CN218662008U - Power-assisted steering transmission mechanism, power-assisted steering assembly and vehicle - Google Patents

Abstract

The utility model provides a power-assisted steering transmission mechanism, a power-assisted steering assembly and a vehicle, the power-assisted steering transmission mechanism comprises a worm-gear pair and a torque transmission piece connected with a worm in the worm-gear pair; the first torque limiting piece is arranged between the torque transmission piece and the worm, torque is transmitted between the torque transmission piece and the worm through the first torque limiting piece, and when the torque transmitted by the worm and the torque transmission piece through the first torque limiting piece is larger than a preset torque threshold value, the worm can rotate relative to the torque transmission piece. Power-assisted steering drive mechanism, when worm and moment of torsion transmission piece were greater than predetermined moment of torsion threshold value through the moment of torsion that first limit turned round the transmission, the worm can overcome its and first limit and turn round the frictional force between the piece and rotate for moment of torsion transmission piece, and then do benefit to and prevent to damage because of the worm wheel that moment of torsion overload caused to do benefit to the extension and turn to power-assisted steering drive mechanism's life.

Description

Power-assisted steering transmission mechanism, power-assisted steering assembly and vehicle

Technical Field

The utility model relates to a vehicle parts technical field, in particular to power-assisted steering drive mechanism. And simultaneously, the utility model discloses still relate to a power assisted steering assembly who has this power assisted steering drive mechanism to and be equipped with the vehicle of this power assisted steering assembly.

Background

At present, in a power steering transmission mechanism with a worm-gear and worm-gear pair, a worm bears the driving force of a rotation driving mechanism to rotate, so as to drive a worm gear to rotate, the worm gear is rigidly connected with a gear shaft, and the gear shaft rotates along with the worm gear to drive a rack to perform power steering.

In the application process of the power steering transmission mechanism, the worm wheel can be driven to rotate in the forward direction or in the reverse direction by changing the rotation direction of the worm, so that the gear on the transmission shaft can drive the rack to move left and right, and finally the steering knuckle and the wheels are driven to rotate through the pull rod, thereby realizing the power steering of the vehicle. However, whether the worm rotates in the forward direction or in the reverse direction, the worm wheel receives the forward driving force from the steering wheel and also receives the reverse force from the road surface and the wheels transmitted through the gear shaft, and the magnitude of the reverse force is mainly influenced by the road surface environment.

When the worm drives the worm wheel to rotate, the positive driving force borne by the worm wheel is stable. When the worm wheel is subjected to a reverse force from the road surface, particularly when the vehicle is running on a bumpy road surface, the impact force from the road surface is severe. The worm wheel in the prior art is generally made of non-metallic materials, the load bearing capacity of the worm wheel is limited, and due to the inertia of the rotation driving part driving the worm to rotate and the worm, the overload inertia force can cause the breakage and damage of the gear teeth of the worm wheel. And the damage of the worm wheel can cause the failure and even the locking of the power steering transmission mechanism, and the service life of the power steering assembly and the reliability and the safety of the vehicle are seriously influenced. Although the above problem can be solved by replacing the diverter with a new one, this solution is costly.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention is directed to a power steering transmission mechanism, which has a long service life.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a power-assisted steering transmission mechanism comprises a worm-and-gear pair and a torque transmission piece connected with a worm in the worm-and-gear pair;

the torque transmission piece and the worm are provided with a first torque limiting piece, torque is transmitted between the torque transmission piece and the worm through the first torque limiting piece, and when the torque transmitted by the torque transmission piece and the torque transmitted by the worm through the first torque limiting piece is larger than a preset torque threshold value, the worm can rotate relative to the torque transmission piece.

Furthermore, the torque transmission piece adopts an elastic coupling with an insertion hole, and one end of the worm is inserted into the insertion hole;

the first torque limiting piece is arranged between the worm and the elastic coupling in an interference press fit mode.

Furthermore, the first torque limiting piece is a torque limiting ring made of spring steel.

Furthermore, the torsion limiting ring is provided with an opening which is communicated along the axial direction of the torsion limiting ring.

Furthermore, reinforcing ribs are arranged on the torsion limiting ring, and at least part of the reinforcing ribs are abutted to the elastic coupling.

Furthermore, the reinforcing ribs are formed by protruding the inner wall of the torsion limiting ring, and the reinforcing ribs extend along the axial direction of the torsion limiting ring; and/or the presence of a gas in the gas,

the strengthening rib is along a plurality of the circumference equipartition setting of limit ring.

Furthermore, the power-assisted steering transmission mechanism also comprises a transmission shaft, and the transmission shaft is connected with a worm wheel in the worm-gear worm pair;

and a gear is arranged on the transmission shaft and is meshed and connected with a rack in the steering gear.

Furthermore, the worm wheel is connected with the transmission shaft in an inserting mode, a second torque limiting piece is arranged between the transmission shaft and the worm wheel, and torque is transmitted between the worm wheel and the transmission shaft through the second torque limiting piece;

when the torque transmitted by the transmission shaft and the worm wheel through the second torque limiting piece is larger than a preset torque threshold value, the transmission shaft can rotate relative to the worm wheel;

the structure of the second torque limiting piece is the same as that of the first torque limiting piece.

Compared with the prior art, the utility model discloses following advantage has:

turn to helping hand drive mechanism, turn round a transmission moment of torsion through first limit between moment of torsion transmission piece and the worm, when worm and moment of torsion transmission piece were greater than preset torque threshold value through the moment of torsion that first limit was turned round a transmission, the worm can overcome its and first limit and turn round the frictional force between the piece and rotate for moment of torsion transmission piece, and then do benefit to and prevent to damage because of the worm wheel that moment of torsion overload caused, can play the effect of protection to the worm wheel to do benefit to the life that the extension turned to helping hand drive mechanism.

In addition, the torque transmission piece adopts an elastic coupling, so that the effects of buffering impact force and damping are achieved, and the first torque limiting piece is arranged between the elastic coupling and the worm in a press fit mode in an interference mode, so that the torque transmission effect of the first torque limiting piece is improved. The torsion limiting ring made of spring steel is easy to arrange and implement, the opening is formed, machining and installation of the torsion limiting ring are facilitated, the structure is simple, and machining forming on the torsion limiting ring is facilitated.

In addition, the reinforcing ribs on the torsion limiting ring are beneficial to improving the structural strength of the torsion limiting ring. The reinforcing rib is formed by the inner wall of the torsion limiting ring protruding outwards and is easy to machine and form. The reinforcing ribs have good effect of improving the strength of the torsion limiting ring. The strengthening rib is along the axial extension of limit torsion ring, does benefit to the intensity that further improves limit torsion ring.

The transmission shaft is arranged and is meshed with the rack in the steering gear through the gear, and the steering assisting effect is favorably realized. The transmission torque is transmitted between the worm wheel and the transmission shaft through the second torque limiting piece, when the transmission shaft and the worm wheel are larger than a preset torque threshold value through the torque transmitted by the second torque limiting piece, the transmission shaft can overcome the friction force between the transmission shaft and the second torque limiting piece and rotate relative to the worm wheel, the torque transmitted between the transmission shaft and the worm wheel is reduced, the worm wheel damage caused by the impact of torque overload on the worm wheel is prevented, the protection effect on the worm wheel can be further improved, and the service life of the steering power-assisted transmission mechanism is further prolonged.

Another object of the present invention is to provide a power steering assembly, which includes a rotation driving portion, and the power steering transmission mechanism as described above;

and the other end of the torque transmission piece is connected with the power output end of the rotation driving part relative to one end of the torque transmission piece connected with the worm.

Power-assisted steering assembly, order about the moment of torsion transmission piece through rotating the drive division and rotate to by moment of torsion transmission piece to worm transmission moment of torsion, conveniently connect, can realize the power-assisted steering of vehicle, still have better use reliability simultaneously, do benefit to the security performance that improves the vehicle.

Another object of the present invention is to provide a vehicle, including a steering gear, the steering gear is provided with the power steering assembly as described above.

Vehicle and foretell power assisted steering assembly beneficial effect that has for prior art the same, no longer give unnecessary details here.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

fig. 1 is a schematic structural view of a power steering transmission mechanism according to an embodiment of the present invention in an applied state;

FIG. 2 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1;

FIG. 4 is an assembly view of a worm gear and drive shaft according to an embodiment of the present invention;

FIG. 5 is a schematic view of the structure of FIG. 4 from another perspective;

fig. 6 is an exploded view of a worm wheel, a transmission shaft and a second torque limiting member according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a first torque limiting member according to an embodiment of the present invention;

fig. 8 is a front view of a first torque limiter according to an embodiment of the present invention;

fig. 9 is a sectional view taken along line C-C in fig. 8.

Description of reference numerals:

1. a worm gear; 2. a worm; 3. a bearing; 4. a drive shaft; 5. a rack; 6. a first torque limiter; 7. a second torque limiter; 8. a torque transmitting member;

101. connecting holes;

401. a gear; 402. a limiting bulge; 403. a second shaft body; 404. a first shaft body; 405. a fourth shaft body;

601. reinforcing ribs; 602. and (4) opening.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "back", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In addition, in the description of the present invention, the terms "mounted," "connected," and "connecting" are to be construed broadly unless otherwise specifically limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. To those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood in combination with the specific situation.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The embodiment relates to a power-assisted steering transmission mechanism which comprises a worm-and-gear pair and a torque transmission part 8 connected with a worm 2 in the worm-and-gear pair, wherein a first torque limiting part 6 is arranged between the torque transmission part 8 and the worm 2, torque is transmitted between the torque transmission part 8 and the worm 2 through the first torque limiting part 6, and when the torque transmitted by the torque transmission part 8 and the torque transmitted by the worm 2 through the first torque limiting part 6 is larger than a preset torque threshold value, the worm 2 can rotate relative to the torque transmission part 8.

An exemplary structure of the power steering transmission mechanism in the present embodiment is shown in fig. 1 to 3 based on the above overall description. The worm gear and worm pair mainly comprises a worm wheel 1 and a worm 2 which are connected in a meshed mode, the worm 2 is arranged on one side of the worm wheel 1, and a torque transmission piece 8 is arranged at one end of the worm 2, wherein the torque transmission piece 8 is mainly used for transmitting the borne rotation driving force to the worm 2 through a first torque limiting piece 6, and the worm gear and worm pair can play a role in reducing the speed and increasing the torque and is beneficial to improving the steering power assisting effect.

As a preferred embodiment, the torque transmission member 8 is a coupling, and preferably, the torque transmission member 8 is an elastic coupling, which can be implemented by using the existing standard member, thereby reducing the cost, and having the effects of reducing the impact force and the vibration. An insertion hole is formed in the elastic coupling, one end of the worm 2 is inserted into the insertion hole, and the first torque limiting piece 6 is pressed between the worm 2 and the elastic coupling in an interference fit mode.

As a preferred embodiment, the first torque limiting element 6 in this embodiment is a torque limiting ring made of spring steel. Here, the torque limiting ring is made of spring steel, so that the torque limiting ring is beneficial to improving the protection effect on the worm wheel 1. Meanwhile, the spring steel is mature, and processing and forming of the torsion limiting ring are facilitated.

In a specific structure, as shown in fig. 1 to 3, the torque limiting ring is press-fitted in the insertion hole of the torque transmission member 8 in an interference manner and sleeved on the outer peripheral wall of the worm 2 near one end, so that torque transmission between the torque transmission member 8 and the worm 2 is realized. In order to improve the use effect of the torsion limiting ring, the length of the torsion limiting ring is matched with the length of the worm 2 inserted into the insertion hole, so that the stability of the torsion limiting ring in use is improved. It can be understood that the scheme that the length of the torque-limiting ring is shorter than the length of the worm 2 inserted into the insertion hole is also feasible, but the scheme that the lengths of the torque-limiting ring and the worm 2 are matched has better reliability and stability.

In this embodiment, because the torque-limiting ring is press-fitted between the insertion hole of the torque transmission member 8 and the outer periphery of the worm 2 in an interference manner, when the torque-limiting ring is in an initial state, the diameter of the outer wall of the torque-limiting ring is larger than that of the insertion hole, and the diameter of the inner wall of the torque-limiting ring is smaller than that of the insertion portion of the worm 2. In this case, the worm 2 and the torque transmission member 8 are fixed to each other, and the torque of the external rotation driving unit received by the torque transmission member 8 can be transmitted to the worm 2 via the torque limiter ring and transmitted to the rack 5 via the worm wheel 1, the transmission shaft 4, and the gear 401 in this order.

The feedback force on the road surface is transmitted to the transmission shaft 4 at the wheel via the engagement of the rack 5 and the gear 401, and is transmitted to the worm wheel 1 and the worm 2, and the worm 2 transmits the torque to the torque transmission mechanism 8 through the torque limit ring. When the torque transmitted between the torque transmission mechanism 8 and the worm 2 is greater than the preset torque threshold, the worm 2 can overcome the friction force between the worm 2 and the torque limiting ring and rotate relative to the torque transmission mechanism 8, so that the overload torque greater than the preset torque threshold is ensured not to damage the worm wheel 1, and the protection of the worm wheel 1 is further realized.

And when the torque is transmitted again between the torque transmitting mechanism 8 and the worm 2 to rotate, the worm 2 and the torque transmitting mechanism 8 are again relatively fixed.

It should be noted that the preset torque threshold in the present embodiment is set according to the specific bearing capacity of the worm wheel 1, and the effect of protecting the worm wheel 1 can be achieved as long as the torque applied to the worm wheel 1 is within the bearing capacity range of the worm wheel 1. In addition, the torsion limiting ring can still maintain good use performance after being used, so that the service life of the torsion limiting ring is prolonged, and the problem that in the prior art, the cost is increased due to the fact that the steering gear needs to be replaced when the worm wheel 1 is damaged is solved.

The power-assisted steering transmission mechanism of the embodiment, transmit the moment of torsion through the first torque limiting piece 6 between the torque transmission piece 8 and the worm 2, and when the moment of torsion transmitted between the two is greater than the preset torque threshold value, the worm 2 can overcome the friction between the first torque limiting piece 6 and the worm 2 and rotate relative to the torque transmission piece 8, so as to reduce the moment of torsion transmitted between the worm 2 and the worm wheel 1, and the power-assisted steering transmission mechanism is beneficial to preventing the damage of the worm wheel 1 caused by torque overload, and can play a role of protection for the worm wheel 1, thereby being beneficial to prolonging the service life of the power-assisted steering transmission mechanism.

As a preferred embodiment, as shown in fig. 7 and 9, the torque-limiting ring in this embodiment is provided with an opening 602 that is through along the axial direction of the torque-limiting ring, where the opening 602 facilitates the assembly of the torque-limiting ring on the worm 2, and the opening 602 has a simple structure, which facilitates the machining and forming on the torque-limiting ring. When the worm 2 is installed, the torsion limiting ring is inserted from one end of the worm 2 until one end of the torsion limiting ring abuts against the limiting convex ring of the worm 2, and the torsion limiting ring is installed on the worm 2 in place.

In this embodiment, the torque limiter ring is provided with a rib 601, and at least a part of the rib 601 abuts against the torque transmission member 8. The reinforcing ribs 601 are beneficial to improving the structural strength of the torsion limiting ring, and at least part of the reinforcing ribs 601 are beneficial to improving the connection strength between the torsion limiting ring and the worm 2 by being abutted against the torque transmission piece 8, so that the torque transmission effect of the torsion limiting ring is improved. Preferably, the reinforcing rib 601 in the embodiment is formed by protruding the inner wall of the torsion-limiting ring, so that the strength of the torsion-limiting ring is improved, and the processing and molding are facilitated.

It should be noted that, in this embodiment, in addition to the reinforced ribs 601 being formed by the inner wall of the torsion-limiting ring protruding outward as shown in fig. 7 to 9, a part of the reinforced ribs 601 may be formed by the outer wall of the torsion-limiting ring protruding inward, and another part of the reinforced ribs 601 may be formed by the inner wall of the torsion-limiting ring protruding outward. Alternatively, all the reinforcing ribs 601 are formed by inward protrusions on the outer wall of the torsion-limiting ring. The reinforcing ribs 601 formed by the schemes can also improve the strength of the torsion limiting ring.

In a specific structure, referring to fig. 9, the reinforcing ribs 601 are uniformly distributed along the circumferential direction of the torsion-limiting ring, and the outer wall of each reinforcing rib 601 is abutted to the inner wall of the insertion hole, so that the strength of the torsion-limiting ring is improved. As a preferable embodiment, the reinforcing rib 601 in this embodiment is disposed to extend along the axial direction of the torque limiting ring, which is beneficial to further improve the use effect of the reinforcing rib 601 when bearing the reverse torque.

Of course, the reinforcing rib 601 in this embodiment may be arranged in other arrangements besides extending along the axial direction of the torsion-limiting ring, but is easier to implement in terms of processing and forming compared with the extending along the axial direction of the torsion-limiting ring.

In addition, as shown in fig. 9, the cross section of the reinforcing rib 601 in this embodiment is preferably arc-shaped, so that the reinforcing rib 601 is in line contact with the inner wall of the insertion hole, which is beneficial to improving the using effect of the reinforcing rib 601. It will be appreciated that the cross-sectional shape of the bar 601 may be other geometries, such as U-shaped, other than arcuate, which facilitates the formation of the bar 601.

In order to facilitate the torque output received by the worm wheel 1, the power steering transmission mechanism in this embodiment further includes a transmission shaft 4, the transmission shaft 4 is connected to the worm wheel 1, and the worm wheel 1 is connected to one end of the transmission shaft 4 and is disposed coaxially with the transmission shaft 4. The transmission shaft 4 is provided with a gear 401, and the gear 401 is meshed with a rack 5 in the steering gear, so that the rack 5 can be driven by the gear 401 to move, and the function of steering assistance is achieved.

As a preferred embodiment, the worm wheel 1 and the transmission shaft 4 are connected in an inserting manner, a second torque limiting piece 7 is arranged between the transmission shaft 4 and the worm wheel 1, the worm wheel 1 and the transmission shaft 4 transmit torque through the second torque limiting piece 7, and the transmission shaft 4 can rotate relative to the worm wheel 1 when the torque transmitted between the worm wheel 1 and the transmission shaft 4 through the second torque limiting piece 7 is greater than a preset torque threshold value. It should be noted that the structure of the second torque limiter 7 is the same as that of the first torque limiter 6, and the structure thereof can still be shown in fig. 7 to 9, and in particular, refer to the following description.

Preferably, the transmission shaft 4 in the present embodiment is inserted into the worm wheel 1, and the second torque limiter 7 is press-fitted between the transmission shaft 4 and the worm wheel 1. Here, the second torque limiting piece 7 is press-fitted between the transmission shaft 4 and the worm wheel 1 in an interference manner, so that the torque transmission effect of the second torque limiting piece 7 is improved, and the arrangement and implementation are facilitated.

In a specific structure, as shown in fig. 4 to 6, one end of the transmission shaft 4 is inserted into the worm wheel 1, and in this embodiment, a connection hole 101 is formed in the middle of the worm wheel 1, and one end of the transmission shaft 4 is inserted into the connection hole 101. The gear 401 is disposed close to the other end of the transmission shaft 4 with respect to one end of the transmission shaft 4 inserted into the connection hole 101, and the gear 401 is disposed corresponding to the rack 5 in the steering gear. The rack 5 and the worm 2 are respectively arranged at two opposite sides of the transmission shaft 4, so that the arrangement and implementation of the rack, the worm and the transmission shaft are facilitated. The worm 2, the worm wheel 1 and the transmission gear 401 in this embodiment are all disposed in a steering gear housing (not shown in the figure), and the specific structure of the steering gear housing and the installation manner of the worm wheel 1, the worm 2 and the rack 5 in the steering gear housing can refer to the prior art, and are not described herein again.

Preferably, as shown in fig. 4 and 5, the gear 401 in this embodiment may specifically adopt helical teeth, and the rack 5 may adopt helical teeth, which is beneficial to improving the smoothness of the transmission between the gear 401 and the rack 5, and simultaneously beneficial to reducing noise, thereby being capable of improving the NVH performance of the power steering transmission mechanism. Of course, in specific implementation, besides the cooperation of the helical teeth and the helical teeth, the structural forms of the gear 401 and the rack 5 can be selected according to the use requirements.

Next, the structure of the transmission shaft 4 will be explained. As shown in fig. 6, a portion of the transmission shaft 4 inserted into the connection hole 101 is referred to as a first shaft body 404, and other portions of the transmission shaft 4 in a direction away from the first shaft body 404 are referred to as a second shaft body 403, a third shaft body, and a fourth shaft body 405, respectively, in this order. The diameters of the respective shafts are gradually reduced in a direction away from the first shaft 404, the gear 401 is specifically provided in the third shaft, and the bearing 3 is attached to the second shaft 403. The transmission shaft 4 has a simple structure, and is beneficial to the connection among the transmission shaft 4, the worm wheel 1 and the torque limiting ring.

Still referring to fig. 6, a limiting protrusion 402 protruding radially outward of the first shaft body 404 is provided at the free end of the first shaft body 404. During specific installation, one end of the transmission shaft 4, which is provided with the fourth shaft body 405, is firstly inserted into the connecting hole 101 until the limiting protrusion 402 abuts against one side of the worm wheel 1, which indicates that the worm wheel 1 is inserted in place on the transmission shaft 4. The limiting protrusion 402 can play a limiting effect, and is beneficial to improving the assembling effect and the assembling efficiency between the transmission shaft 4 and the worm wheel 1.

As a preferred embodiment, the second torque limiting element 7 can still be a torque limiting ring made of spring steel, and the torque limiting ring is press-fitted between the outer periphery of the first shaft body 404 of the transmission shaft 4 and the inner wall of the connecting hole 101 in an interference manner, and the length of the torque limiting ring is matched with the length of the first shaft body 401, so that the stability of the torque limiting ring in use is improved. It is understood that the torque-limiting ring is shorter than the first shaft 404, but the length of the torque-limiting ring is matched with that of the first shaft 404, so that the reliability and the stability are better.

In this embodiment, because the torsion-limiting ring is press-fitted between the inner wall of the connection hole 101 and the outer wall of the first shaft body 404 in an interference manner, when the torsion-limiting ring is in an initial state, the diameter of the outer wall of the torsion-limiting ring is larger than that of the connection hole 101, and the diameter of the inner wall of the torsion-limiting ring is smaller than that of the first shaft body 404. In this case, the worm wheel 1 is fixed to the drive shaft 4, and the worm wheel 1 receives the torque transmitted from the worm 2, transmits the torque to the drive shaft 4 via the torque limiter ring, and transmits the torque to the rack 5 via the gear 401 on the drive shaft 4.

The feedback force on the road surface is transmitted to the propeller shaft 4 at the wheels via the engagement of the rack 5 and the gear 401, and the propeller shaft 4 can transmit torque to the worm wheel 1 through the torque-limiting ring. When the torque transmitted between the transmission shaft 4 and the worm wheel 1 is greater than the preset torque threshold value, the transmission shaft 4 can overcome the friction force between the transmission shaft and the torque limiting ring to rotate relative to the worm wheel 1 under the action of the overload torque, so that the overload torque greater than the preset torque threshold value cannot damage the worm wheel 1, and the protection of the worm wheel 1 is realized.

When the worm wheel 1 rotates again by receiving the torque transmitted by the worm 2, the worm wheel 1 and the transmission shaft 4 are relatively fixed again under the action of the torque, and the torque limiting ring can continuously transmit the torque transmitted from the worm wheel 1 to the transmission shaft 4.

It should be noted that the preset torque threshold is also set according to the specific bearing capacity of the worm wheel 1, and the effect of protecting the worm wheel 1 can be achieved as long as the reverse torque acting on the worm wheel 1 is ensured to be within the bearing capacity range of the worm wheel 1. In addition, the torsion limiting ring can still maintain good use performance after being used, so that the service life of the torsion limiting ring is prolonged, and the problem that in the prior art, the cost is increased due to the fact that the steering gear needs to be replaced when the worm wheel 1 is damaged is solved.

The power-assisted steering transmission mechanism of this embodiment, pass through second limit of torsion 7 transmission moment of torsion between worm wheel 1 and the transmission shaft 4, and when the moment of torsion through the transmission of second limit of torsion 7 is greater than preset torque threshold value between transmission shaft 4 and worm wheel 1, transmission shaft 4 can overcome its and second limit of torsion frictional force between 7 and rotate for the worm wheel, and then reduce the moment of torsion of transmission between transmission shaft 4 and the worm wheel 1, do benefit to and prevent to cause worm wheel 1 to damage because of torque overload, can further improve the effect of playing the protection to worm wheel 1, thereby further prolong power-assisted steering transmission mechanism's life.

As a preferred embodiment, as shown in fig. 7 and 9, the torque-limiting ring in this embodiment is provided with an opening 602 that penetrates along the axial direction of the torque-limiting ring, where the opening 602 facilitates the installation of the torque-limiting ring on the transmission shaft 4, and the opening 602 has a simple structure, which facilitates the machining and forming on the torque-limiting ring. During specific installation, the torque limiting ring is inserted from the end, with the fourth shaft body 405, of the transmission shaft 4 until one end of the torque limiting ring abuts against the limiting protrusion 402, which indicates that the torque limiting ring is installed on the transmission shaft 4 in place.

In this embodiment, the torque-limiting ring is provided with a rib 601, and at least a part of the rib 601 abuts against the worm wheel 1. The reinforcing ribs 601 are beneficial to improving the structural strength of the torsion limiting ring, and at least part of the reinforcing ribs 601 are beneficial to improving the connection strength between the torsion limiting ring and the worm wheel 1 by abutting against the worm wheel 1, so that the torque transmission effect of the torsion limiting ring is improved. Preferably, the reinforcing rib 601 in the embodiment is formed by protruding the inner wall of the torsion-limiting ring, so that the strength of the torsion-limiting ring is improved, and the processing and molding are facilitated.

It should be noted that, in this embodiment, in addition to the reinforced ribs 601 being formed by the inner wall of the torsion-limiting ring protruding outward as shown in fig. 7 to 9, a part of the reinforced ribs 601 may be formed by the outer wall of the torsion-limiting ring protruding inward, and another part of the reinforced ribs 601 may be formed by the inner wall of the torsion-limiting ring protruding outward. Alternatively, all the reinforcing ribs 601 are formed by inward protrusions on the outer wall of the torsion-limiting ring. The reinforcing ribs 601 formed by the schemes can also play a role in improving the strength of the torsion limiting ring.

In a specific structure, referring to fig. 9, the reinforcing ribs 601 are uniformly distributed along the circumferential direction of the torsion-limiting ring, and the outer wall of each reinforcing rib 601 is abutted to the inner wall of the connecting hole 101, so that the improvement of the strength of the torsion-limiting ring is facilitated. As a preferred embodiment, the reinforcing rib 601 in this embodiment is disposed to extend along the axial direction of the torque limiting ring, which is beneficial to further improve the use effect of the reinforcing rib 601 when bearing the reverse torque.

Of course, the reinforcing rib 601 in this embodiment may be arranged in other arrangements besides extending along the axial direction of the torsion-limiting ring, but is easier to implement in terms of processing and forming compared with the extending along the axial direction of the torsion-limiting ring.

In addition, as also shown in fig. 9, the cross section of the reinforcing rib 601 in this embodiment is preferably arc-shaped, so that the reinforcing rib 601 is in line contact with the inner wall of the connecting hole 101, which is beneficial to improving the use effect of the reinforcing rib 601. It will be appreciated that the cross-sectional shape of the bar 601 may be other geometries, such as U-shaped, other than arcuate, which facilitates the formation of the bar 601.

In addition, the embodiment also relates to a power steering assembly, which comprises a rotation driving part and the power steering transmission mechanism. Wherein, relative to the end of the torque transmission member 8 connected with the worm 2, the other end of the torque transmission member 8 is connected with the power output end of the rotation driving part, so that the rotation driving part can drive the worm 2 to rotate through the torque transmission member 8.

As a preferred embodiment, the rotation driving part in this embodiment may adopt a motor, the torque transmission member 8 adopts a coupling, and preferably adopts an elastic coupling, a power output shaft of the motor may be connected to one end of the worm 2 through the elastic coupling, and the worm 2 may drive the worm wheel 1 to rotate forward and backward by changing the rotation direction of the motor, thereby implementing the power assistance to the vehicle steering. Here, the adoption of the motor as the rotation driving portion has the advantages of being beneficial to reducing the fuel consumption of the vehicle, good in aligning performance, easy to maintain and the like.

The power steering assembly of this embodiment drives the worm 2 to rotate through rotating the drive division, and the worm 2 links to each other through the worm wheel 1 transmission in the power steering drive mechanism as above, has better reliability to do benefit to the security that improves the vehicle.

Besides, the embodiment also relates to a vehicle, and the vehicle is provided with a steering gear, and the steering gear is provided with the power steering assembly. The vehicle of the embodiment and the power steering assembly have the same beneficial effects compared with the prior art, and are not described herein again.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A steering power-assisted transmission mechanism is characterized in that:

comprises a worm-gear pair and a torque transmission piece (8) connected with a worm (2) in the worm-gear pair;

the torque transmission piece (8) and be equipped with first limit and twist reverse spare (6) between worm (2), just torque transmission piece (8) with pass through between worm (2) first limit and twist reverse spare (6) transmission moment of torsion when torque transmission piece (8) with worm (2) pass through the moment of torsion that first limit and twist reverse spare (6) transmitted is greater than preset moment of torsion threshold value, worm (2) can for torque transmission piece (8) rotate.

2. The power steering transmission as claimed in claim 1, wherein:

the torque transmission piece (8) adopts an elastic coupling with an insertion hole, and one end of the worm (2) is inserted into the insertion hole;

the first torque limiting piece (6) is arranged between the worm (2) and the elastic coupling in an interference press fit mode.

3. The steering assist transmission mechanism according to claim 2, characterized in that:

the first torsion limiting piece (6) is a torsion limiting ring made of spring steel.

4. The power steering transmission as claimed in claim 3, wherein:

the torsion limiting ring is provided with an opening (602) which is communicated along the axial direction of the torsion limiting ring.

5. The power steering transmission as claimed in claim 3, wherein:

the torsion limiting ring is provided with a reinforcing rib (601), and at least part of the reinforcing rib (601) is abutted to the elastic coupling.

6. The power steering transmission as claimed in claim 5, wherein:

the reinforcing ribs (601) are formed by protruding the inner wall of the torsion limiting ring, and the reinforcing ribs (601) extend along the axial direction of the torsion limiting ring; and/or the presence of a gas in the gas,

the reinforcing ribs (601) are uniformly distributed along the circumferential direction of the torsion limiting ring.

7. The steering assist transmission mechanism according to any one of claims 1 to 6, characterized in that:

the power-assisted steering transmission mechanism further comprises a transmission shaft (4), and the transmission shaft (4) is connected with a worm wheel (1) in the worm-and-gear pair;

and a gear (401) is arranged on the transmission shaft (4), and the gear (401) is meshed with a rack (5) in the steering gear.

8. The power steering transmission as claimed in claim 7, wherein:

the worm wheel (1) is connected with the transmission shaft (4) in an inserted manner, a second torque limiting piece (7) is arranged between the transmission shaft (4) and the worm wheel (1), and torque is transmitted between the worm wheel (1) and the transmission shaft (4) through the second torque limiting piece (7);

when the torque transmitted by the transmission shaft (4) and the worm wheel (1) through the second torque limiting piece (7) is larger than a preset torque threshold value, the transmission shaft (4) can rotate relative to the worm wheel (1);

the structure of the second torsion limiting piece (7) is the same as that of the first torsion limiting piece (6).

9. A power steering assembly characterized by:

comprising a rotary drive and a steering power transmission according to any one of claims 1 to 8;

the other end of the torque transmission piece (8) is connected with the power output end of the rotation driving part relative to the end of the torque transmission piece (8) connected with the worm (2).

10. A vehicle comprising a steering gear, characterized in that: the steering gear is provided with the power steering assembly of claim 9.

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