Ball screw for electronic mechanical brake
By installing a limit block and an anti-rotating pin in the ball screw of the electronic mechanical brake, the damage caused by excessive retraction of the lead screw is solved, and effective protection and maintenance convenience for brake parts are achieved.
Patent Information
- Application Number
- CN202422194060.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-09-06
AI Technical Summary
In the prior art, the ball screw of the electronic mechanical brake lacks an effective limiting mechanism between the nut and the screw, resulting in excessive retraction of the screw, which may cause the ball screw to fall off, damage or break, and thus damage the parts inside the brake.
A ball screw for an electronic mechanical brake is designed. By providing a limiting block on the end cover and an anti-rotation pin shaft and a give way slot on the screw, the contact between the anti-rotation pin shaft and the limiting block is prevented from rotating excessively, and the limiting of the screw is achieved.
It effectively prevents excessive retraction of the lead screw, reduces the risk of damage to the ball screw, improves the reliability of the brake, and makes maintenance and inspection more convenient.
Smart Images
Figure CN222950342U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of brake manufacturing, in particular to a ball screw for an electronic mechanical brake. Background Art
[0002] For the electric control brake dry caliper, the traditional hydraulic braking mode is cancelled and the electric drive is completely adopted. The internal brake pad can be directly pushed by the ball screw pair to realize the braking function. The ball screw pair is composed of a screw rod, a nut and a carrier. The ball screw pair can realize the conversion of the rotational motion of the screw into the linear motion of the nut, and the friction plate is pushed by the nut to tighten the brake disc and achieve the braking purpose. In the existing structure of wire control braking, there is no limit mechanism between the nut and the screw rod or it is difficult to arrange the limit mechanism. After the nut returns to the initial position, it may continue to retreat, which will cause the ball screw carrier to fall off, be damaged or ruptured, thereby causing the spring, gasket and other parts used to adjust the axial clearance inside the brake to be damaged. Therefore, how to limit the ball screw to prevent the screw from continuing to retreat after returning to the initial position and causing damage to the product is a problem that technicians in this field need to consider. Utility Model Content
[0003] The utility model aims to provide a ball screw for an electronic mechanical brake to solve the problems in the prior art that the ball screw in the brake has no limit position and the screw is damaged due to excessive retreat.
[0004] The technical solution of the utility model is: a ball screw for an electronic mechanical brake, comprising a screw nut, an end cover and a screw, wherein the drive shaft can drive the screw to rotate; the end cover is connected to the end of the screw nut, and the end cover and the screw nut together form a barrel-shaped cavity; the screw is arranged in the cavity and connected to the screw nut, and the end of the screw away from the end cover is connected to the drive shaft;
[0005] A limit block is provided at one end of the end cover close to the screw rod, and an anti-rotation pin is connected to one end of the screw rod close to the end cover. When the screw rod rotates in the screw nut and approaches the end cover, the axial side surface of the anti-rotation pin shaft conflicts with the side surface of the limit block, so that the screw rod stops rotating relative to the screw nut.
[0006] Preferably, a clearance groove is provided at one end of the screw rod close to the end cover, and the anti-rotation pin shaft is arranged in the clearance groove;
[0007] When the anti-rotation pin is connected to the limit block, the limit block extends into the clearance groove.
[0008] Preferably, the anti-rotation pin is connected to the bottom of the clearance groove, and the anti-rotation pin and the limit block are eccentrically arranged relative to the screw rod.
[0009] Preferably, the anti-rotation pin is connected to the side wall of the clearance groove, and the limit block is eccentrically arranged relative to the screw rod.
[0010] Preferably, when the anti-rotation pin abuts against the limit block, there is a gap between the end surface of the screw rod close to the end cover and the end cover.
[0011] Preferably, the limiting block and the end cover are integrally formed.
[0012] Compared with the prior art, the advantages of the utility model are:
[0013] (1) The design of the new ball screw in the utility model can effectively reduce the risk of the ball falling off or breaking due to excessive return of the screw nut, which may cause the ball to get stuck or fail. At the same time, the setting of the clearance groove on the screw makes the overall structure more compact without increasing the volume of the brake.
[0014] (2) By adding an anti-rotation structure, when the lead screw nut retracts to a certain position, it stops retracting, providing a reference position for subsequent maintenance, replacement or inspection of the friction plate on the brake, making the maintenance and inspection process more convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The utility model is further described below in conjunction with the accompanying drawings and embodiments:
[0016] Figure 1 This is a schematic diagram of the structure of the electronic mechanical brake of the utility model;
[0017] Figure 2 It is a structural schematic diagram of the ball screw when the anti-rotation pin shaft is connected to the limit block of the utility model;
[0018] Figure 3 It is a structural schematic diagram of the ball screw when the anti-rotation pin shaft of the utility model is not connected to the limit block;
[0019] Figure 4 This is a schematic structural diagram of a ball screw when the anti-rotation pin shaft of the utility model is arranged on the side wall of the clearance groove.
[0020] Among them: actuator 1, drive shaft 11, brake caliper 2, caliper body 21, ball screw 3, screw rod 31, anti-rotation pin 311, clearance groove 312, screw nut 32, end cover 33, limit block 331. DETAILED DESCRIPTION
[0021] The following is a further detailed description of the present invention in conjunction with specific embodiments:
[0022] The utility model is applied to the electronic mechanical brake in the vehicle braking system, such as Figure 1As shown, the electronic mechanical brake includes an actuator 1, a brake caliper 2, and a ball screw 3. The output end of the actuator 1 is connected to the ball screw 3 through a drive shaft 11. The actuator 1 drives the drive shaft 11 to rotate, thereby driving the screw 31 in the ball screw 3 to rotate, and then the rotational motion of the screw 31 is converted into the linear motion of the screw nut 32, generating thrust, driving the two caliper bodies 21 of the brake caliper 2 to approach each other, and the friction plates on the two caliper bodies 21 clamp the brake disc (not shown in the figure) to achieve the braking function. When it is necessary to inspect, repair or replace the friction plate, the actuator 1 transmits torque to the ball screw 3 through the drive shaft 11, and the screw nut 32 and the end cover 33 are driven to axially retreat through the rotation of the screw 31, so that the two caliper bodies 21 are away from each other for easy operation. In this process, if the screw nut 32 retreats too much, it may cause the steel ball between the screw 31 and the screw nut 32 to fall off or break, causing the ball screw 3 to get stuck or fail. The ball screw 3 needs to be optimized to avoid this situation. Specifically:
[0023] like Figure 2-Figure 3 As shown, a ball screw 3 for an electronic mechanical brake includes a screw nut 32, an end cover 33 and a screw rod 31, and a driving shaft 11 can drive the screw rod 31 to rotate; the end cover 33 is connected to the end of the screw nut 32, and the end cover 33 and the screw nut 32 together form a barrel-shaped cavity; the screw rod 31 is arranged in the cavity and connected to the screw nut 32, and the end of the screw rod 31 away from the end cover 33 is connected to the driving shaft 11.
[0024] A limit block 331 is provided at one end of the end cover 33 close to the screw rod 31. The limit block 331 can be formed integrally with the end cover 33, or can be fixedly connected to each other by other means such as welding. An anti-rotation pin 311 is connected to one end of the screw rod 31 close to the end cover 33. One end of the anti-rotation pin 311 is connected to the screw rod 31, and the other end protrudes from the end surface of the screw rod 31. The anti-rotation pin 311 can also be formed integrally with the screw rod 31. Among them, the limit block 331 and the anti-rotation pin 311 are not limited to being set in the shape of a circular shaft, and can also be set in the shape of a polygonal column or the like.
[0025] In order to further reduce the overall volume of the ball screw 3, a clearance groove 312 can be provided at one end of the screw rod 31 close to the end cover 33, and the anti-rotation pin shaft 311 is provided in the clearance groove 312. When the anti-rotation pin shaft 311 is connected to the limit block 331, the limit block 331 extends into the clearance groove 312. The anti-rotation pin shaft 311 is connected to the bottom of the clearance groove 312, and the anti-rotation pin shaft 311 and the limit block 331 are both eccentrically arranged relative to the screw rod 31.
[0026] like Figure 4 As shown, in other embodiments, the anti-rotation pin shaft 311 can also be connected to the side wall of the clearance groove 312, and the limit block 331 is eccentrically arranged relative to the screw rod 31.
[0027] When the actuator 1 drives the screw 31 to rotate through the drive shaft 11, the rotational motion of the screw 31 is converted into the linear motion of the screw nut 32, so that the end cover 33 moves toward the end close to the screw 31, that is, the two calipers 21 of the brake move away from each other. When moving to a certain distance, the axial side of the anti-rotation pin shaft 311 conflicts with the side of the limit block 331, so that the screw 31 stops rotating relative to the screw nut 32. At this time, there is a gap between the end face of the screw 31 close to the end cover 33 and the end cover 33. It should be noted that the purpose of adjusting the maximum retraction distance of the end cover 33 or the screw nut 32 can be achieved by designing or adjusting the height of the limit block 331 protruding from the end cover 33 and the height of the anti-rotation pin shaft 311 protruding from the screw 31.
[0028] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.
Claims
1. A ball screw for an electronic mechanical brake, characterized in that: It includes a lead screw nut, an end cover and a lead screw, wherein the end cover is connected to the end of the lead screw nut, and the end cover and the lead screw nut together form a barrel-shaped cavity; the lead screw is arranged in the cavity and connected to the lead screw nut, and the end of the lead screw away from the end cover is connected to a drive shaft, and the drive shaft can drive the lead screw to rotate; A limit block is provided at one end of the end cover close to the screw rod, and an anti-rotation pin is connected to one end of the screw rod close to the end cover. When the screw rod rotates in the screw nut and approaches the end cover, the axial side surface of the anti-rotation pin shaft conflicts with the side surface of the limit block, so that the screw rod stops rotating relative to the screw nut.
2. The ball screw for an electronic mechanical brake according to claim 1, characterized in that: A clearance groove is arranged at one end of the screw rod close to the end cover, and the anti-rotation pin shaft is arranged in the clearance groove; When the anti-rotation pin is connected to the limit block, the limit block extends into the clearance groove.
3. The ball screw for an electronic mechanical brake according to claim 2, characterized in that: The anti-rotation pin is connected to the bottom of the clearance groove, and the anti-rotation pin and the limit block are both eccentrically arranged relative to the screw rod.
4. The ball screw for an electronic mechanical brake according to claim 2, characterized in that: The anti-rotation pin is connected to the side wall of the clearance groove, and the limit block is eccentrically arranged relative to the screw rod.
5. The ball screw for an electronic mechanical brake according to claim 1, characterized in that: When the anti-rotation pin shaft conflicts with the limit block, there is a gap between the end surface of the screw rod close to the end cover and the end cover.
6. The ball screw for an electronic mechanical brake according to claim 1, characterized in that: The limit block and the end cover are integrally formed.