Hydraulic drive device comprising a cycloidal motor with friction brake

Abstract

A hydraulic drive device (100) is disclosed in which a mechanical friction brake (124, 132, 134) is implemented in a gerotor hydraulic motor (113). The orbital movement of the gerotor star (118) is translated via a brake hub (124) into rotational movement of a set of brake pads (132). The rotational movement of the gerotor outer ring (114) is transmitted to another set of brake pads (134). These two sets of brake pads (132, 134) are axially pressed together to brake the gerotor motor (113). The braking force compressing these brake pads is applied via a spring force (138) and removed by transmitting the operating pressure of the motor to a brake piston (136) via a release member (139, 201) extending through a central shaft (130) and the brake hub (124).

Description

Background Technology

[0001] In many vehicle applications using low-speed, high-torque cycloidal motors, it is desirable for the motor to have some type of parking brake or parking lock designed to engage only after the vehicle has come to a stop. Such a parking brake device is not intended to be a dynamic brake, which engages to stop the vehicle while it is moving. In some cases, the parking brake may be engaged on the motor output shaft external to the motor. In other cases, the parking brake may be engaged within the motor. For example, a pin breakage may occur in the motor, where the pin is inserted into the star-shaped member at a predetermined braking point (e.g., between adjacent splines or teeth of the star-shaped member). However, such braking can only be applied if the pin is aligned with one of the predetermined braking points, which can lead to improper positioning of the motor-driven vehicle. Furthermore, such a braking system can result in difficulty releasing the pin brake on steep slopes, and a shock may occur upon releasing the pin brake. Summary of the Invention

[0002] Some aspects of this disclosure relate to the mounting of mechanical friction brakes on hydraulic drive units. Such friction brakes can be used as parking brakes on cycloidal motors in low-speed, high-torque applications (such as those driving large machinery, vehicles, or construction equipment). When the equipment operator engages the equipment for movement, the hydraulic fluid driving the motor can be used to release the friction brake in the motor. When the equipment operator indicates that the equipment should stop, the pressure change of the hydraulic fluid engages the friction brake in the motor.

[0003] Friction brakes can be engaged and subsequently released at any point during motor rotation, allowing proper positioning of the vehicle or equipment even on steep inclines. Eliminating the need to align the pin with the opening (e.g., between adjacent splines or teeth) prevents shock when the friction brake is released, allows the brake to be released when the vehicle or equipment is on an incline, and increases the safety of vehicle starting.

[0004] According to some aspects of this disclosure, the friction brake includes a first friction brake pad and a second friction brake pad that rotate at different speeds. Braking is applied by pressing the first and second brake pads together to suppress relative movement therebetween. Braking is applied via spring force and removed by the operating pressure of the motor. Thus, braking is applied when the hydraulic actuator is not actuated by the user, and braking is released when the user actuates the hydraulic actuator.

[0005] A first friction brake pad is mounted to a brake hub that rotates relative to a cycloidal hydraulic motor of a hydraulic actuator. A second friction brake pad is mounted to a brake cover that rotates together with an outer ring of the cycloidal hydraulic motor. The brake hub is configured to rotate faster than the outer ring, causing the first brake pad to rotate relative to the second brake pad. Therefore, pressing the first and second brake pads together stops the relative movement between the brake hub and the outer ring.

[0006] Friction brake systems may include a thrust plate that limits the range of motion of the piston driving the brake release mechanism and can reduce the axial load on the brake release mechanism. Shims between components in a friction brake system can help the friction brake function properly by taking into account variations in part dimensions due to manufacturing tolerances. In some examples, a separate brake release lever can reduce mechanical wear. Phosphating certain components can help eliminate the need for additional bushings in motor assemblies.

[0007] This invention provides a hydraulic actuator with mechanical braking. The hydraulic actuator includes a spindle, an actuator housing, and a cycloidal hydraulic motor arrangement, the cycloidal hydraulic motor arrangement including an outer motor ring coupled to the actuator housing such that the outer motor ring and the actuator housing are adapted to rotate uniformly about a central axis. The hydraulic actuator also includes a brake arrangement for braking (e.g., stopping movement) the cycloidal hydraulic motor arrangement and a brake release arrangement for selectively releasing the brake arrangement (e.g., enabling movement of the cycloidal hydraulic motor arrangement).

[0008] In some examples, the spindle has a first mounting flange. The spindle defines a central axis. The actuator housing is mounted on the spindle. The actuator housing includes a second mounting flange. Bearings allow the actuator housing to rotate about the central axis relative to the spindle. The central axis is configured to prevent the cycloidal star from rotating about its axis relative to the spindle while allowing the cycloidal star to orbit about the central axis.

[0009] In some examples, the outer motor ring includes radially inwardly spaced recesses circumferentially spaced around a central axis. The cycloidal hydraulic motor arrangement also includes a cycloidal star with a plurality of convex angles circumferentially positioned around a star axis defined by the cycloidal star. The cycloidal star is positioned within the outer motor ring, wherein the star axis is offset from the central axis, such that the cycloidal star is eccentric relative to the outer motor ring. The cycloidal star is mounted to orbit around the central axis when the outer motor ring is hydraulically driven around the central axis, thereby bringing the convex angles into and out of the recesses of the outer motor ring. One orbit of the cycloidal star around the central axis corresponds to a movement of the outer motor ring around the central axis relative to the cycloidal star by one recess position.

[0010] In some examples, the brake arrangement includes a brake hub comprising a first portion concentric with a central axis and a second portion concentric with a cycloidal star member. The second portion of the brake hub mechanically intersects with the cycloidal star member such that the orbital movement of the cycloidal star member about the central axis drives the rotation of the brake hub about the central axis. Each time the cycloidal star member orbits the central axis, the brake hub rotates once about the central axis. A first brake pad is mounted to rotate about the central axis in conjunction with the brake hub; a second brake pad is mounted to rotate about the central axis in conjunction with the actuator housing and the outer motor ring. A brake piston is configured to axially press the first and second brake pads together to provide braking of the cycloidal hydraulic motor arrangement. The brake piston is spring-biased axially toward the first and second brake pads by a brake spring.

[0011] In some examples, the brake release arrangement includes a brake release member extending through the central shaft and the brake hub. The brake release member is adapted to release the brake of the cycloidal hydraulic motor arrangement by axially pushing the brake piston away from the first and second brake pads against a spring bias of the brake spring.

[0012] Various additional inventive aspects will be set forth in the following description. These inventive aspects may involve individual features as well as combinations of features. It will be understood that both the foregoing general description and the following detailed description are exemplary and illustrative only, and do not limit the broad inventive concept on which the embodiments disclosed herein are based. Attached Figure Description

[0013] The accompanying drawings, which are incorporated in and form part of this specification, illustrate several aspects of this disclosure. A brief description of the drawings is as follows:

[0014] Figure 1 This is an isometric view of a hydraulic actuator configured according to the principles of this disclosure;

[0015] Figure 2 yes Figure 1 The axial section of a first example implementation of a hydraulic actuator;

[0016] Figure 3 yes Figure 1 A perspective view of a hydraulic actuator, in which certain components of the brake arrangement and its brake release arrangement are disassembled outwards;

[0017] Figure 4 yes Figure 1 An elevation view of a hydraulic actuator, wherein the brake arrangement has been removed for ease of observation of the outer motor ring, cycloidal star and brake hub configured according to the principles of this disclosure;

[0018] Figure 5 yes Figure 2 A magnified view of the portion;

[0019] Figure 6 yes Figure 3 An exploded view of the first brake pad and the second brake pad shown.

[0020] Figure 7 This is a perspective view of a first example brake hub configured according to the principles of this disclosure;

[0021] Figure 8 yes Figure 7 Front elevation view of the brake hub;

[0022] Figure 9 yes Figure 7 Rear elevation view of the brake hub;

[0023] Figure 10 yes Figure 2 An enlarged view of another part;

[0024] Figure 11 This is a perspective view of a second example brake hub configured according to the principles of this disclosure and disassembled outward from the cycloidal star component, wherein the components of the second brake hub are disassembled from each other;

[0025] Figure 12 yes Figure 11 A perspective view of the body of the second example brake hub;

[0026] Figure 13 yes Figure 11 The second example is a side elevation view of the main body of a brake hub;

[0027] Figure 14 yes Figure 11 The front elevation view of the main body of the second example brake hub;

[0028] Figure 15 yes Figure 11 The rear elevation view of the main body of the second example brake hub;

[0029] Figure 16 This demonstrates the junction of the outer motor ring with the cycloidal hydraulic actuator. Figure 11 The second example is a brake hub and a cycloidal star component;

[0030] Figure 17 yes Figure 11 A perspective view of the cross-section of the second example brake hub;

[0031] Figure 18 yes Figure 17 A magnified view of the portion;

[0032] Figure 19 yes Figure 1 A second example implementation of the hydraulic actuator, comprising an axial section. Figure 11 The second example brake hub;

[0033] Figure 20 The diagram shows the positions of the brake pads in the actuated and brake-release positions for releasing the brake liner. Figure 19 The brake actuator piston and brake release component;

[0034] Figure 21 yes Figure 20 A magnified view of the portion;

[0035] Figure 22 yes Figure 20 An enlarged view of another part;

[0036] Figure 23 It shows Figure 19 A hydraulic actuator in which bushings and washers are disposed between the brake hub and surrounding components;

[0037] Figure 24 This is a perspective view of a third example brake arrangement configured according to the principles of this disclosure, wherein the components of the third brake hub are disassembled from each other;

[0038] Figure 25 yes Figure 24 Rear perspective view of the brake hub of the third brake arrangement; and

[0039] Figure 26 yes Figure 1 A second example implementation of the hydraulic actuator, comprising an axial section. Figure 24 The third example of brake arrangement. Detailed Implementation

[0040] Reference will now be made to illustrative aspects of this disclosure as shown in the accompanying drawings. Where possible, the same reference numerals will be used in all drawings to refer to the same or similar parts.

[0041] This disclosure relates to a mechanical friction brake on a hydraulic actuator, which can be used to propel large equipment, vehicles, or machinery. In some implementations, the mechanical friction brake is integrated into the hydraulic actuator, thus occupying the space of the hydraulic actuator. In some implementations, the mechanical friction brake can provide braking regardless of the position of the actuator housing around the spindle. Hydraulic actuators configured according to the principles of this disclosure can also be used to drive drill bits, drive wheels or discs, crushing / grinding drums, or other rotatable structures.

[0042] refer to Figures 1 to 4 In some examples, the hydraulic actuator 100 includes a spindle 102 that defines a central axis 104 of a motor. The spindle 102 may have a first mounting flange 106 that can be attached to a support housing or frame of equipment, vehicle, or machinery. An actuator housing 108 is mounted on the spindle 102 and configured to rotate relative to the spindle 102 about the central axis 104. The actuator housing 108 may include a second mounting flange 110 that is attached to a driven member, such as a wheel, sprocket barrel, or other rotatable structure. The hydraulic actuator 100 converts a flow of hydraulic fluid within the actuator housing 108 into rotational movement of the actuator housing 108 relative to the spindle 102. Torque from the hydraulic actuator housing 108 is transmitted to the driven member. In some examples, the hydraulic actuator 100 may include bearings 112 for facilitating rotation of the actuator housing 108 relative to the spindle 102 about the central axis 104.

[0043] In some implementations, the hydraulic actuator 100 includes a cycloidal hydraulic motor arrangement 113 comprising an outer motor ring 114 coupled to an actuator housing 108 such that the outer motor ring 114 and the actuator housing 108 are adapted to rotate co-rotate about a central axis 104. A motor cover 142 is mounted to the outer motor ring 114 to rotate co-rotate with it. In some implementations, a valve plate 115 is mounted between the actuator housing 108 and the outer motor ring 114 to supply hydraulic fluid to the outer motor ring 114.

[0044] Now refer to Figure 4The outer motor ring 114 may include a plurality of radially inwardly spaced recesses 116 circumferentially spaced around a central axis 104. In some examples, the cycloidal hydraulic motor arrangement 113 may also include a cycloidal star 118 having a plurality of protrusions 120 circumferentially positioned about a star axis 122 defined by the cycloidal star 118. The cycloidal star 118 is positioned within the outer motor ring 114, wherein the star axis 122 is offset from the central axis 104, such that the cycloidal star 118 is eccentric relative to the outer motor ring 114. The cycloidal star 118 may be mounted to orbit around the central axis 104 when the outer motor ring 114 is hydraulically driven around the central axis 104, so as to bring the protrusions 120 into and out of the recesses 116 of the outer motor ring 114. In some examples, the orbit of the cycloidal star 118 around the central axis 104 corresponds to the outer motor ring 114 moving one recess position relative to the cycloidal star 118 around the central axis 104. The number of protrusions 120 on the cycloidal star 118 is one less than the number of recesses 116. For example, if the outer motor ring 114 has seven recesses 116, the associated cycloidal star 118 will have six protrusions 120. In some examples, the recesses 116 may be separated by rollers 146 (see, for example, see...). Figure 4 and Figure 16 For example, the cycloidal hydraulic motor arrangement 113 can be supplied by Eaton Corporation. Cycloidal motor. In some examples, the number of recesses 116 is equal to the number of rollers 146.

[0045] Return to reference Figure 2 A central shaft 130 extends between the cycloidal star member 118 and the spindle 102. A first end of the central shaft 130 is splined to or otherwise mechanically interlocked with the spindle 102. A second end of the central shaft 130 is splined to or otherwise mechanically interlocked with the cycloidal star member 118. The engagement between the first end of the central shaft 130 and the spindle 102 inhibits rotation of the central shaft 130, which in turn inhibits rotation of the cycloidal star member 118 relative to the spindle 102. Conversely, the second end of the central shaft 130 moves relative to the first end along the track of the cycloidal star member 118. Additional details regarding the operation of the cycloidal hydraulic motor arrangement 113 can be found in U.S. Patent Nos. 6,132,194 and 8,157,552, the disclosures of which are hereby incorporated herein by reference in their entirety.

[0046] Now for reference Figures 5 to 9The hydraulic actuator 100 includes brake arrangements 123, 209 configured to stop rotation of the actuator housing 108 relative to the spindle 102. In some implementations, brake arrangements 123, 209 function as parking brakes to suppress rotation of the actuator housing 108 when hydraulic fluid is not supplied or discharged from the cycloidal hydraulic motor arrangement 113. When hydraulic fluid is supplied to the cycloidal hydraulic motor arrangement 113, brake arrangements 123, 209 are released. A first example brake arrangement 123... Figures 2 to 10 As shown in the diagram, and the second example brake arrangement 209 is in Figures 11 to 22 As shown in the image.

[0047] In some implementations, brake arrangements 123, 209 are integrated within the space occupied by the hydraulic actuator 100. In some examples, brake arrangements 123, 209 are housed within the actuator housing 108. In some examples, brake cover 156 may be mounted externally to motor cover 142 (e.g., see...). Figure 1 In such an example, the brake cover 156 rotates in unison with the motor cover 142, the outer motor ring 114, and the actuator housing 108. In some examples, the brake chamber 158 is defined between the motor cover 142 and the brake cover 156 (see, for example, see...). Figure 5 ).

[0048] In some implementations, brake arrangements 123, 209 include a first brake pad 132 and a second brake pad 134 disposed within the brake chamber 158 (see, for example, see...). Figure 5 In some examples, the first brake pad 132 and the second brake pad 134 are mounted concentrically with the central axis 104 of the hydraulic actuator 100. When the brake pads 132, 134 are axially spaced apart from each other (e.g., along the central axis 104), the first brake pad 132 rotates relative to the second brake pad 134. When axially pressed together, friction causes the first brake pad 132 to slow down and then stop moving relative to the second brake pad 134. In some examples, the first brake pad and the second brake pad 132 are a single friction brake pad. In other examples, the first brake pad and / or the second brake pad 132 form part of a group of multiple friction brake pads. In some examples, the group of the first brake pad 132 and the second brake pad 134 overlaps (e.g., see...). Figure 5 ).

[0049] The second brake pad 134 is carried by a brake cover 156, which is mounted to a motor cover 142 (e.g., by axial bolts 160) for rotational synchronization with the motor cover 142. Therefore, the second brake pad 134 rotates synchronously with the actuator housing 108 and the outer motor ring 114. In some implementations, the second brake pad 134 includes a flap 242 (e.g., see...). Figure 6 (or other protrusions, which engage with the recess defined by the brake cover 156 to secure the second brake liner 134 to the brake cover 156. Other mounting configurations are possible.)

[0050] A first brake pad 132 is mounted to a brake hub 124, which is configured to rotate relative to a motor cover 142. Therefore, the first brake pad 132 is carried by the brake hub 124 to rotate relative to the brake cover 156 and the second brake pad 132. In some examples, the inner circumference of the first brake pad 132 defines one or more flat surfaces that engage a flat surface 237 on the brake hub 124 (e.g., see...). Figure 7 and Figure 8 In other examples, the first brake pad 132 includes a spline 234 on the brake hub 124 (see, for example, see...). Figure 12 Aligned teeth 232 (e.g., see...) Figure 6 Other installation configurations are possible. The engagement between the first brake pad 132 and the brake hub 124 allows the first brake pad 132 to rotate in unison with the brake hub 124.

[0051] refer to Figure 5 , Figure 7 and Figure 8 The brake hub 124 has a first portion 126 that is mounted to the motor cover 142. The first portion 126 is concentric with the central axis 104, such that the brake hub 124 rotates about the central axis 104 relative to the motor cover 142. The brake hub 124 has a second portion 128 that is concentric with the cycloidal star member 118 (see, for example, [reference needed]). Figure 4 As will be discussed in more detail here, the second part 128 mechanically intersects with the cycloidal star 118 such that the orbital movement of the cycloidal star 118 about the central axis 104 drives the rotation of the brake hub 124 about the central axis 104. In some implementations, the orbital movement of the cycloidal star 118 drives the brake hub 124 to rotate faster than the outer motor ring 114. In some examples, the brake hub 124 rotates once about the central axis 104 each time the cycloidal star 118 orbits about the central axis 104 (i.e., each time the outer motor ring 114 rotates to a recessed position).

[0052] In some examples, the number of rotations of the brake hub 124 is equal to the number of recesses 116 defined by the cycloidal hydraulic motor arrangement 113. For example, if there are seven recesses 116, the brake hub 124 will rotate seven times per rotation relative to the outer motor ring 114. This conversion between the orbital motion of the cycloidal star 118 and the rotational motion of the outer motor ring 114 and the brake hub 124 allows the brake arrangements 123, 209 to be designed for smaller torques. For example, in a system where the brake hub 124 rotates seven times per rotation relative to the outer motor ring 114, the brake arrangements 123, 209 can be designed for approximately a seven-fold reduction in torque. In some examples, this can make the brake arrangements 123, 209 cheaper and use less material.

[0053] In some implementations, a brake hub bushing 164 is positioned between the brake hub 124 and the motor cover 142. In some examples, for reliable motor performance, the brake hub bushing 164 helps hold the brake hub 124 in its proper position. In some examples, a star-shaped bushing 166 is positioned at the central opening 144 of the cycloidal star-shaped member 118. In other examples, the outer surface of the second portion 128 of the brake hub 124 is subjected to phosphate treatment to protect it from mechanical wear and tear.

[0054] In some implementations, brake arrangements 123, 209 include a brake piston 136 configured to selectively press a first brake pad 132 and a second brake pad 134 together axially (e.g., along the central axis 104) to provide braking of the cycloidal hydraulic motor arrangement 113 (e.g., see...). Figure 5 The brake piston 136 can be spring-biased axially toward the first brake pad 132 and the second brake pad 134 by the brake spring 138. Therefore, the brake piston 136 actuates the brake arrangements 123, 209 without a release force overcoming the bias of the brake spring 138. In some examples, the brake piston 136 and the brake spring 138 are disposed within the brake chamber 158. In the example shown, the brake spring 138 is a disc spring. Other types of springs (e.g., coil springs) may also be used.

[0055] The axial pressing of the first brake pad 132 and the second brake pad 134 together stops the relative movement between the brake hub 124 and the outer motor ring 114. Because the rotation of the brake hub 124 is related to the orbital movement of the cycloidal star member 118, stopping the relative movement between the brake hub 124 and the outer motor ring 114 also stops the relative movement between the cycloidal star member 118 and the outer motor ring 114. This stopping of the orbital movement of the star member 118 stops the rotation of the outer motor ring 114. Because the brake hub 124 and the star member 118 are always engaged (rather than engaged along the gear at the indexing position), braking force can be applied at any desired time.

[0056] In some implementations, the hydraulic actuator 100 includes brake release arrangements 139, 201 configured to selectively release brake arrangements 123, 209. Brake release arrangements 139, 201 apply sufficient force to brake piston 136 to overcome the bias of brake spring 138 and move brake piston 136 away from first brake pad 132 and second brake pad 134, thereby allowing axial separation of the first brake pad 132 and second brake pad 134. In some examples, brake release arrangements 139, 201 are automatically actuated when hydraulic fluid is applied to cycloidal hydraulic motor arrangement 113, as will be described in more detail herein. A first example implementation of brake release arrangement 139 is described in... Figures 2 to 10 As shown in the diagram, and in a second example implementation of the brake release arrangement 201, Figures 11 to 22 As shown in the image.

[0057] In some implementations, the brake release arrangements 139, 201 are integrated within the space occupied by the hydraulic actuator 100. In some examples, a portion of the brake release arrangements 139, 201 is disposed within a release chamber 162 formed between the end cap 154 ​​and the thrust plates 150, 216, which are mounted to the spindle 102 (see, for example, [link to relevant documentation]). Figure 10 and Figure 22 In such an example, end cap 154 ​​remains stationary relative to spindle 102. End cap 154 ​​defines hydraulic inlet and outlet ports for hydraulic lines that extend through hydraulic actuator 100 to cycloidal hydraulic motor arrangement 113.

[0058] Brake release arrangements 139, 201 include brake release members 140, 203 extending through the central shaft 130 and through the brake hub 124 (see, for example, see...). Figure 2 and Figure 19 Brake release members 140 and 203 are configured in the braking position relative to the central shaft 130 and relative to the brake hub 124 (see, for example, see...). Figure 2 and Figure 19 ) and release location (for example, see Figure 20 Sliding between the brake release members 140 and 203. The brake release members 140 and 203 are operatively coupled to the brake piston 136 such that, when moved to the release position, the brake release members 140 and 203 release the brakes of the cycloidal hydraulic motor arrangement 113 by axially (e.g., along the central axis 104) pushing the brake piston 136 away from the first brake pad 132 and the second brake pad 134 against the spring bias of the brake spring 138. However, when the brake release members 140 and 203 are positioned in the brake position, the brake release members 140 and 203 allow the brake spring 138 to bias the first brake pad 132 and the second brake pad 134 together via the brake piston 136.

[0059] Now for reference Figure 10 and Figure 22 The brake release components 140 and 203 are hydraulically actuated. The brake release components 140 and 203 are operatively connected to a brake actuation piston 152 located on the spindle side of the hydraulic device 100. The brake actuation piston 152 is configured to be hydraulically actuated to move along the central axis 104 toward and away from the cycloidal hydraulic motor arrangement 113 between a starting position and an actuated position. Moving the brake actuation piston 152 from the starting position to the actuated position moves the brake release components 140 and 203 from the braking position to the release position.

[0060] In some examples, such as Figure 2 and Figure 19 As shown, when the operator selects neutral or parking, the hydraulic oil at the motor inlet can be reduced (in some examples, close to zero pressure), and there will be no force resisting the brake actuation piston 152. Thus, the spring force of the brake spring 138 will be able to apply force to the brake release elements 140, 203 and to the first brake pad 132 and the second brake pad 134. The friction generated between the first brake pad 132 and the second brake pad 134 can slow down or prevent rotation of the brake hub 124 relative to the brake cover 156 (and therefore prevent rotation of the outer motor ring 114, motor cover 142, and actuator housing 108 connected to the brake cover 156), thereby engaging the brake.

[0061] In some examples, such as Figure 20As shown, when the operator selects the drive or driving function, the hydraulic oil at the motor inlet can pressurize the brake actuation piston 152 to move it from the starting position to the actuated position. This axial force is transmitted through brake release members 140, 203 to the brake piston 136 to compress the brake spring 138, thereby releasing the pressure on the brake piston 136 on the first brake pad 132 and the second brake pad 134, thus releasing the brake. In some examples, the axial force can also be transmitted through the spacer 224 and the gasket 228 before being transmitted to the brake release members 140, 203, as will be discussed regarding Figures 19 to 22 To be discussed in more detail.

[0062] In some implementations, the inlet hydraulic pressure applied to the brake actuation piston 152 may exceed the force required to counteract the bias of the brake spring 138. In some examples, the inlet hydraulic pressure may be high enough to cause the brake spring 138 to bottom out, which could lead to deformation of the brake spring 138 or otherwise damage to components of the brake arrangements 123, 209 or brake release arrangements 139, 201. To mitigate the forces applied to these components, some implementations of the brake release arrangements 139, 201 include thrust plates 150, 216 to limit the axial movement range of the brake piston 152, which limits how far the brake piston 152 can push the brake release components 140, 203. The thrust plates 150, 216 are opposite the brake actuation piston 152 and may be bolted between the spindle 102 and the end cap 154. Figure 10 and Figure 22 In the example shown, the brake actuating piston 152 is mounted within the recesses of the thrust plates 150, 216. When the brake actuating piston 152 moves to the actuated position (corresponding to the release position of the brake release members 140, 203), the thrust plates 150, 216 are positioned to engage the brake actuating piston 152. Therefore, the brake actuating piston 152 cannot push the brake release members 140, 203 beyond the release position. In this way, the thrust plates 150, 216 can help transfer this high axial thrust load to the spindle 102 and maintain a low axial thrust load in the brake release members 140, 203 and the brake piston 136. In some examples, this reduction in the applied force can increase the service life and reliability of the brake arrangements 123, 209 and the brake release arrangements 139, 201, and reduce the likelihood of damage to affected components. Furthermore, the stroke of the brake actuation piston 152 can be limited to less than the range of motion of the brake spring 138, which allows the friction brake system to be designed with only a single brake spring 138. However, in other examples, multiple brake springs 138 may be used.

[0063] Now for reference Figures 7 to 9A first example implementation of the brake arrangement 123 includes a one-piece brake hub 124. For example... Figure 8 As shown, the first portion 126 of the brake hub 124 is substantially circular to facilitate rotational mounting to the motor cover 142. The second portion 128 of the brake hub 124 is also substantially circular but larger than the first portion 126. The brake hub 124 defines a channel 127 through which the brake release member 140 extends. In some examples, the channel 127 is centered about a longitudinal axis C1 relative to the first portion 126 of the brake hub 124. Because the first portion 126 is mounted at the motor cover 142, the brake hub 124 rotates about the longitudinal axis C1, which extends coaxially with the central axis 104.

[0064] The second portion 128 of the brake hub 124 has a longitudinal axis C2 that is offset from the longitudinal axis C1. The size of the second portion 128 is determined to be concentrically mounted within the central opening 144 of the cycloidal star 118. In some examples, the longitudinal axis C2 is aligned with the central longitudinal axis 122 of the cycloidal star 118. When the cycloidal star 118 runs in a track, it carries the second portion 128 of the brake hub 124, which acts as a crank arm that rotates the first portion 126. Therefore, for each rotation of the cycloidal star 118, the brake hub 124 rotates once.

[0065] like Figure 2 and Figure 10 As shown, the first example brake release arrangement 139 includes a one-piece brake release member 140 extending between the brake piston 136 and the brake actuation piston 152. In some examples, the one-piece brake release member 140 directly contacts both the brake piston 136 and the brake actuation piston 152. The brake release member 140 extends through a channel 127 defined by the brake hub 124 to reach the brake piston 136. The brake release member 140 also extends through a central shaft 130 to reach the brake actuation piston 152. Therefore, the axial thrust of the hydraulic power applied to the brake actuation piston 152 is transmitted to the brake release member 140, which transmits the axial thrust to the brake piston 136 to compress the brake spring 138.

[0066] Now for reference Figures 11 to 18 The second example brake arrangement 209 includes a multi-piece brake hub 124, which includes a body 210 and an outer ring 212. The outer ring 212 intersects with a cycloidal star member 118 to orbit around the star member axis 122 together with the star member (see, for example, see...). Figure 16The interaction between the outer ring 212 and the body 210 converts the orbital movement of the star-shaped member 118 and the outer ring 212 into rotational movement of the body 210 and the ring 212. This rotational movement is applied to the first brake pad 132 via the body 210. This second example brake arrangement 209 can be used with any of the brake release arrangements 139, 201 disclosed herein.

[0067] Body 210 defines a first portion 126 of brake hub 124. Body 210 and outer ring 212 cooperate to define a second portion 128 of brake hub 124. Body 210 has a brake pad mounting section 233, a hub mounting section 235, and an inner portion 148 (see, for example, see...). Figure 13 The hub mounting section 235 is configured to be rotatably mounted within an opening in the motor cover 142 (see, for example, see...). Figure 19 The brake pad mounting section 233 is configured to support and key to the first brake pad 132, such that the first brake pad 132 rotates in unison with the body 210. For example, the brake pad mounting section 233 may include teeth 232 facing inwards from the first brake pad 132 (see, for example, see...). Figure 6 ) keyed teeth or splines 234 (for example, see Figure 12 and Figure 14 ).

[0068] The inner portion 148 of the main body 210 mates with the outer ring 212. The inner portion 148 has an elongated shape (see, for example, see...). Figure 15 ), having a flat edge 238 facing opposite directions. The inner portion 148 is offset relative to the hub mounting section 235 (e.g., see...). Figure 13 This causes the longitudinal axis C2 of the inner portion 148 to deviate from the longitudinal axis C1 of the hub mounting section 235 (see, for example, see...). Figure 15 This offset allows the inner section 148 to act as a crank to rotate the hub-mounted section 235 of the body 210.

[0069] The outer ring 212 is mounted on the inner portion 148 of the brake hub 124 (see, for example, see...). Figure 11 and Figure 16 The outer ring 212 defines an aperture 215 in the inner portion 148 of the receiving body 210. In some examples, the aperture 215 is keyed to the outer surface of the inner portion 148, such that the outer ring 212 is fixed relative to the inner portion 148 in the rotational direction. In the example shown, the inner surface 218 of the outer ring 212 includes a collar flat edge 236 that mates with the hub flat edge 238 of the inner portion 148 of the body 210. The engagement between the collar flat edge 236 and the hub flat edge 238 allows the body 210 to rotate synchronously with the outer ring 212.

[0070] The outer surface 214 of the outer ring 212 is positioned concentrically with the central opening 144 of the cycloidal star 118 (see, for example, see...). Figure 12 In some implementations, the outer surface 214 of the outer ring 212 undergoes a phosphate treatment. This phosphate treatment helps protect the outer surface 214 from abrasion and tearing, thereby eliminating the need for a star bushing 166 at the central opening 144 of the cycloidal star 118. The star 118 applies track movement to the outer ring 212. Because the body 210 is held by the motor cover 142 at the brake hub mounting section 235, the body 210 cannot move along the track with the outer ring 212. Instead, the track force applied to the outer ring 212 by the star 118 is converted into a rotational force on the outer ring 212 relative to the star 118. The engagement of the flat edges 236, 238 between the outer ring 212 and the body 210 transmits the rotational movement of the outer ring 212 to the body 210.

[0071] In some examples, the outer ring 212 includes a tab 244 that prevents the outer ring 212 from tilting and keeps it properly aligned for reliable motor performance. In some implementations, the engagement of the outer ring 212 with the body 210 creates a gap 246 between the outer ring 212 and the body 210. In some examples, the gap 246 is more pronounced between non-flat edges. The gap 246 can provide clearance to accommodate manufacturing tolerance variations in the brake hub 124.

[0072] Now for reference Figure 17 and Figure 18 In some implementations, the outer surface 214 of the inner portion 148 of the brake hub 124 and the inner surface 218 of the outer ring 212 are opposite each other along the axial thickness T of the outer ring 212. In some implementations, the opposite portions of the outer surface 214 and the inner surface 218 are planar. In other implementations, these opposite portions have curvatures 220 and 222, respectively. In some examples, curvatures 220 and 222 are configured to reduce edge loads between the ring 212 and the inner portion 148, which can reduce stress at the fillet 240 between the inner portion 148 and the hub mounting section 235. For example, curvatures 220 and 222 may have peaks offset from the edge of the outer ring 212, such that the initial contact point between the outer ring 212 and the inner portion 148 is located at a midpoint 223 along the axial thickness T. In some examples, including such curvatures 220 and 222 can help distribute the torque load uniformly through the partial interface, thereby avoiding edge loads and reducing high bending stress in the fillet 240. The reduction of the resulting high bending stress can help increase the fatigue life of the brake hub 124.

[0073] Now for reference Figures 19 to 22Another example brake release arrangement 201 includes a multi-piece release member 203. This brake release arrangement 201 can be used with any of the brake arrangements 123, 209 disclosed herein. In some implementations, the multi-piece release member 203 includes a first rod 202 extending through the central shaft 130 and a separate second rod 204 extending through the brake hub 124. Separating the brake release member 203 into separate rods 202, 204 reduces wear on the brake piston 136 by allowing the first rod 202 to move along the track of the cycloidal star member 118 without imposing track movement on the second rod 204. Therefore, the second rod 204 does not slide on the surface of the brake piston 136. Further, instead of Figure 5 As shown, the wavy or angled surface allows the second rod 204 to be positioned via a generally flat end surface 205 (see, for example, see...). Figure 21 Contact brake piston 136.

[0074] The first rod 202 is angled relative to the central axis 104, such that the first engaging end 206 of the first rod 202 can orbit with the star-shaped member 118, while the opposite end of the first rod 202 remains stationary at the spindle 102. The first rod 202 does not rotate relative to the central axis 130. In some examples, the second rod 204 extends coaxially or parallel to the central axis 104 through the brake hub 124. In some examples, the second rod 204 is configured to rotate with the brake hub 124. For example, a key 207 can engage a recess defined in the brake hub 124 and a recess defined in the second rod 204, such that the brake hub 124 and the second rod 204 rotate synchronously. Other keying configurations are possible.

[0075] In some implementations, the first engaging end 206 of the first rod 202 engages the second engaging end 208 of the second rod 204 (see, for example, see...). Figure 21 In some examples, as the actuator housing 108 and brake hub 124 rotate, the first engagement end 206 and the second engagement end 208 contact each other with a rolling motion. This rolling motion can cause less mechanical wear on the first rod 202 and the second rod 204. In some examples, the first rod 202 is positioned at an angle relative to the central axis 104, and the second rod 204 can be positioned on the central axis 104, and thus the first engagement end 206 will maintain edge contact with the second engagement end 208. Further, the second engagement end 208 rotates together with the brake hub 124, while the first engagement end 206 orbits with the star member 118. These relative movements reduce the pressure-velocity ratio between them.

[0076] In some implementations, the brake release member 203 (e.g., the first lever 202) does not directly contact the brake actuation piston 152. Instead, a spacer 224 (e.g., a slotted pin) separates the brake release member 230 from the brake actuation piston 152. The spacer 224 performs a similar function to the second lever 204 because the brake actuation piston 152 can engage a relatively flat surface instead of the angled surface of the first lever 202. For similar reasons, the actuator spacer 226 is disposed between the central shaft 130 and the thrust plate 216.

[0077] exist Figure 22 In the example shown, spacer 224 extends through a portion of thrust plate 216 to reach brake actuation piston 152. In some examples, spacer 224 directly contacts brake actuation piston 152. In other examples, one or more shims 228 (e.g., metal discs) are disposed between spacer 224 and brake actuation piston 152. Shims 228 can help accommodate variations in the stroke length of brake actuation piston 152 (which may be caused by variations in manufacturing tolerances of motor parts). Shims 228 can also help control variations in the release stroke, which allows the use of a single brake spring 138.

[0078] In some examples, the motor components constituting brake arrangements 123, 209 and / or brake release arrangements 139, 201 can be installed in newly manufactured motors. In some examples, the motor components constituting brake arrangements 123, 209 and / or brake release arrangements 139, 201 can be installed in refurbished motors or placed in motors undergoing maintenance. In other examples, the motor components constituting brake arrangements 123, 209 and / or brake release arrangements 139, 201 can be organized into kits that can be used to retrofit motors that originally had different types of braking systems.

[0079] Figure 23 It shows Figure 19 A second example implementation of a hydraulic drive device, the hydraulic drive device including Figure 11 The second example brake hub 124, except that bushings 260 and 262 are shown surrounding the body 210 and outer ring 212, respectively. Bushings 260 and 262 protect against friction between the brake hub 124, motor cover 142, and cycloidal star 118. Washer 264 may also be provided between the outer ring 212 and the central shaft 130 for protection against friction.

[0080] Figures 24 to 26An alternative example brake arrangement 250 suitable for use with any of the brake release arrangements 139, 201 disclosed herein is shown. Brake arrangement 250 incorporates features of brake arrangements 123, 209. Example brake arrangement 250 includes a one-piece brake hub 252, which is substantially similar to... Figure 7 The brake hub 124, except for the first part 254 of the hub 252. Figure 12 The splined brake pad mounting section 258 of the hub 124 is outside. The spline 258 is configured to engage with the internal teeth 232 of the first brake pad 132, such that the first brake pad 132 rotates together with the brake hub 252.

[0081] Bushing 258 is disposed on the main body 254 to directly interface with the motor cover 142. Like the brake hub 124, the second portion 256 of the brake hub 252 is larger and sized to mate with the cycloidal star 118 so that it orbits around the star axis 122 together with the cycloidal star 118. Another bushing 260 is disposed on the outer ring 256 to directly interface with the cycloidal star 118. Finally, a washer 264 is disposed between the second portion 256 of the brake hub 250 and the central shaft 130.

[0082] Similarly Figure 7 The brake hub 124, hub 252 defines a channel 255 centered relative to a first portion 254 of the brake hub 252. While the first portion 255a of the channel 255 passing through the first portion 254 of the brake hub 252 is generally cylindrical, the second portion 255b of the channel 255 passing through the second portion 256 of the brake hub 252 defines an elliptical shape. The elliptical shape facilitates the initial insertion of the second release lever 204 into the hub 252. In some examples, the second portion of the channel passing through any brake hub 124 disclosed herein may be elliptical. In some implementations, key 207 ( Figure 12 ) can engage with the recess 253 defined in the first portion 255a of the channel 255. Figure 24 The brake hub 252 and the second lever 204 are confined in a recess, causing the brake hub 252 and the second lever 204 to rotate in unison.

[0083] Having described the preferred aspects and implementations of this disclosure, modifications and equivalents of the disclosed concepts will readily occur to those skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the appended claims.

Claims

1. A hydraulic actuator with mechanical braking, the hydraulic actuator comprising: A mandrel having a first mounting flange that defines a central axis; A drive housing mounted on the spindle, the drive housing including a second mounting flange; The bearing is used to allow the drive housing to rotate about the central axis relative to the spindle; A cycloidal hydraulic motor arrangement includes an outer motor ring coupled to a driver housing such that the outer motor ring and the driver housing are adapted to rotate uniformly about a central axis. The outer motor ring includes a plurality of radially inwardly facing recesses circumferentially spaced around the central axis. The cycloidal hydraulic motor arrangement also includes a cycloidal star member including a plurality of convex angles circumferentially positioned about a star member axis defined by the cycloidal star member. The cycloidal star member is positioned within the outer motor ring, wherein the star member axis is offset from the central axis such that the cycloidal star member is eccentric relative to the outer motor ring. The cycloidal star member is mounted to orbit around the central axis when the outer motor ring is hydraulically driven about the central axis, so as to bring the convex angles into and out of the recesses of the outer motor ring. A complete orbit of the cycloidal star member about the central axis corresponds to a movement of the outer motor ring about the central axis relative to the cycloidal star member by one recess position. A brake hub comprising a first portion concentric with the central axis and a second portion concentric with the cycloidal star member, the second portion of the brake hub mechanically intersecting with the cycloidal star member, such that the movement of the cycloidal star member around the central axis drives the brake hub to rotate around the central axis, wherein each time the cycloidal star member moves around the central axis, the brake hub rotates once around the central axis; A central axis is configured to prevent the cycloidal star from rotating relative to the spindle about its axis while allowing the cycloidal star to orbit around the central axis. A first brake pad is mounted to rotate about the central axis in alignment with the brake hub. The second brake pad is mounted to rotate about the central axis in conjunction with the drive housing and the outer motor ring. A brake piston for axially pressing the first brake pad and the second brake pad together to provide braking of the cycloidal hydraulic motor arrangement, the brake piston being spring-biased axially toward the first brake pad and the second brake pad by a brake spring; and A brake release element extending through the central shaft and the brake hub is adapted to release the brake of the cycloidal hydraulic motor arrangement by axially pushing the brake piston away from the first brake pad and the second brake pad against the spring bias of the brake spring.

2. The hydraulic actuator as claimed in claim 1, wherein, When the cycloidal star-shaped component moves around the central axis, the second part of the brake hub rotates within the cycloidal star-shaped component, and when the cycloidal star-shaped component moves around the central axis, the second part of the brake hub acts as a crank for rotating the brake hub around the central axis.

3. The hydraulic actuator as claimed in claim 2, wherein, The first portion of the brake hub is rotatably mounted within an opening defined by a motor cover that rotates in conjunction with the outer motor ring and the drive housing.

4. The hydraulic actuator as claimed in claim 3, wherein, The second part of the brake hub is concentrically mounted within the central opening of the cycloidal star.

5. The hydraulic actuator as claimed in claim 4, wherein, The first and second portions of the brake hub are defined as a single integral piece.

6. The hydraulic actuator as claimed in claim 4, wherein, The brake hub includes a multi-piece configuration.

7. The hydraulic actuator as claimed in claim 6, wherein, The brake hub includes a body defining a first portion of the brake hub and an inner portion of a second portion of the brake hub. The second portion of the brake hub also includes an outer ring mounted on the inner portion of the second portion of the brake hub and including an outer surface concentric with the central opening of the cycloidal star member. The outer ring is configured to rotate together with the body about the central axis. Relative rotation about the axis of the cycloidal star member occurs between the outer ring and the cycloidal star member when the brake hub rotates about the central axis and the cycloidal star member orbits around the central axis.

8. The hydraulic actuator as claimed in claim 7, wherein, The inner surface of the outer ring includes a ring flat edge, wherein the inner portion of the second part of the brake hub includes a hub flat edge, wherein the ring flat edge is aligned with the hub flat edge.

9. The hydraulic actuator as claimed in claim 7, wherein, The outer surface of the outer ring is treated with phosphate.

10. The hydraulic actuator of claim 7, wherein, The outer surface of the inner portion of the second part of the brake hub and the inner surface of the outer ring are opposite each other along the axial thickness, wherein the outer surface of the inner portion of the second part of the brake hub and the inner surface of the outer ring have curvatures with eccentric radii configured to reduce edge loads and concentrate the loads in the central region of the axial thickness.

11. The hydraulic actuator of claim 3, wherein, A brake cover is mounted outside the motor cover and configured to rotate in unison with the motor cover, the outer motor ring, and the drive housing. A brake chamber is defined between the motor cover and the brake cover. The brake hub includes a liner mounting extension extending into the brake chamber. A plurality of first brake liners are mounted on the liner mounting extension within the brake chamber and configured to rotate with the brake hub. A plurality of second brake liners are coupled to the brake cover and configured to rotate in unison with the brake cover. The first and second brake liners overlap.

12. The hydraulic actuator of claim 11, wherein, The brake cover, the motor cover, and the outer motor ring are fastened to the drive housing by axial bolts.

13. The hydraulic actuator of claim 1, wherein, The brake release mechanism includes a single rod that extends through the central shaft and the brake hub.

14. The hydraulic actuator of claim 1, wherein, These recesses are separated by rollers.

15. The hydraulic actuator as claimed in claim 1, wherein, The brake release mechanism includes a first rod extending through the central axis and a second rod extending through the brake hub, wherein the first rod and the second rod engage with each other at an engagement end, wherein the second rod is concentric with the central axis, and the engagement end of the first rod is eccentric relative to the central axis and aligned with the cycloidal star.

16. The hydraulic actuator of claim 15, wherein, The brake release element is hydraulically actuated, wherein a thrust plate is mounted to the spindle, and a brake actuation piston is mounted within the thrust plate. During brake actuation, hydraulic pressure is applied to the brake actuation piston, causing the brake actuation piston to drive the brake release element toward the brake piston, thereby resisting the spring bias of the brake spring and moving the brake piston away from the first brake pad and the second brake pad.

17. The hydraulic actuator of claim 16, wherein, The thrust plate defines a stop member that stops the movement of the brake release piston at a predetermined position, thereby limiting the axial movement range of the brake release member and preventing the brake spring from bottoming out.

18. The hydraulic actuator of claim 16, further comprising a spacer between the brake release member and the brake actuation piston.

19. The hydraulic actuator of claim 18, further comprising a gasket between the spacer and the brake actuating piston.

20. The hydraulic actuator as claimed in any one of claims 1-19, wherein, The first brake pad includes teeth that align with the splines on the brake hub.

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