Ball screw and gear combined transmission device applied to brake

Abstract

The utility model relates to the technical field of brake systems, in particular to a ball screw and gear combined transmission device applied to a brake. A ball screw and gear combined transmission device applied to a brake is characterized in that a driving shaft of a motor is coupled with a motor gear, the motor gear is in meshed connection with an idle gear, and the idle gear is in meshed connection with a planetary gear train; the planetary gear train is connected with the shaft end of the ball screw, the outer side of a threaded section of the ball screw is sleeved with a ball nut, the tail end of the ball nut is connected with an end cover, the outer side of the ball nut is connected with a boss, and the ball nut and the boss are of an integrated structure; a plurality of closed circulation loops are arranged on the outer edge of the threaded section of the ball screw; a plurality of steel balls are arranged in the circulation loop; the circulation loop is composed of a spiral raceway and a ball return channel, and the two ends of the spiral raceway are seamlessly and smoothly communicated with the two ends of the ball return channel. Compared with the prior art, the defects that a traditional ball screw and gear combined transmission mechanism is large in occupied space, low in piston return response speed and the like are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of braking systems, and specifically relates to a ball screw and gear combined transmission device applied to a brake. Background Technique

[0002] In a traditional internal circulation ball screw, the ball circulation is realized through a return device. The return device is embedded in the wall of the ball nut and can float. A ball return channel is designed in the middle position of the return device, and both ends of the ball return channel are communicated with two adjacent spiral raceways on the ball nut, thus forming a circulation loop.

[0003] In a traditional ball screw and gear combined transmission mechanism, the gear is driven by a motor, the ball screw is then driven by the gear, the ball nut is driven by the ball screw, and the ball nut pushes the piston to clamp the brake disc, converting the rotational motion into a linear motion to achieve vehicle braking. Although this braking mechanism can meet the vehicle braking requirements, it has disadvantages such as the structures of the ball screw and the gear being not compact, occupying a large space, low efficiency, and slow piston return response speed. Summary of the Invention

[0004] The utility model aims to overcome the deficiencies of the prior art and provides a ball screw and gear combined transmission device applied to a brake, which overcomes the disadvantages of the traditional ball screw and gear combined transmission mechanism, such as large space occupation, low efficiency, and slow piston return response speed.

[0005] To achieve the above object, a ball screw and gear combined transmission device applied to a brake is designed, including a motor, a planetary gear train, and a ball screw assembly. The characteristics are as follows: the driving shaft of the motor is axially connected to a motor gear, the motor gear is meshed and connected to an idle gear, and the idle gear is meshed and connected to the planetary gear train; the planetary gear train is connected to the shaft end of the ball screw, a ball nut is sleeved outside the threaded section of the ball screw, the end of the ball nut is connected to an end cover, a boss is connected to the outside of the ball nut, and the ball nut and the boss are of an integral structure; several closed circulation loops are provided on the outer edge of the threaded section of the ball screw; several steel balls are provided in the circulation loops; the circulation loop is composed of a spiral raceway and a ball return channel, the pitches between the spiral raceways of two adjacent circulation loops are the same, the ball return channels of two adjacent circulation loops are arranged in a staggered manner, and both ends of the spiral raceway are seamlessly and smoothly communicated with both ends of the ball return channel.

[0006] A return groove is provided on the threaded section of the ball screw, a return device is embedded in the return groove, the circulation loop is composed of a spiral raceway and a ball return channel, the ball return channel is located in the return device, the pitches between the spiral raceways of two adjacent circulation loops are the same, the ball return channels of two adjacent circulation loops are arranged in a staggered manner, and both ends of the spiral raceway are smoothly communicated with both ends of the ball return channel.

[0007] The threaded section of the ball screw is provided with an insertion plate groove, and an insertion plate is embedded in the insertion plate groove. The circulation circuit is composed of a spiral raceway and a ball return passage. The ball return passage is located on the insertion plate. The pitches between the spiral raceways of two adjacent circulation circuits are the same. The ball return passages of two adjacent circulation circuits are arranged in parallel, and the spiral raceways are smoothly connected to both ends of the ball return passage.

[0008] The planetary gear train includes a sun gear, a driving gear, planetary gears, bearings, needle bearings, a planetary carrier, an internal gear ring, and an MGU housing. An idle gear is meshed and connected with the sun gear. One side of the sun gear is axially connected to the driving gear. The outer edge of the driving gear is meshed and connected with one side of a number of planetary gears. The other side of the planetary gears is meshed and connected with the internal gear ring. The planetary carrier is located inside the internal gear ring, and the internal gear ring is fixed to the MGU housing. Bearings are press-fitted on the planetary gears, and the planetary shafts pass through the bearings, the planetary gears and are connected to the planetary carrier. The shaft end of the driving gear is in clearance fit with the needle bearing, and the needle bearing is located inside the planetary carrier.

[0009] The sun gear, the driving gear, and the ball screw are coaxially connected.

[0010] The axial direction of the ball screw is supported by a bearing washer, a flat thrust bearing, and a support washer, and the bearing washer, the flat thrust bearing, and the support washer are located inside the ball nut.

[0011] The end cover is connected to the ball nut by interference fit or threading or welding; or the end cover and the ball nut are of an integral structure.

[0012] Compared with the prior art, the present utility model provides a ball screw and gear combined transmission device applied to a brake, which overcomes the disadvantages of the traditional ball screw and gear combined transmission mechanism, such as large occupied space, low efficiency, slow piston return response speed, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the first embodiment of the present utility model.

[0014] Figure 2 It is a schematic structural diagram of the second embodiment of the present utility model.

[0015] Figure 3 It is a schematic structural diagram of the third embodiment of the present utility model.

[0016] See Figures 1 to 3As shown in the figure, 1 is a motor, 2 is a motor gear, 3 is an idler gear, 4 is a sun gear, 5 is a drive gear, 6 is a planet carrier, 7 is a planet gear, 8 is an internal gear ring, 9 is a bearing, 10 is a planet shaft, 11 is a needle roller bearing, 12 is a ball screw, 13 is a bearing washer, 14 is a thrust plane bearing, 15 is a support washer, 16 is a steel ball, 17 is a ball nut, 18 is an end cover, 19 is a boss, 20 is an MGU housing, 21 is a reverser, and 22 is a plug board. Specific embodiments

[0017] The following further describes the present utility model with reference to the accompanying drawings.

[0018] As Figure 1 shown, it is the structure of Embodiment 1 of the present utility model.

[0019] It includes a motor 1, a motor gear 2, an idler gear 3, a sun gear 4, a drive gear 5, a planet carrier 6, a planet gear 7, an internal gear ring 8, an MGU housing 20, a bearing 9, a planet shaft 10, a needle roller bearing 11, a ball screw 12, a bearing washer 13, a thrust plane bearing 14, a support washer 15, a steel ball 16, a ball nut 17, and an end cover 18. The motor gear 2 is press-fitted on the motor shaft and drives the idler gear 3. The idler gear 3 drives the sun gear 4. The drive gear 5 is press-fitted on the sun gear 4. The bearing 9 is press-fitted inside the planet gear 7. The needle roller bearing 11 is press-fitted inside the planet carrier 6. The planet shaft 10 passes through the bearing 9 inside the planet carrier 6 and the planet gear 7, and is riveted or welded or interference-connected to the planet carrier 6 at both ends. The drive gear 5 is installed in the planet carrier 6 and meshes with the planet gear 7. The shaft end of the drive gear 5 has a clearance fit with the needle roller bearing 11. The planet gear 7 meshes with the internal gear ring 8. The internal gear ring 8 is fixed to the MGU housing 20. The drive gear 5 drives a plurality of planet gears 7 to rotate and revolve. The revolution of the planet gear 7 drives the planet carrier 6 to rotate. The planet carrier 6 is connected to the ball screw 12 through a spline and drives the ball screw 12. The ball screw 12 is axially supported by the support washer 15, the thrust plane bearing 14, and the bearing washer 13. The ball nut 17 is integrated with the boss 19 and is guided by the boss 19. The end cover 18 is connected to the ball nut 17 by interference or thread or welding, or the end cover 18 is integrated with the ball nut 17, and can axially bear the thrust of the ball screw 12 without displacement.

[0020] When clamping, the motor 1 drives the motor gear 2. The motor gear 2 drives the planetary gear train through the idler gear 3. The planetary gear train drives the ball screw 12. The ball screw 12 drives the ball nut 17. The steel balls 16 circulate through the ball return channels on the threaded section of the ball screw 12. The ball nut 17 is guided by the boss 19 to convert the rotational motion into a linear motion, realizing the braking function. When releasing, the motor 1 rotates in reverse, and each gear and the ball screw 12 rotate in reverse. The ball nut 17 returns to its position in a timely and accurate manner under the drive of the threaded section of the ball screw 12. There are several spiral raceways and ball return channels on the threaded section of the ball screw 12. All the spiral raceways have the same pitch. Both ends of each spiral raceway are seamlessly and smoothly connected to both ends of a ball return channel, thus forming a closed circulation loop. The several ball return channels are arranged in a staggered manner. Each set of spiral raceways and ball return channels is equipped with several steel balls 16. During operation, the steel balls 16 return to the starting position through the ball return channels.

[0021] The ball screw and gear combined transmission mechanism used in the first embodiment of the present invention replaces the traditional ball screw and gear combined transmission mechanism, reducing the weight, axial dimension and moment of inertia of the ball screw, and reducing the difficulty of software control; the ball return channels are designed on the threaded section of the ball screw and are seamlessly and smoothly connected to both ends of the spiral raceways, increasing the compliance of ball return; the integrally formed ball nut eliminates the original piston, increasing the rigidity of the integrated ball nut, and the support washer, flat thrust bearing and bearing washer can be hidden inside the ball nut, increasing the overall envelope, achieving the purpose of saving space, improving the efficiency of the ball screw, increasing the return response speed, reducing noise and reducing the manufacturing cost of the ball screw. The structure is simple and practical.

[0022] As Figure 2 shown, it is the structure of the second embodiment of the present invention.

[0023] It includes motor 1, motor gear 2, idler gear 3, sun gear 4, drive gear 5, planet carrier 6, planet gear 7, internal gear ring 8, MGU housing 20, bearing 9, planet shaft 10, needle roller bearing 11, ball screw 12, bearing washer 13, flat thrust bearing 14, support washer 15, steel ball 16, ball nut 17, end cover 18 and reverser 21. The motor gear 2 is press-fitted on the motor shaft and drives the idler gear 3, the idler gear 3 drives the sun gear 4, the drive gear 5 is press-fitted on the sun gear 4, the bearing 9 is press-fitted inside the planet gear 7, the needle roller bearing 11 is press-fitted inside the planet carrier 6, the planet shaft 10 passes through the bearing 9 inside the planet carrier 6 and the planet gear 7, and is riveted or welded or interference-connected to the planet carrier 6 at both ends. The drive gear 5 is installed in the planet carrier 6 and meshes with the planet gear 7, and the shaft end of the drive gear 5 has a clearance fit with the needle roller bearing 11. The planet gear 7 meshes with the internal gear ring 8, and the internal gear ring 8 is fixed to the MGU housing 20. The drive gear 5 drives several planet gears 7 to rotate and revolve. The revolution of the planet gear 7 drives the planet carrier 6 to rotate. The planet carrier 6 is connected to the ball screw 12 through a spline and drives the ball screw 12. The ball screw 12 is axially supported by the support washer 15, flat thrust bearing 14 and bearing washer 13. The ball nut 17 is integrated with the boss 19 and is guided by the boss 19. The end cover 18 is connected to the ball nut 17 by interference or thread or welding, or the end cover 18 is integrated with the ball nut 17, and can axially bear the thrust of the ball screw 12 without displacement.

[0024] When clamping, the motor 1 drives the motor gear 2, the motor gear 2 drives the planetary gear train through the idler gear 3, the planetary gear train drives the ball screw 12, the ball screw 12 drives the ball nut 17, and the steel balls 16 circulate through the reverser 21 on the threaded section of the ball screw 12. The ball nut 17 is guided by the boss 19 to convert the rotary motion into a linear motion to achieve the braking function. When releasing, the motor 1 rotates in reverse, and each gear and the ball screw 12 rotate in reverse. The ball nut 17 returns to its position in a timely and accurate manner under the drive of the threaded section of the ball screw 12. There are several spiral raceways and reverse grooves on the threaded section of the ball screw 12. Each reverse groove is embedded with a reverser 21. A ball return channel is designed in the middle of each reverser 21. All the spiral raceways have the same pitch, and each spiral raceway is connected to the ball return channel of a reverser, thus forming a circulation loop. The several reversers 21 are arranged in a staggered manner. Several steel balls 16 are installed in each group of spiral raceways and reversers 21. During operation, the steel balls 16 return to the starting position through the reverser 21.

[0025] In the second embodiment of the present utility model, the ball screw and gear combined transmission mechanism used replaces the traditional ball screw and gear combined transmission mechanism, reducing the weight, axial dimension and moment of inertia of the ball screw, and reducing the difficulty of software control; the returner can be formed by die casting, reducing the processing cost of the ball return channel; after the ball nut is integrally formed, the original piston is omitted, increasing the rigidity of the integrated ball nut, and the support washer, flat thrust bearing and bearing washer can be hidden inside the ball nut, increasing the overall envelope, achieving the purpose of saving space, improving the efficiency of the ball screw, increasing the return response speed and reducing the manufacturing cost of the ball screw. The structure is simple and practical.

[0026] As Figure 3 shown, it is the structure of the third embodiment of the present utility model.

[0027] It includes a motor 1, a motor gear 2, an idler gear 3, a sun gear 4, a driving gear 5, a planet carrier 6, a planet gear 7, an internal gear ring 8, an MGU housing 20, a bearing 9, a planet shaft 10, a needle bearing 11, a ball screw 12, a bearing washer 13, a flat thrust bearing 14, a support washer 15, a steel ball 16, a ball nut 17, an end cover 18 and a plug board 22. The motor gear 2 is press-fitted on the motor shaft and drives the idler gear 3. The idler gear 3 drives the sun gear 4. The driving gear 5 is press-fitted on the sun gear 4. The bearing 9 is press-fitted inside the planet gear 7. The needle bearing 11 is press-fitted inside the planet carrier 6. The planet shaft 10 passes through the bearing 9 inside the planet carrier 6 and the planet gear 7, and is riveted or welded or interference-connected to the planet carrier 6 at both ends. The driving gear 5 is installed in the planet carrier 6 and meshes with the planet gear 7. The shaft end of the driving gear 5 has a clearance fit with the needle bearing 11. The planet gear 7 meshes with the internal gear ring 8. The internal gear ring 8 is fixed to the MGU housing 20. The driving gear 5 drives several planet gears 7 to rotate and revolve. The revolution of the planet gear 7 drives the planet carrier 6 to rotate. The planet carrier 6 is connected to the ball screw 12 through a spline and drives the ball screw 12. The ball screw 12 is axially supported by the support washer 15, the flat thrust bearing 14 and the bearing washer 13. The ball nut 17 is integrated with the boss 19 and is guided by the boss 19. The end cover 18 is connected to the ball nut 17 by interference or thread or welding, or the end cover 18 is integrated with the ball nut 17, and can axially bear the thrust of the ball screw 12 without displacement.

[0028] When clamping, the motor 1 drives the motor gear 2. The motor gear 2 drives the planetary gear train through the idler gear 3. The planetary gear train drives the ball screw 12. The ball screw 12 drives the ball nut 17. The steel balls 16 circulate through the ball return channels on the insertion plate 22. The ball nut 17 is guided by the boss 19 to convert the rotary motion into a linear motion, realizing the braking function. When releasing, the motor 1 rotates reversely, and each gear and the ball screw 12 rotate reversely. The ball nut 17 returns to its position in a timely and accurate manner under the drive of the threaded section of the ball screw 12. There are several spiral raceways and insertion plate grooves on the threaded section of the ball screw 12. An insertion plate 22 is embedded in the insertion plate groove. Several ball return channels are designed on each insertion plate 22. The pitches of all the spiral raceways are the same. Each spiral raceway communicates with one of the ball return channels in the insertion plate 22, thus forming a circulation loop. Several steel balls 16 are installed in each group of spiral raceways and the ball return channels in the insertion plate 22. During operation, the steel balls 16 return to the starting position through the insertion plate 22.

[0029] The ball screw and gear combined transmission mechanism used in the third embodiment of the present utility model replaces the traditional ball screw and gear combined transmission mechanism, reducing the weight, axial dimension and moment of inertia of the ball screw, and reducing the difficulty of software control; the insertion plate can be formed by die casting, reducing the processing cost of the ball return channels; after the ball nut is integrally formed, the original piston is omitted, increasing the rigidity of the integrated ball nut, and the support washer, flat thrust bearing and bearing washer can be hidden inside the ball nut, increasing the overall envelope, achieving the purpose of saving space, improving the efficiency of the ball screw, increasing the return response speed and reducing the manufacturing cost of the ball screw. The structure is simple and practical.

Claims

1. A ball screw and gear combination transmission device for a brake, comprising a motor, a planetary gear train, and a ball screw assembly, characterized in that: The driving shaft of the motor (1) is connected to the motor gear (2), the motor gear (2) is meshedly connected to the idler gear (3), and the idler gear (3) is meshedly connected to the planetary gear train; the planetary gear train is connected to the shaft end of the ball screw (12), a ball nut (17) is sleeved on the outer side of the threaded section of the ball screw (12), the end of the ball nut (17) is connected to the end cover (18), the outer side of the ball nut (17) is connected to the boss (19), and the ball nut (17) and the boss (19) are an integrated structure; a plurality of closed circulation loops are provided at the outer edge of the threaded section of the ball screw (12); a plurality of steel balls (16) are provided in the circulation loop; the circulation loop is composed of a spiral raceway and a ball return channel, the pitches of the spiral raceways of two adjacent circulation loops are the same, the ball return channels of the two adjacent circulation loops are staggered, and the two ends of the spiral raceway are seamlessly and smoothly connected to the two ends of the ball return channel.

2. A ball screw and gear combination transmission device for brake according to claim 1, characterized in that: A return groove is provided on the threaded section of the ball screw (12), a return device (21) is embedded in the return groove, and the circulation loop is composed of a spiral rolling track and a ball return channel, and the ball return channel is located in the return device (21).

3. The ball screw and gear combination transmission device for brake according to claim 1, characterized in that: The threaded section of the ball screw (12) is provided with a plug plate groove, in which a plug plate (22) is embedded. The circulation loop consists of a spiral rolling track and a ball return channel. The ball return channel is located on the plug plate (22). The pitches of the spiral rolling tracks of two adjacent circulation loops are the same. The ball return channels of the two adjacent circulation loops are arranged in parallel, and the spiral rolling tracks are smoothly connected to both ends of the ball return channel.

4. A ball screw and gear combination transmission device for brake according to claim 1, characterized in that: The planetary gear train comprises a sun gear, a driving gear, a planetary gear, a bearing, a needle bearing, a planetary carrier, an inner gear ring, and an MGU housing. The idler gear (3) is meshedly connected to the sun gear (4). One side of the sun gear (4) is axially connected to a driving gear (5). The outer edge of the driving gear (5) is meshedly connected to one side of a plurality of planetary gears (7). The other side of the planetary gear (7) is meshedly connected to an inner gear ring (8). The planetary carrier (6) is located in the inner gear ring (8), and the inner gear ring (8) is fixed to the MGU housing (20). A bearing (9) is press-fitted on the planetary gear (7), and the planetary shaft (10) passes through the bearing (9), and the planetary gear (7) is connected to the planetary carrier (6). The shaft end of the driving gear (5) is clearance-matched with the needle bearing (11), and the needle bearing (11) is located in the planetary carrier (6).

5. A ball screw and gear combination transmission device for brake according to claim 4, characterized in that: The sun gear (4), the driving gear (5), and the ball screw (12) are coaxially connected.

6. A ball screw and gear combination transmission device for brake according to claim 1, characterized in that: The ball screw (12) is supported axially by a bearing washer (13), a planar thrust bearing (14) and a support washer (15), and the bearing washer (13), the planar thrust bearing (14) and the support washer (15) are located inside the ball nut (17).

7. A ball screw and gear combination transmission device for brake according to claim 1, characterized in that: The end cover (18) and the ball nut (17) are connected by interference fit, threading or welding; or the end cover (18) and the ball nut (17) are an integrated structure.

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