Mechanical brake using reverse circulation lead screw assembly

Abstract

The utility model discloses a mechanical brake using a reverse circulation lead screw assembly, which belongs to the technical field of mechanical brakes and comprises a caliper body, a piston groove is arranged in the caliper body, a nut is coupled in the piston groove, a lead screw is correspondingly arranged in the nut, a steel ball groove is annularly arranged on the inner wall of the nut, and the steel ball groove is connected with the lead screw. A first lead screw groove and a second lead screw groove which are connected end to end to form a circulating groove are annularly formed in the outer wall of the lead screw; steel balls are arranged between the first lead screw groove and the second lead screw groove and the steel ball groove; the maximum depth of the first lead screw groove is smaller than the radius of the steel ball, and the maximum depth of the second lead screw groove is not smaller than the diameter of the steel ball. According to the mechanical brake using the reverse circulation lead screw assembly, a traditional phase inverter is not needed for steel ball reversing, the machining difficulty and the installation difficulty can be reduced, the machining cost is saved, and the transmission efficiency of the lead screw is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical brakes, in particular to a mechanical brake using a reverse circulation lead screw assembly. Background Art

[0002] An electro-mechanical braking device (EMB) uses a motor and a mechanical transmission mechanism in cooperation to drive the brake to brake. The electro-mechanical braking device has the characteristics of simple structure, sensitive response, stable transmission of load and no need to set up hydraulic pipelines, etc., has a high braking efficiency, and can improve the safety, controllability and comfort of the vehicle.

[0003] In the prior art, the ball screw nut pair used in electro-mechanical braking has a positive circulation structure, that is, structures such as a circulator are installed on the ball nut. The raceway on the ball nut is long, while the raceway on the lead screw is short. This requires drilling holes in the lead screw nut, which results in the lead screw nut not being a complete surface, and there will be a situation where it cannot be sealed when the nut extends outside the piston hole, and ultimately it will lead to water seepage in the brake caliper and damage to the entire mechanical brake caliper.

[0004] At the same time, due to the use of the circulator, it not only increases the processing cost of the braking device, but also has higher requirements for the processing and installation of the braking device, and will also reduce the transmission efficiency of the braking device to a certain extent. Summary of the Invention

[0005] The purpose of the utility model is to provide a mechanical brake using a reverse circulation lead screw assembly, which does not require a traditional inverter for the reverse of steel balls, can reduce the processing difficulty and installation difficulty, save the processing cost, and improve the transmission efficiency of the lead screw.

[0006] To achieve the above purpose, the utility model provides a mechanical brake using a reverse circulation lead screw assembly, including a caliper body. A piston groove is arranged inside the caliper body, a nut is coupled in the piston groove, a lead screw is correspondingly arranged inside the nut, a ball groove is annularly arranged on the inner wall of the nut, a first lead screw groove and a second lead screw groove are annularly arranged on the outer wall of the lead screw. The first lead screw groove and the second lead screw groove are connected end to end to form a circulating groove, and a transition surface is smoothly arranged at the connection; both the first lead screw groove and the second lead screw groove are smoothly connected with the ball groove and steel balls are arranged therebetween; the maximum depth of the first lead screw groove is less than the radius of the steel ball, and the maximum depth of the second lead screw groove is not less than the diameter of the steel ball.

[0007] Preferably, a through radial through hole is arranged at the inner end of the lead screw, and a circlip is inserted into the radial through hole to fix the lead screw in the caliper body.

[0008] Preferably, a needle roller bearing, a gasket, and a force sensor are sequentially arranged between the flange surface of the lead screw and the inner wall of the piston groove from outside to inside.

[0009] Preferably, a nut groove is formed on the outer side of the nut, and a dust cover is clamped therein.

[0010] Preferably, a waterproof groove is formed on the inner wall of the piston groove, and an O-ring sleeved on the outer wall of the nut is arranged in the waterproof groove.

[0011] Preferably, a sliding groove is formed at the top of the nut, a threaded hole is formed at the top of the pliers body and is threadedly connected with a rotation-preventing screw, and the bottom of the rotation-preventing screw passes into the sliding groove.

[0012] Preferably, a mounting hole is formed at the inner end of the pliers body, and an actuator is mounted through a locking screw.

[0013] Preferably, the actuator includes an actuator lower housing, an output gear is mounted in the actuator lower housing, the inner end of the output gear is an output shaft, and the end of the output shaft is clamped inside the lead screw; an actuator upper cover mounted on the actuator lower housing is arranged outside the output gear.

[0014] Preferably, an inner friction plate is mounted on the outer end face of the nut, the outer side of the pliers body is connected with a pliers frame through a guide pin and is mounted and fixed through a mounting screw, an outer friction plate is mounted inside the pliers frame, and a brake disc mounted on the pliers body is arranged between the inner friction plate and the outer friction plate.

[0015] Therefore, by adopting the above mechanical brake using a reverse circulation lead screw assembly, the present invention does not require a traditional inverter for steel ball reversal, can reduce the processing difficulty and installation difficulty, save the processing cost, and improve the transmission efficiency of the lead screw.

[0016] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic cross-sectional structure view of an embodiment of a mechanical brake using a reverse circulation lead screw assembly of the present invention;

[0018] Figure 2 is an exploded view of a reverse circulation lead screw assembly of an embodiment of a mechanical brake using a reverse circulation lead screw assembly of the present invention;

[0019] Figure 3 is a schematic cross-sectional structure view of a reverse circulation lead screw assembly of an embodiment of a mechanical brake using a reverse circulation lead screw assembly of the present invention;

[0020] Figure 4 is a schematic cross-sectional view of the reverse circulating lead screw assembly of an embodiment of a mechanical brake using the reverse circulating lead screw assembly of the present utility model;

[0021] Figure 5 is a schematic structural view of the lead screw of an embodiment of a mechanical brake using the reverse circulating lead screw assembly of the present utility model;

[0022] Figure 6 is a schematic three-dimensional structural view of an embodiment of a mechanical brake using the reverse circulating lead screw assembly of the present utility model;

[0023] Figure 7 is an enlarged view of part A of an embodiment of a mechanical brake using the reverse circulating lead screw assembly of the present utility model.

[0024] Reference numerals

[0025] 1. Caliper body; 2. Outer friction plate; 3. Brake disc; 4. Inner friction plate; 5. Steel ball; 6. Nut; 61. Steel ball groove; 62. Raceway rib; 63. Nut groove; 64. Sliding groove; 7. Lead screw; 71. First lead screw groove; 72. Second lead screw groove; 8. Anti-rotation screw; 9. Needle roller bearing; 10. Force sensor; 11. Lower housing of actuator; 12. Upper cover of actuator; 13. Output gear; 131. Output shaft; 14. Gasket; 15. Waterproof groove; 16. O-ring; 17. Dust cover; 18. Caliper bracket; 19. Guide pin; 20. Mounting screw; 21. Locking screw; 22. Snap ring. Detailed implementation manners

[0026] The technical solutions of the present utility model will be further described below with reference to the drawings and embodiments.

[0027] Unless otherwise defined, the technical terms or scientific terms used in the present utility model shall have the ordinary meanings understood by those of ordinary skill in the field to which the present utility model belongs. The "first", "second" and similar terms used in the present utility model do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0028] Embodiment 1

[0029] As Figure 1As shown, the present utility model provides a mechanical brake using a reverse circulating lead screw assembly, including a clamp body 1. A piston groove is provided inside the clamp body 1, and a nut 6 is coupled in the piston groove. As Figure 2 and Figure 3 shown, a lead screw 7 is correspondingly arranged inside the nut 6. As Figure 4 shown, a steel ball groove 61 is annularly arranged on the inner wall of the nut 6, and a first lead screw groove 71 and a second lead screw groove 72 are annularly arranged on the outer wall of the lead screw 7. As Figure 5 shown, a circulating groove is formed by connecting the first lead screw groove 71 and the second lead screw groove 72 end to end, and a transition surface is smoothly arranged at the connection. Both the first lead screw groove 71 and the second lead screw groove 72 are smoothly connected with the steel ball groove 61, and steel balls 5 are arranged therebetween. This design can ensure that when the lead screw 7 rotates, it can drive the steel balls 5 to always circulate and rotate in the same set of the first lead screw groove 71 and the second lead screw groove 72, and can ensure that the lead screw 7 can smoothly rotate inside the nut 6. The same set of corresponding first lead screw groove 71, second lead screw groove 72 and several steel balls 5 together form a circulating raceway group. Multiple sets of circulating raceway groups are provided, which can greatly reduce the friction force during the rotation of the lead screw 7. Among them, the maximum depth of the first lead screw groove 71 is less than the radius of the steel ball 5, and the maximum depth of the second lead screw groove 72 is not less than the diameter of the steel ball 5.

[0030] As Figure 6 shown, a through radial through hole is provided at the inner end of the lead screw 7, and a snap ring 22 is inserted into the radial through hole to fix the lead screw 7 inside the clamp body 1 for locking the lead screw 7 to prevent the lead screw 7 from disengaging from the piston groove of the clamp body 1.

[0031] As Figure 1 shown, a waterproof groove 15 is formed on the inner wall of the piston groove, and an O-ring 16 sleeved on the outer wall of the nut 6 is arranged in the waterproof groove 15. As Figure 2 shown, a nut groove 63 is provided on the outside of the nut 6 and a dust cover 17 is snap-fitted. Both the O-ring 16 and the dust cover 17 can provide good sealing for the piston groove. When the dust cover 17 is broken, only the O-ring 16 can also provide a good sealing effect for the piston groove, so that the piston groove of the clamp body 1 will not leak. Since the brake of this embodiment does not require a reverse circulator to be installed on the surface of the nut 6, there is no need to drill holes on the surface of the nut 6. At the same time, due to the presence of the O-ring 16, the brake of this embodiment will not be like a traditional brake that has no waterproof device once the dust cover 17 falls off. The design scheme of the brake of this embodiment can make the waterproof level of the piston groove reach IP69 level, and can make the life of the whole brake longer and safer.

[0032] As Figure 1As shown, a sliding groove 64 is provided at the top of the nut 6, and a threaded hole is provided at the top of the pliers body 1 and a non-rotating screw 8 is threadedly connected thereto. The bottom of the non-rotating screw 8 extends into the sliding groove 64. Due to the limitation of the non-rotating screw 8, the nut 6 can only translate horizontally in the piston groove and will not rotate, which can effectively improve the transmission efficiency of the lead screw 7 and is beneficial to improving the braking efficiency of the brake.

[0033] As Figure 6 shown, an installation hole is provided at the inner end of the pliers body 1 and an actuator is installed through a locking screw 21. As Figure 1 shown, the actuator includes an actuator lower housing 11. An output gear 13 is installed in the actuator lower housing 11. The inner end of the output gear 13 is an output shaft 131. The end of the output shaft 131 is clamped inside the lead screw 7. The lead screw 7 can be driven to rotate together through the forward and reverse rotation of the output gear 13 to achieve corresponding braking and cancellation of braking control. An actuator upper cover 12 installed on the actuator lower housing 11 is provided outside the output gear 13 to provide protection for the internal output gear 13.

[0034] As Figure 1 and Figure 6 shown, an inner friction plate 4 is installed on the outer end face of the nut 6. The outer side of the pliers body 1 is connected to a pliers frame 18 through a guide pin 19 and is installed and fixed through a mounting screw 20. An outer friction plate 2 is installed inside the pliers frame 18. A brake disc 3 installed on the pliers body 1 is provided between the inner friction plate 2 and the outer friction plate 4.

[0035] As Figure 7 shown, a needle roller bearing 9, a gasket 14 and a force sensor 10 are sequentially arranged between the flange surface of the lead screw 7 and the inner wall of the piston groove from outside to inside. When the inner friction plate 4 is pushed outward through the nut 6 end face so that the inner friction plate 4 and the outer friction plate 2 clamp the brake disc 3 for braking, the braking force reacts on the force sensor 10 through the lead screw 7 and the needle roller bearing 9, and the change of the force value can be monitored. The needle roller bearing 9 can also act as a rolling element to eliminate the friction force when the lead screw 7 rotates.

[0036] When installing the brake of this embodiment, first install the O-ring 16 into the waterproof groove 15 of the piston groove of the pliers body 1, and at the same time screw the non-rotating screw 8 into the threaded hole of the pliers body 1. Then, sequentially install the needle roller bearing 9, the gasket 14 and the force sensor 10 on the flange surface of the lead screw 7. At this time, the lead screw 7 has been installed with the nut 6 and the steel ball 5, and the nut 6 has been installed with the dust cover 17 at the same time. Then, install the entire assembly into the piston groove of the pliers body 1 at the same time, and insert a circlip 22 into the radial through hole at the inner end of the lead screw 7 for locking to fix the entire assembly in the piston groove of the pliers body 1.

[0037] Next, the output gear 13 is installed into the hole of the actuator lower housing 11, and the output shaft 131 is inserted into the axial through-hole at the inner end of the lead screw 7 for connection. Then, the actuator upper cover 12 is connected to the actuator lower cover 11. Next, the actuator lower housing 11 is connected to the mounting hole of the pliers body 1 with the locking screw 20. Finally, the pliers body 1 and the pliers bracket 18 are connected through the guide pin 19 and the mounting screw 19 to complete the assembly of the brake. The whole operation is very simple and the installation difficulty is low.

[0038] The basic braking principle of the brake in this embodiment is as follows: by adjusting the rotation of the output gear 13, the output shaft 131 drives the lead screw 7 to rotate accordingly. Among them, the lead screw 7, the nut 6, and the steel balls 5 together form an integral reverse circulation lead screw assembly. In this reverse circulation lead screw assembly, the lead screw 7 can achieve infinite cyclic rotation in the nut 6 without the aid of other structures. Through the rotation of the lead screw 7, the nut 6 should have been driven to rotate, but due to the anti-rotation effect of the anti-rotation screw 8 outside the nut 6, finally the nut 6 can only move linearly in the piston groove. At this time, the nut 6 generates a linear translation, pushing the inner friction plate 4 to translate outward. At the same time, the pliers body 1 pulls the pliers bracket 18 backward through the guide pin 19, so that the outer friction plate 2 and the inner friction plate 4 simultaneously clamp the brake disc 3 to generate friction for decelerating braking.

[0039] Among them, the basic principle of the reverse circulation lead screw assembly is as follows: the rotation of the lead screw 7 can drive the steel balls 5 to roll in the first lead screw groove 71, and at the same time, the steel balls 5 can also drive the nut 6 to rotate. When the steel balls 5 roll to the second lead screw groove 72, since the maximum depth of the second lead screw groove 72 is not less than the diameter of the steel balls 5, the steel balls 5 can jump into the second lead screw groove 72, so that the steel balls 5 can avoid the raceway ribs 62 between the adjacent steel ball grooves 61 on the inner wall of the nut 6 from continuing to exert a lateral force on the steel balls 5. The steel balls 5 can return to the first lead screw groove 71 again through the rotation of the lead screw 7 for the next cycle, enabling the lead screw 7 to achieve infinite cyclic rotation in the nut 6. This cyclic method does not require a traditional circulator to reverse the steel balls 5.

[0040] Therefore, the mechanical brake of the present invention using the above-mentioned reverse circulation lead screw assembly does not require a traditional inverter to reverse the steel balls, which can reduce the processing difficulty and installation difficulty, save the processing cost, and improve the transmission efficiency of the lead screw.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mechanical brake using a reverse circulation screw assembly, characterized in that: It includes a caliper body, a piston groove is arranged inside the caliper body, a nut is coupled in the piston groove, a lead screw is arranged in the nut accordingly, a steel ball groove is arranged in an annular manner on the inner wall of the nut, and a first lead screw groove and a second lead screw groove are arranged in an annular manner on the outer wall of the lead screw, the first lead screw groove and the second lead screw groove are connected end to end to form a circulation groove and a transition curved surface is smoothly arranged at the connection; the first lead screw groove and the second lead screw groove are both smoothly connected with the steel ball groove and a steel ball is arranged between them; the maximum depth of the first lead screw groove is less than the radius of the steel ball, and the maximum depth of the second lead screw groove is not less than the diameter of the steel ball.

2. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: The inner end of the lead screw is provided with a penetrating radial through hole, and a retaining spring is inserted into the radial through hole to fix the lead screw in the caliper body.

3. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: A needle bearing, a gasket and a force sensor are arranged in sequence from outside to inside between the flange surface of the lead screw and the inner wall of the piston groove.

4. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: A nut groove is provided on the outer side of the nut and a dust cover is clamped thereon.

5. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: A waterproof groove is provided on the inner wall of the piston groove, and an O-ring sleeved on the outer wall of the nut is arranged in the waterproof groove.

6. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: A sliding groove is provided on the top of the nut, a threaded hole is provided on the top of the pliers body and a locking screw is threadedly connected thereto, and the bottom of the locking screw passes into the sliding groove.

7. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: The inner end of the clamp body is provided with a mounting hole and an actuator is mounted on the inner end through a locking screw.

8. A mechanical brake using a reverse circulation screw assembly according to claim 7, characterized in that: The actuator comprises an actuator lower shell, an output gear is installed in the actuator lower shell, the inner end of the output gear is an output shaft, and the end of the output shaft is clamped inside the lead screw; an actuator upper cover installed on the actuator lower shell is arranged on the outer side of the output gear.

9. A mechanical brake using a reverse circulation screw assembly according to claim 1, characterized in that: An inner friction plate is installed on the outer end face of the nut, the outer side of the caliper body is connected to a caliper frame via a guide pin and is fixed by mounting screws, an outer friction plate is installed on the inner side of the caliper frame, and a brake disc installed on the caliper body is arranged between the inner friction plate and the outer friction plate.

Images