Brake caliper

Abstract

The present invention discloses a brake caliper including an actuator, a brake caliper body, a motion conversion mechanism, and an adjustment member disposed in the flow of axial force transmission between the actuator and a brake disc. The adjustment member is operably connected to a counter member so that the motion conversion mechanism has degrees of freedom for adjustment in terms of rotation angle and radial displacement. The brake caliper of the present invention includes the adjustment member, which provides the motion conversion mechanism with adjustment space for rotation angle and radial displacement, thereby eliminating the effects of braking tangential force, brake pad wear, and caliper body deformation on the motion conversion mechanism. This makes it possible to extend the service life of the motion conversion mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field of braking systems. Specifically, the present invention relates to a brake caliper.

Background Art

[0002] With the electrification shift of vehicles, the brake-by-wire system is becoming a major growth trend in the automotive industry. One of them, the electromechanical brake (EMB) system, adopts a direct drive form by a wheel-side motor. In this system, a motion conversion mechanism converts the torque and rotational motion of the motor into the pressing force and linear motion of the connecting member, and pushes the brake pad to clamp the brake disc, thereby obtaining braking force. This system has advantages such as simplicity of arrangement, quick response, and high efficiency.

[0003] In the prior art, the EMB system has not yet been widely used in vehicles. This is due to the following reasons. First, the motion conversion mechanism that meets the usage requirements is costly and has a complex structure, so it is not suitable for mass production (for example, planetary roller screws, tilting mechanisms, etc.). Also, the motion conversion mechanism that meets the requirements of cost and production process cannot adapt to the complex operating conditions of the service brake and has insufficient service life (for example, structures such as ball screws and sliding screws). For example, in the case of a ball screw, in order to meet the requirements of braking capacity, usually, the outer diameter of the ball screw is designed to be very large to resist the axial force. However, even then, the ball screw is likely to lose its function in the service brake system. The reasons are as follows.

[0004] 1. Ball screws are subjected not only to axial forces during braking, but also to radial forces. This is one of the causes of ball screw failure. In a vehicle's braking system, the brake disc rotates with the wheel. Therefore, during braking, the brake pads are also subjected to tangential forces from the brake disc. This force is transmitted to the ball screw, which is equivalent to applying a radial force to the ball screw. When a radial force is applied to the output end of a ball screw, a moment is generated that tilts the ball screw around one of its points. This moment is called the inversion moment. The inversion moment causes a misalignment between the nut and the screw shaft axis. As a result, the force is applied to only a few balls, leading to ball crushing or permanent deformation of the screw groove.

[0005] 2. Due to the structure of the floating caliper, the caliper body may deform due to the reaction force of the braking clamping force, causing a tilt in the axis of the cylinder bore in the caliper body. Normally, the operating axis of the screw shaft also tilts along with the deformation of the caliper body, but the axis of the nut tends to remain perpendicular to the plane of the brake pad or brake disc. This causes a misalignment between the operating axis of the screw shaft and the nut. This misalignment results in an uneven axial load distribution in the cross-section of the ball screw, and as a result of the uneven Hertz contact stress acting on the ball, it also leads to a loss of function of the ball screw.

[0006] Patent Document 1 proposes a solution to the above problem by forming an arch-shaped connecting surface between the piston and the nut, creating a contact form similar to an arc surface, thereby compensating for the misalignment between the piston axis and the ball screw axis. However, Patent Document 1 has the problem that it only considers the deformation of the caliper body and does not consider the effect of brake pad wear. The tangential force generated during braking also deforms the caliper body relative to the frame. The result of such deformation appears as a difference in the amount of wear at the entry and exit ends of the brake pad, and is called the brake pad wear phenomenon. This condition also causes a misalignment between the piston axis and the ball screw axis. Since the direction of this misalignment is perpendicular to the direction of misalignment caused by the deformation of the caliper body, it is not possible to adjust or compensate for it with the structure of Patent Document 1.

[0007] Patent Document 2 proposes a structure that forms conical contacts between the screw shaft and the flange, and between the nut and the piston, to address the above-mentioned problems. In this case as well, the misalignment between the piston axis and the ball screw axis can be adjusted and compensated for. However, in Patent Document 2, the diameter of the ball screw must be increased in order to meet the load capacity requirements. Consequently, the diameter of the conical surface also increases, which leads to an increase in the length of the moment arm of the overturning moment, resulting in a problem where the supported overturning moment also increases.

[0008] Next, there are considerable limitations on the space available in a vehicle for arranging brake calipers. The front wheels have a drive system, and the drive shaft swings from side to side when changing direction, as well as up and down when passing over dips. Therefore, it is considered desirable for brake calipers to have a low axial height and a compact structure. Patent document 3 uses a hollow ball screw, and by arranging planetary gears inside the screw shaft and coaxially arranging the motor and cylinder bore, the structure is made very compact. However, the axial size is still large, and it does not completely solve the above-mentioned problems regarding the arrangement of the EMB.

[0009] Therefore, the challenge lies in how to guarantee the fatigue life of the motion conversion mechanism under various operating conditions such as tipping moment, caliper body deformation, and brake pad wear, while also reducing the axial height of the brake caliper.

[0010] In summary, the challenges inherent in conventional brake calipers are as follows:

[0011] 1. The overturning moment caused by the tangential force of the brakes, deformation of the caliper body, and wear of the brake pads can cause the forces acting on the motion conversion mechanism to become excessively large or excessively uneven, leading to an excessively premature loss of function.

[0012] 2. When using a conical contact structure, as the diameter of the ball screw increases, the diameter of the conical surface also increases, resulting in an increase in the radius of the friction torque and thus an increase in the overturning moment being supported.

[0013] 3. Due to space limitations for mounting brake calipers in vehicles, it is generally considered desirable to have a smaller axial height, but currently there is no effective method to achieve this. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] Chinese Patent Application Publication No. 107076237 Specification [Patent Document 2] U.S. Patent No. 8607939 [Patent Document 3] U.S. Patent Application Publication No. 20050034936 [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] The present invention aims to solve at least one of the technical problems that exist in the prior art. Therefore, the present invention provides a brake caliper that aims to extend the service life of the motion conversion mechanism. [Means for solving the problem]

[0016] To achieve the above objectives, the technical means used in this invention are as follows.

[0017] The brake caliper includes an actuator, a brake caliper body, a motion conversion mechanism, and an adjustment member positioned in the flow of axial force transmission between the actuator and the brake disc. The adjustment member is operably connected to a paired member such that the motion conversion mechanism has a degree of freedom of adjustment with respect to rotational angle and / or radial displacement.

[0018] In some embodiments, the adjusting member forms a spherical pair, a conical pair, a planar pair, or a combination of two of these with an adjacent paired member.

[0019] In some embodiments, the adjustment member is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends. The spherical surfaces at both ends of the adjustment member contact adjacent paired members, respectively, to form a two-spherical paired mechanism.

[0020] In some embodiments, the intermediate portion of the adjustment member is divided into at least two engaging portions with different cross-sectional sizes. The adjacent pair members engage with the two engaging portions of the intermediate portion, and the adjacent pair members rotate synchronously.

[0021] In some embodiments, the brake caliper further includes a shaft coupling. The actuator is connected to the motion conversion mechanism via the shaft coupling.

[0022] In some embodiments, the motion conversion mechanism includes a translation member and a rotating member. The rotating member is connected to the shaft coupling. The adjusting member is disposed between the shaft coupling and the rotating member. The adjusting member forms a spherical pair mechanism with the shaft coupling and the rotating member respectively.

[0023] In some embodiments, the engaging portion has a non-cylindrical structure. The shaft coupling and the rotating member are connected via the adjusting member to achieve synchronous rotation.

[0024] In some embodiments, the engaging portion has a spline or flat rectangular structure.

[0025] In some embodiments, the engaging portion has a cylindrical structure. The shaft coupling and the rotating member are connected by a spline or flat rectangular structure to achieve synchronous rotation.

[0026] In some embodiments, the brake caliper further includes a piston. The motion conversion mechanism includes a translation member and a rotating member. The adjusting member is disposed between the translation member and the piston. The adjusting member forms a spherical pair mechanism with the piston and the translation member respectively.

[0027] In some embodiments, a fixed connection is formed between the shaft coupling and the rotating member by means of a screw, riveting or welding. An operable connection is formed between the translation member and the piston by means of a retaining ring.

[0028] In some embodiments, the piston has a cavity. The cavity completely accommodates the motion conversion mechanism. The outer wall of the piston engages with the cylinder hole of the brake caliper body.

[0029] In some embodiments, the piston has a cavity. The cavity completely accommodates a part of the motion conversion mechanism. The outer wall of the translation member engages with the cylinder hole of the brake caliper body.

[0030] In some embodiments, a radial spring is installed between the translation member and the piston.

[0031] In some embodiments, the engaging portion has a non-cylindrical structure. The translation member and the piston are connected via the adjustment member to achieve synchronous movement in the axial direction.

[0032] In some embodiments, the engaging portion has a spline or a flattened rectangular structure.

[0033] In some embodiments, a rotation prevention mechanism is provided between the parallel-moving member and the brake caliper body, or between the piston and the brake caliper body.

[0034] In some embodiments, an elastic ring and a dust cover are installed between the parallel moving member and the cylinder bore of the brake caliper body, or between the piston and the cylinder bore of the brake caliper body.

[0035] In some embodiments, the brake caliper further includes a bearing. The bearing and the two spherical pair mechanism are located inside the translation member or the piston.

[0036] In some embodiments, a mutually compatible position regulating mechanism is provided between the rotating member and the parallel moving member. [Effects of the Invention]

[0037] The brake caliper of the present invention is equipped with an adjustment member that provides adjustment space for rotation angle and radial displacement in the motion conversion mechanism, thereby eliminating the influence of braking tangential force, brake pad wear, and caliper body deformation on the motion conversion mechanism. This makes it possible to extend the service life of the motion conversion mechanism. [Brief explanation of the drawing]

[0038] [Figure 1] Figure 1 is a schematic diagram of the overall structure of the brake caliper in Example 1. [Figure 2] Figure 2 is a schematic diagram showing how forces are applied when the caliper body deforms or when the brake pads wear down in Example 1. [Figure 3] Figure 3 is a schematic diagram showing how forces are applied when subjected to radial forces in Example 1. [Figure 4] Figure 4 is a schematic diagram of the two-spherical pair mechanism in Example 2. [Figure 5] Figure 5 is a schematic diagram of the overall structure of the brake caliper in Example 3. [Figure 6] Figure 6 is a schematic diagram of the two-spherical pair mechanism in Example 4. [Figure 7] Figure 7 is a schematic diagram of the adjustment member in Examples 1 and 3. [Figure 8] Figure 8 is a schematic diagram of the adjustment member in Examples 2 and 4. [Modes for carrying out the invention]

[0039] Next, specific embodiments of the present invention will be described in more detail by referring to the drawings and describing examples. This is intended to help those skilled in the art to understand the concept and technical means of the present invention more completely, accurately, and deeply, and to facilitate their implementation.

[0040] Below, we will discuss the two-sphere pair mechanism as an example. As shown in Figures 1 to 5, the present invention mainly provides a brake caliper comprising a brake caliper body 3, an actuator 1, an inner brake pad 16, an outer brake pad 18, and a motion conversion mechanism 4. The actuator 1 includes at least a motor and a reduction / torque amplification mechanism. The motion conversion mechanism 4 is located in the cylinder bore of the brake caliper body 3. Torque and rotational motion supplied from the motor are transmitted to the motion conversion mechanism 4 through the reduction / torque amplification mechanism, where they are converted into pressing force and linear motion of a translation member 4b, which pushes the brake pads and clamps the brake disc 17. An adjustment member 8 is located in the flow of axial force transmission between the actuator 1 and the brake disc 17. Furthermore, the adjustment member 8 and its surrounding paired members constitute a two-spherical paired mechanism.

[0041] The brake caliper provided by the present invention has the following advantages:

[0042] 1.2 By using a spherical pair mechanism, the effects of tipping moment, brake pad wear, caliper body deformation, etc. on the motion conversion mechanism 4 can be eliminated, thereby extending the service life of the motion conversion mechanism 4.

[0043] In this invention, an egg-shaped adjustment member 8 is used. Both ends of the adjustment member 8 are spherical. The intermediate portion of the adjustment member 8 is cylindrical or has a structure capable of realizing other functions (for example, a polyhedron, a flattened rectangle, a spline, etc., capable of transmitting torque). The adjustment member 8 is positioned in the flow of axial force transmission between the actuator 1 and the brake disc 17. Furthermore, the adjustment member 8 forms spherical pairs with adjacent pair members, thereby constituting a two-spherical pair mechanism. Compared to a single-spherical pair mechanism, the two-spherical pair mechanism in this invention has the characteristic of having not only a degree of freedom in rotation angle but also a degree of freedom in radial displacement.

[0044] To illustrate the case where the motion conversion mechanism is a ball screw pair, in the present invention, the adjustment member 8 can be positioned between the shaft coupling 2 and the screw shaft. The parts of the shaft coupling 2 and the screw shaft that come into contact with the adjustment member 8 are both spherical. Therefore, both the adjustment member 8 and the shaft coupling 2, and the adjustment member 8 and the screw shaft, constitute a spherical pair.

[0045] (1) Method to eliminate the effect of overturning moment: In conventional technology, when a ball screw pair is subjected to a superposition load of axial force and radial force, an overturning moment is generated that causes it to rotate around one of the points. This causes a misalignment between the screw shaft and the nut axis, resulting in the gap between the inner and outer screw threads and screw grooves not matching, and as a result the force is applied to only some of the balls, it leads to loss of function.

[0046] In this invention, when a radial force from the ball screw, caused by the braking tangential force, acts on the parallel movement member 4b, the ball screw pair has a degree of freedom of radial displacement due to the action of the adjustment member 8 and the shaft coupling 2, and the adjustment member 8 and the position regulating mechanism 4c. As a result, the entire ball screw pair moves to the other side of the cylinder bore of the caliper body. This causes the adjustment member 8 to tilt by a certain angle while the axis of the shaft coupling 2 remains unchanged, but torque transmission is still possible. In addition, a relative horizontal displacement occurs between the axis of the ball screw pair and the axis of the shaft coupling 2. When the outer wall of the parallel movement member 4b comes into contact with the inner wall of the cylinder bore, the radial force is transmitted to the caliper body and converted into deformation of the caliper body. However, during this process, the axes of the rotating member 4a and the parallel movement member 4b always remain aligned, and the axial and radial load distribution of the ball screw pair becomes uniform, so no loss of function occurs.

[0047] (2) Method for eliminating the effects of brake pad wear: In conventional technology, the axis of the screw shaft generally remains aligned with the axis of the cylinder bore in the caliper body, while the axis of the nut tends to remain perpendicular to the plane of the brake pad. Therefore, when the brake pads wear down, and the amount of wear on one side is greater than the amount of wear on the other side, the axis of the nut tilts, causing a misalignment between the axis of the nut and the axis of the screw shaft. This results in an uneven axial load distribution in the cross-section of the ball screw pair, leading to loss of function.

[0048] In this invention, the shaft coupling 2 receives rotational speed and torque transmitted from the actuator 1. The axis of the shaft coupling 2 always coincides with the axis of the cylinder bore in the brake caliper body 3. The shaft coupling 2 transmits rotational speed and torque to the rotating member 4a through the adjustment member 8. Due to the adjustment function of the two spherical pair mechanism, the axis of the rotating member 4a or the translation member 4b can have a constant inclination angle. Furthermore, if the translation member 4b tilts due to wear of the brake pads, the rotating member 4a can also tilt in conjunction with the translation member 4b. In addition, the angle that the adjustment member 8 can tilt is greater than the inclination angle of the translation member 4b caused by wear of the brake pads. Therefore, the axis of the rotating member 4a can always tilt in conjunction with the axis of the translation member 4b, and the torque transmission function from the shaft coupling 2 to the rotating member 4a is not affected. As a result, the axial load distribution of the ball screw pair becomes uniform, and no loss of function occurs.

[0049] (3) Method to eliminate the effects of caliper body deformation: In the conventional technology, when the nut acts as an output member to push the inner brake pad, the reaction force of the axial force is transmitted to the caliper body, causing the caliper body to deform. The axis of the nut tends to remain perpendicular to the plane of the brake pad, but the axis of the rotating member 4a tilts due to the deformation of the caliper body, resulting in a misalignment between the axis of the nut and the axis of the rotating member 4a. As a result, the axial load distribution in the cross-section of the ball screw pair becomes uneven, leading to loss of function.

[0050] In this invention, when the axis of the shaft coupling 2 tilts due to deformation of the caliper body, the adjustment member 8 tilts by a certain angle first, but the rotating member 4a does not tilt along with the shaft coupling 2 and tends to maintain its alignment with the axis of the parallel moving member 4b. Furthermore, the angle by which the adjustment member 8 can tilt is greater than the tilt angle of the shaft coupling 2 caused by the deformation of the brake caliper body 3. Therefore, the axis of the rotating member 4a can always tilt in conjunction with the axis of the parallel moving member 4b. As a result, the axial load distribution of the ball screw pair becomes uniform, and no loss of function occurs.

[0051] 2. The radius of the spherical pair is small, and the deflection radius is reduced, resulting in a smaller overturning moment.

[0052] In this invention, since a spherical pair is constructed with a single adjusting member 8 and a pair member, it is possible to make the radius of the spherical pair very small regardless of the diameter size of the ball screw. As a result, the deflection radius when subjected to radial force is reduced, and the overturning moment can be reduced.

[0053] 3. By arranging each component in an overlapping manner along the axial direction, the axial length is reduced to avoid occupying unnecessary space.

[0054] In this invention, the ball screw pair has a hollow structure, and components such as the adjustment member 8 and bearings are arranged inside the cavity of the rotating member 4a. This eliminates the need to occupy extra axial space, making it possible to minimize the axial length of the brake caliper.

[0055] In summary, the present invention incorporates a two-spherical pair mechanism within the axial force transmission flow by arranging an adjustment member 8 in the brake caliper. This allows the motion conversion mechanism 4 to have a degree of freedom to adjust the rotation angle and radial displacement, so that during operation, the axes of the rotating member 4a and the parallel moving member 4b of the motion conversion mechanism 4 tend to always overlap. As a result, a uniform distribution of axial and radial loads is guaranteed, preventing loss of function due to force being applied to some balls, and extending the service life of the motion conversion mechanism 4. Furthermore, since the spherical radius of the adjustment member 8 can be designed to be sufficiently small, the deflection radius and overturning moment are reduced. In addition, by arranging each component inside a hollow screw, the axial height of the brake caliper is reduced. This allows the brake caliper of the present invention to withstand the influence of various factors in the operation of the service brake, thus guaranteeing the service life of the motion conversion mechanism 4. Furthermore, the reduced axial height of the brake caliper makes it easier to mount on the vehicle.

[0056] Next, we will explain by combining specific examples. [Examples]

[0057] As shown in Figures 1 to 3, the brake caliper of this embodiment includes a brake caliper body 3, an actuator 1, a motion conversion mechanism 4, and an adjustment member 8.

[0058] The brake caliper body 3 has a floating caliper structure and includes a cylinder bore and a hook structure. Inside the hook structure, an inner brake pad 16, a brake disc 17, and an outer brake pad 18 are mounted in order. The actuator 1 includes a motor and a reduction / torque amplification mechanism.

[0059] As shown in Figures 1 to 3, the motion conversion mechanism 4 includes a rotating member 4a and a translation member 4b. In this embodiment, the motion conversion mechanism 4 is an internally circulating ball screw. The rotating member 4a is a screw shaft, and the translation member 4b is a nut, and the translation member 4b and the rotating member 4a constitute a ball screw pair. In addition, the actuator 1 and the rotating member 4a are connected via a shaft coupling 2 to transmit torque and rotational speed. A second bearing 10 is installed between the shaft coupling 2 and the brake caliper body 3. The second bearing 10 is a sliding bearing.

[0060] As shown in Figures 1 to 3, the adjustment member 8 has an egg-shaped structure. Furthermore, the end faces at both ends of the adjustment member 8 are spherical. The adjustment member 8 is positioned within the flow of axial force transmission between the actuator 1 and the brake disc 17. The adjustment member 8, through its spherical ends, forms a two-spherical pair mechanism together with the paired member. In this embodiment, the paired members are the shaft coupling 2 and the rotating member 4a. The adjustment member 8 provides the ball screw pair with degrees of freedom in the rotation angle around the spherical core of the spherical end face of the adjustment member 8 and degrees of freedom in the radial displacement of the cylinder bore. The range within which the ball screw pair can be radially displaced relative to the shaft coupling 2 includes at least the radial displacement of the parallel moving member 4b within the cylinder bore. The angle at which the ball screw pair can tilt relative to the shaft coupling 2 or the rotating member 4a includes at least the maximum tilt angle of the shaft coupling 2 due to deformation of the brake caliper body 3 and the maximum tilt angle of the parallel moving member 4b due to wear of the brake pads.

[0061] As shown in Figures 1-3 and Figure 7, the adjustment member 8 is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends in the longitudinal direction. The spherical surfaces at both ends of the adjustment member 8 contact adjacent paired members, respectively, to form a two-spherical paired mechanism. Relative deflection may occur between the adjustment member 8 and the paired members. The intermediate portion of the adjustment member 8 is divided into at least two engaging parts with different cross-sectional sizes. All engaging parts are arranged sequentially along the longitudinal direction of the intermediate portion. Adjacent paired members engage with the two engaging parts of the intermediate portion, respectively. Also, adjacent paired members rotate synchronously.

[0062] The intermediate portion of the adjustment member 8 may be a structure capable of transmitting torque, such as a polyhedron, spline, or flattened rectangle. The adjustment member 8 has the function of transmitting torque between the shaft coupling 2 and the rotating member 4a. The shaft coupling 2 makes the rotating member 4a rotatable through the adjustment member 8. In this embodiment, as shown in Figure 7, the engagement portion of the intermediate portion of the adjustment member 8 is a hexahedron. Two engagement portions are provided, and the two engagement portions are of different sizes. The centers of the engagement portions and the spherical cores of both end faces of the adjustment member 8 are located on the axis of the adjustment member 8. Inside the shaft coupling 2, there is a first recessed groove that accommodates the spherical end face of one end of the adjustment member 8, and a first internal hole that accommodates one of the engagement portions. The first internal hole is a hexagonal hole with the same shape as the engagement portion. A small gap exists between the inner wall surface of the first internal hole and the outer wall surface of the engagement portion. The rotating member 4a is provided with a second groove for accommodating the spherical end face of the other end of the adjusting member 8, and a second inner hole for accommodating the other engaging portion. A small gap exists between the inner wall surface of the second inner hole and the outer wall surface of the engaging portion. The second inner hole is a hexagonal hole, the same shape as the engaging portion. The first and second grooves are spherical grooves. The size of the engaging portion that engages with the rotating member 4a is larger than the size of the engaging portion that engages with the shaft coupling 2. A corrugated spring 9 is installed between the adjusting member 8 and the rotating member 4a. The corrugated spring 9 is located in the second inner hole. The corrugated spring 9 is sandwiched between the engaging portion that engages with the rotating member 4a and the inner wall surface of the second inner hole. The corrugated spring 9 applies an axial elastic force to the rotating member 4a, biasing the rotating member 4a to move axially toward a position away from the shaft coupling 2. As a result, the corrugated spring 9 eliminates the axial gap between the shaft coupling 2 and the adjustment member 8, and also maintains the adjustment member 8 in its restored state when no force is being applied. The interior of the rotating member 4a has a rectangular groove and a spherical surface. An annular groove is provided in the side wall, and a retaining ring 11 is fitted inside the annular groove. The retaining ring 11 achieves relative axial fixing between the shaft coupling 2 and the rotating member 4a. The retaining ring 11 fixes the rotating member 4a and the shaft coupling 2 so that they are movably connected.

[0063] As shown in Figure 1, the brake caliper of this embodiment further includes an anti-rotation mechanism. The anti-rotation mechanism is provided between the translation member 4b and the brake caliper body 3. The anti-rotation mechanism includes an anti-rotation screw 7 and a groove. The anti-rotation screw 7 is provided in the brake caliper body 3. The groove is provided on the outer wall of the translation member 4b and extends in the axial direction of the translation member 4b. The anti-rotation screw 7 is inserted into the groove to prevent the translation member 4b from rotating in conjunction with the rotating member 4a. This makes it possible to move the translation member 4b linearly in the axial direction when the rotating member 4a rotates.

[0064] As shown in Figure 1, a mutually compatible position regulating mechanism 4c is provided between the rotating member 4a and the translation member 4b. The position regulating mechanism 4c is used to prevent the translation member 4b from getting stuck due to excessive rotation of the rotating member 4a.

[0065] As shown in Figure 1, the brake caliper of this embodiment further includes a first bearing 5. The first bearing 5 is a thrust needle bearing. The rotating member 4a has an open end and a sealed end, and is hollow inside. Since both the first bearing 5 and the two spherical pair mechanism are located in the internal cavity of the rotating member 4a, the axial size of the caliper can be reduced.

[0066] As shown in Figure 1, an elastic ring 12 and a dust cover 13 are installed between the parallel movement member 4b and the cylinder bore of the brake caliper body 3 for sealing. The elastic ring 12 and the dust cover 13 are arranged sequentially along the axial direction of the cylinder bore. Furthermore, the inner circumferences of the elastic ring 12 and the dust cover 13 and the outer wall of the parallel movement member 4b are both in an interlocking fit. In addition, since the elastic ring 12 and the dust cover 13 provide two support points to the parallel movement member 4b, the parallel movement member 4b can maintain a coaxial state with the cylinder bore during rotation and rotation. [Examples]

[0067] As shown in Figures 4 and 8, the structure of the brake caliper provided in this embodiment differs from the structure of the brake caliper provided in Embodiment 1 in the following respects. Specifically, in this embodiment, the intermediate portion of the adjustment member 8 has a cylindrical structure, and the engaging portion is a cylindrical body. The adjustment member 8 does not have the function of transmitting torque between the shaft coupling 2 and the rotating member 4a. Synchronous rotation of the shaft coupling 2 and the rotating member 4a is achieved by connecting the end of the shaft coupling 2 and the rotating member 4a with a torque-transmitting structure such as a spline or a square-shaped structure.

[0068] Compared to Example 1, the brake caliper provided in this embodiment has the advantage of reducing the overall backlash and thus the risk of generating operating noise, as the adjustment member 8 is removed from the torque transmission path and the engagement size is reduced by one set. [Examples]

[0069] As shown in Figure 5, the structure of the brake caliper provided in this embodiment differs from the structure of the brake caliper provided in Embodiment 1 in the following respects. Specifically, the brake caliper provided in this embodiment further includes a piston 6. The piston 6 completely houses the ball screw pair. The outer wall of the piston 6 engages with the inner wall of the cylinder bore.

[0070] As shown in Figure 5, the brake caliper of this embodiment includes a brake caliper body 3, an actuator 1, a piston 6, a motion conversion mechanism 4, and an adjustment member 8.

[0071] The brake caliper body 3 has a floating caliper structure and includes a cylinder bore and a hook structure. An inner brake pad 16, a brake disc 17, and an outer brake pad 18 are mounted in order within the hook structure. The actuator 1 includes a motor and a reduction / torque amplification mechanism. The structures of the brake caliper body 3 and actuator 1 are similar to those known to those skilled in the art and are therefore not described in detail here.

[0072] As shown in Figure 5, the motion conversion mechanism 4 includes a rotating member 4a and a translation member 4b. In this embodiment, the motion conversion mechanism 4 is an internally circulating ball screw. The rotating member 4a is a screw shaft, and the translation member 4b is a nut, and the translation member 4b and the rotating member 4a constitute a ball screw pair. In addition, the actuator 1 and the rotating member 4a are connected via a shaft coupling 2 to transmit torque and rotational speed. A second bearing 10 is installed between the shaft coupling 2 and the brake caliper body 3. The second bearing 10 is a sliding bearing. The piston 6 has an open end and a sealed end, and is hollow inside. The translation member 4b is located entirely within the internal cavity of the piston 6.

[0073] As shown in Figure 5, the translation member 4b is hollow inside, has an inwardly recessed bottom, and has a groove and a spherical surface in its central portion. The piston 6 is also hollow inside, has a protruding bottom, and is provided with a groove and a spherical surface. The adjustment member 8 is positioned between the translation member 4b and the piston 6. The adjustment member 8 forms spherical pairs with the translation member 4b and the piston 6, respectively, to form a two-spherical pair mechanism.

[0074] As shown in Figure 5, the adjustment member 8 has an egg-shaped structure. Furthermore, the end faces at both ends of the adjustment member 8 are spherical. The adjustment member 8 is positioned within the flow of axial force transmission between the actuator 1 and the brake disc 17. The adjustment member 8, along with its counterpart members via the spherical ends, constitutes a two-spherical counterpart mechanism. In this embodiment, the counterpart members are the parallel movement member 4b and the piston 6.

[0075] The adjustment member 8 provides the piston 6 and the ball screw pair with degrees of freedom in the rotation angle of the spherical end face of the adjustment member 8 around the spherical core, and degrees of freedom in the radial displacement of the cylinder bore. Furthermore, the range in which the piston 6 can be displaced radially relative to the ball screw pair includes at least the amount of radial displacement of the piston 6 within the cylinder bore. In addition, the angle in which the piston 6 can be tilted relative to the ball screw pair includes at least the maximum tilt angle of the shaft coupling 2 due to deformation of the brake caliper body 3 and the maximum tilt angle of the parallel movement member 4b due to wear of the brake pads.

[0076] As shown in Figures 5 and 7, the adjustment member 8 is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends in the longitudinal direction. The spherical surfaces at both ends of the adjustment member 8 contact adjacent paired members, respectively, to form a two-spherical paired mechanism. Relative deflection may occur between the adjustment member 8 and the paired members. The intermediate portion of the adjustment member 8 is divided into at least two engaging parts with different cross-sectional sizes. All engaging parts are arranged sequentially along the longitudinal direction of the intermediate portion. Adjacent paired members engage with the two engaging parts of the intermediate portion, respectively. Also, adjacent paired members rotate synchronously.

[0077] The intermediate portion of the adjustment member 8 may have a structure capable of transmitting torque, such as a polyhedron, spline, or flattened square. BookIn this embodiment, as shown in Figure 7, the engagement portion in the middle part of the adjustment member 8 is hexahedron-shaped. Two engagement portions are provided, and the two engagement portions are of different sizes. The centers of the engagement portions and the spherical cores of both end faces of the adjustment member 8 are located on the axis of the adjustment member 8. Inside the translation member 4b, there is a first groove that accommodates the spherical end face of one end of the adjustment member 8, and a first inner hole that accommodates one of the engagement portions. The first inner hole is a hexagonal hole with the same shape as the engagement portion. A small gap exists between the inner wall surface of the first inner hole and the outer wall surface of the engagement portion. Inside the piston 6, there is a second groove that accommodates the spherical end face of the other end of the adjustment member 8, and a second inner hole that accommodates the other engagement portion. A small gap exists between the inner wall surface of the second inner hole and the outer wall surface of the engagement portion. The second inner hole is a hexagonal hole with the same shape as the engagement portion. The first and second grooves are spherical grooves. The size of the engagement portion that engages with the translation member 4b is larger than the size of the engagement portion that engages with the piston 6. A corrugated spring 9 is installed between the adjustment member 8 and the translation member 4b. The corrugated spring 9 is located in the first inner bore. The corrugated spring 9 is sandwiched between the engagement portion that engages with the translation member 4b and the inner wall surface of the first inner bore. The corrugated spring 9 applies an axial elastic force to the translation member 4b, thereby biasing the translation member 4b to move axially toward a position closer to the shaft coupling 2. As a result, the corrugated spring 9 eliminates the axial gap between the shaft coupling 2 and the adjustment member 8, and also allows the adjustment member 8 to be maintained in its restored state when no force is being applied. The interior of the translation member 4b has a rectangular groove and a spherical surface. An annular groove is provided in the side wall of the translation member 4b, and a retaining ring 11 is installed in the annular groove. The translation member 4b is connected to the piston 6 via the retaining ring 11. The retaining ring 11 secures the piston 6 and the translation member 4b in the axial direction relative to each other. The retaining ring 11 fixes the translation member 4b and the piston 6 so that they are movably connected.

[0078] As shown in Figure 5, the brake caliper of this embodiment further includes an anti-rotation mechanism. The anti-rotation mechanism is provided between the piston 6 and the brake caliper body 3. The anti-rotation mechanism includes an anti-rotation screw 7 and a groove. The anti-rotation screw 7 is provided on the brake caliper body 3. The groove is provided on the outer wall of the piston 6. The groove also extends in the axial direction of the piston 6. The anti-rotation screw 7 is inserted into the groove to prevent the piston 6 and the translation member 4b from rotating in conjunction with the rotating member 4a. This makes it possible to move the translation member 4b and the piston 6 linearly in the axial direction when the rotating member 4a rotates.

[0079] As shown in Figure 5, the brake caliper of this embodiment further includes a first bearing 5. The first bearing 5 is a thrust needle bearing. The rotating member 4a has an open end and a sealed end, and is hollow inside. Since both the first bearing 5 and the two spherical pair mechanism are located in the internal cavity of the rotating member 4a, the axial size of the caliper can be reduced.

[0080] As shown in Figure 5, an elastic ring 12 and a dust cover 13 are installed between the piston 6 and the cylinder bore of the brake caliper body 3 for sealing. The elastic ring 12 and the dust cover 13 are arranged sequentially along the axial direction of the cylinder bore. Furthermore, the inner circumferences of the elastic ring 12 and the dust cover 13 are in an interference fit with the outer wall of the piston 6. In addition, since the elastic ring 12 and the dust cover 13 provide two support points to the piston 6, the piston 6 can maintain a coaxial state with the cylinder bore during retraction and retraction.

[0081] As shown in Figure 5, the shaft coupling 2 and the rotating member 4a are fixedly connected by means of screws, welding, or other methods. In addition, a movable connection is formed between the parallel moving member 4b and the piston 6 by providing a retaining ring 11. The intermediate portion of the adjustment member 8 is designed to be non-circular in order to prevent the piston 6 from rotating relative to the parallel moving member 4b. [Examples]

[0082] As shown in Figures 6 and 8, the structure of the brake caliper provided in this embodiment differs from the structure of the brake caliper provided in Embodiment 3 in the following respects. Specifically, in this embodiment, the piston 6 accommodates only a portion of the ball screw pair. Part of the translation member 4b is located inside the internal cavity of the piston 6, while another portion of the translation member 4b is located outside the piston 6. In addition, the groove for the anti-rotation mechanism is provided on the outer wall of the translation member 4b. The outer wall of the translation member 4b engages with the inner wall of the cylinder bore. A radial spring 14 is provided between the piston 6 and the translation member 4b. Even if the piston 6 is subjected to a radial force and undergoes radial displacement, the normal operation of the ball screw pair is not affected by the adjustment of the two spherical pair mechanism. Furthermore, when the brake is released, the piston 6 returns to its initial position due to the restoring force of the radial spring 14.

[0083] As shown in Figure 8, in this embodiment, the intermediate portion of the adjustment member 8 has a cylindrical structure, and the engaging portion is a cylindrical body. The adjustment member 8 does not have a function of transmitting torque.

[0084] In the brake calipers of Examples 3 and 4, the position of the adjustment member 8 is mainly changed, but since the operating principle of the brake caliper is the same as that of the brake caliper of Example 1, it will not be described in detail here.

[0085] The present invention has been described illustratively above, with reference to the drawings. Needless to say, the specific implementation of the present invention is not limited to the above-described methods. Various substantive improvements made using the methods, concepts and technical means of the present invention, or direct applications of the above-described concepts and technical means of the present invention to other situations without modification, are all within the scope of the protection of the present invention. [Explanation of Symbols]

[0086] 1 Actuator 2-axis coupling 3. Brake caliper body 4. Motion conversion mechanism 4a Rotating member 4b Translation member 4c Position regulation mechanism 5. First bearing 6 pistons 7. Anti-rotation screw 8 Adjustment Member 9 Springs 10. Second bearing 11 Retaining ring 12 Elastic rings 13. Dust cover 14 Radial spring 15 screws 16 Inner brake pads 17 Brake Disc 18 Outer brake pads

Claims

1. A brake caliper including an actuator, a brake caliper body, and a motion conversion mechanism, Furthermore, it includes an adjustment member positioned in the flow of axial force transmission between the actuator and the brake disc, the adjustment member being operably connected to the paired member such that the motion conversion mechanism has a degree of freedom of adjustment with respect to rotational angle and / or radial displacement. The adjustment member is composed of spherical surfaces at both ends and an intermediate portion located between the spherical surfaces at both ends, and the spherical surfaces at both ends of the adjustment member contact adjacent paired members to form a two-spherical paired mechanism. The brake caliper is characterized in that the intermediate portion of the adjustment member is divided into at least two engaging portions with different cross-sectional sizes, the adjacent pair members engage with the two engaging portions of the intermediate portion respectively, and the adjacent pair members rotate synchronously.

2. Furthermore, the brake caliper according to claim 1, further comprising a shaft coupling, wherein the actuator is connected to the motion conversion mechanism via the shaft coupling.

3. The brake caliper according to claim 2, wherein the motion conversion mechanism includes a translation member and a rotation member, the rotation member is connected to the shaft coupling, the adjustment member is positioned between the shaft coupling and the rotation member, the adjustment member and the shaft coupling and the rotation member each constitute a spherical paired mechanism, and the paired member includes the shaft coupling and the rotation member.

4. The brake caliper according to claim 3, characterized in that the engaging portion has a non-cylindrical structure, and the shaft coupling and the rotating member are connected via the adjustment member to achieve synchronous rotation.

5. The brake caliper according to claim 4, characterized in that the engaging portion has a spline or a flattened rectangular structure.

6. The brake caliper according to claim 3, characterized in that the engaging portion has a cylindrical structure, and the shaft coupling and the rotating member are connected by a spline or a flattened rectangular structure to achieve synchronous rotation.

7. Furthermore, the brake caliper according to claim 2, further comprising a piston, wherein the motion conversion mechanism comprises a translation member and a rotation member, the adjustment member is positioned between the translation member and the piston, the adjustment member constitutes a spherical pair mechanism with the piston and the translation member, and the pair member comprises the piston and the translation member.

8. The brake caliper according to claim 7, characterized in that a fixed connection is formed between the shaft coupling and the rotating member by screw, riveting, or welding, and an operable connection is formed between the parallel moving member and the piston by a retaining ring.

9. The brake caliper according to claim 8, characterized in that the piston has a cavity, the cavity completely houses the motion conversion mechanism, and the outer wall of the piston engages with a cylinder bore of the brake caliper body.

10. The brake caliper according to claim 8, characterized in that the piston has a cavity, the cavity completely houses a part of the motion conversion mechanism, and the outer wall of the translation member engages with the cylinder hole of the brake caliper body.

11. The brake caliper according to claim 10, characterized in that a radial spring is installed between the parallel moving member and the piston.

12. The brake caliper according to claim 7, characterized in that the engaging portion has a non-cylindrical structure, and the parallel moving member and the piston are connected via the adjusting member to achieve synchronous movement in the axial direction.

13. The brake caliper according to claim 12, characterized in that the engaging portion has a spline or a flattened rectangular structure.

14. The brake caliper according to claim 7, characterized in that the engaging portion has a cylindrical structure.

15. The brake caliper according to any one of claims 7 to 13, characterized in that a rotation prevention mechanism is provided between the parallel moving member and the brake caliper body, or between the piston and the brake caliper body.

16. The brake caliper according to any one of claims 7 to 13, characterized in that an elastic ring and a dust cover are installed between the parallel moving member and the cylinder bore of the brake caliper body, or between the piston and the cylinder bore of the brake caliper body.

17. Furthermore, the brake caliper according to any one of claims 7 to 13, further comprising a bearing, wherein the bearing and the two spherical pair mechanism are arranged inside the parallel moving member or the piston.

18. The brake caliper according to any one of claims 3 to 13, characterized in that a mutually compatible position regulating mechanism is provided between the rotating member and the parallel moving member.

Images