Wear regulator for a braking system

Abstract

A wear adjuster for a brake caliper having a piston body and a brake pad. The wear adjuster includes a piston engaged with the brake pad, a piston shaft, and a clutch system. The piston shaft is threadably engaged with the piston and supported by the piston body. The clutch system is configured to periodically enable relative rotation between the piston and the piston shaft and includes an inner race frictionally engaged with the piston shaft, an outer race, and a pre-tension spring. The outer race is unidirectionally coupled to the inner race for transmitting torque between the outer race and the inner race such that rotation of the outer race in a first direction rotates the inner race in the first direction and rotation of the outer race in a second direction does not rotate the inner race. The pre-tension spring urges the inner race into engagement with the piston shaft.

Description

[0001] Cross-references to related applications

[0002] This patent application claims priority and all benefits to U.S. Provisional Patent Application No. 63 / 545,446, filed October 24, 2023, and U.S. Provisional Patent Application No. 63 / 545,459, filed October 24, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Wear conditioners for disc brakes are a critical component of modern braking systems, designed to maintain optimal braking performance and safety. Disc brakes operate by pressing brake pads against a rotating disc or brake plate, generating friction and slowing the vehicle. Over time, the brake pads wear down, which can lead to decreased braking effectiveness and increased braking distance. Wear conditioners compensate for this wear by automatically adjusting the position of the brake pads, ensuring that the brake pads remain in close contact with the brake disc and maintain consistent braking performance.

[0004] Wear adjuster mechanisms typically consist of a series of mechanical or hydraulic components that detect wear on the brake pads and adjust their position accordingly. In mechanical systems, this may involve a ratchet and pawl mechanism that gradually moves the brake pads closer to the brake disc as they wear. In hydraulic systems, a brake fluid reservoir provides additional fluid to the system to adjust the brake pad position. This automatic adjustment not only enhances safety by maintaining effective braking but also extends the service life of the brake components by ensuring even wear.

[0005] In addition to improving safety and extending component life, wear adjusters also contribute to enhanced driver comfort and convenience. Without wear adjusters, drivers would need to manually adjust brake pads or replace them more frequently, which can be both time-consuming and expensive. By automating this process, wear adjusters reduce maintenance requirements and ensure the braking system operates with maximum efficiency and minimal intervention. Summary of the Invention

[0006] One aspect discloses an electrically actuated brake caliper for a vehicle. The brake caliper includes a piston body, brake pads, and a wear adjuster. The wear adjuster includes a piston, a piston shaft, and a clutch system. The piston is arranged to engage with the brake pads. The piston shaft is threadedly engaged with the piston and supported by the piston body. The clutch system is configured to periodically achieve relative rotation between the piston and the piston shaft. The clutch system includes an inner race, an outer race, and a preload spring. The inner race frictionally engages with the piston shaft. The outer race is unidirectionally connected to the inner race for transmitting torque between the outer race and the inner race, such that rotation of the outer race in a first direction causes rotation of the inner race in that first direction, while rotation of the outer race in a second direction does not cause rotation of the inner race. The preload spring is operably arranged between the piston shaft and the inner race and is configured to cause engagement of the inner race with the piston shaft. In some embodiments, the engagement between the inner race and the piston shaft may be via friction coupling.

[0007] On the other hand, a wear adjuster for a brake caliper is disclosed. The brake caliper may include a piston body and brake pads. The wear adjuster includes a piston, a piston shaft, and a clutch system. The piston is arranged to engage with the brake pads. The piston shaft is threadedly engaged with the piston and supported by the piston body. The clutch system is configured to periodically achieve relative rotation between the piston and the piston shaft. The clutch system includes an inner race, an outer race, and a preload spring. The inner race frictionally engages with the piston shaft. The outer race is unidirectionally connected to the inner race for transmitting torque between the outer race and the inner race, such that rotation of the outer race in a first direction causes rotation of the inner race in that first direction, while rotation of the outer race in a second direction does not cause rotation of the inner race. The preload spring is operably arranged between the piston shaft and the inner race and is configured to cause engagement of the inner race with the piston shaft.

[0008] Any of the foregoing aspects may be combined in whole or in part. Any feature of the foregoing aspects may be combined in whole or in part. Any of the foregoing embodiments of any aspect may be combined with any other aspect. Whether for the same or different aspects, any of the foregoing embodiments may be combined with any other embodiment. Attached Figure Description

[0009] The advantages of this disclosure will become readily apparent, and even more readily understood, when considered in conjunction with the accompanying drawings, by referring to the following detailed description.

[0010] Figure 1 It is a perspective view of a braking system used in automobiles, showing the brake disc, caliper bracket, and electromechanical friction brake.

[0011] Figure 2 yes Figure 1A cross-sectional view of the braking system shows the brake disc, electromechanical friction brake, a pair of brake pads, and wear adjuster mechanism.

[0012] Figure 3 yes Figure 2 An exploded view of an electromechanical friction brake shows the caliper body separated from the actuator assembly, which includes an electric actuator, a piston assembly, a cam, a lever, and a transmission assembly.

[0013] Figure 4 yes Figure 3 A partial exploded view of the actuator assembly shows a cam, lever, and piston assembly, including a first embodiment of a wear adjuster.

[0014] Figure 5 yes Figure 4 A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the unacted position and the wear adjuster shown in the retracted configuration.

[0015] Figure 6 yes Figure 5 A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the actuated position and the wear adjuster shown in the extended configuration.

[0016] Figure 7 yes Figure 5 A cross-sectional perspective view of the lever, piston assembly, and wear adjuster, with the lever shown in the unacted position and the wear adjuster shown in the extended configuration.

[0017] Figure 8 yes Figure 5 A cross-sectional perspective view of the lever, piston assembly, and wear adjuster, with the lever shown in the actuated position and the wear adjuster shown in the extended configuration.

[0018] Figure 9A yes Figure 7 A side view of the actuator of the lever, piston assembly, and wear adjuster, wherein the lever is shown in the unacted position.

[0019] Figure 9B yes Figure 8 A side view of the actuator of the lever, piston assembly, and wear adjuster, wherein the lever is shown in the actuated position.

[0020] Figure 10 This is a partial exploded view of the actuator assembly, showing a second embodiment of the lever and piston assembly, which includes a wear adjuster.

[0021] Figure 11 yes Figure 10A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the actuated position and the wear adjuster shown in the retracted configuration.

[0022] Figure 12 yes Figure 10 A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the unacted position and the wear adjuster shown in the extended configuration.

[0023] Figure 13 yes Figure 10 A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the actuated position and the wear adjuster shown in the retracted configuration.

[0024] Figure 14 yes Figure 10 A cross-sectional view of the lever, piston assembly, and wear adjuster, with the lever shown in the unacted position and the wear adjuster shown in the retracted configuration.

[0025] Figure 15 This is a third embodiment of the wear regulator assembly and piston assembly. Detailed Implementation

[0026] Figure 1 and Figure 2 A basic braking system 50 for a motor vehicle is shown, specifically an electromechanical friction braking system, which can be used to decelerate or stop a vehicle without using the hydraulic system commonly found in typical braking systems. The braking system 50 shown here includes a brake disc 52, a caliper bracket 54, and an electromechanical friction brake assembly 100. The electromechanical friction brake assembly 100 (referred to as brake assembly 100) includes an actuator assembly 102 that is movable between an unactuated position and an actuated position to apply force to brake pads 56 to engage the brake pads 56 with the brake disc 52, thereby stopping or decelerating the vehicle. The brake disc 52 rotates together with the vehicle's wheels about a brake disc axis 58.

[0027] As mentioned above, brake assembly 100 is part of an electromechanical friction braking system that does not use the hydraulic system common in typical braking systems. Therefore, brake assembly 100 utilizes electricity to move actuator assembly 102 between an unactuated position and an actuated position. Specifically, actuator assembly 102 includes an electric actuator 104 that generates mechanical force from electricity to move actuator assembly 102. In the exemplary embodiment shown here, electric actuator 104 can be implemented as an electric motor that converts electricity into torque, which moves actuator assembly 102.

[0028] The brake assembly 100 further includes a caliper body 106 having a mounting portion 108 and a brake pad portion 110. An actuator housing 112 is removably attached to the mounting portion 108 and encloses the actuator assembly 102. The actuator housing 112 includes a mounting portion for receiving and supporting an electric actuator 104. The mounting portion 108 of the caliper body 106 is coupled to a caliper bracket 54 such that the brake pad portion 110 is arranged around a brake disc 52.

[0029] Go to Figure 3 The actuator side of the brake assembly 100 is shown, with the actuator housing 112 removed. Here, the actuator assembly 102 is shown as a mounting portion 108 coupled to the caliper body 106. In addition to the electric actuator 104, the actuator assembly 102 further includes a transmission assembly 114, a cam 116, a lever 118, and a piston assembly 120. The cam 116 is operatively coupled to the electric actuator 104 via the transmission assembly 114 to increase the torque of the electric actuator 104 and to rotate the cam 116. The piston assembly 120 engages with the mounting portion 108 of the caliper body 106 and is slidable relative to this mounting portion along a piston axis 122. The piston assembly 120 further engages with one of the brake pads 56, such that movement of the piston assembly 120 causes the brake pad 56 to engage with the brake disc 52, thereby decelerating the brake disc 52 and the vehicle.

[0030] The caliper body 106 further includes a pair of caliper fork arms 124 that project from the mounting portion 108 and define a fork arm opening 126 between each caliper fork arm 124 and the mounting portion 108. More specifically, each caliper fork arm 124 includes a fork arm boss 128 formed on the mounting portion 108 and a fork arm block 130 connected to each fork arm boss 128 by fasteners. The fork arm opening 126 is defined between the fork arm block 130 and the mounting portion 108 of the caliper body 106. A lever 118 is arranged in the fork arm opening 126 between the mounting portion 108 and the fork arm block 130. The caliper body 106 further includes a pair of drive mounts 138 that project from the mounting portion 108 and are configured to support a drive assembly 114. The drive mounts 138 are arranged radially inward, or closer to the brake disc axis 58 of the brake disc 52 than the caliper fork arms 124.

[0031] Continue to refer to Figure 3The piston assembly 120 is slidably engaged with the caliper body 106 and disposed in a piston opening 140 defined in a mounting portion 108. The piston assembly 120 extends through the piston opening 140 and into a brake pad portion 110 of the caliper body 106 for engagement with one of the brake pads 56. The piston assembly 120 includes a piston body 142 having a main portion 144 and two lateral portions 146 disposed on opposite sides of the main portion 144. The piston body 142 defines an adjuster bore 148 extending along a piston axis 122 through the main portion 144. The piston assembly 120 further includes a wear adjuster 200 and a plurality of return springs 150. The wear adjuster 200 is coupled to the piston body 142 and extends through the adjuster bore 148, aligned with the piston axis 122. The plurality of return springs 150 are disposed between the piston body 142 and the mounting portion 108 of the caliper body 106. More specifically, a plurality of return springs 150 are arranged around the piston axis 122, wherein a first end of each return spring 150 engages the mounting portion 108, and an opposing second end of each return spring 150 engages the piston body 142. The return springs 150 are compressed by the movement of the piston assembly 120 from the unactuated position toward the actuated position. In other words, as the actuator assembly 102 moves from the unactuated position toward the actuated position, the piston assembly 120 moves toward the mounting portion 108, which compresses the return springs 150. The return springs 150 exert a restoring force on the piston body 142, which moves the piston assembly 120 away from the mounting portion 108 as the actuator assembly 102 moves from the actuated position toward the unactuated position.

[0032] Piston assembly 120 engages with lever 118 at a transverse portion 146 of piston body 142 for actuation of piston assembly 120. Lever 118 has a first lever arm and a second lever arm 154, and a ridge 156 coupled to the lever arm 154. Lever arm 154 is disposed at a first end of lever 118 and radially outward of ridge 156, which is disposed at a second end of lever 118. Lever 118 further engages with cam 116 for transmitting force between the lever and the cam. More specifically, force from transmission assembly 114 is transmitted to lever 118 via cam 116. Cam 116 can be rotated via transmission assembly 114 to move lever 118 between an unactuated position and an actuated position, which correspond to the unactuated position and the actuated position of actuator assembly 102. For this purpose, lever 118 further includes roller 160 rotatably coupled to ridge 156. Roller 160 engages cam 116 to transmit force from transmission assembly 114 to lever 118. Roller 160 reduces friction between lever 118 and cam 116. Roller 160 can be supported on a bearing, which further reduces friction between lever 118 and cam 116.

[0033] In the exemplary embodiment shown herein, each of the lever arms 154 includes a pair of fingers 162 projecting away from the ridge 156. In other words, the lever 118 includes four fingers 162, with two fingers 162 arranged on each of the lever arms 154. Each pair of fingers 162 supports a reaction pin 164 and a force pin 166. Specifically, there are two reaction pins 164 and two force pins 166, with one reaction pin and one force pin arranged on each lever arm 154. Each of the reaction pins 164 and force pins 166 is supported by fingers 162 at opposite ends. The reaction pin 164 is arranged radially outward of the force pin 166, such that it is further away from the brake disc axis 58 than the force pin 166. Here, the reaction pins 164 and force pins 166 have a cylindrical shape and may be formed of an elastic material, such as hardened steel. The lever 118 further includes an adjusting pin 168, which is coupled to one of the lever arms 154 and protrudes toward the piston axis 122.

[0034] Now go to Figures 4-8 A first embodiment of the piston assembly 120 is shown in more detail. As mentioned above, the piston assembly 120 includes a wear adjuster 200 coupled to the piston body 142 and configured to compensate for wear on the brake pads 56. The wear adjuster 200 is disposed in an adjuster bore 148 and moves along the piston axis 122 with the piston body 142 in response to actuation of the lever 118. The wear adjuster 200 is movable between a retracted configuration and an extended configuration. The retracted configuration is... Figure 5 As shown in the diagram, the extension configuration is... Figures 6-8 As shown in the image.

[0035] To enable movement between the retracted and extended configurations, the wear adjuster 200 includes a piston 202 and a piston shaft 208. The piston 202 has a head portion 204 and a threaded tail portion 206, the head portion being arranged to engage one of the brake pads 56, and the threaded tail portion being configured to threadedly engage the piston shaft 208. For this purpose, the piston shaft 208 defines a threaded piston bore 210, which is configured to threadedly engage the tail portion 206 of the piston 202. The piston shaft 208 has a flange portion 212, a shoulder portion 214, a support portion 216, and a retaining portion 218. The flange portion 212 and the retaining portion 218 are disposed at opposite ends of the piston shaft 208, and the shoulder portion 214 and the support portion 216 are disposed between the flange portion and the retaining portion. The shoulder portion 214 is adjacent to the flange portion 212, and the support portion 216 is adjacent to the retaining portion 218.

[0036] Piston 202 can be in a retracted configuration relative to piston shaft 208. Figure 5 ) and extended configuration ( Figure 6 The piston 202 moves between the piston head portion 204 and the piston bore 210 of the piston shaft 208 via a threaded engagement. The retracted configuration is defined by the tail portion 206 fully seated in the piston bore 210, wherein the head portion 204 of the piston 202 engages the flange portion 212 of the piston shaft 208. The extended configuration is defined as any position of the piston 202 relative to the piston shaft 208 where the head portion 204 is spaced apart from the flange portion 212.

[0037] The wear adjuster 200 further includes a clutch system 220 coupled to the piston shaft 208 and operable to allow movement of the wear adjuster 200 between a retracted configuration and an extended configuration, as will be discussed below. The clutch system 220 includes an inner race 222 having a lip 224, a ratchet 226, and an outer race 228. The inner race 222 is supported on a support portion 216 of the piston shaft 208, wherein the lip 224 engages the support portion 216, and the ratchet 226 is supported on the inner race 222. The outer race 228 is similarly supported on the ratchet 226. In other words, the ratchet 226 is arranged between the inner race 222 and the outer race 228.

[0038] Ratchet 226 allows periodic rotation of the outer race 228 to disengage the piston 202 from the piston shaft 208, thereby increasing the effective length of the piston assembly 120 in response to an increase in the clearance between the brake pad 56 and the brake disc 52. Ratchet 226 unidirectionally connects the inner race 222 to the outer race 228 so that rotational movement about the piston shaft 122 occurs only in one direction. In other words, ratchet 226 transmits torque and rotation between the inner race 222 and the outer race 228 only in one direction. Here, ratchet 226 can be implemented as a one-way bearing. As will be discussed in further detail below, ratchet 226 rotatably connects the outer race 228 to the inner race 222 for rotation in one direction. When the outer race 228 rotates in the first direction, ratchet 226 connects the outer race 228 to the inner race 222, such that the rotation of the outer race 228 is transmitted to the inner race 222. Conversely, when the outer race 228 rotates in the second direction, the ratchet 226 disengages the outer race 228 from the inner race 222, so that the rotation of the outer race 228 is not transmitted to the inner race 222. In other words, the inner race 222 rotates in the first direction in response to the rotation of the outer race 228 in the first direction, but the inner race 222 does not rotate in response to the rotation of the outer race 228 in the second direction.

[0039] The clutch system 220 of the wear adjuster 200 further includes a distance ring 230 supported on a fixed portion 218 of the piston shaft 208 and one or more Belville washers 232. The distance ring 230 engages on a first side with the lip 224 of the inner race 222 and on a second side with the Belville washer 232. A fastener 234 is attached to the fixed portion 218 of the piston shaft 208 and applies a preload to the Belville washer 232, the distance ring 230, and the lip 224 against a support portion 216 of the piston shaft 208. The fastener 234 shown herein is a slotted nut with a cross pin; however, alternative embodiments of the clutch system 220 may utilize a retaining clip instead of a slotted nut.

[0040] As mentioned above, the wear adjuster 200 is disposed in the adjuster bore 148. More specifically, the shoulder portion 214 of the piston shaft 208 is supported in the adjuster bore 148. The wear adjuster 200 may further include a wave spring 236 supported on the support portion 216 of the piston shaft 208 and arranged between the inner and outer races 222 and the piston body 142. In other words, the wave spring 236 engages with the piston body 142 on a first side and with the outer race 228 on a second side. When the piston assembly 120 returns from the actuated position to the unacted position, the wave spring 236 allows force to be transmitted from the piston body 142 to the piston shaft 208. Additionally, the friction between the wave spring 236 and the outer race 228 generates a minimum torque on the outer race 228, which the adjusting pin 168 must overcome to produce any rotation, thus avoiding unwanted rotation caused by small volume forces (such as those experienced under severe vibration conditions). The wear adjuster 200 may further include a spacer 238 supported on the shoulder portion 214 of the piston shaft 208 and arranged between the flange portion 212 and the piston body 142. The spacer 238 engages with the flange portion 212 of the piston shaft 208 on a first side and with the piston body 142 on a second side.

[0041] Go to Figure 7 The notch 240 is defined in the outer race 228 and configured to receive the adjusting pin 168, and to convert the movement of the lever 118 into rotation of the outer race 228. When the lever 118 is in the unacted position ( Figure 9A ) and actuation position ( Figure 9B When the brake pads 56 move downwards, the adjusting pin 168 moves in the downward direction. When the lever 118 is actuated, the engagement between the adjusting pin 168 and the notch 240 generates torque on the outer race 228. If one (or both) of the brake pads 56 are worn, the torque applied to the outer race 228 by the adjusting pin 168 will cause the wear adjuster 200 to operate in the extended configuration. The notch 240 has a notch width 242 that is larger than the diameter of the adjusting pin 168. The difference between the notch width 242 and the diameter of the adjusting pin 168 corresponds to a predetermined gap between the brake pads 56 and the brake disc 52. When the adjusting pin 168 moves downwards, it must move a short distance before contacting the notch 240 and operating the wear adjuster 200, which maintains the predetermined gap between the brake pads 56 and the brake disc 52. By maintaining this predetermined gap, excessive friction is reduced when braking is not required, thereby increasing vehicle efficiency. In addition, excessive wear of the brake pads 56 is avoided.

[0042] As mentioned above, if one (or both) of the brake pads 56 are worn, the torque applied to the outer race 228 when lever 118 moves from the unactuated position to the actuated position causes the wear adjuster 200 to operate. More specifically, when actuator assembly 102 is actuated, lever 118 moves from the unactuated position to the actuated position, which causes adjusting pin 168 to move to apply torque to the outer race 228. Adjusting pin 168 moves from... Figure 9A The indicated position moves downward and contacts the lower edge of the notch 240. As the lever 118 is further actuated, the adjusting pin 168 moves towards... Figure 9B The position shown continues to move downwards, causing the outer race 228 to rotate counterclockwise (relative to the direction shown). Figure 9A and Figure 9B The outer race 228 causes the ratchet 226 to rotate, which, when rotated counterclockwise, transmits rotation to the inner race 222, and similarly, rotates counterclockwise. The counterclockwise rotation of the outer race 228 is transmitted to the inner race 222 via the ratchet 226. Friction between the distance ring 230, the lip 224 of the inner race 222, and the piston shaft 208 further transmits the rotation of the inner race 222 to the piston shaft 208. In other words, when the outer race 228 rotates counterclockwise, the friction between the distance ring 230, the lip 224 of the inner race 222, and the piston shaft 208, in conjunction with the ratchet 226, causes the outer race 228, ratchet 226, inner race 222, and piston shaft 208 to rotate as a single unit. The brake pad 56 prevents the piston 202 from rotating, which results in relative rotation between the piston 202 and the piston shaft 208. In response to the counterclockwise rotation of piston shaft 208, the tail portion 206 of piston 202 emerges from piston bore 210, causing piston 202 to move toward an extended configuration, thereby increasing the effective length of piston assembly 120. This increased length of piston assembly 120 compensates for the reduction in thickness of brake pad 56 due to wear. When actuator assembly 102 is moved to return from the actuated position to the unactuated position, lever 118 moves adjusting pin 168 upward, causing outer race 228 to rotate clockwise. Because ratchet 226 unidirectionally connects inner race 222 to outer race 228 for rotational movement only counterclockwise around piston axis 122, clockwise rotation of outer race 228 is not transmitted to inner race 222 and piston shaft 208. Therefore, wear adjuster 200 automatically increases the effective length of piston assembly 120 but does not automatically decrease it. When the replacement brake pad 56 is installed, the wear adjuster 200 can be manually reset to the retracted configuration by a technician.

[0043] Without the need for compensation for wear and adjustment of brake pad 56, rotation is not transmitted from inner race 222 to piston shaft 208. As mentioned above, friction in the first region between spacer ring 230, the lip 224 of inner race 222, and piston shaft 208 causes rotation of inner race 222 to be transmitted to piston shaft 208; however, if the static friction in the first region is overcome, inner race 222 will slip. Friction in the second region between piston body 142, spacer 238, and piston shaft 208, as well as friction between the tail portion 206 of piston 202 and the threads of piston bore 210, prevents rotation of wear adjuster 200, thereby preventing undesirable or excessive adjustment. Friction in the first region includes friction between spacer ring 230, the lip 224 of inner race 222, and piston shaft 208. The friction in the second region includes friction between the piston body 142, spacer 238, and piston shaft 208, as well as friction between the tail portion 206 of piston 202 and the threads of piston bore 210. When the friction in the first region is greater than the friction in the second region, rotation of the outer race 228 activates the wear adjuster 200. Conversely, when the friction in the second region is greater than the friction in the first region, rotation of the outer race 228 does not activate the wear adjuster 200.

[0044] The frictional force between the distance ring 230, the lip 224 of the inner seat ring 222, and the piston shaft 208 (i.e., the first region) is controlled by the amount of preload supplied to the distance ring 230 by the Belville washer 232. Additionally, the fastener 234 can be tightened to increase or decrease the preload supplied by the Belville washer 232. Increasing the preload will cause the wear adjuster 200 to more actively increase the effective length of the piston assembly 120, while decreasing the preload will cause the wear adjuster 200 to less actively increase the effective length of the piston assembly 120.

[0045] Now go to Figures 10-14 Another embodiment of the wear conditioner 200' is shown. As will be apparent from the following description, the second wear conditioner 200' is similar to the one described above. Figures 2-9B The wear conditioner 200 is described. Therefore, components and structural features of the second embodiment of the wear conditioner 200′ that are identical or corresponding to those of the first embodiment of the wear conditioner 200 are given the same reference numerals and apostrophed (e.g., 200 and 200′). While the specific differences between these embodiments will be described in detail for the purposes of clarity, consistency, and brevity, only certain structural features and components common to these embodiments will be discussed and depicted in the drawings of the second embodiment of the wear conditioner 200′. Here, unless otherwise indicated, the above description of the first embodiment of the wear conditioner 200 can be incorporated by reference to the second embodiment of the wear conditioner 200′ without limitation.

[0046] As described above, the piston assembly 120′ includes a wear adjuster 200′ that is coupled to the piston body 142′ and extends through an adjuster bore 148′, aligned with the piston axis 122′. The wear adjuster 200′ is movable between a retracted configuration and an extended configuration. The retracted configuration is... Figure 11 , Figure 13 and Figure 14 As shown in the diagram, and extended in the configuration Figure 12 As shown in the image.

[0047] To enable movement between the retracted and extended configurations, the wear adjuster 200′ includes a piston 202′ and a piston shaft 208′. The piston 202′ has a body portion 204′ arranged to engage one of the brake pads 56 and defines a threaded bore portion 206′ configured to threadedly engage the piston shaft 208′. The piston shaft 208′ has a threaded flange portion 212′, a shoulder portion 214′, a support portion 216′, and a retaining portion 218′ configured to threadedly engage the bore portion 206′ of the piston 202′. The flange portion 212′ and the retaining portion 218′ are located at opposite ends of the piston shaft 208′, with the shoulder portion 214′ and the support portion 216′ located between the flange portion and the retaining portion. The shoulder portion 214′ is adjacent to the flange portion 212′, while the support portion 216′ is adjacent to the retaining portion 218′. Piston 202′ can be in a retracted configuration relative to piston shaft 208′. Figure 11 ) and extended configuration ( Figure 12 The piston moves between the drilled portion 206' of piston 202' and the flange portion 212' of piston shaft 208'. The retracted configuration is defined by the flange portion 212' which is fully seated in the drilled portion 206'.

[0048] Here, the wear adjuster 200′ further includes a clutch system 220′, which is coupled to the piston shaft 208′ and operable to allow movement of the wear adjuster 200′ between a retracted configuration and an extended configuration, as will be discussed below. The clutch system 220′ includes an inner race 222′ having a lip 224′ and an outer surface 248′, a coil spring 250′, and an outer race 228′ having an outer surface 252′. The inner race 222′ is supported on a support portion 216′ of the piston shaft 208′, wherein the lip 224′ engages the support portion 216′, and the outer race 228′ is arranged on the support portion 216′, adjacent to and abutting the inner race 222′. The outer surfaces 248′ of the inner race 222′ and 252′ of the outer race 228′ are aligned with each other and have approximately the same diameter. The coil spring 250′ is arranged on the outer surface 248′ of the inner race 222′ and the outer surface 252′ of the outer race 228′.

[0049] Similar to the ratchet 226' described above, the coil spring 250' allows periodic rotation of the outer race 228' to disengage the piston 202' from the piston shaft 208', thereby increasing the effective length of the piston assembly 120' in response to an increase in the clearance between the brake pad 56 and the brake disc 52. The coil spring 250' has an inner diameter that is approximately equal to the diameter of the outer surface 248' of the inner race 222' and the outer surface 252' of the outer race 228'. However, the inner diameter of the coil spring 250' varies during operation as the coil tightens or loosens. More specifically, if the opposite ends of the coil spring 250' twist in the direction of the coil, its inner diameter decreases, and if the opposite ends of the coil spring 250' twist in the direction opposite to the direction of the coil, its inner diameter increases.

[0050] The engagement between the coil spring 250', the inner race 222', and the outer race 228' transmits rotation from the outer race 228' to the inner race 222'. The coil spring 250' unidirectionally connects the inner race 222' to the outer race 228' so that rotational motion about the piston axis 122' occurs only in one direction. In other words, the coil spring 250' transmits torque and rotation only in one direction between the inner race 222' and the outer race 228'. As the outer race 228' rotates in the first direction, friction between the outer surface 252' of the outer race 228' and the coil spring 250' causes the coil to tighten, which reduces the diameter of the coil spring 250'. The coil tightens on both the outer race 228' and the inner race 222', and friction between the outer surface 248' of the inner race 222' and the coil spring 250' causes the inner race 222' to rotate in the first direction. Conversely, when the outer race 228' rotates in the second direction, the friction between the outer surface 252' of the outer race 228' and the coil spring 250' loosens the coil, causing the diameter of the coil spring 250' to increase. As the diameter of the coil spring 250' increases, the friction between the coil spring 250' and the outer race 228' decreases, thereby allowing the outer race 228' to rotate relative to the coil spring 250' and preventing torque and rotation from being transmitted to the inner race 222'. An alternative concept could be to connect the inner race 222', the outer race 228', and the piston shaft 208' while rotating the outer race 228' in the first direction, and achieve the same disengagement effect in the second direction by generating relative rotation between the coil spring 250' and the outer race 228' or relative movement within the coil spring 250' and the inner race 222'.

[0051] The clutch system 220' of the wear adjuster 200' may further include a preload spring 254' and a spring seat 256'. The preload spring 254' and spring seat 256' are arranged on the fixed portion 218' of the piston shaft 208' and disposed within the outer race 228'. The preload spring 254' engages with the spring seat 256', and the spring seat 256' engages with the lip 224' of the inner race 222'. A fastener 234' compresses the preload spring 254', spring seat 256', and inner race 222' against the support portion 216' of the piston shaft 208'. The fastener 234' shown in this embodiment is a retaining washer, which is axially held by a set screw 258'. Alternative embodiments of the clutch system 220' may utilize other fasteners, such as slotted nuts. The wear adjuster 200′ may further include a wave spring 236′ supported on a support portion 216′ of the piston shaft 208′ and arranged between the inner seat ring 222′ and the piston body 142′. In other words, the wave spring 236′ engages with the piston body 142′ on a first side and with the inner seat ring 222′ on a second side.

[0052] The notch 240' is defined within the outer race 228' and is configured to receive the adjusting pin 168' and convert the movement of the lever 118' into rotation of the outer race 228'. When the lever 118' is in the unacted position ( Figure 12 and Figure 14 ) and actuation position ( Figure 11 and Figure 13 When the brake pads 56 move downwards, the adjusting pin 168' moves in the downward direction. When the lever 118' is actuated, the engagement between the adjusting pin 168' and the notch 240' generates torque on the outer race 228'. If one (or both) of the brake pads 56 are worn, the torque applied to the outer race 228' by the adjusting pin 168' will cause the wear adjuster 200' to operate in the extended configuration. The notch 240' has a notch width 242' larger than the diameter of the adjusting pin 168'. The difference between the notch width 242' and the diameter of the adjusting pin 168' corresponds to a predetermined clearance between the brake pads 56 and the brake disc 52. When the adjusting pin 168' moves downwards, it must move a short distance before contacting the notch 240' and operating the wear adjuster 200', which maintains the predetermined clearance between the brake pads 56 and the brake disc 52. By maintaining this predetermined clearance, excessive friction is reduced when braking is not required, thereby increasing vehicle efficiency. In addition, it avoids excessive wear of brake pad 56.

[0053] When one (or both) of the brake pads 56 have worn, lever 118' moves from the unacted position to the actuated position, and torque is applied to the outer race 228', which activates the wear adjuster 200'. More specifically, when actuator assembly 102' is actuated, lever 118' moves from the unacted position to the actuated position, which moves adjusting pin 168' to apply torque to the outer race 228'. Adjusting pin 168' moves downward and contacts the lower edge of recess 240'. As lever 118' is further actuated, adjusting pin 168' continues to move downward, which causes the outer race 228' to rotate counterclockwise (relative to...). Figure 13 and Figure 14 The friction between the outer surface 252' of the outer race 228' and the coil spring 250' causes the coil spring 250' to tighten, thereby causing the coil spring 250' to rotate together with the outer race 228'. The counterclockwise rotation of the coil spring 250' transmits rotation to the inner race 222', which also rotates counterclockwise. The counterclockwise rotation of the outer race 228' is transmitted to the inner race 222' via the coil spring 250'. The friction between the lip 224' of the inner race 222' and the piston shaft 208' further transmits the rotation of the inner race 222' to the piston shaft 208'. In other words, when the outer race 228' rotates counterclockwise, the friction between the lip 224' of the inner race 222' and the piston shaft 208' cooperates with the coil spring 250' to cause the outer race 228', coil spring 250', inner race 222', and piston shaft 208' to rotate as a single unit. The brake pad 56 prevents the piston 202' from rotating, which results in relative rotation between the piston 202' and the piston shaft 208'. In response to the counterclockwise rotation of the piston shaft 208', the drilled portion 206' of the piston 202' unscrews from the flange portion 212' of the piston shaft 208', causing the piston 202' to move toward an extended configuration, thereby increasing the effective length of the piston assembly 120'. The increased length of the piston assembly 120' compensates for the reduction in the thickness of the brake pad 56 due to wear. When actuator assembly 102' is moved to return from the actuated position to the unactuated position, lever 118' moves adjusting pin 168' upward, thereby rotating outer race 228' clockwise. Because coil spring 250' unidirectionally connects inner race 222' to outer race 228' so that rotational movement is only in the counter-clockwise direction about piston axis 122', clockwise rotation of outer race 228' is not transmitted to inner race 222' and piston axis 208'. Therefore, wear adjuster 200' automatically increases the effective length of piston assembly 120' but does not automatically decrease the effective length of piston assembly 120'. When a replacement brake pad 56 is fitted, wear adjuster 200' can be manually reset to the retracted configuration by a technician.

[0054] Without the need for compensation for wear and adjustment of brake pad 56, rotation is not transmitted from the inner race 222' to the piston shaft 208'. As mentioned above, friction in the first region between the lip 224' of the inner race 222' and the piston shaft 208' causes the rotation of the inner race 222' to be transmitted to the piston shaft 208'; however, if the friction is too small, the inner race 222' will slip. Friction in the second region between the piston body 142' and the piston shaft 208', as well as friction between the threads of the drilled portion 206' and the flange portion 212' of the piston 202', prevents rotation of the wear adjuster 200', thereby preventing undesirable or excessive adjustment. The friction in the first region includes friction between the lip 224' of the inner race 222' and the piston shaft 208'. The friction in the second region includes friction between the piston body 142' and the piston shaft 208', and friction between the threads of the drilled portion 206' of the piston 202' and the flange portion 212' of the piston shaft 208'. When the friction in the first region is greater than the friction in the second region, the rotation of the outer race 228' activates the wear adjuster 200'. Conversely, when the friction in the second region is greater than the friction in the first region, the rotation of the outer race 228' does not activate the wear adjuster 200'.

[0055] The frictional force between the lip 224' of the inner race 222' and the piston shaft 208' (i.e., the first region) is controlled by the amount of preload supplied by the preload spring 254' to the spring seat 256'. Additionally, the fastener 234' can be tightened to increase or decrease the preload supplied by the preload spring 254'. Increasing the preload will cause the wear adjuster 200' to more actively increase the effective length of the piston assembly 120', while decreasing the preload will cause the wear adjuster 200' to less actively increase the effective length of the piston assembly 120'.

[0056] Now go to Figure 15 A third embodiment of the wear regulator 200′′ is shown. As will be apparent from the following description, the third wear regulator 200′′ is similar to the one described above. Figures 10-14 The wear regulator 200′ is described. Therefore, components and structural features of the third embodiment of the wear regulator 200′′ that are identical or corresponding to those of the second embodiment of the wear regulator 200′′ are given the same reference numerals and are prefixed with a second apostrophe (e.g., 200′ and 200′′). While specific differences between these embodiments will be described in detail for the purposes of clarity, consistency, and brevity, only certain structural features and components common to these embodiments will be discussed and depicted in the drawings of the third embodiment of the wear regulator 200′′. Here, unless otherwise indicated, the above description of the first embodiment of the wear regulator 200 can be incorporated by reference to the third embodiment of the wear regulator 200′′ without limitation.

[0057] As mentioned above, piston assembly 120′′ includes a wear adjuster 200′′ that is coupled to piston body 142′′ and extends through adjuster bore 148′′, aligned with piston axis 122′′. Wear adjuster 200′′ is available in retracted and extended configurations. Figure 15 The wear adjuster 200′′ moves between the retracted and extended configurations. To enable movement between the retracted and extended configurations, the wear adjuster 200′′ includes a piston 202′′ that is threadedly engaged with the piston shaft 208′′.

[0058] The wear adjuster 200′′ further includes a clutch system 220′′ coupled to the piston shaft 208′′ and operable to allow movement of the wear adjuster 200′′ between a retracted configuration and an extended configuration. The clutch system 220′′ includes an inner race 222′′, an outer race 228′′, and a coil spring 250′′. The inner race 222′′ is supported on and rotatably coupled to the piston shaft 208′′, for example via a press fit. In some embodiments, the piston shaft 208′′ may be integrally formed with the inner race 222′′. The coil spring 250′′ is disposed on the inner race 222′′, while the outer race 228′′ is supported on the coil spring 250′′. The clutch system 220′′ further includes a coil spring 260′′ and a piston body sleeve 262′′, each disposed in an adjuster bore 148′′. The piston body sleeve 262′′ is coupled to the piston body 142′′ and rotatably fixed, for example, via a press fit. One end of the coil spring 250′′ is anchored to the piston body sleeve 262′′, while the other end is anchored to the outer race 228′′. The coil spring 250′′, the inner race 222′′, and the outer race 228′′ are shaped and wound such that a small-angle rotation in the direction opposite to the winding direction of the coil spring 250′′ will disengage the inner race 222′′ from the piston body sleeve 262′′. The helical spring 260′′ is operably engaged between the piston body 142′′ and the piston shaft 208′′ and stores potential energy to allow relative rotation between the piston body and the piston shaft. The tapered washer 264′′ provides resistance to the free rotation of the piston shaft 208′′.

[0059] Similar to the above, when adjustment is required, the wear adjuster 200′′ consists of lever 118 and adjusting pin 168 ( Figure 4 and Figure 10 This triggers, causing the outer race 228'' to pivot. When the adjusting pin 168 causes the notch 240 ( Figure 4 and Figure 10As the piston moves and the outer race 228′′ rotates, the diameter of the coil spring 250′′ around the inner race 222′′ increases slightly, causing the piston body sleeve 262′′ to rotate out of contact with the inner race 222′′. When the piston body sleeve 262′′ disengages from the inner race 222′′, the piston shaft 208′′ is able to rotate within the adjuster bore 148′′, allowing the coil spring 260′′ to release its stored potential energy and cause the piston shaft 208′′ to rotate in the opposite direction. The rotation of the piston shaft 208′′ causes the piston 202′′ to unscrew from the piston shaft 208′′, moving the piston 202′′ toward the extended configuration. When lever 118 moves toward the unacted position, brake pad 56 and piston 202′′ remain in contact with brake disc 52 until outer race 228′′ has rotated sufficiently in the opposite direction, causing the diameter of coil spring 250′′ around inner race 222′′ to decrease sufficiently to re-engage the connection between inner race 222′′ and piston body sleeve 262′′. Conversely, when adjustment of wear adjuster 200′′ is not necessary, even when lever 118 rotates outer race 228′′ and disengages outer race 228′′ from inner race 222′′, friction between piston 202′′ and piston shaft 208′′, and friction between piston shaft 208′′ and piston body 142′′, overcomes the force of coil spring 260′′ and prevents rotation of piston shaft 208′′.

[0060] Several examples have been discussed in the foregoing description. However, the aspects discussed herein are not intended to be exhaustive or to limit this disclosure to any particular form. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this disclosure. The terminology used is intended to describe the words essentially, not to be limiting. Based on the teachings above, many modifications and variations are possible, and this disclosure can be practiced in ways other than those specifically described.

Claims

1. A wear adjuster for a brake caliper having a piston body, the wear adjuster comprising: Piston, which is arranged to engage with brake pads; A piston shaft, which is threadedly engaged with the piston and supported by the piston body; A clutch system for periodically achieving relative rotation between the piston and the piston shaft, the clutch system comprising: Inner race, which frictionally engages with the piston shaft; An outer race, unidirectionally connected to the inner race, is used to transmit torque between the outer race and the inner race, wherein rotation of the outer race in a first direction causes rotation of the inner race in the first direction, and wherein rotation of the outer race in a second direction does not cause rotation of the inner race; and A preload spring is operably disposed between the piston shaft and the inner race and is configured to cause the inner race to engage with the piston shaft.

2. The wear regulator according to claim 1, wherein, The piston has a first portion and is movable between a retracted configuration and an extended configuration, wherein the first portion of the piston engages with the piston shaft in the retracted configuration and is spaced apart from the piston shaft in the extended configuration.

3. The wear regulator according to claim 2, wherein, The piston shaft has a flange portion and a shoulder portion, wherein the flange portion engages with a first portion of the piston in the retracted configuration.

4. The wear regulator according to claim 3, wherein, The piston shaft is arranged to increase the frictional engagement between the flange portion and the piston body when the brake caliper is actuated.

5. The wear regulator according to claim 1, wherein, The piston shaft has a support portion, and the inner race has a lip, wherein the lip frictionally engages with the support portion for transmitting torque between the lip and the support portion.

6. The wear regulator according to claim 5, wherein, The piston shaft further has a fixed portion, wherein the lip is disposed on the fixed portion, and wherein the preload spring is disposed on the fixed portion.

7. The wear regulator according to claim 1, wherein, The clutch system further includes a ratchet disposed between the inner race and the outer race, wherein the ratchet unidirectionally connects the inner race and the outer race.

8. The wear regulator according to claim 7, wherein, The ratchet is further defined as a one-way bearing.

9. The wear regulator according to claim 7, wherein, The preload spring is further defined as a Belville washer.

10. The wear regulator according to claim 1, wherein, The clutch system further includes a coil spring that engages with the outer surface of the outer race and the outer surface of the inner race, wherein the coil spring is configured to transmit rotation from the outer race to the inner race.

11. An electrically actuated brake caliper for a vehicle, the brake caliper comprising: Piston body; Wear conditioner, including: Piston, which is arranged to engage with brake pads; A piston shaft, which is threadedly engaged with the piston and supported by the piston body; A clutch system for periodically achieving relative rotation between the piston and the piston shaft, the clutch system comprising: Inner race, which frictionally engages with the piston shaft; An outer race, unidirectionally connected to the inner race, is used to transmit torque between the outer race and the inner race, wherein rotation of the outer race in a first direction causes rotation of the inner race in the first direction, and wherein rotation of the outer race in a second direction does not cause rotation of the inner race; and A preload spring is operably disposed between the piston shaft and the inner race and is configured to cause the inner race to engage with the piston shaft.

12. The electrically actuated brake caliper according to claim 11, wherein, The piston has a first portion and is movable between a retracted configuration and an extended configuration, wherein the first portion of the piston engages with the piston shaft in the retracted configuration and is spaced apart from the piston shaft in the extended configuration.

13. The electrically actuated brake caliper according to claim 12, wherein, The piston shaft has a flange portion and a shoulder portion, wherein the flange portion engages with a first portion of the piston in the retracted configuration.

14. The electrically actuated brake caliper according to claim 13, wherein, The piston shaft is arranged to increase the frictional engagement between the flange portion and the piston body when the brake caliper is actuated.

15. The electrically actuated brake caliper according to claim 11, wherein, The piston shaft has a support portion, and the inner race has a lip, wherein the lip frictionally engages with the support portion for transmitting torque between the lip and the delivery support portion.

16. The electrically actuated brake caliper according to claim 15, wherein, The piston shaft further has a fixed portion, wherein the lip is disposed on the fixed portion, and wherein the preload spring is disposed on the fixed portion.

17. The electrically actuated brake caliper according to claim 11, wherein, The clutch system further includes a ratchet disposed between the inner and outer races, wherein the ratchet unidirectionally connects the inner and outer races.

18. The electrically actuated brake caliper according to claim 17, wherein, The ratchet is further defined as a one-way bearing.

19. The electrically actuated brake caliper according to claim 17, wherein, The preload spring is further defined as a Belville washer.

20. The electrically actuated brake caliper according to claim 11, wherein, The clutch system further includes a coil spring that engages with the outer surface of the outer race and the outer surface of the inner race, wherein the coil spring is configured to transmit rotation from the outer race to the inner race.

21. A wear adjuster for a brake caliper having a piston body, the wear adjuster comprising: Piston, which is arranged to engage with brake pads; A piston shaft, which is threadedly engaged with the piston and supported by the piston body; and A clutch system for periodically achieving relative rotation between the piston and the piston shaft, the clutch system comprising: Outer seat ring; Inner race, which is connected to the piston shaft and disposed inside the outer race; and A coil spring, which frictionally engages with the inner and outer races, is configured to unidirectionally connect the inner race to the outer race for transmitting torque between the outer and inner races, wherein rotation of the outer race in a first direction causes rotation of the inner race in the first direction, and wherein rotation of the outer race in a second direction does not cause rotation of the inner race.

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