Anti-rotation structure of ball screw

Abstract

The utility model relates to the technical field of electronic hydraulic brake systems, in particular to an anti-rotation structure of a ball screw, which comprises a first clamping part arranged on a front end cover of a motor and a second clamping part arranged on a shell of the motor. And the first clamping part and the second clamping part can be clamped and matched, so that the motor shell can limit the motor front end cover in the circumferential direction of the motor front end cover. The first clamping part and the second clamping part can serve as a nut anti-rotation structure, and the motor front end cover can provide stable supporting force for the nut through the center through hole by improving the installation stability between the motor front end cover and the motor shell, so that circumferential rotation of the nut on the lead screw is limited; the first clamping part and the second clamping part are respectively arranged on the motor front end cover and the motor shell, and are disassembled and assembled in a clamping matching manner, so that the influence on the use performance of the valve block can be well avoided, meanwhile, the use of fixing pieces such as screws or rivets is avoided, the process difficulty during disassembly and assembly is reduced, and the use is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic hydraulic brake systems, in particular to a ball screw anti-rotation structure. Background Art

[0002] The existing brake-by-wire system uses a motor to drive the transmission mechanism to push the master cylinder to provide braking assistance to the driver. In the transmission mechanism, a ball screw direct drive solution is generally adopted. The motor rotor drives the screw to rotate, and the nut drives the master cylinder piston to move linearly to achieve the pressure building or pressure relief function. Therefore, the rotation of the nut needs to be restricted. The existing nut anti-rotation structure is mostly fixed on the valve block of the pressure building unit, connected by screws or rivets, which is easy to affect the performance of the valve block, and has a large number of parts, high requirements for the assembly process, and requires more assembly time, which has certain limitations. Utility Model Content

[0003] In view of the above problems existing in the prior art, the utility model provides a ball screw anti-rotation structure.

[0004] In order to solve the above technical problems, the utility model is solved by the following technical solutions:

[0005] A ball screw anti-rotation structure comprises a first clamping portion arranged on a front end cover of a motor, and a second clamping portion arranged on a motor housing;

[0006] The first clamping portion and the second clamping portion can be clamped together to achieve the limitation of the motor front end cover by the motor housing in the circumferential direction thereof.

[0007] Preferably, the motor housing is in the shape of a cylinder with one end open; the first clamping portion is arranged at the circumferential side wall of the front end cover of the motor; and the second clamping portion is arranged at the opening of the motor housing.

[0008] Preferably, an annular mounting platform is provided on the inner side wall of the opening of the motor housing, and the second clamping portion is provided on the mounting platform.

[0009] Preferably, the first clamping portion includes a protrusion and / or a groove.

[0010] Preferably, when the motor front end cover and the motor housing are in an installed state, the first clamping portion and the second clamping portion are interference fit.

[0011] Preferably, the front end cover of the motor is in a ring shape with a central through hole; the motor housing is provided with a motor rotor, a screw rod and a nut;

[0012] The motor rotor is rotatably disposed in the motor housing;

[0013] The screw rod is coaxially arranged with the central through hole, and one end of the screw rod is connected to the motor rotor;

[0014] The nut is sleeved on the screw rod;

[0015] The motor rotor can drive the screw rod to rotate so as to drive the nut to reciprocate along the axial direction of the screw rod.

[0016] Preferably, a first anti-rotation portion is provided at the central through hole, and a second anti-rotation portion is provided at the nut;

[0017] The first anti-rotation portion can abut against the second anti-rotation portion to limit the nut in its circumferential direction.

[0018] Preferably, the first anti-rotation portion includes an abutment groove and / or an abutment block.

[0019] Preferably, the first anti-rotation portion includes an abutment surface.

[0020] Preferably, when the first anti-rotation portion and the second anti-rotation portion are in abutment, the first anti-rotation portion and the second anti-rotation portion are in point contact or line contact.

[0021] The utility model has at least the following beneficial effects:

[0022] In the present application, the first clamping part and the second clamping part can serve as a nut anti-rotation structure, by improving the installation stability between the front end cover of the motor and the motor housing, so that the front end cover of the motor can provide a stable supporting force to the nut through the central through hole, so as to limit the circumferential rotation of the nut on the screw rod; the first clamping part and the second clamping part are respectively arranged on the front end cover of the motor and the motor housing, and disassembly and assembly are achieved by clamping cooperation, which can better avoid affecting the performance of the valve block, and at the same time avoid the use of fixings such as screws or rivets, reduce the process difficulty during disassembly and assembly, and facilitate use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An exploded schematic diagram of a motor housing, a motor front end cover, a screw rod and a screw nut in some embodiments of the present application is shown;

[0024] Figure 2 A schematic diagram showing the cooperation between the central through hole and the nut through the first abutment surface and the second abutment surface in some embodiments of the present application is shown;

[0025] Figure 3 A schematic diagram showing that in some embodiments of the present application, when the first anti-rotation portion includes an abutment groove and the second anti-rotation portion includes an abutment block, the side wall of the abutment groove in the circumferential direction of the nut is arc-shaped;

[0026] Figure 4 A schematic diagram is shown in which, in some embodiments of the present application, the first anti-rotation portion includes a first abutting surface, and the second anti-rotation portion includes a second abutting surface, and the second abutting surface is arc-shaped.

[0027] The parts indicated by the numbers in the accompanying drawings are as follows:

[0028] 100, motor housing; 101, mounting platform; 110, motor rotor; 120, screw rod; 130, nut; 131, second anti-rotation part; 140, second clamping part; 200, motor front end cover; 210, center through hole; 211, first anti-rotation part; 220, first clamping part; 310, first abutting surface; 320, second abutting surface. DETAILED DESCRIPTION

[0029] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are only used to explain the utility model but not to limit it.

[0030] In the existing wire-controlled brake system, the motor drives the transmission mechanism to push the master cylinder to provide braking assistance to the driver. The transmission mechanism generally adopts a ball screw direct drive method. The motor rotor 110 drives the screw rod 120 to rotate, so that the nut 130 on the screw rod 120 moves linearly on the screw rod 120, so that the nut 130 drives the master cylinder piston to move linearly, thereby realizing the function of building up or releasing pressure.

[0031] When the nut 130 moves linearly on the screw rod 120, the rotation of the nut 130 in the circumferential direction needs to be restricted. The existing nut anti-rotation structure is generally fixed on the valve block of the pressure building unit and connected by screws or rivets, which can easily affect the performance of the valve block. In addition, there are a large number of parts, and the assembly process is relatively high. It takes a long time to operate and assemble, which has certain limitations and is inconvenient to use.

[0032] Therefore, a ball screw anti-rotation structure is provided in the present embodiment. By optimizing the design of the motor housing 100, the motor front end cover 200 and the nut 130, the circumferential limitation of the nut 130 can be achieved without setting a nut anti-rotation structure on the valve block by screws or rivets, thereby better avoiding the performance of the valve block, and the number of parts is small, which is convenient for assembly and use.

[0033] Example 1

[0034] like Figure 1As shown, this embodiment provides a ball screw anti-rotation structure, including a motor housing 100 and a motor front end cover 200; the motor housing 100 is a cylindrical shape with one end open, the motor front end cover 200 is annular with a central through hole 210, and the motor front end cover 200 can be covered on one end of the motor housing 100. A motor rotor 110, a screw rod 120 and a nut 130 are arranged in the motor housing 100, the motor rotor 110 is rotatably arranged in the motor housing 100, one end of the screw rod 120 is connected to the motor rotor 110, in the installed state, the nut 130 is matched with the central through hole 210 of the motor front end cover 200 and is sleeved on the screw rod 120, and the motor front end cover 200 can limit the nut 130 in the circumferential direction of the nut 130. When the motor rotor 110 rotates, it can directly drive the screw rod 120 to rotate. Since the nut 130 is limited in the circumferential direction, the nut 130 will make a linear motion in the axial direction of the screw rod 120 as the screw rod 120 rotates, so that the nut 130 can drive the main cylinder piston to move linearly, thereby realizing the function of building up or releasing pressure.

[0035] Furthermore, a first clamping portion 220 is provided on the motor front end cover 200 and a second clamping portion 140 is provided on the motor housing 100 , and the motor front end cover 200 and the motor housing 100 can be installed and disassembled by the clamping cooperation between the first clamping portion 220 and the second clamping portion 140 .

[0036] When the motor front end cover 200 and the motor housing 100 are assembled, since the first clamping portion 220 on the motor front end cover 200 is clamped on the second clamping portion 140 on the motor housing 100, the second clamping portion 140 can limit the first clamping portion 220. Therefore, the motor front end cover 200 can be circumferentially limited in the circumferential direction of the motor front end cover 200, thereby preventing the motor front end cover 200 from shaking on the motor housing 100 when the nut 130 moves linearly on the screw rod 120, and preventing the nut 130 from circumferentially displacing on the screw rod 120.

[0037] It can be understood that the first clamping portion 220 and the second clamping portion 140 can serve as a nut anti-rotation structure, by improving the installation stability between the motor front end cover 200 and the motor housing 100, so that the motor front end cover 200 can provide a stable supporting force to the nut 130 through the center through hole 210, thereby limiting the circumferential rotation of the nut 130 on the screw rod 120.

[0038] In particular, the first clamping portion 220 and the second clamping portion 140 are respectively arranged on the front end cover 200 of the motor and the motor housing 100, and disassembly and assembly are achieved by means of clamping cooperation, which can better avoid affecting the performance of the valve block and avoid the use of fixing parts such as screws or rivets, thereby reducing the process difficulty during disassembly and assembly and facilitating use.

[0039] In some embodiments, the maximum radial dimension of the motor front end cover 200 is smaller than or equal to the inner diameter of the cylinder of the motor housing 100, the first clamping portion 220 is arranged on the circumferential outer wall of the motor front end cover 200, and the second clamping portion 140 is arranged at the opening at one end of the motor housing 100; during installation, the motor front end cover 200 is installed in the cylinder of the motor housing 100 through the clamping fit of the first clamping portion 220 and the second clamping portion 140.

[0040] It can be understood that installing the front end cover 200 of the motor in the cylinder of the motor housing 100 can better achieve the hiding of the front end cover 200 of the motor. Since the front end cover 200 of the motor is connected by the clamping action of the first clamping part 220 and the second clamping part 140, the hidden installation of the front end cover 200 of the motor can better avoid the connection between the first clamping part 220 and the second clamping part 140 from being hit, thereby better achieving the protection effect. Furthermore, it can also improve the stability of the relative position between the front end cover 200 of the motor and the motor housing 100, so that the front end cover 200 of the motor can provide a stable limiting effect on the nut 130 through the center through hole 210, thereby avoiding the circumferential rotation of the nut 130.

[0041] In some embodiments, a ring-shaped mounting platform 101 is disposed on the inner side wall of the opening at one end of the motor housing 100 , and the second clamping portion 140 is disposed on the mounting platform 101 .

[0042] It should be noted that by setting a mounting platform 101 on the inner wall of the motor housing 100 and setting the second clamping portion 140 on the mounting platform 101, it is possible to avoid directly changing the structure of the motor housing 100 itself, and the second clamping portion 140 can be better set without affecting the structural strength of the motor housing 100. For example, when the second clamping portion 140 is a groove body, a groove can be directly made on the mounting platform 101, thereby avoiding making a groove on the motor housing 100.

[0043] Furthermore, the mounting platform 101 can also provide a reference when installing between the motor front end cover 200 and the motor housing 100. Since the first clamping portion 220 is arranged on the circumferential outer wall of the motor front end cover 200, when the motor front end cover 200 and the motor housing 100 are assembled, the first clamping portion 220 and the mounting platform 101 can be observed from the opening at one end of the motor housing 100. The staff can determine whether the motor front end cover 200 is installed in place on the motor housing 100 by observing the relative position between the first clamping portion 220 and the mounting platform 101, which can provide the staff with a reference and feedback for easy disassembly and assembly.

[0044] In some embodiments, the first clamping portion 220 includes at least one of a protrusion structure and a groove structure, and correspondingly, the second clamping portion 140 also includes at least one of a protrusion structure and a groove structure. There is no special limitation on this, but it should be emphasized that since the first clamping portion 220 and the second clamping portion 140 can achieve a snap-fit ​​fit, if one of the matching first clamping portion 220 and the second clamping portion 140 is a protrusion structure, the other is a groove structure.

[0045] In some embodiments, the first clamping portion 220 and the second clamping portion 140 are clamped together by interference fit. For example, when the first clamping portion 220 is a semicircular protrusion structure and the second clamping portion 140 is a semicircular groove structure, the size of the second clamping portion 140 is slightly smaller than the size of the first clamping portion 220. For another example, when the first clamping portion 220 is a groove structure and the second clamping portion 140 is a protrusion structure, the first clamping portion 220 is a semicircular groove structure, and the second clamping portion 140 is a semi-arc protrusion structure.

[0046] It is understandable that the first clamping portion 220 and the second clamping portion 140 may be of different sizes and shapes, as long as an interference fit between the two can be achieved, and there is no particular limitation on this.

[0047] Example 2

[0048] Combination Figure 1-4 As shown, this embodiment is an improvement on the basis of the embodiment 1, a ball screw anti-rotation structure includes a first stop portion 211 arranged at the center through hole 210 and a second stop portion 131 arranged at the nut 130. In the installed state, the nut 130 is passed through the center through hole 210 and is sleeved on the outside of the screw rod 120. When the nut 130 is passed through the center through hole 210, the first stop portion 211 and the second stop portion 131 can abut against each other, thereby realizing the limitation of the nut 130 in the circumferential direction to prevent the nut 130 from circumferentially rotating on the screw rod 120.

[0049] It can be understood that the first stop portion 211 and the second stop portion 131 can serve as a nut anti-rotation structure, and the motor front end cover 200 directly acts on the second stop portion 131 at the nut 130 through the first stop portion 211 at the center through hole 210, thereby achieving direct limiting of the nut 130 by the motor front end cover 200 and preventing the nut 130 from circumferential rotation.

[0050] In particular, the first stop 211 and the second stop 131 are respectively arranged on the front end cover 200 of the motor and the nut 130, which can better avoid affecting the performance of the valve block, while avoiding the use of fasteners such as screws or rivets, reducing the process difficulty during disassembly and assembly, and facilitating use.

[0051] Furthermore, the first anti-rotation portion 211 and the second anti-rotation portion 131 can cooperate with the first clamping portion 220 and the second clamping portion 140 to jointly limit the nut 130 in the circumferential direction, thereby improving the stability of the operation of the entire mechanism.

[0052] In some embodiments, the first stop portion 211 includes at least one of an abutment groove and an abutment block, and correspondingly, the second stop portion 131 also includes at least one of an abutment groove and an abutment block. There is no special limitation on this, but it should be emphasized that since the first stop portion 211 and the second stop portion 131 can cooperate with each other to achieve circumferential limitation of the nut 130, the first stop portion 211 and the second stop portion 131 that cooperate with each other, if one of them is an abutment groove, the other is an abutment block.

[0053] Combination Figure 1 and Figure 3 As shown, for example, when the first stop portion 211 is an abutment groove and the second stop portion 131 is an abutment block, the first stop portion 211 and the second stop portion 131 both extend along the axial direction of the screw rod 120 and are in the shape of a long strip. During installation, the nut 130 is inserted into the central through hole 210 so that the second stop portion 131 which is a snap-in block extends into the first stop portion which is the abutment groove, so that the first stop portion 211 and the second stop portion 131 are connected in a snap-fit ​​manner. When the screw rod 120 drives the nut 130 to move by rotation, the first stop portion 211 can limit the second stop portion 131, thereby blocking the nut 130 in the circumferential direction of the nut 130, thereby limiting the circumferential rotation of the nut 130 and avoiding rotation of the nut 130.

[0054] In some embodiments, the first anti-rotation portion 211 further includes an abutment surface, and correspondingly, the second anti-rotation portion 131 also includes an abutment surface. Figure 2 and Figure 4As shown, the first stop portion 211 includes a first abutment surface 310, and the second stop portion 131 includes a second abutment surface 320. When the nut 130 is inserted into the central through hole 210, the position of the first abutment surface 310 corresponds to the position of the second abutment surface 320. When the screw rod 120 drives the nut 130 to move by rotation, the first abutment surface 310 can resist the second abutment surface 320 to prevent the second abutment surface 320 from rotating in the circumferential direction of the screw rod 120, thereby limiting the nut 130, so that the nut 130 is limited in the circumferential direction, thereby preventing the nut 130 from rotating circumferentially on the screw rod 120.

[0055] In some embodiments, when the first anti-rotation portion 211 and the second anti-rotation portion 131 are in abutment, the first anti-rotation portion 211 and the second anti-rotation portion 131 are in point contact or line contact.

[0056] It can be understood that when the screw rod 120 drives the nut 130 to make a linear motion along the axial direction of the screw rod 120, the front end cover 200 of the motor limits the circumferential rotation of the nut 130 by the abutment of the first stop part 211 against the second stop part 131 on the nut 130. Therefore, in the process of the nut 130 making a linear motion along the axial direction of the screw rod 120, a friction force will inevitably be generated between the first stop part 211 and the second stop part 131. The friction force will affect the efficiency of the linear motion of the nut 130, making it necessary to provide a greater thrust to the nut 130 to overcome the friction force, which also increases the working requirements for the motor rotor 110 to a certain extent. This embodiment optimizes the first stop portion 211 and the second stop portion 131 so that the first stop portion 211 and the second stop portion 131 can achieve point contact or line contact in the abutment state, which can better reduce the friction between the first stop portion 211 and the second stop portion 131 and facilitate the movement of the nut 130 in the center through hole 210.

[0057] More specifically, Figure 3 As shown, for example, when the first anti-rotation portion 211 includes an abutment groove and the second anti-rotation portion 131 includes an abutment block, the side walls of the abutment groove and / or the abutment block in the circumferential direction of the nut 130 are arc-shaped, which can better achieve point contact or line contact between the first anti-rotation portion 211 and the second anti-rotation portion 131; Figure 4 As shown, for example, when the first stop portion 211 includes a first abutting surface 310 and the second stop portion 131 includes a second abutting surface 320, the first abutting surface 310 and / or the second abutting surface 320 are arc-shaped, which can better achieve point contact or line contact between the first stop portion 211 and the second stop portion 131.

[0058] In particular, in order to achieve point contact between the first stop part 211 and the second stop part 131, balls (not shown in the figure) can also be provided on the first stop part 211 and / or the second stop part 131, so that point contact between the first stop part 211 and the second stop part 131 can be achieved, and rolling friction between the first stop part 211 and the second stop part 131 can also be achieved, thereby preferably reducing friction.

[0059] In short, the above is only a preferred embodiment of the present utility model, and all equivalent changes and modifications made according to the scope of the patent application of the present utility model should fall within the scope of the present utility model patent.

Claims

1. A ball screw anti-rotation structure, characterized in that: It includes a first clamping portion arranged on the front end cover of the motor, and a second clamping portion arranged on the motor housing; The first clamping portion and the second clamping portion can be clamped together to achieve the limitation of the motor front end cover by the motor housing in the circumferential direction thereof.

2. The ball screw anti-rotation structure according to claim 1, characterized in that: The motor housing is in the shape of a cylinder with one end open; the first clamping portion is arranged at the circumferential side wall of the front end cover of the motor; and the second clamping portion is arranged at the opening of the motor housing.

3. The ball screw anti-rotation structure according to claim 2, characterized in that: An annular mounting platform is provided on the inner side wall of the opening of the motor housing, and the second clamping portion is provided on the mounting platform.

4. The ball screw anti-rotation structure according to claim 1, characterized in that: The first clamping portion includes a protrusion and / or a groove.

5. The ball screw anti-rotation structure according to claim 4, characterized in that: When the motor front end cover and the motor housing are in an installed state, the first clamping portion and the second clamping portion are interference-fitted.

6. The ball screw anti-rotation structure according to any one of claims 1 to 5, characterized in that: The front end cover of the motor is in the shape of a ring with a central through hole; the motor housing is provided with a motor rotor, a screw rod and a screw nut; The motor rotor is rotatably disposed in the motor housing; The screw rod is coaxially arranged with the central through hole, and one end of the screw rod is connected to the motor rotor; The nut is sleeved on the screw rod; The motor rotor can drive the screw rod to rotate so as to drive the nut to reciprocate along the axial direction of the screw rod.

7. The ball screw anti-rotation structure according to claim 6, characterized in that: The central through hole is provided with a first anti-rotation portion, and the nut is provided with a second anti-rotation portion; The first anti-rotation portion can abut against the second anti-rotation portion to limit the nut in its circumferential direction.

8. The ball screw anti-rotation structure according to claim 7, characterized in that: The first anti-rotation portion includes an abutment groove and / or an abutment block.

9. The ball screw anti-rotation structure according to claim 7, characterized in that: The first anti-rotation portion includes an abutment surface.

10. The ball screw anti-rotation structure according to any one of claims 7 to 9, characterized in that: When the first anti-rotation portion and the second anti-rotation portion are in abutment, the first anti-rotation portion and the second anti-rotation portion are in point contact or line contact.

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