm to rotate;

the elastic tolerance ring is arranged between the input end of the worm and the output shaft of the driving unit;

and/or the elastic tolerance ring is arranged between the driving gear shaft and the worm wheel.

The invention also provides an assembling device which is used for assembling the coaxiality adjusting device; the assembly device includes:

a first clamping structure for clamping one press-fit member in the coaxiality adjusting device;

a second clamping structure for clamping the other press-fit component in the coaxiality adjusting device, one of the first clamping structure and the second clamping structure being swingable;

The press-fitting machine is used for driving the first clamping structure to drive the clamped press-fitting component to axially approach the other press-fitting component so as to sleeve the hole component outside the shaft component and clamp the elastic tolerance ring between the outer peripheral surface of the shaft component and the inner peripheral surface of the hole component.

The invention has the beneficial effects that: according to the coaxiality adjusting device, the worm gear steering machine and the assembly device, the elastic tolerance ring is arranged between the hole part and the shaft part, when the hole part and the shaft part are assembled in a press-fitting mode, the elastic tolerance ring is firstly arranged on the hole part or the shaft part, if deflection exists between the hole part and the shaft part in the press-fitting process, the elastic tolerance ring can elastically deform under the extrusion action of the shaft part and the hole part and acts against the hole part and the shaft part, so that one of the hole part and the shaft part swings, the hole part and the shaft part are coaxial, press-bias and press-fitting failure are prevented, the assembly precision of the two press-fitting parts is improved, torque fluctuation when the two connected press-fitting parts transmit power is reduced, and the NVH performance of the worm gear steering machine is improved.

Because elastic tolerance ring can take place elastic deformation, set up elastic tolerance ring between the inner peripheral face of hole class part and the outer peripheral face of axle class part, vibrations and noise when not only can reduce worm gear steering machine work, even the vibrations when work make between hole class part and the axle class part produce not hard up or the limit operating mode down hole class part and axle class part produce circumference relative slip, but can not destroy the moment of torsion transmission between hole class part and the axle class part, elastic tolerance ring still can continue to provide stable friction torque, can guarantee moment of torsion normal transmission effectively, thereby play the effect of protecting the connection between two pressure equipment parts, prevent hole class part and axle class part from being damaged or the phenomenon of skidding appears. Compared with the method that one end of the shaft part is set as the optical axis, the sensitivity of the shaft part to press in the press mounting process can be reduced, and the requirements on the machining precision and the surface roughness of the shaft part and the hole part are reduced; compared with the method that the spline matched with the hole-type component is arranged on the shaft-type component, the machining cost of the component can be reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following description will briefly explain the drawings needed in the description of the embodiments of the present invention, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the contents of the embodiments of the present invention and these drawings without inventive effort for those skilled in the art.

Fig. 1 is a schematic structural diagram of a worm and gear steering system according to an embodiment of the present invention;

fig. 2 is a partial exploded view of a worm gear steering engine according to an embodiment of the present invention;

FIG. 3 is an assembly view of a worm gear and worm in a worm gear and worm steering engine provided by an embodiment of the present invention;

FIG. 4 is a cross-sectional view I of FIG. 3;

FIG. 5 is a second cross-sectional view of FIG. 3;

fig. 6 is a second partial exploded view of the worm gear steering engine according to the embodiment of the present invention;

fig. 7 is a sectional view showing an assembled state of an output shaft of a motor and an input end of a worm in a worm gear steering machine according to an embodiment of the present invention;

FIG. 8 is a schematic illustration of a resilient tolerance ring provided by an embodiment of the present invention;

FIG. 9 is a process diagram of a spring tolerance ring provided by an embodiment of the present invention.

In the figure:

1. a motor; 11. an output shaft; 2. a worm; 3. a worm wheel; 4. a drive gear shaft; 5. a coupling; 51. a driving end; 52. a passive end; 53. an elastic pad;

6. a large end bearing; 7. a small end bearing; 8. aligning the bearing; 9. a bearing inner ring clamp;

20. an input shaft; 30. a drive controller;

40. a resilient tolerance ring; 401. a first elastic tolerance ring; 402. a second resilient tolerance ring; 41. a correction body; 42. a deformation convex part; 43. a deformation groove; 44. deformation space.

Detailed Description

In order to make the technical problems solved, the technical scheme adopted and the technical effects achieved by the invention more clear, the technical scheme of the invention is further described below by a specific embodiment in combination with the attached drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the drawings related to the present invention are shown.

As shown in fig. 1 to 7, this embodiment provides a worm gear steering machine and an electric power steering system, taking a double-pinion electric power steering system as an example, the double-pinion electric power steering system includes a worm gear steering machine, the worm gear steering machine includes a worm wheel 3, a worm 2 and a driving unit, wherein, an input end of the worm 2 is connected with an output shaft of the driving unit through a coupling 5, the driving unit is a motor 1, an output shaft of the driving unit is an output shaft 11 of the motor 1, the worm wheel 3 is meshed with the worm 2, the worm wheel 3 is connected with a driving gear shaft 4, and the driving gear shaft 4 is connected with a rack-and-pinion structure. The input shaft 20 of the double pinion electric power steering system is connected to the intermediate shaft for receiving torque input from the driver's steering wheel and outputting to the wheel end; meanwhile, an input signal is sent to the driving controller 30 through the detection unit, the control of the motor 1 is achieved, the motor 1 is controlled to drive the worm 2 to rotate through the coupler 5, the worm 2 drives the worm wheel 3 to rotate, and the worm wheel 3 drives the rack of the gear-rack structure to reciprocate through the driving gear shaft 4 so as to output torque to a wheel end, and the auxiliary steering function of the electric power steering system is achieved.

In the prior art, the output shaft 11 of the motor 1 is connected with the driving end 51 of the coupler 5, and the driven end 52 of the coupler 5 is press-fitted with the input end of the worm 2. The passive end 52 of the coupling 5 and the input end of the worm 2 are biased during the press fitting process, so that the power transmission between the motor 1 and the worm 2 is affected. The worm wheel 3 and the driving gear shaft 4 are also connected in a press-fitting mode, so that the problem of pressure deviation is also caused in the press-fitting process.

In this embodiment, the driven end 52 of the coupling 5 and the input end of the worm 2, the worm wheel 3 and the drive gear shaft 4 are respectively recorded as a pair of press-fitting components, in order to prevent deflection during press-fitting of two press-fitting components in pair, this embodiment provides a coaxiality adjusting device for press-fitting of a hole component and a shaft component, the hole component is press-fitted and sleeved outside the shaft component, and an elastic tolerance ring 40 is provided between the inner peripheral surface of the hole component and the outer peripheral surface of the shaft component, and the elastic tolerance ring 40 is configured to be elastically deformed during the press-fitting process, so that at least one press-fitting component swings to make the two press-fitting components coaxial.

In this embodiment, the passive end 52 of the coupling 5 and the input end of the worm 2 are hole members, and the input end of the worm 2 is a shaft member. Among the worm wheel 3 and the drive gear shaft 4, the worm wheel 3 is a hole type member, and the drive gear shaft 4 is a shaft type member.

In order to facilitate the assembly of the two press-fit components, a limiting surface is arranged on the shaft component, the shaft component is fixed, and the elastic tolerance ring 40 is sleeved on the shaft component, so that the elastic tolerance ring 40 is abutted against the limiting surface; an axial force is applied to the bore member to axially bring the bore member into close proximity with the shaft member to sleeve the shaft member outside the bore member, and the elastic tolerance ring 40 is interposed between the outer peripheral surface of the shaft member and the inner peripheral surface of the bore member.

In other embodiments, the shaft member may be fixed, a limiting surface may be provided in the hole member, the elastic tolerance ring 40 may be mounted in the hole member and abut against the limiting surface, an axial force may be applied to the hole member to axially abut against the shaft member, the shaft member may be sleeved outside the hole member, and the elastic tolerance ring 40 may be sandwiched between an outer circumferential surface of the shaft member and an inner circumferential surface of the hole member. The hole-like member may be fixed, the elastic tolerance ring 40 may be fitted into the hole-like member or fitted into the shaft-like member, and an axial force may be applied to the shaft-like member so that the shaft-like member is fitted into the hole-like member, and the elastic tolerance ring 40 may be interposed between the outer peripheral surface of the shaft-like member and the inner peripheral surface of the hole-like member.

In order to assemble the two press-fit components by press-fitting, the present embodiment also provides an assembling device by which the two press-fit components are assembled. The assembly device comprises a press-fitting machine, a first clamping structure and a second clamping structure, wherein the first clamping structure is used for clamping one press-fitting component, the second clamping structure is used for clamping the other press-fitting component, and one of the first clamping structure and the second clamping structure can swing; the press-fitting machine is used for driving the first clamping structure to drive the clamped press-fitting component to axially approach the other press-fitting component so as to sleeve the hole-type component outside the shaft-type component, and the elastic tolerance ring 40 is clamped between the outer peripheral surface of the shaft-type component and the inner peripheral surface of the hole-type component. The press is illustratively a hydraulic press that provides a press force of 20KN to 25KN.

If there is a deflection between the hole-like member and the shaft-like member during the press-fitting process, the elastic tolerance ring 40 will elastically deform under the extrusion action of the shaft-like member and the hole-like member, and will react to the hole-like member and the shaft-like member, so that one of the hole-like member and the shaft-like member swings, thereby making the hole-like member and the shaft-like member coaxial, preventing the press-fitting failure and the press-fitting failure, improving the assembly precision of the two press-fitting members, and reducing the torque fluctuation when the two connected press-fitting members transmit power.

Because the elastic tolerance ring 40 can elastically deform, the elastic tolerance ring 40 is arranged between the inner peripheral surface of the hole part and the outer peripheral surface of the shaft part, vibration and noise generated when the worm gear steering machine works can be reduced, even if the vibration generated when the worm gear steering machine works loosens the hole part and the shaft part or the hole part and the shaft part generate circumferential relative sliding under the limiting working condition, torque transmission between the hole part and the shaft part cannot be damaged, the elastic tolerance ring 40 still can continuously provide stable friction torque, normal torque transmission can be effectively ensured, and the function of protecting the connection between two press-fitting parts is achieved, and the hole part and the shaft part are prevented from being damaged or slipping phenomenon occurs. Compared with the method that one end of the shaft part is set as the optical axis, the sensitivity of the shaft part to press in the press mounting process can be reduced, and the requirements on the machining precision and the surface roughness of the shaft part and the hole part are reduced; compared with the method that the spline matched with the hole-type component is arranged on the shaft-type component, the machining cost of the component can be reduced.

In order to enable the two press-fitting components to be coaxial, the swinging angle of each press-fitting component is limited, for example, a first clamping structure is mounted on the press-fitting machine, so that the first clamping structure can swing around the axis of the press-fitting machine applying axial force as a central axis by taking the connecting point of the first clamping structure and the press-fitting machine as a swinging point, and the swinging angle of the first clamping structure is less than or equal to 3 degrees. Illustratively, the above-described swing angle may be any one of values of 0.5 °, 1 °, 1.5 °, 2 °, 2.5 °, and 3 °. In other embodiments, the second clamping structure may be further mounted on the support, where a connection point of the second clamping structure and the press machine is on an axis of the press machine applying an axial force, and the second clamping structure may swing around the axis of the press machine applying the axial force as a central axis with a connection point of the second clamping structure and the press machine as a swinging point, and a swinging angle of the second clamping structure is less than or equal to 3 °.

It should be noted that, the specific structures of the press-fitting machine, the first clamping structure and the second clamping structure are all in the prior art, and are not described in detail. The connection between the first clamping structure and the press-fitting machine and the connection between the second clamping structure and the bracket are improved on the basis of the existing structure, so that the first clamping structure and the second clamping structure can swing, such as ball hinge and the like, and are not specifically described herein.

Further, the elastic tolerance ring 40 is provided with a deformation space 44, and the deformation space 44 is used for providing space for elastic deformation of the elastic tolerance ring 40 during the press-fitting process. Illustratively, the resilient tolerance ring 40 includes a rectifying body 41, the rectifying body 41 being a C-shaped ring, and the deformation space 44 being an axial opening on the outer periphery of the C-shaped ring. Optionally, the angle of the axial opening of the C-shaped ring is 10 ° to 25 °, and two opposite opening end faces of the axial opening are radial planes passing through the central axis of the C-shaped ring, and the angle of the axial opening of the C-shaped ring is an included angle between the two radial planes, so that a space is provided for elastic deformation in the press-fitting process, material flow is facilitated, and material accumulation during press-fitting is prevented so as to affect the process performance. The angle of the axial opening of the C-ring may be any one of 10 °, 11 °, 12 °, 13 °, 14 °, 15 °, 16 °, 17 °, 18 °, 19 °, 20 °, 21 °, 22 °, 23 °, 24 °, and 25 °.

In the process of applying axial force to the hole-like member to sleeve the hole-like member outside the shaft-like member, when the press-fitting is deflected, the elastic tolerance ring 40 will elastically deform under the pressing action of the hole-like member and the shaft-like member, and the setting of the deformation space 44 provides space for the elastic deformation of the elastic tolerance ring 40, and at the same time, the elastic tolerance ring 40 will apply radial force to the hole-like member and the shaft-like member to swing the deflected press-fitting member, thereby making the hole-like member and the shaft-like member coaxial. The elastic tolerance ring 40 is capable of elastic deformation and also facilitates the sleeve of the elastic tolerance ring 40 on the shaft component prior to press fitting.

In other embodiments, the deviation rectifying body 41 is not limited to a C-shaped ring, but an annular deviation rectifying body 41 may be adopted, and the two axial end surfaces of the deviation rectifying body 41 are respectively provided with an avoidance groove penetrating through the inner circumferential surface and the outer circumferential surface of the deviation rectifying body 41, the axial length of the avoidance groove is smaller than that of the deviation rectifying body 41, the avoidance grooves at the two axial ends of the deviation rectifying body 41 are arranged in a staggered manner, the sum of the axial lengths of two adjacent avoidance grooves at the two axial ends of the deviation rectifying body 41 is larger than that of the deviation rectifying body 41, and the deformation space 44 is formed by the avoidance grooves, so that a space is provided for extrusion deformation of the deviation rectifying body 41 in the press-fitting process of the passive end 52 of the coupling 5 and the input end of the worm 2, and the passive end 52 of the coupling 5 and the input end of the worm 2 are coaxial.

Further, when two press-fit components in the prior art are connected by using a spline, the spline is extremely easy to be damaged under the condition of high torque under the limit working condition, such as the condition that the motor 1 is in a locked state, so that the power transmission between the two press-fit components is influenced. In order to solve this problem, as shown in fig. 8, the elastic tolerance ring 40 provided in the present embodiment further includes a plurality of deformation protrusions 42, and the deformation protrusions 42 are protruded on the outer peripheral surface of the deviation rectifying body 41 at intervals and are abutted against the hole-like member.

The deformation convex parts 42 are arranged, so that friction torque between two press-fitting parts can be increased, even if the two press-fitting parts slide relatively in the circumferential direction under the limit working condition, the elastic tolerance ring 40 can also provide stable friction torque, and normal torque transmission can be effectively ensured, thereby playing a role in protecting connection between the two press-fitting parts and preventing the hole parts and the shaft parts from being damaged or slipping; the deformation convex portions 42 can also be utilized to absorb shock generated when the two press-fit components are operated.

Alternatively, the deformation convex portion 42 includes a protrusion protruding from the inner peripheral surface to the outer peripheral surface of the rectification body 41. Specifically, the inner peripheral surface of the deviation rectifying body 41 is recessed toward the outer peripheral surface thereof to form a deformation groove 43, so that the outer peripheral surface of the deviation rectifying body 41 forms a convex deformation protrusion 42. The deformation groove 43 may also provide room for elastic deformation of the elastic tolerance ring 40. Alternatively, the cross section of the deformation groove 43 is a sector, a rectangle, or a trapezoid. Illustratively, the cross-section of the deformation channel 43 is fan-shaped. In other embodiments, the deformation protrusions 42 may be protruded on the inner peripheral surface of the deviation rectifying body 41 at intervals and contact with the shaft member, and the outer peripheral surface of the deviation rectifying body 41 may be recessed toward the inner peripheral surface to form the deformation grooves 43, so that the inner peripheral surface of the deviation rectifying body 41 may form the protruded deformation protrusions 42.

By providing the elastic tolerance ring 40 with the deformation convex portion 42 between the outer peripheral surface of the shaft-like member and the inner peripheral surface of the hole-like member, a relatively large friction torque is provided by the elastic tolerance ring 40, so that the effect of transmitting torque can be achieved on the one hand, and on the other hand, under extreme conditions, when the transmission torque between the shaft-like member and the hole-like member is greater than the threshold value of the friction torque, even if the shaft-like member and the hole-like member relatively slide in the circumferential direction, the friction torque can still maintain a relatively stable value due to the elastic deformation of the elastic tolerance ring 40, thereby achieving the effect of permanently protecting the connection of the two press-fit members.

Because of the limitation of the processing precision, there is a difference between the sizes of the respective deformation projections 42, and therefore the hardness of the hole-like member is limited to be smaller than that of the elastic tolerance ring 40, so that the deformation projections 42 are at least partially embedded in the hole-like member. Optionally, the resilient tolerance ring 40 has a hardness greater than HRC60.

When deformation convex part 42 is convexly arranged on the outer peripheral surface of rectifying body 41, in the press mounting process, along with gradual increase of acting force between elastic tolerance ring 40 and press mounting parts, the inner peripheral surface of the hole part is subjected to extrusion deformation under the extrusion action, so that deformation convex part 42 is embedded into the inner hole of the hole part, friction torque between the hole part and the shaft part is increased, the problem that the matching performance of the joint is weakened due to the fact that two press mounting parts are prone to creep caused by long-time operation can be effectively solved, the connection stability of the hole part and the shaft part is improved, and the phenomenon that torque transmission looseness between the hole part and the shaft part is effectively avoided.

Further, the deformation protrusions 42 are elastically deformed during the press-fitting process, so that a certain pressure, friction force and friction torque are generated, and thus the number and shape and size of the deformation protrusions 42 directly affect the working effect thereof. To ensure that the resilient tolerance ring 40 has a proper press fit and to provide sufficient friction torque, the resilient tolerance ring 40 has a radial thickness of 2% to 5% of its inner diameter. Illustratively, the radial thickness of the elastomeric tolerance ring 40 is controlled between 0.4mm and 1.0mm when the inner diameter of the elastomeric tolerance ring 40 is 20 mm. Alternatively, the radial thickness of the elastic tolerance ring 40 is any one of 2%, 2.5%, 3%, 3.5%, 4%, 4.5% and 5% of its inner diameter, preferably the radial thickness of the elastic tolerance ring 40 is 2% of its inner diameter, and the radial thickness of the elastic tolerance ring 40 is 0.4mm when the inner diameter of the elastic tolerance ring 40 is 20 mm.

In order to balance the relationship between the press-fitting force and the friction torque, when the deformation convex portion 42 is provided on the outer peripheral surface of the elastic tolerance ring 40, the occupied area of the deformation convex portion 42 is 33% to 55% of the surface area of the inner peripheral surface of the elastic tolerance ring 40. The occupied area of the deformation convex portion 42 refers to the sum of the projected areas of the deformation convex portion 42 on the outer peripheral surface of the elastic tolerance ring 40. Alternatively, the footprint of the deformation protrusion 42 is any one of 30%, 35%, 40%, 45%, 50% and 55% of the surface area of the outer peripheral surface of the elastic tolerance ring 40. The axial length of the deformation protrusion 42 is 1.2mm to 3.0mm, and the axial length of the deformation protrusion 42 may be any one of 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, and 3.0 mm. The circumferential width of the deformation convex portion 42 is 0.8mm to 2.0mm, and the circumferential width of the deformation convex portion 42 may be any one of 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, and 2.0 mm.

To ensure that the yield strength of the resilient tolerance ring 40 meets the requirements, in this embodiment, the material from which the resilient tolerance ring 40 is made has a yield strength greater than 450MPa. Illustratively, the spring tolerance ring 40 is fabricated from a high strength titanium alloy steel plate. In other embodiments, other materials such as stainless steel may be used to form the resilient tolerance ring 40, requiring the material from which the resilient tolerance ring 40 is formed to have a yield strength greater than 450MPa.

As shown in fig. 9, the elastic tolerance ring 40 is manufactured as follows: selecting a high-strength titanium alloy steel plate with the thickness of 0.5 mm; stamping the high-strength titanium alloy steel plate by stamping, forming a deformation groove 43 on one side of the high-strength titanium alloy steel plate, and forming a deformation convex part 42 on the other side; cutting the punched steel plate; bending the cut steel plate to obtain the elastic tolerance ring 40.

As shown in fig. 2 to 5, for example, an elastic tolerance ring 40 between the outer peripheral surface of the drive gear shaft 4 and the inner peripheral surface of the worm wheel 3 is denoted as a first elastic tolerance ring 401, and the assembly of the worm wheel 3 and the drive gear shaft 4 in the worm gear steering machine is described below with reference to the drawings.

The driving gear shaft 4 is provided with a first limiting step, the driving gear shaft 4 on one side of the first limiting step is sleeved with the worm wheel 3, a first elastic tolerance ring 401 is clamped between the outer peripheral surface of the driving gear shaft 4 and the inner peripheral surface of the worm wheel 3, and the first elastic tolerance ring 401 and the worm wheel 3 are abutted against the first limiting step so as to axially limit the first elastic tolerance ring 401 and the worm wheel 3. The driving gear shaft 4 at the other side of the first limiting step is sleeved with a self-aligning bearing 8, the self-aligning bearing 8 is illustratively a four-point bearing, one side of the self-aligning bearing 8, which is opposite to the first limiting step, is provided with a bearing inner ring clamp 9 clamped on the driving gear shaft 4, and the self-aligning bearing 8 is clamped between the first limiting step and the bearing inner ring clamp 9 so as to ensure that the driving gear shaft 4 rotates smoothly.

In the process of assembling the worm wheel 3 and the driving gear shaft 4, the first elastic tolerance ring 401 is sleeved on the driving gear shaft 4 and the first elastic tolerance ring 401 is abutted against the first limiting step; the worm wheel 3 is then press fitted onto the worm 2. Utilize first elastic tolerance ring 401 to play automatic centering's effect to the assembly of worm wheel 3 and drive gear axle 4, rectify worm wheel 3 and drive gear axle 4, prevent to press the off-set, guarantee worm wheel 3 and drive gear axle 4 coaxial, improve worm wheel 3 and drive gear axle 4's assembly precision, can play the effect of reducing the fluctuation of torque in the transmission process of worm wheel 3 and drive gear axle 4. In addition, since the first elastic tolerance ring 401 has elasticity, even if the worm wheel 3 and the driving gear shaft 4 slide relatively along the circumferential direction under the limit working condition, the torque transmission between the worm wheel and the driving gear shaft 4 is not damaged, the first elastic tolerance ring 401 still can provide stable friction torque, thereby playing a role of permanently protecting the connection between the worm wheel 3 and the driving gear shaft 4, and enabling the worm wheel and the driving gear shaft 4 to still normally transmit torque. The first elastic tolerance ring 401 may also play a role in damping and noise reduction, and improve NVH performance of the worm gear steering gear.

Illustratively, as shown in fig. 6 and 7, the elastic tolerance ring 40 between the inner peripheral surface of the driven end 52 of the coupler 5 and the outer peripheral surface of the worm 2 is denoted as a second elastic tolerance ring 402, and the assembly of the motor 1 and the worm 2 in the worm gear steering machine is described below with reference to the drawings.

Each axial end of the worm 2 is provided with a step limiting surface opposite to the other end, wherein one end of the worm 2 connected with the motor 1 is provided with a first step limiting surface and a second step limiting surface, and the other end is provided with a third step limiting surface. The axial one end of worm 2 is equipped with big end bearing 6, big end bearing 6 butt in the spacing face of first step, and the driven end 52 cover of shaft coupling 5 is located on the worm 2 of first step spacing face one side and is butt in big end bearing 6, sets up second elasticity tolerance ring 402 between the inner peripheral surface of driven end 52 of shaft coupling 5 and the outer peripheral surface of worm 2, and second elasticity tolerance ring 402 butt is in the spacing face of second step. The other end of the worm 2 is provided with a small end bearing 7, and the small end bearing 7 is abutted against the third step limiting surface.

The driving end 51 of the coupling 5 is connected to the output shaft 11 of the motor 1, and an elastic spacer 53 is provided between the driven end 52 of the coupling 5 and the driving end 51 of the coupling 5.

By providing the second elastic tolerance ring 402 between the passive end 52 of the coupling 5 and the input end of the worm 2, it is ensured on the one hand that the coupling 5 can stably transmit torque from the output shaft 11 of the motor 1 to the input end of the worm 2 and that the assembly accuracy between the passive end 52 of the coupling 5 and the input end of the worm 2 can also be improved. In addition, because the second elastic tolerance ring 402 can elastically deform, even under the limit working condition, the passive end 52 of the coupler 5 and the input end of the worm 2 slide relatively along the circumferential direction, but the torque transmission between the passive end 52 of the coupler 5 and the input end of the worm 2 is not damaged, the second elastic tolerance ring 402 can still provide stable friction torque, thereby playing a role of permanently protecting the connection between the passive end 52 of the coupler 5 and the input end of the worm 2, and enabling the motor 1 to still transmit torque to the worm 2 through the coupler 5; the provision of the second resilient tolerance ring 402 may also act as a damping noise reduction to improve the NVH performance of the worm gear steering engine.

In other embodiments, a resilient tolerance ring 40 may also be provided between the drive end 51 of the coupling 5 and the output shaft 11 of the motor 1; it is also possible to dispense with the coupling 5 and to connect the input of the worm 2 directly to the output shaft 11 of the motor 1.

It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Claims

1. A worm gear steering machine comprising:

a driving unit;

the driving unit is used for driving the worm (2) to rotate;

the worm wheel (3), the worm wheel (3) is meshed with the worm (2), and the worm wheel (3) is connected with a driving gear shaft (4);

the coaxiality adjusting device is connected with two press-fitting parts, the two press-fitting parts are respectively a hole part and a shaft part, and the hole part is sleeved outside the shaft part;

the coaxiality adjusting device is characterized by comprising:

an elastic tolerance ring (40), wherein the elastic tolerance ring (40) is clamped between the inner peripheral surface of the hole-type component and the outer peripheral surface of the shaft-type component, and is arranged between the input end of the worm (2) and the output shaft of the driving unit;

The resilient tolerance ring (40) is configured to be elastically deformable in a radial direction during press fitting to allow one of the press fitting components to oscillate and to be coaxial with the other of the press fitting components;

the elastic tolerance ring (40) comprises a deviation rectifying body (41) and a plurality of deformation convex parts (42), wherein the deformation convex parts (42) are at least partially embedded into the press-fit component, and the hardness of the press-fit component embedded with the deformation convex parts (42) is smaller than that of the elastic tolerance ring (40).

2. The worm and gear steering machine according to claim 1, characterized in that a deformation space (44) is provided on the elastic tolerance ring (40), the deformation space (44) being used for providing space for elastic deformation of the elastic tolerance ring (40) during press fitting.

3. The worm and gear steering machine according to claim 2, characterized in that the deviation rectifying body (41) is a C-shaped ring, and the deformation space (44) is an axial opening on the outer periphery of the C-shaped ring.

4. A worm gear steering machine according to claim 3, wherein a plurality of the deformation projections (42) are provided at intervals on the outer peripheral surface of the deviation correcting body (41) so as to abut against the hole-like member; and/or the interval is convexly arranged on the inner peripheral surface of the deviation rectifying body (41) and is in contact with the shaft component.

5. The worm gear steering machine according to claim 4, wherein the deformation protrusion (42) includes a protrusion protruding from an inner peripheral surface to an outer peripheral surface of the deviation rectifying body (41);

and/or the number of the groups of groups,

a protrusion protruding from the outer peripheral surface to the inner peripheral surface of the deviation rectifying body (41).

6. The worm gear steering machine according to claim 5, characterized in that the radial thickness of the elastic tolerance ring (40) is 2% -5% of its inner diameter.

7. The worm gear steering machine according to claim 5, wherein the deformation protrusion (42) is formed with a deformation groove (43) at the bottom thereof, and the deformation groove (43) has a sector-shaped, rectangular or trapezoidal cross section.

8. The worm gear steering machine according to claim 7, wherein the cross section of the deformation groove (43) is a sector, the axial length of the deformation convex portion (42) is 1.2 mm-3.0 mm, and the circumferential arc length of the deformation convex portion (42) is 0.8 mm-2.0 mm.

9. The worm gear steering machine according to claim 4, wherein the deformation protrusion (42) is provided on an inner peripheral surface of the elastic tolerance ring (40), and a footprint of the deformation protrusion (42) is 33% to 55% of a surface area of the inner peripheral surface of the elastic tolerance ring (40);

Or alternatively, the process may be performed,

the deformation convex part (42) is arranged on the outer peripheral surface of the elastic tolerance ring (40), and the occupied area of the deformation convex part (42) is 33% -55% of the surface area of the outer peripheral surface of the elastic tolerance ring (40).

10. The worm gear steering machine according to any one of claims 1 to 9, characterized in that the yield strength of the material from which the elastic tolerance ring (40) is made is greater than 450MPa.

11. A worm gear steering machine comprising:

a driving unit;

the input end of the worm (2) is connected with the output shaft of the driving unit through a coupler (5), and the driving unit is used for driving the worm (2) to rotate;

the coaxiality adjusting device is characterized by comprising:

12. The worm and gear steering machine according to claim 11, characterized in that a deformation space (44) is provided on the elastic tolerance ring (40), the deformation space (44) being used to provide space for elastic deformation of the elastic tolerance ring (40) during press fitting.

13. The worm and gear steering machine according to claim 12, characterized in that the deviation rectifying body (41) is a C-shaped ring, and the deformation space (44) is an axial opening on the outer periphery of the C-shaped ring.

14. The worm wheel and worm gear steering machine according to claim 11, wherein a plurality of the deformation protrusions (42) are provided at intervals protruding to the outer peripheral surface of the deviation rectifying body (41) and are abutted against the hole-like member; and/or the interval is convexly arranged on the inner peripheral surface of the deviation rectifying body (41) and is in contact with the shaft component.

15. The worm gear steering machine according to claim 11, wherein the deformation protrusion (42) includes a protrusion protruding from an inner peripheral surface to an outer peripheral surface of the deviation rectifying body (41);

and/or the number of the groups of groups,

16. The worm gear steering machine according to claim 11, characterized in that the radial thickness of the elastic tolerance ring (40) is 2% -5% of its inner diameter.

17. The worm gear steering machine according to claim 11, characterized in that the deformation protrusion (42) is formed with a deformation groove (43) at the bottom, and the deformation groove (43) has a sector-shaped, rectangular or trapezoid cross section.

18. The worm gear steering machine according to claim 17, wherein the cross section of the deformation groove (43) is a sector, the axial length of the deformation convex portion (42) is 1.2 mm-3.0 mm, and the circumferential arc length of the deformation convex portion (42) is 0.8 mm-2.0 mm.

19. The worm gear steering machine according to claim 11, wherein the deformation protrusion (42) is provided on an inner peripheral surface of the elastic tolerance ring (40), and a footprint of the deformation protrusion (42) is 33% to 55% of a surface area of the inner peripheral surface of the elastic tolerance ring (40);

Or alternatively, the process may be performed,

20. The worm gear steering machine according to any of claims 11 to 19, characterized in that the yield strength of the material from which the elastic tolerance ring (40) is made is greater than 450MPa.

21. A worm gear steering machine comprising:

a driving unit;

the input end of the worm (2) is connected with the output shaft of the driving unit, and the driving unit is used for driving the worm (2) to rotate;

the coaxiality adjusting device is characterized by comprising:

an elastic tolerance ring (40), wherein the elastic tolerance ring (40) is clamped between the inner peripheral surface of the hole-type component and the outer peripheral surface of the shaft-type component, and is arranged between the drive gear shaft (4) and the worm wheel (3);

22. The worm and gear steering machine according to claim 21, characterized in that a deformation space (44) is provided on the elastic tolerance ring (40), the deformation space (44) being used to provide space for elastic deformation of the elastic tolerance ring (40) during press fitting.

23. The worm and gear steering machine according to claim 22, characterized in that the rectifying body (41) is a C-ring, and the deformation space (44) is an axial opening on the outer periphery of the C-ring.

24. The worm wheel and worm gear steering machine according to claim 21, wherein a plurality of the deformation protrusions (42) are provided at intervals protruding to the outer peripheral surface of the deviation rectifying body (41) and abutting against the hole-like member; and/or the interval is convexly arranged on the inner peripheral surface of the deviation rectifying body (41) and is in contact with the shaft component.

25. The worm gear steering machine according to claim 21, wherein the deformation protrusion (42) includes a protrusion protruding from an inner peripheral surface to an outer peripheral surface of the deviation rectifying body (41);

and/or the number of the groups of groups,

26. The worm gear steering machine according to claim 21, characterized in that the radial thickness of the elastic tolerance ring (40) is 2% -5% of its inner diameter.

27. The worm gear steering machine according to claim 21, characterized in that the deformation protrusion (42) is formed with a deformation groove (43) at the bottom, and the deformation groove (43) has a sector-shaped, rectangular or trapezoid cross section.

28. The worm and gear steering machine according to claim 27, characterized in that the cross section of the deformation groove (43) is a sector, the axial length of the deformation convex portion (42) is 1.2 mm-3.0 mm, and the circumferential arc length of the deformation convex portion (42) is 0.8 mm-2.0 mm.

29. The worm gear steering machine according to claim 21, wherein the deformation protrusion (42) is provided on an inner peripheral surface of the elastic tolerance ring (40), and a footprint of the deformation protrusion (42) is 33% to 55% of a surface area of the inner peripheral surface of the elastic tolerance ring (40);

Or alternatively, the process may be performed,

30. The worm gear steering machine according to any of claims 21 to 29, characterized in that the yield strength of the material from which the elastic tolerance ring (40) is made is greater than 450MPa.