CN115325054A

CN115325054A - Thrust actuating mechanism and brake

Info

Publication number: CN115325054A
Application number: CN202210801870.3A
Authority: CN
Inventors: 董敏
Original assignee: Wuhan Buruike Automotive Industry Technology Co ltd
Current assignee: Wuhan Buruike Automotive Industry Technology Co ltd
Priority date: 2022-07-07
Filing date: 2022-07-07
Publication date: 2022-11-11

Abstract

The application discloses a thrust actuator and a brake. In the technical scheme, in the process of executing braking, the circumferential width of the movable space reserved for the shifting protrusion structure by the movable groove of the transmission part is configured to be matched with the braking gap of the friction plate, so that the friction plate is just attached to the friction plate when the transmission part is just driven by the second rotating shaft, even if the torque protector slips at the moment, the circumferential relative fixation is removed between the unidirectional rotating structure and the lead screw nut, and the lead screw nut does not stop moving linearly due to the transmission of the second rotating shaft. According to the technical scheme, braking and returning under the drive of the motor can be met, and the accuracy of automatic compensation is improved.

Description

Thrust actuator and brake

Technical Field

The application relates to the technical field of brakes, in particular to a thrust actuating mechanism and a brake.

Background

A brake is a device having a function of decelerating, stopping, or maintaining a stopped state of a moving member (or a moving machine), and is commonly called a brake. The electric brake is one of the brakes, a motor is adopted as a driving power source, and the circumferential rotation motion output by the motor is converted into linear motion through a mechanical transmission structure, so that the friction plate is pushed axially. Compared with other brakes, the electric brake is gradually and widely used due to the advantages of energy conservation, environmental protection, convenience in integrated control and the like. However, during braking, the friction pad is worn continuously as a friction target, and the braking gap between the friction pad and the brake disc is gradually increased, so that it is necessary to compensate the braking gap of the electric brake in real time after the friction pad is worn to ensure the sensitivity during braking.

In the related art, the compensation is not accurate enough for the clearance compensation of the friction plate caused by abrasion.

Disclosure of Invention

In view of the above, the present application provides a thrust actuator and a brake, which can improve the supplement accuracy of the clearance compensation caused by the friction plate wear.

In a first aspect, the present application is directed to a thrust actuator comprising:

a first rotation axis for receiving the input of the rotation external force;

the second rotating shaft is in transmission connection with the first rotating shaft in a coaxial and reverse rotating mode;

the screw shaft is in transmission connection with the first rotating shaft;

the screw nut is in threaded connection with the screw shaft and used for generating linear thrust acting on the friction plate;

the poking convex structure is fixedly arranged on the periphery of the second rotating shaft;

the transmission piece is provided with a transmission groove extending along the circumferential direction of the transmission piece, the poking bulge structure is contained in the transmission groove in a manner of leaving a moving space along the circumferential direction of the transmission piece, and the circumferential width of the moving space is configured to be matched with the braking gap of the friction plate;

and a torque protector configured to release circumferential relative fixation between the one-way rotation structure and the lead screw nut when a braking gap of the friction plate is eliminated, or to form circumferential relative fixation between the one-way rotation structure and the lead screw nut when the braking gap of the friction plate is present;

optionally, the first rotating shaft is in transmission connection with the second rotating shaft through a commutator.

Optionally, the drive groove extends in an axial direction of the drive member to enable the axial movement of the drive member.

Optionally, the screw driver further comprises an elastic member for acting on the screw nut.

In a second aspect, the present application provides a brake, including a brake disc, a friction plate and the above-mentioned thrust actuator, the thrust actuator is in transmission connection with the friction plate, so that the friction plate makes a linear motion of fitting or releasing the fitting of the brake disc.

According to the thrust executing mechanism and the brake, in the process of executing braking, the circumferential width of the movable space reserved for the poking protrusion structure by the movable groove of the transmission piece is configured to be matched with the braking gap of the friction plate, so that the friction plate is just attached to the friction plate when the transmission piece is just driven by the second rotating shaft, and even if the torque protector slips at the moment, the circumferential relative fixation is removed between the unidirectional rotating structure and the screw nut, and the screw nut does not rotate by the transmission of the second rotating shaft and stops linear traveling. According to the technical scheme, braking and returning under the drive of the motor can be met, and the accuracy of automatic compensation is improved.

Drawings

The technical solution and other advantages of the present application will become apparent from the detailed description of the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a thrust actuator according to an embodiment of the present application.

Fig. 2 is a perspective structural view of an assembly of a transmission member and a second rotating shaft according to an embodiment of the present disclosure.

Fig. 3 is a top view of the transmission member and the second rotating shaft assembly provided in the embodiment of the present application.

Fig. 4 is a schematic structural diagram of the torque protector provided in the embodiment of the present application when mounted.

Fig. 5 is a schematic structural diagram of a commutator provided in an embodiment of the present application.

Wherein the elements in the figures are identified as follows:

1-a first rotating shaft; 2-an intermediate gear; 3-a jackscrew nut; 4-a screw gear; 5,17, 21-shaft sleeve; 6, mounting a plate; 7-a caliper cavity; 8-a thrust bearing; 9-a screw shaft; 10-a lead screw nut; 11-a reference seat; 12-a resilient member; 13-nut ring gear; 14-a commutator; 15-a second axis of rotation; 15 a-poke the convex structure; 16-a transmission member; 16 a-a drive slot; 18-a torque protector; 19-intermediate ring gear; 20-a one-way bearing; 22-a retainer ring for a shaft; 23-a push plate; 24-bevel gear.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or as implying that the number of indicated technical features is indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.

The following disclosure provides many different embodiments or examples for implementing different features of the application. To simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize the application of other processes and/or the use of other materials.

Before the technical solutions of the present application are introduced, it is necessary to explain the background of the invention of the present application.

It is common in the related art that a brake generally includes a friction plate, a brake disc, and a power mechanism for pushing the friction plate forward to clamp the brake disc. The power mechanism comprises a motor and a motion mechanism connected with the output end of the motor, the motion mechanism can convert the rotary motion of the motor into linear motion, the electronic mechanical brake also comprises a gap self-adjusting device arranged between the motion mechanism and a friction plate, the gap self-adjusting device comprises a feeding unit and a compensation unit, the feeding unit is driven by the motion mechanism to axially move, and the compensation unit is used for limiting the backward axial motion of the feeding unit after the braking is finished so as to compensate the braking gap.

In view of the above technical problems, the inventor has creatively proposed a thrust actuator and a brake, which abandon the solution of relying on extra feeding for compensating the braking gap, in the process of executing braking, since the circumferential width of the movable space reserved for the toggle projection structure 15a by the transmission groove 16a of the transmission member 16 is configured to match the braking gap of the friction plate, and in the process of executing braking, since the circumferential width of the movable space reserved for the toggle projection structure by the transmission member movable groove 16 is configured to match the braking gap of the friction plate, the friction plate just fits the friction plate when the transmission member 16 just is driven by the second rotating shaft 15, and at this time, the torque protector 18 slips even though the relative fixation in the circumferential direction is released between the screw nut 10 and the unidirectional rotating structure, the screw nut 10 stops traveling straight without being driven by the second rotating shaft 15. The compensation clearance of the abrasion of the non-friction plate generated by the inherent deformation of each part of the thrust actuating mechanism and the like can not be superposed to the linear advance of the screw nut, so that the interference of the compensation clearance of the abrasion of the non-friction plate on the clearance compensation caused by the abrasion of the friction plate is avoided, and the compensation accuracy is improved. Therefore, the invention is created.

As used herein, the term "forward rotation" refers to the direction of rotation of the various driving members that drive or entrain the friction discs during braking. Here, the rotational member means an element capable of inputting power to the linear motion of the friction plate to generate or release the braking, or having a direct or indirect transmission, such as the lead screw nut 10, the lead screw shaft 9, the first rotational shaft 1, and the second rotational shaft 15 in this document. It should be noted that the respective rotation directions may be different from each other due to differences of the respective transmission members, and thus the forward rotation is based on the respective body objects.

The term "reverse rotation" refers to the direction of rotation of the transmission components that transmit or carry the friction plates during the brake release process.

With reference to fig. 1, the present application provides a thrust actuator comprising:

a first rotation axis 1 for receiving an input of a rotation external force;

a second rotating shaft 15, which is connected with the first rotating shaft 1 in a transmission way in a coaxial and reverse rotating way;

a screw shaft 9, wherein the screw shaft 9 is connected with the first rotating shaft 1 in a transmission way;

a screw nut 10 screwed to the screw shaft 9 for generating a linear thrust acting on the friction plate;

a toggle bulge structure 15a fixed on the periphery of the second rotating shaft 15;

a transmission member 16 connected to the screw nut 10 by a unidirectional rotation structure, wherein the unidirectional rotation structure is used for allowing the transmission member 16 to transmit the forward rotation of the screw nut 10 and forbidding the transmission member 16 to transmit the reverse rotation of the screw nut 10, the transmission member 16 is provided with a transmission groove 16a extending along the circumferential direction of the transmission member 16, the toggle projection structure 15a is accommodated in the transmission groove 16a in a manner of leaving a moving space along the circumferential direction of the transmission member 16, and the circumferential width of the moving space is configured to match with the braking gap of the friction plate;

and a torque protector 18 configured to release the circumferential relative fixation between the one-way rotation structure and the lead screw nut when the brake clearance of the friction plate is eliminated, or to form the circumferential relative fixation between the one-way rotation structure and the lead screw nut when the brake clearance of the friction plate is present.

The above functional description of the torque protector 18, that is, the torque protector 18 has a structure for releasing or forming relative circumferential fixation between the unidirectional rotation structure and the lead screw nut 10. Note that, the circumferential relative fixation means that the two cannot move relative to each other in the circumferential direction, i.e. the movement of one will inevitably bring the driving effect to the other. The contact is circumferentially relatively fixed, that is, the two are circumferentially relatively movable, for example, the unidirectional rotating structure is "idle" relative to the lead screw nut 10.

It will be understood that the reason why the torque protector 18 has an operating state in which the unidirectional rotation structure and the relative circumferential fixation between the lead screw nut 10 are released is that, during the braking operation, the lead screw nut 10 is "jammed" by the friction plate engaging with the brake disk so as not to rotate any more, and the transmission member 16 is also in a jammed state under the constraint of the lead screw nut 10. And the driving action is directly acted on the screw nut 10 which is dead against by the driving action of the rotation of the second rotating shaft 15, thereby generating instantaneous overlarge torque force. The inherent function of the torque protector 18 is to produce a loosening action under a preset torque force.

Similarly, the reason why the torque protector 18 has the working state in which the unidirectional rotation structure and the lead screw nut 10 are circumferentially fixed to each other is that the torque protector 18 returns to the state of holding the unidirectional rotation structure when the excessive torque force is lost.

During braking, when the torque protector 18 is in an operating state that the unidirectional rotation structure and the screw nut 10 are released from relative fixation in the circumferential direction, the unidirectional rotation structure generates idle rotation relative to the screw nut 10. At this time, even if the unidirectional rotation structure provides locking to the transmission member, that is, the screw nut 10 is allowed to be rotated by the external force, the unidirectional rotation structure generates "idling" with respect to the screw nut 10, so that the screw nut 10 is damaged by the driving of the rotational external force, and the screw nut 10 stops the linear travel.

When the torque protector 18 is in an operating state that the unidirectional rotation structure and the lead screw nut 10 are circumferentially fixed relatively, the unidirectional rotation structure generates synchronous motion relative to the lead screw nut 10. When the wear clearance compensation caused by the friction plate is needed, the one-way rotating structure provides locking for the transmission piece 16, namely the lead screw nut 10 is allowed to rotate under the action of external force to generate forward linear travel, and the process of the wear clearance compensation caused by the friction plate is completed.

In the process of releasing the brake, because the unidirectional rotation structure releases the lock on the transmission element 16, the transmission element 16 is in a state of "free rotation" on the unidirectional rotation structure, even if the torque protector 18 tightly holds the unidirectional rotation structure, at this time, even if the unidirectional rotation structure and the lead screw nut 10 are relatively fixed in the circumferential direction, the "free rotation" of the transmission element 16 on the unidirectional rotation structure makes the rotation of the transmission element 16 unable to be input to the lead screw nut 10 without driving the linear travel of the lead screw nut 10.

In addition to this effect, the torque protector 18 can also avoid excessive torque forces acting on the second rotating shaft 15. Specifically, when the brake is applied, the screw nut 10 is "jammed" and cannot rotate, and the transmission member 16 is transmitted by the second rotation shaft 15, and a rotation torque remains.

It should be noted that, those skilled in the art can easily think of the assembly relationship between the torque protector 18 and the unidirectional rotation structure and the lead screw nut 10 according to the fact that the torque protector 18 has the unidirectional rotation structure and the lead screw nut 10 is circumferentially released or fixed relatively, and specific examples will be given later. As for the specific configuration of the torque protector 18, various types of torque protectors 18 that are widely used may be employed.

The understanding that the circumferential width of the active space is configured to match the braking gap of the friction plates is explained above, i.e. when the transmission member 16 is just driven by the second rotary shaft 15 (when the toggle projection is moved to the extreme position stopped by the transmission groove), the friction plates just abut the friction plates (i.e. the braking gap of the friction plates is eliminated). In order to achieve this function, in actual operation, through the general experimental ability held by those skilled in the art, the installation position of the thrust actuator of the present application is adjusted, even when the friction plate connected to the thrust actuator is in the position of the initial braking gap, the position of the toggle bulge structure 15a relative to the transmission groove 16a at the two circumferential side wall positions can be adjusted when the friction plate is not worn, and finally the friction plate just fits the friction plate when the toggle bulge structure 15a moves to the limit position stopped by the transmission groove 16 a.

Referring to fig. 5, as an exemplary implementation of the coaxial counter-rotation of the second rotating shaft 15, the first rotating shaft 1 is in transmission connection with the second rotating shaft 15 through a commutator 14. In view of the implementation manner of the commutator, the commutator can be widely applied to the field of mechanical transmission, and the description is omitted again.

In an exemplary embodiment, the drive groove 16a extends in the axial direction of the drive member to enable the axial movement of the drive member 16.

In this way, the reciprocating linear travel of the spindle nut 10 is adapted by the axial displacement of the transmission element 16 relative to the second rotational axis.

In an exemplary embodiment, a resilient member 12 is included to act on the lead screw nut 10.

The shape of the transmission groove 16a may be a strip-shaped groove with an arc-shaped cross section, and the height direction of the strip-shaped groove is along the axial direction of the transmission member 16. The number of the transmission grooves 16a may be one, or may be four as shown in the figure. The plurality of driving grooves 16a may be arranged at evenly spaced angles.

The shape of the toggle projection 15a may be similar to the shape of the transmission slot 16a, such as a tab with a cross section of a strip-shaped slot or the like. The number of toggle boss structures 15a may be one, or may be four, for example. The plurality of transmission slots 16a may be arranged at evenly spaced angles.

Referring again to fig. 1, the installation and matching relationship of the screw nut, the screw shaft, the first rotating shaft, the second rotating shaft 15 and the transmission member 16 of the present application will now be described with respect to a common application scenario. It should be noted that this common embodiment is not to be considered as a basis for understanding the essential features of the technical problem which the present application claims to solve, and it is merely exemplary.

Illustratively, the first rotating shaft 1 passes through the mounting plate 6, and the commutator 14 is provided at the lower end thereof, and the commutator 14 is a rotary reversing device composed of three bevel gears 24 and functions to change the rotating direction of the first rotating shaft 1 to the second rotating shaft 15 of the adjusting mechanism.

The mounting plate 6 is fixedly connected with the caliper cavity 7 through bolts, the intermediate gear is meshed with the two lead screw gears 4, and the jackscrew nut 3 axially limits the lead screw gears 4. The ball screw shaft 9 passes through the mounting plate 7 and the shaft sleeves 5,17,21 and is axially positioned by the thrust bearing 8. The commutator 14 is fixedly connected with the caliper cavity 7 through bolts. The output shaft of the commutator 14 is connected with a second rotating shaft 15, and the output shaft is matched with a transmission piece 16 to realize the function of self-adjusting the clearance. The transmission member 16 passes through the torque protector 18 and is axially fixed by a shaft retainer 22. Wherein, the torque protector 18 is provided with a one-way bearing 20 which is pressed and assembled with the transmission piece 16 in an interference way. The middle gear ring 19 is clamped between the two friction plates of the torque protector 18, and the nut gear ring 13 is fixedly connected with the screw nut 10 in a welding mode. The middle gear ring 19 is meshed with the nut gear ring 13 to realize self-regulation of the clearance. An elastic member 12 (e.g., a wave spring) is fitted between the nut ring 13 and the reference seat 11. The reference seat 11 is fixedly connected with the push plate 23 through a bolt.

Referring again to fig. 1-5, the specific operation of the present application for braking or braking release will now be described with respect to a common application scenario. It should be noted that this common embodiment is not to be taken as an identification basis for understanding the essential features of the technical problem to be solved as claimed in the present application, which is merely exemplary.

In the braking process, after the motor passes through the speed reducing mechanism, the torque is transmitted to the first rotating shaft, and the first rotating shaft converts the rotating torque into axial thrust through two transmission lines to form braking. In the first line, the first rotating shaft drives the intermediate gear 2 to rotate positively, the intermediate gear 2 is meshed with the screw gear 4, so the screw gear 4 is driven to rotate, the screw gear 4 drives the screw shaft 9 to rotate, and the screw shaft is positioned by the thrust bearing 8 in the axial direction, so the screw nut 10 is pushed to move axially towards the push plate 23. In the second line, the first rotary shaft transmits the rotary motion in the reverse direction to the second rotary shaft 15 via a commutator 14 composed of three bevel gears 24, and the second rotary shaft 15 has a toggle projection 15a which first rotates idly in a transmission groove 16a of a transmission member 16 from a position a to a position b. The size of the transmission groove 16a of the transmission piece 16 is consistent with the sum of the clearances of the friction plates and the brake disc, namely, the toggle projection structure 15a of the second rotating shaft 15 rotates from the position a to the position b, and the disc-edge clearance is just eliminated to zero at the moment. At this time, the first rotating shaft continues to rotate under the action of the motor, the screw shaft 9 and the second rotating shaft 15 continue to transmit the torque to the push plate 23, and since the disc edge clearance of the brake disc is zero at this time, the remaining micro-rotation angle is formed by deformation quantities of system components such as the friction disc, the brake disc, the push plate 23 and the like, at this time, due to a large friction force, the screw nut 10 cannot rotate, the nut ring gear 13 fixed with the screw nut cannot rotate, the engaged middle ring gear 19 cannot rotate, and the second rotating shaft 15 drives the torque protector 18 to slip and idle through the locked one-way bearing 20 at this time.

Note that: the one-way bearing 20 is press-fitted with the center hole of the torque protector 18 in an interference manner. When the transmission member 16 rotates in the forward direction (i.e., the braking rotational direction), the one-way bearing 20 is now in the locking direction. When the brake is released, the motor rotates reversely, the first rotating shaft 1 rotates by the original angle, namely, the angle of the first rotating shaft rotates forwards by a certain angle when the brake is released, and the angle of the first rotating shaft rotates by a certain angle when the brake is released. At this time, the screw shaft 9 is rotated, the screw nut 10 is axially returned to the initial position, and the one-way bearing in the torque protector 18 is rotated in the return direction, so that the transmission member 16 idles in the one-way bearing 20, and the torque protector 18 and the intermediate ring gear 19 are not rotated, without affecting the return position. This completes a conventional braking action.

And (3) compensation process: when the sum of the clearances between the friction plate and the brake disc is larger than the preset clearance, the self-adjusting mechanism automatically compensates for the excessive clearance so as to ensure that the clearances between the friction plate and the brake disc are always stable and consistent. During normal braking, the size of the transmission groove 16a of the transmission piece 16 is consistent with the sum of the clearances of the friction plates and the brake disc, namely, the toggle projection structure 15a of the second rotating shaft 15 rotates from the position a to the position b, and the disc-edge clearance is just eliminated to zero. If the friction plate is replaced or worn, the disc edge gap is not completely eliminated at the moment, the protrusion structure 15a is shifted to drive the transmission piece 16 to continuously rotate, and the one-way bearing 20 is in the locking direction during forward rotation, so that the transmission piece 16 drives the torque protector 18 and the middle gear ring 19 to continuously rotate through the one-way bearing 20, the middle gear ring 19 drives the nut gear ring 13 and the lead screw nut 10 to rotate together until the friction plate is attached to the brake disc to generate a braking force, at the moment, due to huge friction force, the lead screw nut 10 cannot rotate, the nut gear ring 13 fixed with the lead screw nut 10 cannot rotate, the engaged middle gear ring 19 cannot rotate, and the second rotating shaft 15 drives the torque protector (18) to slip and idle through the locked one-way bearing 20 at the moment. During the rotation, the spindle shaft (9) brings the spindle nut (10) back into the starting position, while the transmission element (16) rotates idly relative to the one-way bearing (20) without the torque protector (18) and the intermediate ring gear (19) because the one-way bearing (20) in the torque protector (18) is in the direction of rotation during the return. The angle of rotation of the spindle nut 10 therefore compensates for the excessive clearance of wear.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application.

Claims

1. A thrust actuator, comprising:

a first rotation axis for receiving the input of the rotation external force;

the screw shaft is in transmission connection with the first rotating shaft;

and a torque protector configured to release circumferential relative fixation between the unidirectional rotation structure and the lead screw nut when a braking gap of the friction plate is eliminated, or to form circumferential relative fixation between the unidirectional rotation structure and the lead screw nut when the braking gap of the friction plate is present.

2. The thrust actuator of claim 1, wherein said first rotatable shaft is drivingly connected to said second rotatable shaft by a commutator.

3. The thrust actuator of claim 1, wherein said drive slot extends in an axial direction of said drive member to enable axial movement of said drive member.

4. The thrust actuator of claim 1, further comprising a resilient member for acting on the lead screw nut.

5. A brake comprising a brake disc, a friction pad and a thrust actuator according to claim 1, said thrust actuator drivingly connecting said friction pad to cause linear movement of said friction pad into and out of engagement with said brake disc.