Brake assembly with split raceway

Abstract

The present disclosure relates to a brake assembly with a split raceway, comprising: a rotatable portion configured to be rotatable by an actuator; a translatable portion operably coupled with the rotatable portion and configured to be axially translatable relative to the rotatable portion to move the brake pad according to rotation of the rotatable portion; and a bearing assembly configured to support the rotatable portion. The bearing assembly includes: an inner ring including a front inner ring portion and a rear inner ring portion; an outer ring; and a rollable body. The front inner ring portion closer to the brake pad than the rear inner ring portion is made of a material different from a material of the rear inner ring portion farther away from the brake pad than the front inner ring portion and / or a material firmer than the material of the rear inner ring portion farther away from the brake pad than the front inner ring portion. And / or the rear inner ring part farther from the brake pad than the front inner ring part is smaller than the front inner ring part closer to the brake pad than the rear inner ring part.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. patent application serial number 63 / 553,577, filed on February 14, 2024, entitled "FOUR-POINTBALL BEARING STRUCTURE FOR EMB SYSYEM," which is incorporated herein by reference in its entirety. Technical Field

[0003] Various embodiments of the present disclosure relate generally to brake assemblies for vehicles and, more particularly, to brake assemblies having bearing assemblies with split type races. Background Art

[0004] An electromechanical brake (EMB) is a brake assembly actuated by electrical energy. For example, EMB systems typically provide vehicle braking using an electric motor that is selectively energized in response to a signal from an electronic control unit (ECU) or a sensed depression of a brake input device. Typically, an EMB system may include a rotor, a brake caliper, and brake pads located on opposite sides of the rotor. The caliper is slidably supported on a pin secured to an anchor bracket secured to a non-rotating component of the vehicle. The caliper includes one or more piston bores, each housing a piston that is movable along a piston axis during brake application and release. The brake pads are connected to one or more electrically powered pistons for movement between a non-braking position and a braking position, in which the pads are moved into frictional engagement with the rotor's opposing braking surface. For example, when the vehicle operator depresses the brake pedal, an actuator can move the pistons into contact with one brake pad, which then moves the brake pad into contact with one side of the rotor while the opposing brake pad moves into contact with the opposite side of the rotor.

[0005] By way of example and not limitation, such an EMB system provides required braking in a much shorter time than that provided by conventional hydraulic braking systems and allows for selective control of each individual wheel or other selectively movable component of the vehicle, thereby improving the effectiveness of many operating strategies, such as anti-skid or anti-lock braking strategies or strategies generally referred to as integrated vehicle dynamic strategies. Summary of the Invention

[0006] The features and advantages of the present disclosure will be more readily understood and apparent from the following detailed description and appended claims, which should be read in conjunction with the accompanying drawings.

[0007] According to some embodiments of the present disclosure, a brake assembly may include: a rotatable part configured to be rotated by an actuator; a translatable part operably connected to the rotatable part, the translatable part being configured to be axially translated relative to the rotatable part to move the brake pad according to the rotation of the rotatable part; and a bearing assembly configured to support the rotatable part, the bearing assembly including: an inner ring including a front inner ring portion and a rear inner ring portion; an outer ring; and a rollable body rollably arranged between the inner ring and the outer ring.

[0008] The material of the front inner race portion that is closer to the brake pad than the rear inner race portion may be different from the material of the rear inner race portion that is farther from the brake pad than the front inner race portion.

[0009] The rotatable part may have a protrusion that protrudes outward toward the bearing assembly to form a front inner race portion that is closer to the brake pad than the rear inner race portion, so that the front inner race portion of the inner race is integrally formed as a single piece on the outer side of the rotatable part, and the rear inner race portion that is farther away from the brake pad than the front inner race portion can be attached to the outer side of the rotatable part.

[0010] The shapes of the front inner race portion closer to the brake pad than the rear inner race portion and the rear inner race portion farther from the brake pad than the front inner race portion may be asymmetrical to each other.

[0011] The rear inner race portion, which is farther away from the brake pad than the front inner race portion, may be smaller than the front inner race portion, which is closer to the brake pad than the rear inner race portion.

[0012] A gap between the rollable body and the rear inner race portion farther from the brake pad than the front inner race portion may be larger than a gap between the rollable body and the front inner race portion closer to the brake pad than the rear inner race portion.

[0013] A gap between the rear inner race portion farther from the brake pad than the front inner race portion and the rollable body may be larger than a gap between the outer race and the front inner race portion closer to the brake pad than the rear inner race portion and the rollable body.

[0014] A portion of the front inner race portion closer to the brake pad than the rear inner race portion may lie in a plane passing through the center of the rollable body such that a boundary or gap between the front and rear inner race portions deviates from the plane passing through the center of the rollable body.

[0015] The weight of the rear inner race portion farther from the brake pad than the front inner race portion may be smaller than the weight of the front inner race portion closer to the brake pad than the rear inner race portion.

[0016] The strength of the rear inner race portion farther from the brake pad than the front inner race portion may be smaller than the strength of the front inner race portion closer to the brake pad than the rear inner race portion.

[0017] The inner curvature radius of the inner surface of the front inner ring portion facing the rollable body closer to the brake pad than the rear inner ring portion may be smaller than the inner curvature radius of the inner surface of the rear inner ring portion facing the rollable body farther from the brake pad than the front inner ring portion.

[0018] The center point of the inner curvature radius of the inner surface of the front inner ring portion facing the rolling body, which is closer to the brake pad than the rear inner ring portion, can deviate from the center point of the inner curvature radius of the inner surface of the rear inner ring portion facing the rolling body, which is farther away from the front inner ring portion.

[0019] An inner surface of a front inner race portion closer to the brake pad than the rear inner race portion facing the rollable body may be curved, and an inner surface of a rear inner race portion farther from the brake pad than the front inner race portion facing the rollable body may be flat.

[0020] The brake assembly may further include a retainer configured to support the rear inner race portion farther from the brake pad than the front inner race portion to restrict movement of the rear inner race portion in the axial direction of the rotatable portion.

[0021] The retainer may extend between a gear or pulley provided on the rotatable body and a side of the rear inner race portion farther from the brake pad than the front inner race portion, so that the retainer supported by the gear provided on the rotatable body supports the rear inner race portion.

[0022] The brake assembly may further include a gear or a pulley provided on the rotatable body and supporting a side of the rear inner race portion farther from the brake pad than the front inner race portion to retain the rear inner race portion in the bearing assembly.

[0023] A rear inner race portion, which is further away from the brake pad than the front inner race portion, may be press-fitted onto the rotatable body.

[0024] According to certain embodiments of the present disclosure, a brake assembly may include: a brake pad configured to move toward or away from a rotor; a nut-screw mechanism configured to move the brake pad, the nut-screw mechanism including a nut portion and a screw portion, the nut portion configured to be rotatable, the screw portion operably coupled to the nut portion and configured to be axially translated relative to the nut portion according to rotation of the nut portion to move the brake pad; and a bearing assembly configured to support the nut portion, the bearing assembly including: an inner ring including a front inner ring portion and a rear inner ring portion; an outer ring; and a rollable body rollably disposed between the inner ring and the outer ring.

[0025] The material of the front inner race portion that is closer to the brake pad than the rear inner race portion may be different from the material of the rear inner race portion that is farther from the brake pad than the front inner race portion.

[0026] The strength of the rear inner race portion farther from the brake pad than the front inner race portion may be smaller than the strength of the front inner race portion closer to the brake pad than the rear inner race portion.

[0027] The rear inner race portion, which is farther away from the brake pad than the front inner race portion, may be smaller than the front inner race portion, which is closer to the brake pad than the rear inner race portion.

[0028] The nut portion may have a protrusion that protrudes outward toward the bearing assembly to form a front inner race portion that is closer to the brake pad than the rear inner race portion, so that the front inner race portion of the inner race is integrally formed as a single piece on the outer side of the nut portion, and the rear inner race portion that is farther away from the brake pad than the front inner race portion can be attached to the outer side of the nut portion.

[0029] The shapes of the front inner race portion closer to the brake pad than the rear inner race portion and the rear inner race portion farther from the brake pad than the front inner race portion may be asymmetrical to each other.

[0030] The rear inner race portion, which is farther away from the brake pad than the front inner race portion, may be smaller than the front inner race portion, which is closer to the brake pad than the rear inner race portion.

[0031] A gap between the rollable body and the rear inner race portion farther from the brake pad than the front inner race portion is larger than a gap between the rollable body and the front inner race portion closer to the brake pad than the rear inner race portion.

[0032] A portion of the front inner race portion closer to the brake pad than the rear inner race portion may lie in a plane passing through the center of the rollable body such that a boundary or gap between the front and rear inner race portions deviates from the plane passing through the center of the rollable body.

[0033] This summary is provided to introduce a selection of concepts in a simplified form that are further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various embodiments according to the present disclosure will be described with reference to the accompanying drawings, in which:

[0035] Figure 1 is a schematic cross-sectional view of an electromechanical brake system according to an embodiment of the present disclosure;

[0036] Figure 2 According to an embodiment of the present disclosure Figure 1 an enlarged view of the bearing assembly taken from section A in FIG;

[0037] Figure 3 According to an embodiment of the present disclosure Figure 2 An enlarged view of the bearing assembly taken from part B in FIG.

[0038] Figure 4 According to another embodiment of the present disclosure Figure 1 an enlarged view of the bearing assembly taken from section A in FIG;

[0039] Figure 5A illustrates a purely axial load path generated in a brake assembly during actuation of an actuator assembly according to an embodiment of the present disclosure;

[0040] Figure 5B illustrates a purely radial load path generated in a brake assembly during actuation of an actuator assembly according to an embodiment of the present disclosure;

[0041] Figure 5C shows a load path of a combination of an axial load and a radial load generated in a bearing assembly included in a brake assembly according to an embodiment of the present disclosure;

[0042] Figures 6A to 6C shows the process of assembling the bearing assembly and the rotatable portion of the nut-screw mechanism; and

[0043] Figure 7 A partial cross-sectional view of an electromechanical brake system according to another embodiment of the present disclosure is shown.

[0044] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0045] In the following detailed description, reference is made to the accompanying drawings which form a part of this disclosure, in which specific embodiments in which the invention may be practiced are shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it should be understood that other embodiments may be utilized and that structural, logical, and electrical changes may be made without departing from the spirit and scope of the invention. Therefore, the following detailed description should not be considered restrictive, and the scope of the invention is limited only by the appended claims and their equivalents. Like numbers in the figures represent like parts, which should be apparent from the context of use.

[0046] Figure 1 is a schematic cross-sectional view of an electromechanical brake system according to an embodiment of the present disclosure.

[0047] Reference Figure 1 The electromechanical brake (EMB) system 10 may include a brake caliper 110 that is floatingly mounted via a brake carrier. When the vehicle is in motion, a brake rotor 125 may rotate with the wheel about the vehicle's axis. A brake pad assembly (or brake lining assembly) 120 is disposed within the brake caliper 110. The brake caliper 110 may include a bridge having fingers, and the fingers of the brake caliper 110 may contact the brake pad assembly 120. In the released position, the brake pad assembly 120 is disposed with a small air gap to one side of the brake rotor 125 (e.g., a brake disc) to prevent significant residual drag torque.

[0048] The electromechanical brake system 10 may include a drive mechanism 200 (e.g., a nut-screw mechanism or a ball-nut-screw mechanism) configured to convert rotational motion generated by the actuator assembly 500 into linear motion to axially move the brake pad assembly 120 toward or away from the brake rotor 125. The drive mechanism 200 may include a rotatable portion 210 and a translatable portion 240. For example, the rotatable portion 210 may include a nut or a ball-nut, and the translatable portion 240 may include a lead screw or a ball screw, but this is not required. The nut-screw mechanism 200 may be contained within a housing 600. The rotatable portion 210 and the translatable portion 240 may be concentrically mounted within a cavity formed by the inner wall of the housing 600. The housing 600 may be fixedly coupled to the brake caliper 110. The rotatable portion 210 is operably coupled to the actuator assembly 500 and is configured to rotate upon actuation of the actuator assembly 500.

[0049] The actuator assembly 500 may include an electric motor 520. For example, the electric motor 520 may be directly coupled to the rotatable portion 210 of the drive mechanism 200. Alternatively, as Figure 1 As shown, the motor 520 may be indirectly connected to the rotatable portion 210 via a device for transmitting the rotational force generated by the motor 520 (e.g., via one or more gears, one or more belts, one or more pulleys, any other connection devices, and combinations thereof).

[0050] The actuator assembly 500 may include a multi-stage drive mechanism 540, but this is not required. The multi-stage drive mechanism 540 may be implemented as, for example, but not limited to, a two-stage drive mechanism including a belt drive mechanism 541 and a gear drive mechanism 546 to multiply the torque from the motor 520, thereby providing rotational force to the rotatable body 210 of the drive mechanism 200. The belt drive mechanism 541 multiplies the torque from the motor 520 by utilizing a motor shaft 522, a driving pulley 524 rotatably connected by a drive belt 542, and a driven pulley 543. The multiplied torque from the belt drive mechanism 541 is transmitted to the gear drive mechanism 546 via an intermediate shaft 545. The intermediate shaft 545 can connect the driven pulley 543 of the belt drive mechanism 541 to the first gear 548 of the gear drive mechanism 546, thereby transmitting the rotational torque generated by the motor 520 and transmitted through the belt drive mechanism 541 to the gear drive mechanism 546. The first gear 548 is rotatably engaged with the second gear 549 to rotate the second gear 549 by the rotational torque transmitted through the intermediate shaft 545. The second gear 549 may be directly formed on a partial circumferential surface of the rotatable body or nut 210 of the drive mechanism or the screw-nut mechanism 200, or may be mounted on the rotatable body 210 of the drive mechanism 200 to rotate the rotatable body or nut 210.

[0051] The controller 700 may be configured to control the actuator assembly 500 and the parking lock mechanism 560. The parking lock mechanism 560 is configured to lock the movement of components of the electromechanical brake system 10 by mechanically interlocking with at least one component of the electromechanical brake system 10 (e.g., a gear, pulley, shaft, nut, etc.). For example, in the parking lock state, a post or pin of the parking lock mechanism 560 may be inserted into one of the teeth formed on a surface of the driven pulley 543 facing the parking lock mechanism 560. The controller 700 controls the motor 520 to perform service and parking brake operations, such as applying or releasing the service and parking brakes. The controller 700 may be, for example, but not limited to, a microcontroller unit (MCU), a circuit chip, a semiconductor circuit, or a circuit board having a memory, one or more processors, and electrical components. Furthermore, the controller 700 may be configured to communicate with other controllers, such as a central electronic control unit (ECU). Therefore, according to the control of the controller 700, the actuator assembly 500 can provide a rotational torque to the nut-screw mechanism 200 to move the brake pad assembly 120 in the brake applying direction or the brake releasing direction.

[0052] The actuator assembly 500 rotates the rotatable portion 210 of the nut-screw mechanism 200, which then converts the rotational motion of the rotatable portion 210 into linear motion of the translatable portion 240 to move the brake pad assembly 120 between its brake applied position and brake released position. For example, actuation of the actuator 500 rotates the rotatable portion 210, which in turn causes the translatable portion 240 to linearly move. Specifically, the rotatable portion 210 can rotate relative to the housing 600, and the rotation of the rotatable portion 210 relative to the housing 600 causes the translatable portion 240 to axially advance or retract depending on the direction of rotation of the rotatable portion 210. When the rotatable portion 210 rotates in the deployment direction, the translatable portion 240 linearly translates relative to the rotatable portion 210 and the housing 600, allowing the translatable portion 240 to translate outward from the rotatable portion 210 and the housing 600 toward the brake rotor 125. When the rotatable portion 210 rotates in the retracting direction, the translatable portion 240 linearly translates relative to the rotatable portion 210 and the housing 600, allowing the translatable portion 240 to move linearly toward the rotatable portion 210 and the housing 600 in a direction away from the brake rotor 125. The brake pad foot 205 is fixedly coupled to the translatable portion 240 so that the brake pad foot 205 can move linearly with the translatable portion 240. When the nut-screw mechanism 200 is in the deployed state, the brake pad foot 205 pushes the brake pad assembly 120 toward the brake rotor 125. When the ball-screw mechanism 200 is in the retracted state, the brake pad foot 205 moves away from the brake rotor 125.

[0053] While the direction of expansion or contraction depends on whether the nut or ball nut of the rotatable portion 210 and the screw or ball screw of the translatable portion 240 are left-handed or right-handed, the specific direction is not important for some embodiments of the present disclosure, and most embodiments of the present disclosure can work in either case.

[0054] The rotatable portion 210 may have a tubular shape with an axially open end, and the translatable portion 240 is accommodated within the interior space of the rotatable portion 210. The rotatable portion 210 and the translatable portion 240 are operably connected to each other so that when the rotatable portion 210 rotates, the translatable portion 240 can move linearly relative to the rotatable portion 210. In other words, the translatable portion 240 can slide relative to the rotatable portion 210, but the translatable portion 240 cannot rotate relative to the rotatable portion 210, so when the rotatable portion 210 rotates, the translatable portion 240 moves linearly. For example, the translatable portion 240 has a structure that is configured to prevent the translatable portion 240 from rotating relative to the rotatable portion 210 while allowing the translatable portion 240 to translate in the axial direction.

[0055] At least a portion of the translatable portion 240 is retained within the rotatable portion 210. The rotatable portion 210 has an internally threaded track groove, and the translatable portion 240 has an externally threaded track groove for the rolling element 220 (e.g., balls). The rolling element 220 is positioned between the internally threaded track groove of the rotatable portion 210 and the externally threaded track groove of the translatable portion 240. A ball return system internally or externally brings the rolling element 220 back to the starting point from the end of its path, completing its cyclical path. A return tube facilitates the cyclical movement of the rolling element 220. The internally threaded track groove of the rotatable portion 210 and the externally threaded track groove of the translatable portion 240 form a series of ball tracks, providing a spiral raceway for receiving a train of circulating rolling elements 220. The rolling elements 220 may be metal balls, which reduce friction and transfer load between adjacent components. The rotatable portion 210 is rotatably supported by the translatable portion 240 via the rolling elements 220 and the bearing assembly 400. However, in an alternative embodiment of the present disclosure, the rotatable portion 210 and the translatable portion 240 may be directly engaged with each other without the rollable body 220 .

[0056] The bearing assembly 400 is configured to rotatably support the drive mechanism 200, such as a nut-and-screw mechanism. The bearing assembly 400 may be positioned between the rotatable portion 210 of the drive mechanism 200 and a non-rotating structure (such as, but not limited to, the housing 600). The bearing assembly 400 is configured to rotatably support the rotatable portion 210, allowing it to rotate relative to the non-rotating structure of the brake assembly 10.

[0057] Bearing assembly 400 may include an inner race 410, an outer race (or outer ring) 420, a plurality of rolling elements 430 (e.g., bearing balls), and a bearing cage 440. Bearing assembly 400 may include any number of rolling elements 430, such as more than two balls. Outer race 420 may be positioned concentrically with inner race 410, with rolling elements 430 positioned therebetween, in a plane generally perpendicular to the rotational axis of rotatable portion 210 or inner race 410, or the translational axis of translatable portion 240. Inner race 410 is rotatable, but outer race 420 is substantially non-rotatable.

[0058] The rolling bodies 430 are configured to assist in the rotation of the inner race 410, formed on and / or coupled to the rotatable portion 210, relative to the outer race (or outer ring) 420. The rolling bodies 430 are disposed within the annular cavity defined by the inner race 410 and the outer race 420, located between the inner race 410 and the outer race 420. The rolling bodies 430 are supported within a bearing retainer 440 such that the rolling bodies 430 are appropriately spaced circumferentially and retained by the bearing retainer 440. The bearing retainer 440 is disposed between the inner race 410 and the outer race 420. In an exemplary embodiment, the rolling bodies 430 may be spherical, such as, but not limited to, balls.

[0059] The inner ring 410 defines an inner circumferential surface of the bearing assembly 400 and is disposed outside the rotatable portion 210 (eg, a ball nut of the ball-screw mechanism 200 ).

[0060] In the embodiment of the present disclosure, the inner ring 410 has a split raceway structure, such that the inner ring 410 includes a front inner ring portion 411 and a rear inner ring portion 412. The front inner ring portion 411 is closer to the brake pad assembly 120 than the rear inner ring portion 412. The rear inner ring portion 412 is farther away from the brake pad assembly 120 than the front inner ring portion 411.

[0061] The front inner ring portion 411 closer to the brake pad assembly 120 may be formed directly on the outer surface of the rotatable portion 210 of the nut-screw mechanism 200. For example, Figure 1 and Figure 2 As shown, a portion of the outer surface of the rotatable portion 210 defines a front inner race portion 411. More specifically, the rotatable portion 210 has a protrusion that projects outward toward the bearing assembly 400 to form the front inner race portion 411. Therefore, the front inner race portion 411 can be integrally formed with the rotatable portion 210 as a single piece, thereby simplifying the assembly process and reducing manufacturing costs. Alternatively, the front inner race portion 411 can be coupled to the outer surface of the rotatable portion 210 as a separate piece.

[0062] The rear inner race portion 412, which is further away from the brake pad assembly 120, may be fixedly attached to the rotatable portion 210. For example, the rear inner race portion 412 may be coupled to the outer surface of the rotatable portion 210 by a press fit or a heat drop.

[0063] During the assembly of the bearing assembly 400, as shown in FIG. Figure 6A As shown, the rotatable portion 210 of the driving mechanism 200 formed with the front inner ring portion 411 is formed to be inserted into the center of the outer ring 420 assembled with the rollable body 430, and as shown in FIG. Figure 6B and Figure 6C As shown, the rear inner race portion 412 is inserted into the bearing assembly 400 to couple to the rotatable portion 210 of the drive mechanism 200 .

[0064] Alternatively, the rear inner ring portion 412 may be fixed in position on the outer side of the rotatable portion 210 using a retainer 490. The retainer 490 may serve as a stopper for the rear inner ring portion 412. Figure 7 As shown, the retaining member 490 may be supported by the second gear 549 attached to the rotatable portion 210, so that the retaining member 490 can limit the axial movement of the rear inner ring portion 412 and the rear inner ring portion 412 can be firmly fixed in place by being supported by the retaining member 490. As another example, a groove may be formed on the outer surface of the rotatable portion 210 around one side of the rear inner ring portion 412, and the retaining member 490, such as a snap-on ring (e.g., a generally C-shaped retaining ring), may be removably positioned within the groove of the rotatable portion 210, so that the retaining member 490 can support one side of the rear inner ring portion 412 or provide an axial stop for the rear inner ring portion 412. Alternatively, a portion of a gear or pulley (e.g., the second gear 549) provided on the outer surface of the rotatable portion 210 may extend to support one side of the rear inner ring portion 412, so that a portion of the gear or pulley provided on the outer surface of the rotatable portion 210 can serve as a stopper, rather than including the retaining member 490 as a separate member. For example, the holder 490 may be integrated into a gear or a pulley provided on the outer surface of the rotatable portion 210 .

[0065] In the diagram showing the pure axial load path in the brake assembly 10 according to an embodiment of the present disclosure, Figure 5AIn Figure 5, actuation of the actuator assembly 500 generates a compressive load on the translatable portion 230 (e.g., a ball screw). This compressive load on the translatable portion 230 can be transmitted to the rotatable portion 210 via the rolling body 430. A first action arrow 612 represents an axial load caused by the force transmitted to the rotatable portion 210 (e.g., a ball nut) via the rolling body 261 (e.g., an inner ball nut / screw balls). The force transmitted to the rotatable portion 210 then acts on the bearing assembly 400. The force transmitted through the bearing assembly 400 forms a load support line 613. As the inner race 410 and outer race 420 move in opposite axial directions relative to each other, each rolling body 430 forms two contact points. One contact point 616 for each rolling body 430 is formed on the front inner race portion 411, and the other contact point 617 for each rolling body 430 is formed on the outer race 420. Therefore, of the front inner ring portion 411 and the rear inner ring portion 412 included in the inner ring 410, one contact point for each rolling element 430 is formed only at the front inner ring portion 411. The force on the bearing assembly 400 is transmitted to a portion of the housing 600. A second action arrow 614 shows the force transmitted axially from the outer ring 232 of the bearing assembly 230 to a portion of the housing 600 (e.g., the EMB bridge).

[0066] In the diagram showing the purely radial load path in the brake assembly 10 according to an embodiment of the present disclosure, Figure 5B In the example, actuation of the actuator assembly 500 exerts a relatively small radial load on the translatable portion 230 (e.g., a ball screw). This radial load on the translatable portion 230 can be transmitted to the rotatable portion 210 via the rolling body 430. A first action arrow 622 illustrates the radial load, which is caused by the force transmitted to the rotatable portion 210 (e.g., the ball nut) via the rolling body 430 (e.g., the inner ball nut / screw balls). The force transmitted to the rotatable portion 210 then acts on the bearing assembly 400. The force transmitted through the bearing assembly 400 generates two load support lines 623 and 624, resulting in four contact points for each rolling body 430 as the inner race 410 and outer race 420 move radially toward each other. The first load support line 623 can form a first contact point 631 on the front inner race portion 411 and a second contact point 632 on a portion of the outer race 420. Second load support line 624 can form a third contact point 633 on rear inner race portion 412 and a fourth contact point 634 on outer race 420. Thus, each rolling element 430 forms two contact points, one at inner race 410 and one at outer race 420. Forces on bearing assembly 400 are transmitted to a portion of housing 600. Second action arrow 625 illustrates the radial transmission of forces from outer race 420 of bearing assembly 400 to a portion of housing 600 (e.g., an EMB bridge).

[0067] Figure 5C 1 shows the combined load path of the axial load and the radial load generated in the brake assembly 10 according to an embodiment of the present disclosure. Figure 6A and Figure 6B As shown, during brake application, actuation of actuator assembly 500 generates a relatively large axial load vector, while simultaneously generating a radial load vector that is relatively much smaller than the axial load vector. The deflection of caliper 110 during a braking event can be a source of radial load. The combination of the large axial load vector and the small radial load vector creates a load-bearing line 643, resulting in two contact points 647 and 648 for each rolling element 430 in bearing assembly 400. One contact point 647 for the combined load is formed on the front inner race portion 411, while no contact point is formed on the rear inner race portion 412. The other contact point 648 is formed on the outer race 420. Therefore, during a braking event, the front inner race portion 411 can act as the high-load bearing inner race portion, applying the load, while the rear inner race portion 412 can act as the non-load bearing inner race portion. Of the front and rear inner race portions 411, 412 of inner race 410, the front inner race portion 411, where each rolling element 430 forms a contact point, bears the high axial load. Different from the front inner race portion 411 , the rear inner race portion 412 does not need to bear the load generated by the brake assembly 10 during the braking operation, but only plays the role of holding the rollable body 430 and preventing the bearing assembly 400 from being disassembled.

[0068] Therefore, according to some embodiments of the present disclosure, the front inner ring portion 411 and the rear inner ring portion 412 of the inner ring 410 may be made of different materials and have different shapes, and / or be configured differently from each other.

[0069] Since no load or a relatively small load is applied to the rear inner ring portion 412 during the braking operation of the brake assembly 10, and the rear inner ring portion 412 only performs the functions of holding the rollable body 430 and preventing the bearing assembly 400 from being disassembled, the rear inner ring portion 412 can have less material than the front inner ring portion 411, and the rear inner ring portion 412 can be made of a material with lower strength and weight than the front inner ring portion 411.

[0070] Low-cost materials (such as, but not limited to, unheat-treated steel, aluminum, plastic, etc.) can be used for the rear inner race portion 412 without affecting the performance of the bearing assembly 400 during braking operation of the brake assembly 10 , thereby reducing the cost of manufacturing the bearing assembly 400 .

[0071] Additionally, by making the rear inner race portion 412 lighter, the overall weight of the bearing assembly 420 may be reduced without affecting the ability of the inner race 410 to withstand the loads generated during braking operation of the brake assembly 10 .

[0072] The front inner ring portion 411 and the rear inner ring portion 412 may have different shapes from each other. The front inner ring portion 411 and the rear inner ring portion 412 may be asymmetrical about the axis of the rollable body 430.

[0073] For example, the rear inner race portion 412 can be smaller than the front inner race portion 411. The reduction in size of the rear inner race portion 412 does not affect the function of the bearing assembly 400 in supporting the load generated when the brake assembly 10 performs a braking operation. Therefore, less material can be used for the rear inner race portion 412, and the size of the rear inner race portion 412 can be made smaller without reducing the performance of the bearing assembly 400 in the braking operation of the brake assembly 10.

[0074] A portion of the front inner ring portion 411 can be located in a plane perpendicular to the rotation axis of the rotatable portion 210 and / or passing through the center of the scrollable body 430, so that the boundary or gap formed between the front inner ring portion 411 and the rear inner ring portion 412 deviates from the plane perpendicular to the rotation axis of the rotatable portion 210 and / or passing through the center of the scrollable body 430.

[0075] Due to the reduced size of the rear inner race portion 412 and the offset center of the front inner race portion 411, the overall length and / or diameter of the bearing assembly can be shorter than that of a conventional Conrad-type bearing, while maintaining the ability to withstand the high loads generated by braking operations. Furthermore, the split design and construction of the inner race 410, including the front inner race portion 411 and the rear inner race portion 412, allows the bearing assembly 400 to have a greater number of rolling elements 430 (e.g., balls) between the split inner race 410 and the outer race 420, compared to conventional Conrad-type bearings, which have a lower limit on the number of balls, thereby providing a higher load-carrying capacity.

[0076] exist Figure 2In the illustrated bearing configuration, in an unloaded state, the gap between the rear inner race portion 412 and the rolling body 430 can be larger than the gap between the front inner race portion 411 and / or the outer race 420 and the rolling body 430. The inner radius of curvature of the concave spherical surface of the front inner race portion 411 is smaller than the inner radius of curvature of the concave spherical surface of the rear inner race portion 412, thereby generating a first gap between the outer surface of the rolling body 430 and the concave spherical surface of the front inner race portion 411. This first gap is smaller than a second gap between the outer surface of the rolling body 430 and the concave spherical surface of the rear inner race portion 412. The center point of the inner curvature radius of the concave spherical surface of the front inner ring portion 411 can also be axially and / or radially deviated from the center point of the inner curvature radius of the concave spherical surface of the rear inner ring portion 412 in space, so as to be different from the second gap between the outer surface of the rolling body 430 and the concave spherical surface of the rear inner ring portion 412, and aligned with the first gap between the outer surface of the rolling body 430 and the concave spherical surface of the front inner ring portion 411, so as to achieve asymmetric load and contact stress characteristics between the rolling body 430 and the inner surfaces of the front inner ring portion 411, the rear inner ring portion 412 and the outer ring 420.

[0077] Therefore, according to certain embodiments of the present disclosure, through the center offset of the front inner ring portion 411 and the rear inner ring portion 412, and the difference between the first gap between the front inner ring portion 411 and the rolling body 430 and the second gap between the rear inner ring portion 412 and the rolling body 430, the rolling body 430 can mainly contact the front inner ring portion 411 under a no-load condition to provide optimal performance of the bearing assembly 400.

[0078] Alternatively, the inner surface of the rear inner ring portion 412 facing the rollable body 430 may be formed as follows: Figure 4 The flat surface 443 or the inclined groove is shown to use a simpler shape configuration to reduce manufacturing costs and simplify the manufacturing process of the bearing assembly 400.

[0079] According to certain embodiments of the present disclosure, due to the asymmetric raceway profiles of the inner surfaces of the front inner ring portion 411 and the rear inner ring portion 412, radial and axial load capacities in an axial direction can be achieved in the front inner ring portion 411 even if the overall size and weight of the bearing assembly 400 are reduced.

[0080] According to some embodiments of the present disclosure, the rear inner race portion 412 may be constructed using more cost-effective or less expensive materials and a simpler design or shape than the front inner race portion 411 without affecting the performance of the bearing assembly 400 .

[0081] According to certain embodiments of the present disclosure, the costly ring matching process is unnecessary because the rear inner race portion 412 merely serves to retain the rolling element 430 and prevent the bearing assembly 400 from being disassembled. When assembling the bearing assembly 400, the manufacturer needs to control the radial clearance of the bearing assembly 400 before coupling the rear inner race portion 412 to the bearing assembly 400. Once the rear inner race portion 412 is assembled to the bearing assembly 400, the bearing assembly 400 including the rear inner race portion 412 according to certain embodiments of the present disclosure may not reduce the radial clearance within the bearing assembly 400, and thus, the bearing assembly 400 according to certain embodiments of the present disclosure may not require a ring matching process. Therefore, by having a split raceway configuration of the inner ring including the front inner race portion 411 and the rear inner race portion 412, the bearing assembly 400 can utilize a lower-precision production method.

[0082] Although outer ring 420 is shown as a single-piece raceway in certain embodiments of the present disclosure, outer ring 420 may also have a split construction, such that outer ring 420 includes a front outer ring portion and a rear outer ring portion. However, the front outer ring portion of outer ring 420 may be implemented using the description regarding rear inner ring portion 412 described above, and the rear outer ring portion of outer ring 420 may be implemented using the description regarding front inner ring portion 411 described above.

[0083] Although the exemplary embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0084] Furthermore, the scope of the present application is not limited to the particular embodiments of the processes, machines, manufacture, and compositions of matter, apparatus, methods, and steps described in the specification. As will be readily understood by one of ordinary skill in the art from this disclosure, according to embodiments and alternative embodiments, processes, machines, manufacture, compositions of matter, apparatus, methods, or steps currently existing or later developed may be utilized that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, apparatus, methods, or steps.

[0085] The explanations and illustrations provided herein are intended to familiarize others skilled in the art with the present invention, its principles, and its practical applications. The foregoing description is intended to be illustrative and not limiting. Those skilled in the art may adapt and apply the present invention in various forms that best suit the requirements of a particular application.

[0086] Therefore, the specific embodiments of the present invention described are not intended to be exhaustive or to limit the teachings. Accordingly, the scope of the teachings should be determined not with reference to this embodiment, but rather with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The omission from the following claims of any aspect of subject matter disclosed herein is not a disclaimer of such subject matter, nor should it be construed as an admission by the inventors that such subject matter is not considered part of the disclosed inventive subject matter.

[0087] Multiple elements or steps can be provided by a single integrated element or step. Alternatively, a single element or step can be divided into separate multiple elements or steps.

[0088] Disclosure describing “a” or “an” an element or step is not intended to exclude additional elements or steps.

[0089] Although the terms first, second, third etc. can be used to describe various elements, components, regions, layers and / or parts in this article, these elements, components, regions, layers and / or parts should not be restricted by these terms. These terms can be used to distinguish an element, component, region, layer or part from another region, layer or part. Unless the context clearly indicates, otherwise such as "first", "second" and other numerical terms used herein do not mean sequence or order. Therefore, the first element, component, region, layer or part discussed below can be referred to as the second element, component, region, layer or part, without departing from teaching.

[0090] For ease of description, spatially relative terms such as "inside," "outside," "below," "beneath," "lower," "above," and "upper" may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. Spatially relative terms may also encompass different orientations of the device when in use or operation, in addition to the orientation shown in the figures. For example, if the device in the figures is turned over, an element described as "below" or "beneath" other elements or features would be positioned "above" the other elements or features. Thus, the example term "below" can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

Claims

1. A brake assembly comprising: a rotatable portion configured to be rotatable by an actuator; a translatable portion operatively coupled to the rotatable portion, the translatable portion being configured to be axially translated relative to the rotatable portion to move the brake pad according to rotation of the rotatable portion; as well as a bearing assembly configured to support the rotatable portion, the bearing assembly comprising: an inner ring, comprising a front inner ring portion and a rear inner ring portion, wherein the rear inner ring portion, which is farther away from the brake pad than the front inner ring portion, is smaller than the front inner ring portion, which is closer to the brake pad than the rear inner ring portion; outer ring; and The rollable body is rollably disposed between the inner ring and the outer ring.

2. The brake assembly according to claim 1, wherein: The rotatable portion has a protrusion that protrudes outward toward the bearing assembly to form the front inner race portion closer to the brake pad than the rear inner race portion, so that the front inner race portion of the inner race is integrally formed as a single piece on the outer side of the rotatable portion, and The rear inner race portion, which is farther from the brake pad than the front inner race portion, is attached to the outer side of the rotatable portion.

3. The brake assembly according to claim 1, wherein: The shapes of the front inner race portion closer to the brake pad than the rear inner race portion and the rear inner race portion farther from the brake pad than the front inner race portion are asymmetrical to each other.

4. The brake assembly according to claim 1, wherein: A gap between the rollable body and the rear inner race portion farther from the brake pad than the front inner race portion is larger than a gap between the rollable body and the front inner race portion closer to the brake pad than the rear inner race portion.

5. The brake assembly according to claim 1, wherein: A gap between the rear inner ring portion farther from the brake pad than the front inner ring portion and the rollable body is larger than a gap between the outer ring and the rollable body, the front inner ring portion closer to the brake pad than the rear inner ring portion.

6. The brake assembly according to claim 1, wherein: A portion of the front inner race portion that is closer to the brake pad than the rear inner race portion is located in a plane passing through the center of the rollable body, so that the boundary or gap between the front inner race portion and the rear inner race portion deviates from the plane passing through the center of the rollable body.

7. The brake assembly according to claim 1, wherein: The material of the front inner race portion closer to the brake pad than the rear inner race portion is different from the material of the rear inner race portion farther from the brake pad than the front inner race portion.

8. The brake assembly according to claim 1, wherein: The weight of the rear inner race portion farther from the brake pad than the front inner race portion is smaller than the weight of the front inner race portion closer to the brake pad than the rear inner race portion.

9. The brake assembly according to claim 1, wherein: The strength of the rear inner race portion farther from the brake pad than the front inner race portion is smaller than the strength of the front inner race portion closer to the brake pad than the rear inner race portion.

10. The brake assembly of claim 1, wherein: The inner curvature radius of the inner surface of the front inner ring portion facing the rollable body, which is closer to the brake pad than the rear inner ring portion, is smaller than the inner curvature radius of the inner surface of the rear inner ring portion facing the rollable body, which is farther from the brake pad than the front inner ring portion.

11. The brake assembly according to claim 1 , wherein: The center point of the inner curvature radius of the inner surface of the front inner ring portion facing the rolling body, which is closer to the brake pad than the rear inner ring portion, deviates from the center point of the inner curvature radius of the inner surface of the rear inner ring portion facing the rolling body, which is farther away from the front inner ring portion.

12. The brake assembly of claim 1, wherein: An inner surface of the front inner race portion, which is closer to the brake pad than the rear inner race portion, facing the rollable body is curved, and An inner surface of the rear inner race portion, which is farther from the brake pad than the front inner race portion, facing the rollable body is flat. 13 . The brake assembly according to claim 1 , further comprising a retainer configured to support the rear inner race portion farther from the brake pad than the front inner race portion to restrict movement of the rear inner race portion in the axial direction of the rotatable portion.

14. The brake assembly according to claim 13, wherein: The retainer extends between a gear or pulley provided on the rotatable portion and a side of the rear inner race portion farther from the brake pad than the front inner race portion, so that the retainer supported by the gear provided on the rotatable portion supports the rear inner race portion.

15. The brake assembly according to claim 1, further comprising a gear or a pulley provided on the rotatable portion and supporting a side of the rear inner race portion farther from the brake pad than the front inner race portion to retain the rear inner race portion in the bearing assembly.

16. The brake assembly of claim 1, wherein: The rear inner race portion, which is farther away from the brake pad than the front inner race portion, is press-fitted on the rotatable portion.

17. A brake assembly comprising: a rotatable portion configured to be rotatable by an actuator; a translatable portion operatively coupled to the rotatable portion, the translatable portion being configured to be axially translated relative to the rotatable portion to move the brake pad according to rotation of the rotatable portion; as well as a bearing assembly configured to support the rotatable portion, the bearing assembly comprising: an inner ring, comprising a front inner ring portion and a rear inner ring portion, wherein a material of the front inner ring portion closer to the brake pad than the rear inner ring portion is different from a material of the rear inner ring portion farther from the brake pad than the front inner ring portion; outer ring; and The rollable body is rollably disposed between the inner ring and the outer ring.

18. The brake assembly of claim 17, wherein: The strength of the rear inner race portion farther from the brake pad than the front inner race portion is smaller than the strength of the front inner race portion closer to the brake pad than the rear inner race portion.

19. A brake assembly comprising: a rotatable portion configured to be rotatable by an actuator; a translatable portion operatively coupled to the rotatable portion, the translatable portion being configured to be axially translated relative to the rotatable portion to move the brake pad according to rotation of the rotatable portion; as well as a bearing assembly configured to support the rotatable portion, the bearing assembly comprising: an inner ring, comprising a front inner ring portion and a rear inner ring portion, wherein a strength of the rear inner ring portion farther from the brake pad than the front inner ring portion is smaller than a strength of the front inner ring portion closer to the brake pad than the rear inner ring portion; outer ring; and The rollable body is rollably disposed between the inner ring and the outer ring.

20. The brake assembly of claim 19, wherein: The rear inner race portion, which is farther away from the brake pad than the front inner race portion, is smaller than the front inner race portion, which is closer to the brake pad than the rear inner race portion.

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