electric brake
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2026-08-11
AI Technical Summary
[0012] An electric brake according to an embodiment of the present invention can improve positive efficiency and achieve small size and light weight.
Smart Images
Figure CN122555656A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an electric brake for braking vehicles. Background Technology
[0002] For example, in the disc brake described in Patent Document 1, the brake holding mechanism for maintaining the braking position includes: a rotating member whose rotational force from an electric motor is transmitted to one end of the bottom wall of the cylinder; a direct-acting member that engages with the other end of the rotating member, causing the piston to move by direct-acting through the rotation of the rotating member; a bottomed cylindrical member disposed between the rotating member and the bottom wall of the cylinder, having an annular plate portion opposite to the bottom wall of the cylinder, and a cylindrical portion integrally connected to and covering the outer circumference of the annular plate portion; and a clutch mechanism disposed between the outer circumferential surface of the rotating member and the inner circumferential surface of the cylindrical portion, causing the bottomed cylindrical member to rotate in the same direction only when the rotating member rotates in one direction. After the piston is pressed against the pair of bushings by the rotational drive of the electric motor, the bottomed cylindrical member is clamped between the annular plate portion and the bottom wall of the cylinder in a non-rotating manner by the reaction force applied to the rotating member, and the rotation of the rotating member in the return direction of the piston is restricted by the clutch mechanism.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent Document 1: International Publication No. 2015 / 151618 Summary of the Invention
[0006] The technical problem that the invention aims to solve
[0007] In the disc brake described in the aforementioned Patent Document 1, the brake holding mechanism is located downstream of the reduction mechanism on the rotation transmission path. The rotational torque from the electric motor is amplified by the reduction mechanism and transmitted to the brake holding mechanism. Therefore, the brake holding mechanism is enlarged as a whole, and thus the disc brake may be enlarged.
[0008] Furthermore, in disc brakes of related technologies, during parking braking, a locking mechanism is not required to maintain the braking force by means of a differential planetary gear reduction mechanism. However, in order to meet the requirement of a reverse efficiency (rotational efficiency in the release direction) of 0% or less for self-holding, the positive efficiency (rotational efficiency in the application direction), which is in a roughly proportional relationship, must be suppressed to 50% or less, and it is currently difficult to improve the positive efficiency.
[0009] Furthermore, in view of the above-mentioned technical problems, the object of the present invention is to provide an electric brake that improves positive efficiency and achieves small size and lightweight.
[0010] Technical solutions for solving technical problems
[0011] As a technical solution to solve the above-mentioned technical problems, the electric brake of the present invention is characterized by comprising: an electric motor; a reduction mechanism having an input component that receives rotation from the electric motor and an output component that reduces the rotation of the input component and outputs it; a braking mechanism that generates braking force by pressing the braking component against the braked component through rotation from the output component of the reduction mechanism; and a brake holding mechanism that holds the braking force generated by the brake mechanism. In the rotation transmission path from the electric motor, when the brake mechanism is positioned downstream and the electric motor is positioned upstream, the brake holding mechanism is positioned upstream of the output component. The device comprises: a rotating component that rotates via the electric motor; a support component that rotatably supports the rotating component; a clutch mechanism that can rotate relative to a corresponding component when the electric motor rotates in the direction that presses the braking component against the braked component, and cannot rotate relative to the corresponding component when the electric motor rotates in the direction that disengages the braking component from the braked component; a bearing that allows the rotating component and the support component to rotate relative to each other when the clutch mechanism can rotate relative to the corresponding component; and a rotating part that allows the rotating component and the support component to rotate relative to each other when the clutch mechanism cannot rotate relative to the corresponding component.
[0012] An electric brake according to an embodiment of the present invention can improve positive efficiency and achieve small size and light weight. Attached Figure Description
[0013] Figure 1 This is an external view of the disc brake according to the first embodiment.
[0014] Figure 2 This is a cross-sectional view of the disc brake according to the first embodiment.
[0015] Figure 3 yes Figure 2 Enlarged view of the main parts.
[0016] Figure 4 This is an enlarged cross-sectional view of the main part of the disc brake in the second embodiment.
[0017] Figure 5 This is an enlarged cross-sectional view of the main part of the disc brake in the third embodiment.
[0018] Figure 6 This is an enlarged cross-sectional view of the main part of the disc brake in the fourth embodiment. Detailed Implementation
[0019] The following is based on Figures 1-6 This embodiment will be described in detail. The electric brake, specifically the disc brake 1, of this embodiment generates braking force during normal driving by being driven by the electric motor 45. It should be noted that in the following description, the outer side of the vehicle (outer side) will be referred to as one end side (brake disc D side), and the inner side of the vehicle (inner side) will be referred to as the other end side (cover member 38 side), as appropriate. That is, in Figures 2-6 In this context, the right side will be referred to as one end side, and the left side as the other end side, with appropriate explanations provided.
[0020] First, based on Figures 1-3 The disc brake 1A of the first embodiment is described in detail.
[0021] Reference Figure 1 and Figure 2 The disc brake 1A of the first embodiment is an electric brake, comprising a pair of inner brake pads 2 and outer brake pads 3 arranged on both axial sides of a brake disc D mounted on a rotating part (not shown) of the vehicle, and a brake caliper 4. It should be noted that the inner and outer brake pads 2 and 3 correspond to braking components. The brake disc D corresponds to the braked component. The disc brake 1A of the first embodiment is configured as a floating brake caliper type. It should be noted that the pair of inner and outer brake pads 2 and 3 and the brake caliper 4 are supported on a bracket 5 in a manner that allows them to move axially along the brake disc D. The bracket 5 is fixed to a non-rotating part of the vehicle, such as a steering knuckle (not shown), and is arranged to span the outer periphery of the brake disc D.
[0022] The bracket 5 includes: a pair of pin connecting portions 9, 9 that connect to the sliding pins 7, 7 (described later); and an inner support portion 11 and an outer support portion 12 that are integrally connected to the pair of pin connecting portions 9, 9 and independently support the inner and outer brake pads 2, 3, respectively. The pair of pin connecting portions 9, 9 are spaced apart along the rotation direction of the brake disc D. A pair of bottomed cylindrical pin sliding portions 15, 15 are integrally formed on the cylindrical portion 23 of the brake caliper body 30, protruding radially outward from the brake disc D. The pair of pin sliding portions 15, 15 extend along the axial direction of the brake disc D.
[0023] A pair of sliding pins 7 are axially slidably inserted into each of a pair of sliding portions 15, 15. Each sliding portion 15, 15 is positioned inward of the pair of pin connections 9 of the bracket 5. Furthermore, the pair of sliding pins 7, 7 are axially slidably inserted into each sliding portion 15, 15 from the outside. Each mounting bolt 17, 17 is inserted into the through holes 18, 18 of each pin connection 9, 9 and fixed to each sliding pin 7. As a result, each sliding pin 7, 7 is fixed to each pin connection 9, 9 by the mounting bolts 17, 17. It should be noted that reference numeral 19 is a pin cover having a corrugated portion that extends and retracts freely in a manner covering the sliding pin 7.
[0024] The brake caliper body 22, which is the main body of the brake caliper 4, includes: a cylindrical body portion 23, which is disposed on the base end side opposite to the inner brake pad 2 and is open opposite to the inner brake pad 2; a pair of claw portions 24, 24, which extend outward from the cylindrical body portion 23 across the brake disc D and are disposed on the front end side opposite to the outer brake pad 3; and a pair of pin sliding portions 15, 15, which are provided to protrude radially outward from the cylindrical body portion 23 toward the two outer sides of the brake disc D.
[0025] The piston 30 is housed within the cylinder portion 23 of the brake caliper body 22, specifically in the cylinder bore 26 of the cylinder portion 23, in a manner that prevents relative rotation with respect to the cylinder portion 23 but allows axial movement. The piston 30 presses against the inner brake pad 2, forming a bottomed cup shape. The piston 30 is housed within the cylinder bore 26 of the cylinder portion 23 with its bottom facing the inner brake pad 2. A sealing member (not shown) is disposed on the inner circumferential surface at the other end of the cylinder bore 26 of the cylinder portion 23. The piston 30 is housed within the cylinder bore 26 in a state of contact with this sealing member, allowing free axial movement.
[0026] A dust cover 34 is installed between the outer peripheral surface of the bottom side of the piston 30 and one end side of the cylinder portion 23. These sealing components and the dust cover 34 prevent foreign objects from entering the cylinder bore 26 of the cylinder portion 23. A housing 36 is installed at the bottom of the cylinder portion 23 of the brake caliper body 22. The open portion at the other end of the housing 36 is airtightly sealed by a cover component 38. The housing 36 maintains airtightness. The housing 36 includes: a first housing portion 41 that houses the reduction mechanism 46 (described later) in a manner covering the outer periphery of the bottom of the cylinder portion 23; and a second housing portion 42 that is integrally connected to the first housing portion 41 in a parallel manner, housing the electric motor 45 (described later).
[0027] Reference Figure 2The brake caliper body 22 includes: an electric motor 45; a reduction mechanism 46 having a pinion 71 that receives rotational input from the electric motor 45 and a rotating internal gear 85 that reduces the rotation of the pinion 71 and outputs it; a braking mechanism 47 that generates braking force by pressing the piston 30 against the brake pad 2 through the rotation of the rotating internal gear 85 from the reduction mechanism 46; and a brake holding mechanism 48 that holds the braking force generated by the braking mechanism 47. It should be noted that the pinion 71 is equivalent to an input component. On the other hand, the rotating internal gear 85 is equivalent to an output component. The electric motor 45 is a brushless DC motor having a rotor body 53 (permanent magnet) and a stator 54, etc. It should be noted that the electric motor 45 may also be other known motors such as a brushed DC motor.
[0028] As described above, the electric motor 45 is housed in the second housing portion 42 of the housing 36. A rotating shaft 50 extending from the rotor body portion 53 of the electric motor 45 to one end is rotatably supported by a rolling bearing 58 within a receiving recess 57 provided in the second housing portion 42. Conversely, the rotating shaft 50 extending from the rotor body portion 53 to the other end is rotatably supported by a rolling bearing 58 in a through hole 60 provided in the second housing portion 42 and extends to the other end. (See reference...) Figure 1 An electronic control unit (ECU) 63 for controlling the rotation of the electric motor 45 is electrically connected to the electric motor 45. During braking in normal driving, the ECU 63 controls the drive of the electric motor 45 based on detection signals from sensors corresponding to the driver's request (not shown), various sensors detecting different braking conditions (not shown), a rotation angle detection mechanism (not shown) of the electric motor 45, and a thrust sensor (not shown). Additionally, a parking switch 64, which is operated when the parking brake is engaged / disengaged, is electrically connected to the ECU 63. It should be noted that the ECU 63 can also activate the parking brake based on signals from the vehicle side, independent of the parking switch 64.
[0029] Reference Figure 2The reduction mechanism 46 comprises a multi-stage gear reduction mechanism 67 and a differential planetary gear reduction mechanism 68. The multi-stage gear reduction mechanism 67 is composed of spur gears or helical gears. The multi-stage gear reduction mechanism 67 is housed within the first housing portion 41 of the housing 36. The multi-stage gear reduction mechanism 67 includes a pinion 71 and a reduction gear 72. The pinion 71 is cylindrical and is pressed into and fixed to the rotating shaft 50 of the electric motor 45. The pinion 71 and the reduction gear 72 are, for example, made of sintered or forged metal parts or resin molded parts. A shaft hole 74 extends axially through the radial center of the reduction gear 72. A gear shaft 77 is inserted through the shaft hole 74 of the reduction gear 72. One end of the gear shaft 77 is integrally fixed to the wall portion of the first housing portion 41 near the second housing portion 42. As a result, the reduction gear 72 is rotatably supported by the gear shaft 77. The reduction gear 72 is integrally connected by a large-diameter gear 79 that meshes with the pinion 71 and a small-diameter shaft gear 80 that extends concentrically from the large gear 79 to the other end. The small-diameter shaft gear 80 of the reduction gear 72 meshes with the differential planetary gear reduction mechanism 68.
[0030] The differential planetary gear reduction mechanism 68 has its reverse efficiency set to 0 or less so that, during braking, the braking state can be maintained even with the reaction force from the pressing force from the brake disc D acting via the piston 30. As a result, a parking locking mechanism is not required to maintain the braking position after the piston 30 reaches it. (See reference...) Figure 2 and Figure 3 The differential planetary gear reduction mechanism 68 is housed within the first housing portion 41 of the housing 36. The differential planetary gear reduction mechanism 68 includes a sun gear 82, a plurality of planetary gears 83, a fixed internal gear 84, and a rotating internal gear 85. These sun gears 82, the plurality of planetary gears 83, the fixed internal gear 84, and the rotating internal gear 85 are, for example, made of sintered or forged metal parts or resin molded parts.
[0031] The sun gear 82, the fixed internal gear 84, and the rotating internal gear 85 are arranged concentrically. The sun gear 82 has a support hole 88 extending radially through its center. The other end of the main shaft 120 of the braking mechanism 47 (described later) is inserted through this support hole 88. Furthermore, the sun gear 82 is rotatably supported by the main shaft 120. The sun gear 82 is composed of a large-diameter gear 90 that meshes with the small-diameter shaft gear 80 of the reduction gear 72, and a small-diameter shaft gear 91 that extends axially concentrically from the large-diameter gear 90. The small-diameter shaft gear 91 extends toward one end. Each planetary gear 83 meshes with this small-diameter shaft gear 91.
[0032] The planetary gear 83 is cylindrical and includes: a gear portion 93 that meshes with the small diameter shaft gear 91 of the sun gear 82, the internal teeth 84A of the fixed internal gear 84, and the internal teeth 85A of the rotating internal gear 85; and a hole portion 94 through which the large diameter shaft portion 112 of the support shaft 110 (described later) is inserted. Multiple planetary gears 83 are arranged at equal intervals around the small diameter shaft gear 91 of the sun gear 82. In this embodiment, four planetary gears 83 are arranged. The fixed internal gear 84 is supported so that it cannot rotate relative to the first housing portion 41 of the housing 36. Internal teeth 84A are formed on one end of the fixed internal gear 84. On the other end of the fixed internal gear 84, an annular stop portion 100 protruding inward is integrally formed at intervals from the internal teeth 84A toward the other end. The other end of each planetary gear 83 meshes with the internal teeth 84A of the fixed internal gear 84. A rotating internal gear 85 is arranged on one end of the fixed internal gear 84.
[0033] The rotating internal gear 85 is rotatably supported on the first housing portion 41 of the housing 36. Internal teeth 85A are formed at the other end of the rotating internal gear 85. One end of each planetary gear 83 meshes with the internal teeth 85A of the rotating internal gear 85. At one end of the rotating internal gear 85, an annular stop portion 101 is integrally formed, spaced apart from the internal teeth 85A and protruding inwards. A cylindrical rotating portion 103 protruding inwards is integrally connected to the inner side of the annular stop portion 101. The inner circumferential surface of the cylindrical rotating portion 103 of the rotating internal gear 85 engages with the outer circumferential surface of the main shaft 120 of the braking mechanism 47 (described later) in a manner that prevents relative rotation, for example, by spline engagement.
[0034] The number of teeth on the internal gear 84A of the fixed internal gear 84 is different from the number of teeth on the internal gear 85A of the rotating internal gear 85. For example, in this embodiment, the number of teeth on the internal gear 84A of the fixed internal gear 84 is less than the number of teeth on the internal gear 85A of the rotating internal gear 85, and the difference in the number of teeth is 4. Furthermore, when the rotating shaft 50 of the electric motor 45 rotates, the sun gear 82 of the differential planetary gear reduction mechanism 68 rotates via the pinion 71 and the reduction gear 72 of the multi-stage gear reduction mechanism 67. Through the rotation of the sun gear 82, each planet gear 83 rotates on its own axis and revolves around the axis of the sun gear 82, thereby rotating the internal gear 85. That is, since the number of teeth on the rotating internal gear 85 is slightly different from the number of teeth on the fixed internal gear 84, the rotating internal gear 85 rotates only slightly by the amount corresponding to the difference in the number of teeth, thereby obtaining a larger reduction ratio (single planetary gear reduction mechanism). The rotation from the rotating internal gear 85 is transmitted to the main shaft 120. It should be noted that in this embodiment, the differential planetary gear reduction mechanism 68 is configured as a singular planetary gear reduction mechanism, but the planetary gear 83 can also be configured as a stepped gear to change the number of teeth.
[0035] Reference Figure 2 and Figure 3 A brake holding mechanism 48 is provided in the differential planetary gear reduction mechanism 68. The brake holding mechanism 48 includes: a plurality of planetary gears 83; a planet carrier 106 that supports each planetary gear 83 so that it can rotate freely about its own axis and about the axis of the sun gear 82; and a clutch mechanism 107 that allows relative rotation between the planet carrier 106 and the minor diameter shaft portion 113 (described later) when the electric motor 45 rotates in the application direction, i.e., in the direction that presses the inner and outer brake pads 2 and 3 against the brake disc D; and prevents relative rotation between the planet carrier 106 and the minor diameter shaft portion 113 (described later) when the electric motor 45 rotates in the release direction, i.e., in the direction that separates the inner and outer brake pads 2 and 3 from the brake disc D. It should be noted that each planetary gear 83 is equivalent to a rotating component, and the planet carrier 106 is equivalent to a supporting component.
[0036] A pair of planetary carriers 106 are respectively disposed at both ends of each planetary gear 83, 83. The planetary carrier 106 is formed in the shape of an annular plate. The planetary carrier 106 has a plurality of holes 116 corresponding to each planetary gear 83. The holes 116 are formed at intervals in the circumferential direction in a manner corresponding to each planetary gear 83. In this embodiment, there are 4 holes 116 corresponding to the number of planetary gears 83. The small diameter shaft gear portion 91 of the sun gear 82 is inserted into the inner side of the pair of planetary carriers 106, 106. The pair of planetary carriers 106, 106 are integrally connected by a plurality of bridging portions (not shown). A plurality of these bridging portions are arranged at intervals along the circumferential direction between each planetary gear 83, 83, i.e., between the planetary gears 83, 83. It should be noted that in this embodiment, there are 4 spaces corresponding to the number of bridging portions and each planetary gear 83, 83.
[0037] A planetary carrier 106 located at one end is positioned between the annular stop 101 of each planetary gear 83 and the rotating internal gear 85, restricting its axial movement. Conversely, a planetary carrier 106 located at the other end is positioned between the annular stop 100 of each planetary gear 83 and the fixed internal gear 84, restricting its axial movement as well. Each planetary gear 83 is supported by a pair of planetary carriers 106, 106, rotatably about its own axis and about the axis of the sun gear 82, via support shafts 110. The support shafts 110 consist of a large-diameter shaft portion 112 located axially in the middle and a pair of small-diameter shaft portions 113, 113 extending axially from the two axial end faces of the large-diameter shaft portion 112, respectively.
[0038] Furthermore, the large-diameter shaft portion 112 of the support shaft 110 is inserted into the bore portion 94 of the planetary gear 83. The outer peripheral surface of this large-diameter shaft portion 112 and the inner peripheral surface of the bore portion 94 of the planetary gear 83 function as a rotating portion 97. In other words, this rotating portion 97 allows the planetary carrier 106 and the planetary gear 83 to rotate relative to each other (rotation relative to the planetary gear 83 itself around its axis) when the clutch mechanism 107 described later cannot rotate relative to the planetary carrier 106 and the small-diameter shaft portion 113 located at the other end (when released). It should be noted that in this embodiment, the planetary gear 83 is directly supported by the large-diameter shaft portion 112, but it can also be supported by a known bearing such as a bushing.
[0039] A pair of minor-diameter shaft portions 113, 113 are respectively inserted into the bore portions 116, 116 of a pair of planetary carriers 106, 106. A clutch mechanism 107 is disposed between the inner circumferential surface of one end of the bore portion 116 of the planetary carrier 106 located at the other end and the outer circumferential surface of one end of the minor-diameter shaft portion 113. Additionally, a rolling bearing 118 is disposed between the inner circumferential surface of the other end of the bore portion 116 of the planetary carrier 106 located at the other end and the outer circumferential surface of the other end of the minor-diameter shaft portion 113. That is, between the bore portion 116 and the minor-diameter shaft portion 113 of the planetary carrier 106 located at the other end, the clutch mechanism 107 is disposed at a position closer to one end than the rolling bearing 118. A rolling bearing 118 is also disposed between the inner circumferential surface of the planetary carrier 106 located at one end and the outer circumferential surface of the minor-diameter shaft portion 113.
[0040] It should be noted that the pair of planetary carriers 106, 106 and the pair of minor diameter shafts 113, 113 can rotate freely relative to each other via rolling bearings 118, 118. However, as long as they can be supported by bearing elements with sufficiently low rotational resistance, other known technologies such as journal bearings can also be used. When the clutch mechanism 107 described later can rotate relative to the planetary carriers 106 and minor diameter shafts 113 located at the other end (when applied), these rolling bearings 118, 118 enable the planetary carriers 106 and planetary gears 83 to rotate relative to each other (rotation about the axis relative to the planetary gears 83 themselves).
[0041] The clutch mechanism 107 is a so-called one-way clutch, in which rotation relative to one direction is allowed (rotation of one component allows the other component to idle and rotate relative to each other), while rotation relative to the other direction is restricted (the two corresponding components transmit rotational torque to each other without rotating relative to each other). The clutch mechanism 107 may be a helical spring clutch, a cam clutch, or the like. Furthermore, in this embodiment, when the electric motor 45 rotates in the application direction, i.e., in the direction that presses the inner and outer brake pads 2 and 3 against the brake disc D, the clutch mechanism 107 can rotate relative to the planetary carrier 106 and the small-diameter shaft portion 113 located on the other end. On the other hand, when the electric motor 45 rotates in the release direction, i.e., in the direction that separates the inner and outer brake pads 2 and 3 from the brake disc D, the clutch mechanism 107 cannot rotate relative to the planetary carrier 106 and the small-diameter shaft portion 113 located on the other end.
[0042] It should be noted that when the planetary gear 83 rotates in the applied direction (rotating in the applied direction with its own axis as the center), the rotational resistance of the rotating portion 97 between the outer peripheral surface of the large-diameter shaft portion 112 of the support shaft 110 and the inner peripheral surface of the bore portion 94 of the planetary gear 83 is greater than the sum of the rotational resistance when the clutch mechanism 107 is idling and the rotational resistance of the bore portion 116 (inner peripheral surface) of the planetary carrier 106 relative to the small-diameter shaft portion 113 (outer peripheral surface) via the rolling bearings 118, 118. Therefore, when the planetary gear 83 rotates in the applied direction (rotating in the applied direction with its axis as the center), the planetary carrier 106 and the small-diameter shaft portion 113 located on the other end rotate relative to each other via the clutch mechanism 107, and the rotational resistance of the planetary gear 83 relative to the planetary carrier 106 is reduced by the action of the rolling bearings 118, 118.
[0043] On the other hand, for the rotation of the internal gear 85 in the release direction (rotation in the release direction centered on the axis of the planetary gear 83 itself), the planet carrier 106 located on the other end cannot rotate relative to the minor diameter shaft 113 via the clutch mechanism 107. The rotational resistance of the rotating portion 97 between the bore 94 of the planetary gear 83 and the major diameter shaft 112 increases, thus increasing the rotational resistance of the planetary gear 83 relative to the planet carrier 106. It should be noted that in this embodiment, a brake holding mechanism 48 is provided for all four planetary gears 83, but it can also be provided for one to three planetary gears 83.
[0044] The braking mechanism 47 is composed of a rotary-to-linear conversion mechanism with reverse action that actuates via a reaction force from the braking mechanism 47. That is, referring to... Figure 2The braking mechanism 47 converts the rotational motion from the electric motor 45 and the reduction mechanism 72 (multi-stage gear reduction mechanism 67 and differential planetary gear reduction mechanism 68), that is, the rotational motion transmitted from the rotating internal gear 85 of the differential planetary gear reduction mechanism 68 to the main shaft 120, into linear motion relative to the direct-acting member 121. The movement of the direct-acting member 121 applies a thrust to the piston 30, causing the piston 30 to advance (move to one end). The main shaft 120 is rotatably supported relative to the cylinder portion 23, and one end of it is disposed within the cylinder bore 26.
[0045] Reference Figure 2 The portion of the main shaft 120 protruding from the support hole 88 of the sun gear 82 of the differential planetary gear reduction mechanism 68 engages with the cylindrical rotating portion 103 of the rotating internal gear 85 in a manner that prevents them from rotating relative to each other. This allows rotational torque to be transmitted between the rotating internal gear 85 and the main shaft 120. A braking mechanism 47, including one end of the main shaft 120, is disposed within the cylinder bore 26 and between the bottom surface of the cylinder bore 26 and the piston 30. Furthermore, when the main shaft 120 rotates along with the rotating internal gear 85 of the differential planetary gear reduction mechanism 68, the braking mechanism 47 causes the direct-acting member 121 to advance towards one end, thereby advancing the piston 30. The piston 30 presses the inner brake pad 2 against the brake disc D, generating braking force for the vehicle.
[0046] Next, the function of the disc brake 1A in the first embodiment will be explained.
[0047] First, the functions of braking and brake release during normal driving will be explained.
[0048] During normal braking, such as when the driver depresses the brake pedal, the electric motor 45 rotates in the positive direction (the direction of application) according to the command from the electronic control unit 63. This rotation causes the sun gear 82 of the differential planetary gear reduction mechanism 68 to rotate via the multi-stage gear reduction mechanism 67. Due to the rotation of the sun gear 82, each planetary gear 83 rotates on its own axis and revolves around the axis of the sun gear 82, thereby rotating the inner gear 85. The rotation from the inner gear 85 is transmitted to the main shaft 120. As the main shaft 120 rotates with the action of the differential planetary gear reduction mechanism 68, the direct-acting member 121 advances, causing the piston 30 to advance, through the action of the braking mechanism 47. This advance of the piston 30 presses the inner brake pad 2 against the brake disc D. Furthermore, the reaction force relative to the pressing force of the piston 30 on the inner brake pad 2 causes the brake caliper body 22 to move inward relative to the bracket 5. Figure 2The inner and outer brake pads 2 and 3 move to the left and press the outer brake pads 3 against the brake disc D through the claws 24, 24. As a result, the brake disc D is clamped by a pair of inner and outer brake pads 2 and 3, generating friction and thus generating braking force for the vehicle.
[0049] On the other hand, when the driver releases the brake pedal and the brakes are released, according to the command from the electronic control unit 63, the electric motor 45 rotates in the opposite direction, i.e., in the release direction, and this rotation in the opposite direction is transmitted to the main shaft 120 via the multi-stage gear reduction mechanism 67 and the differential planetary gear reduction mechanism 68. Furthermore, as the main shaft 120 rotates in the opposite direction, the direct-acting component 121 retracts and returns to its initial state through the action of the braking mechanism 47, releasing the braking force of the pair of inner and outer brake pads 2 and 3 and the pair of brake discs D.
[0050] Next, the function of the parking brake, as an example of a device used to keep a vehicle stationary, will be explained.
[0051] First, when the parking brake is engaged (applied) by operating the parking switch 64 from the released state, the electric motor 45 rotates in the positive direction, i.e., the direction of application, according to the command from the electronic control unit 63. This rotation causes the sun gear 82 of the differential planetary gear reduction mechanism 68 to rotate via the multi-stage gear reduction mechanism 67. Through the rotation of the sun gear 82, each planetary gear 83 rotates on its own axis and revolves around the axis of the sun gear 82, thereby rotating the internal gear 85. The rotation from the internal gear 85 is then transmitted to the main shaft 120.
[0052] Therefore, when the rotation from the electric motor 45 in the application direction is transmitted to the differential planetary gear reduction mechanism 68 via the multi-stage gear reduction mechanism 67, the planet carrier 106 located on the other end rotates relative to the minor diameter shaft 113 via the clutch mechanism 107, and the rotational resistance of the planetary gear 83 (rotation around its own axis) relative to the planet carrier 106 is reduced by the action of the rolling bearings 118, 118. As a result, during braking, even if the reaction force from the pressing force of the brake disc D is applied via the piston 30, in order to maintain the braking state, although the reverse efficiency (rotational efficiency in the release direction) is set to 0% or less, the positive efficiency (rotational efficiency in the application direction), which is approximately proportional to the reverse efficiency, can be improved to more than 50%.
[0053] Next, as the main shaft 120 rotates with the action of the differential planetary gear reduction mechanism 68, the direct-acting component 121 advances due to the action of the braking mechanism 47, causing the piston 30 to advance. This advance of the piston 30 presses the inner brake pad 2 against the brake disc D. Furthermore, the reaction force relative to the pressing force of the piston 30 on the inner brake pad 2 causes the brake caliper body 22 to move inward relative to the bracket 5 (…). Figure 2 (Move to the left) and press the outer brake pad 3 against the brake disc D through each claw part 24, 24.
[0054] As a result, the brake disc D is clamped by a pair of inner and outer brake pads 2 and 3, generating friction and thus producing braking force to maintain the braking state. It should be noted that in the electronic control unit 63, the electric motor 45 is driven before the pressing force from the pair of inner and outer brake pads 2 and 3 onto the brake disc D reaches a predetermined value, for example, before the current value of the electric motor 45 reaches a predetermined value. Then, when the electronic control unit 63 detects that the pressing force on the brake disc D has reached a predetermined value due to the current value of the electric motor 45 reaching the predetermined value, it stops energizing the electric motor 45. Alternatively, a sensor for detecting the pressing force on the brake disc D can be provided in the braking mechanism 47, and energizing can be stopped based on the pressing force detected by the sensor.
[0055] In the differential planetary gear reduction mechanism 68, during braking, the reaction efficiency is set to 0 or less, so that even if there is a reaction force from the pressing force from the brake disc D via the piston 30, the braking state can be maintained. Furthermore, through the brake holding mechanism 48, even if the internal gear 85 rotates in the release direction due to the reaction force from the pressing force from the brake disc D via the piston 30, the planet carrier 106 and the minor diameter shaft 113 on the other end cannot rotate relative to each other via the clutch mechanism 107. The rotational resistance of the rotating portion 97 between the bore 94 of the planetary gear 83 and the major diameter shaft 112 increases, thus increasing the rotational resistance of the planetary gear 83 (rotation around its own axis) relative to the planet carrier 106. As a result, the braking state can be reliably maintained.
[0056] On the other hand, when the brake is released, according to the command from the electronic control unit 63, the electric motor 45 rotates in the opposite direction, i.e., the release direction, and this rotation in the opposite direction is transmitted to the main shaft 120 via the multi-stage gear reduction mechanism 67 and the differential planetary gear reduction mechanism 68. That is, in the differential planetary gear reduction mechanism 68, each planetary gear 83 rotates in the opposite direction (rotates in the opposite direction) while rotating relative to the large-diameter shaft portion 112 of each support shaft 110, thereby transmitting the reverse rotation of the inner gear 85 to the main shaft 120. As a result, with the rotation of the main shaft 120 in the opposite direction, the direct-acting component 121 retracts and returns to its initial state through the action of the braking mechanism 47, and the braking force of the pair of inner and outer brake pads 2 and 3 on the brake disc D is released.
[0057] As explained above, the disc brake 1A in the first embodiment includes a brake holding mechanism 48 that retains the braking force generated by the braking mechanism 47. This brake holding mechanism 48 includes: planetary gears 83 that rotate via an electric motor 45; a planet carrier 106 that rotatably supports each planetary gear 83; and a clutch mechanism 107 that can rotate relative to corresponding components (planet carrier 106 and minor diameter shaft 113 in the first embodiment) when the electric motor 45 rotates in the application direction, and relative to corresponding components when the electric motor 45 rotates in the release direction. The components (in the first embodiment, the planetary carrier 106 and the minor diameter shaft 113) cannot rotate relative to each other; the rotary bearing 118 allows the planetary gear 83 to rotate relative to the planetary carrier 106 when the components corresponding to the clutch mechanism 107 (in the first embodiment, the planetary carrier 106 and the minor diameter shaft 113) can rotate relative to each other; the rotating part 97 allows the planetary gear 83 to rotate relative to the planetary carrier 106 when the clutch mechanism 107 cannot rotate relative to the corresponding components (in the first embodiment, the planetary carrier 106 and the minor diameter shaft 113), thus achieving the above-mentioned functions.
[0058] Therefore, firstly, a parking locking mechanism is not required, thus enabling miniaturization, weight reduction, and cost reduction. Furthermore, in the disc brake 1A of the first embodiment, during braking, in order to maintain the braking state even with the reaction force from the pressing force from the brake disc D acting via the piston 30, the positive efficiency, which is approximately proportional to the reverse efficiency, can be improved to over 50%, even though the reverse efficiency is set to 0% or less. It should be noted that by placing the brake holding mechanism 48 upstream of the rotating internal gear 85 of the reduction mechanism 46 in the rotational transmission path, compared to placing it downstream of the rotating internal gear 85 (see Patent Document 1), the load torque applied to the clutch mechanism 107 can be reduced. Therefore, a smaller clutch mechanism 107 can be used, and the enlargement of the disc brake 1A itself can be prevented. Additionally, when the parking brake is released, the clutch mechanism 107 can operate without forced disengagement, thus suppressing abnormal noises (such as stick-slip) during operation.
[0059] Furthermore, in the disc brake 1A of the first embodiment, when the parking brake is applied, the rolling bearing 118 reduces the rotational resistance of the planetary gear 83 relative to the planetary carrier 106 when the clutch mechanism 107 can rotate relative to its corresponding components (the planetary carrier 106 and the minor diameter shaft 113 in the first embodiment). Conversely, when braking, even if the reaction force from the pressing force of the brake disc D is applied via the piston 30, the rotating part 97 increases the rotational resistance of the planetary gear 83 relative to the planetary carrier 106 when the clutch mechanism 107 cannot rotate relative to its corresponding components (the planetary carrier 106 and the minor diameter shaft 113 in the first embodiment). Therefore, when the parking brake is applied, the rotational resistance of the planetary gear 83 relative to the planetary carrier 106 can be further reduced by the rolling bearing 118. On the other hand, during braking, the rotational part 97 can further increase the rotational resistance of the planetary gear 83 relative to the planetary carrier 106 when the reaction force from the pressing force of the brake disc D is applied.
[0060] Furthermore, in the disc brake 1A of the first embodiment, the planetary gear 83 is supported on the planetary carrier 106 via the support shaft 110. The rolling bearing 118 and the clutch mechanism 107 are disposed between the inner circumferential surface of the bore 116 of the planetary carrier 106 and the outer circumferential surface of the minor diameter shaft portion 113 of the support shaft 110. The rotating portion 97 is disposed between the inner circumferential surface of the bore 94 of the planetary gear 83 and the outer circumferential surface of the major diameter shaft portion 112 of the support shaft 110. That is, the rolling bearing 118 is disposed around the axis of the minor diameter shaft portion 113, and the rotating portion 97 is disposed around the axis of the major diameter shaft portion 112. As a result, the rotational resistance of the rolling bearing 118 when the parking brake is applied can be further reduced. On the other hand, during braking, the rotational resistance of the rotating portion 97 when the reaction force from the pressing pressure of the brake disc D is applied can be further increased.
[0061] Furthermore, in the disc brake 1A of the first embodiment, by providing a brake holding mechanism 48 to the differential planetary gear reduction mechanism 68, which is in principle greatly affected by the rotational resistance between the planetary gear 83 and the large-diameter shaft 112 in terms of the forward and reverse efficiency during braking, the difference between the forward and reverse efficiencies can be further increased, and the reliability of brake force holding can be improved (reduction of reverse efficiency) and the forward efficiency during application can be improved at the same time.
[0062] Furthermore, when the clutch mechanism 107 of the disc brake 1A in the first embodiment adopts a cam-type clutch, the idle torque of the clutch mechanism 107 generated when the braking force is increased during the application of the parking brake is small, which can further improve the positive efficiency. In addition, when a coil spring clutch is adopted as the clutch mechanism 107, cost reduction can be achieved.
[0063] Next, refer to Figure 4 The disc brake 1B according to the second embodiment will be described. In this description, only the differences from the disc brake 1A of the first embodiment will be explained. The brake holding mechanism 48 of the disc brake 1B of the second embodiment will be described in detail. Each planetary gear 83 and a pair of planet carriers 106, 106 are rotatably supported by a support shaft 123. In other words, each planetary gear 83 is rotatably supported by a pair of planet carriers 106, 106 via the support shaft 123 about its own axis and about the axis of the sun gear 82. A clutch mechanism 107 and a pair of rolling bearings 118, 118 are respectively provided between the inner circumferential surface of the bore 94 of the planetary gear 83 and the outer circumferential surface of the support shaft 123. The pair of rolling bearings 118, 118 are respectively disposed on both axial sides of the clutch mechanism 107.
[0064] In the disc brake 1B of this second embodiment, the inner circumferential surfaces of the bores 116 of the pair of planetary carriers 106 and 106 respectively function as rotating parts 97 and 97 between the outer circumferential surface of the support shaft 123. It should be noted that, similarly to the disc brake 1A of the first embodiment, in the disc brake 1B of the second embodiment, the planetary gear 83 corresponds to a rotating component, and the planetary carrier 106 corresponds to a supporting component. In the disc brake 1B of the second embodiment, the components corresponding to the clutch mechanism 107 are the planetary gear 83 and the support shaft 123. It should be noted that, in the disc brake 1B of the second embodiment, the sun gear 82 is rotatably supported by the gear shaft 122. The other end of the gear shaft 122 is integrally fixed to the cover component 38.
[0065] Furthermore, when each planetary gear 83 rotates in the applied direction, the planetary gear 83 rotates relative to the support shaft 123 via the clutch mechanism 107, and the rotational resistance of the planetary gear 83 relative to the planet carrier 106 decreases due to the action of the rolling bearings 118, 118. On the other hand, when the rotating internal gear 85 rotates in the release direction, the planetary gear 83 cannot rotate relative to the support shaft 123 via the clutch mechanism 107, and the rotational resistance of the rotating portions 97, 97 between the bores 116, 116 of the pair of planet carriers 106, 106 and the support shaft 123 increases, thus increasing the rotational resistance of the planetary gear 83 relative to the planet carriers 106, 106.
[0066] As a result, the disc brake 1B of the second embodiment can also achieve the same effect as the disc brake 1A of the first embodiment. Moreover, in the disc brake 1B of the second embodiment, a clutch mechanism 107 and a pair of rolling bearings 118, 118 are arranged inside the planetary gear 83, so it can be miniaturized along the axial direction of the brake disc D.
[0067] Next, refer to Figure 5The disc brake 1C of the third embodiment will be described. In this description, only the differences from the disc brake 1A of the first embodiment will be explained. In the disc brake 1C of the third embodiment, the brake holding mechanism 48 is provided in the rotational transmission path in a multi-stage gear reduction mechanism 67 upstream of the rotating internal gear 85 of the differential planetary gear reduction mechanism 68. The brake holding mechanism 48 will be described in detail. A clutch mechanism 107 and a pair of rolling bearings 118, 118 are respectively provided between the inner circumferential surface of the shaft hole 74 of the reduction gear 72, which is the structure of the multi-stage gear reduction mechanism 67, and the outer circumferential surface of the gear shaft 77. The pair of rolling bearings 118, 118 are respectively arranged on both axial sides of the clutch mechanism 107. It should be noted that in the disc brake 1C of the third embodiment, the small diameter shaft gear 80 of the reduction gear 72 extends from the large gear 79 to one end. One end of the gear shaft 77 is rotatably supported in a support recess 125 provided in the wall portion of the first housing portion 41 near the second housing portion 42, while the other end of the gear shaft 77 is rotatably supported in a support recess 124 of the cover member 38.
[0068] In the disc brake 1C of this third embodiment, the outer peripheral surface of one end of the gear shaft 77 and the inner peripheral surface of the support recess 125 of the first housing portion 41, and the outer peripheral surface of the other end of the gear shaft 77 and the inner peripheral surface of the support recess 124 of the cover member 38, respectively function as rotating parts 97 and 97. It should be noted that in the disc brake 1C of the third embodiment, the reduction gear 72 corresponds to a rotating member. Furthermore, the cover member 38 and the first housing portion 41 correspond to supporting members. The components corresponding to the clutch mechanism 107 are the reduction gear 72 and the gear shaft 77.
[0069] Furthermore, when the reduction gear 72 rotates in the applied direction, the reduction gear 72 rotates relative to the gear shaft 77 via the clutch mechanism 107, and the rotational resistance of the reduction gear 72 relative to the cover member 38 and the first housing part 41 (wall part) decreases due to the action of the rolling bearings 118, 118. On the other hand, when the rotating internal gear 85 rotates in the release direction, the reduction gear 72 cannot rotate relative to the gear shaft 77 via the clutch mechanism 107, and the rotational resistance of the rotating parts 97, 97 between the support recesses 124, 125 of the cover member 38 and the first housing part 41 and the gear shaft 77 increases. Therefore, the rotational resistance of the reduction gear 72 relative to the cover member 38 and the first housing part 41 increases.
[0070] It should be noted that sliding bearings can also be provided between one end of the gear shaft 77 and the support recess 125 of the first housing portion 41, and between the other end of the gear shaft 77 and the support recess 124 of the cover member 38. It should be noted that the rolling bearing 118 reduces mutual rotational resistance compared to the sliding bearing. Furthermore, the disc brake 1C of the third embodiment can achieve the same effect as the disc brake 1A of the first embodiment. Moreover, in the disc brake 1C of the third embodiment, a clutch mechanism 107 and a pair of rolling bearings 118 are provided inside the reduction gear 72, thus enabling miniaturization along the axial direction of the brake disc D.
[0071] Next, refer to Figure 6 The disc brake 1D according to the fourth embodiment will be described. In this description, only the differences from the disc brake 1A of the first embodiment will be explained. In the disc brake 1D of the fourth embodiment, the brake holding mechanism 48 is provided on the upstream side of the rotating internal gear 85 of the differential planetary gear reduction mechanism 68, and is provided in the electric motor 45 and the second housing portion 42 of the housing 36 that houses the electric motor 45. The brake holding mechanism 48 will be described in detail. A support recess 130 with an opening at one end face is formed in the rotor body portion 53 of the electric motor 45. A first rotating shaft 51 is rotatably housed and supported in the support recess 130. The first rotating shaft 51 is composed of a first large-diameter rotating shaft portion 133 rotatably supported in the support recess 130 and a first small-diameter rotating shaft portion 134 extending from the first large-diameter rotating shaft portion 133 toward one end.
[0072] The first small-diameter rotating shaft portion 134 is rotatably supported within a receiving recess 57 provided in the second housing portion 42. A clutch mechanism 107 and a rolling bearing 118 are provided between the outer peripheral surface of the first small-diameter rotating shaft portion 134 and the inner peripheral surface of the receiving recess 57. The rolling bearing 118 is disposed at one end of the clutch mechanism 107. On the electric motor 45, a second rotating shaft 52 extends integrally from the rotor body portion 53 toward the other end. The second rotating shaft 52 passes through a through hole 60 provided in the second housing portion 42 via a rolling bearing 58. In this disc brake 1D of the fourth embodiment, the inner peripheral surface of the support recess 130 of the rotor body portion 53 and the outer peripheral surface of the first large-diameter rotating shaft portion 133 function as a rotating part 97. It should be noted that in the disc brake 1D of the fourth embodiment, the rotor body portion 53 of the electric motor 45 is equivalent to a rotating component, and the second housing portion 42 of the housing 36 is equivalent to a supporting component. In addition, the components corresponding to the clutch mechanism 107 are the second housing portion 42 and the first small-diameter rotating shaft portion 134.
[0073] Furthermore, when the rotor body 53 of the electric motor 45 rotates in the applied direction, the second housing 42 rotates relative to the first minor diameter rotating shaft 134 via the clutch mechanism 107, and the rotational resistance of the rotor body 53 relative to the second housing 42 decreases due to the action of the rolling bearing 118. On the other hand, when the rotating internal gear 85 rotates in the release direction, the second housing 42 and the first minor diameter rotating shaft 134 cannot rotate relative to each other via the clutch mechanism 107, and the rotational resistance of the rotating portion 97 between the rotor body 53 and the first major diameter rotating shaft 133 increases, thus increasing the rotational resistance of the rotor body 53 relative to the second housing 42.
[0074] As a result, the disc brake 1D of the fourth embodiment can also achieve the same effect as the disc brake 1A of the first embodiment. Moreover, in the disc brake 1D of the fourth embodiment, the clutch mechanism 107 is arranged around the electric motor 45 where the rotational torque is the smallest, so the clutch mechanism 107 can be further miniaturized.
[0075] It should be noted that the brake holding mechanism 48 described above is applicable to the disc brake 1 that uses an electric motor 45 to drive both the service brake and the parking brake in this embodiment, but it can also be applied to other known electric brakes that require maintaining braking force, such as electric parking brakes that use hydraulic pressure to operate the service brake.
[0076] This application claims priority based on Japanese Patent Application No. 2024-004810, filed January 16, 2024. The entire disclosure of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2024-004810, filed January 16, 2024, is incorporated herein by reference in its entirety.
[0077] Explanation of reference numerals in the attached figures
[0078] 1A, 1B, 1C, 1D: Disc brake (equivalent to electric brake)
[0079] 2: Inner brake pad (equivalent to brake component)
[0080] 3: External brake pads (equivalent to brake components)
[0081] 4: Brake calipers
[0082] 30: Piston
[0083] 38: Cover component (equivalent to a support component in the third embodiment)
[0084] 41: First housing portion (equivalent to a support component in the third embodiment)
[0085] 42: Second housing portion (equivalent to a support component in the fourth embodiment)
[0086] 45: Electric motor
[0087] 46: Speed reduction mechanism
[0088] 47: Braking mechanism
[0089] 48: Brake holding mechanism
[0090] 53: Rotor body (equivalent to a rotating component in the fourth embodiment)
[0091] 67: Multi-stage gear reduction mechanism
[0092] 71: Pinion gear (input component)
[0093] 72: Reduction gear (equivalent to a rotating component in the third embodiment)
[0094] 85: Rotating internal gear (output component)
[0095] 83: Planetary gear (equivalent to a rotating component in the first and second embodiments)
[0096] 97: Rotating part
[0097] 106: Planetary carrier (equivalent to a support component in the first and second embodiments)
[0098] 107: Clutch Mechanism
[0099] 110: Support shaft
[0100] 112: Large diameter shaft section
[0101] 113: Small diameter shaft section
[0102] 118: Rolling bearing (equivalent to a bearing)
[0103] 123: Support shaft
[0104] D: Brake disc (the braked component).
Claims
1. An electric brake, characterized in that, have: Electric motor; A speed reduction mechanism having an input component that receives rotation from the electric motor and an output component that reduces the rotation of the input component and outputs it. The braking mechanism presses the braking component against the braked component by the rotation of the output component from the reduction mechanism, thereby generating braking force. as well as A brake holding mechanism that retains the braking force generated by the braking mechanism. In the rotational transmission path from the electric motor, when the braking mechanism is positioned downstream and the electric motor is positioned upstream, the brake holding mechanism is located upstream of the output component. In addition, the brake holding mechanism includes: A rotating component that rotates via the electric motor; A support component that rotatably supports the rotating component; A clutch mechanism that, when the electric motor rotates in the direction that presses the braking component against the braked component, can rotate relative to the corresponding component, and cannot rotate relative to the corresponding component when the electric motor rotates in the direction that separates the braking component from the braked component; A bearing, which, when the clutch mechanism is rotatable relative to a corresponding component, enables the rotating component to rotate relative to the supporting component; and A rotating part that enables the rotating component to rotate relative to the supporting component when the clutch mechanism cannot rotate relative to the corresponding component.
2. The electric brake according to claim 1, characterized in that, When the clutch mechanism is able to rotate relative to the corresponding component, the bearing reduces the rotational resistance of the rotating component relative to the support component. When the clutch mechanism cannot rotate relative to the corresponding component, the rotating part increases the rotational resistance of the rotating component relative to the supporting component.
3. The electric brake according to claim 2, characterized in that, The rotating component is supported by the supporting component via a supporting shaft. The support shaft is stepped, having a large-diameter shaft portion and a small-diameter shaft portion extending axially from the large-diameter shaft portion. The bearing and the clutch mechanism are disposed between the support member and the small-diameter shaft portion. The rotating part is disposed between the rotating component and the large-diameter shaft.
4. The electric brake according to claim 2, characterized in that, The rotating component is supported by the supporting component via a supporting shaft. The bearing and the clutch mechanism are disposed between the rotating component and the support shaft. The rotating part is disposed between the support component and the support shaft.
5. The electric brake according to claim 1, characterized in that, The reduction mechanism has a differential planetary gear mechanism. The brake holding mechanism is disposed on the differential planetary gear mechanism.
6. The electric brake according to claim 1, characterized in that, The reduction mechanism has a multi-stage gear reduction mechanism. The brake holding mechanism is disposed on the multi-stage gear reduction mechanism.
7. The electric brake according to claim 1, characterized in that, The brake holding mechanism is disposed on the electric motor and the housing that houses the electric motor.
8. The electric brake according to any one of claims 1 to 7, characterized in that, The clutch mechanism is a cam-type clutch.
9. The electric brake according to any one of claims 1 to 7, characterized in that, The clutch mechanism is a helical spring clutch.
Citation Information
Patent Citations
Method of manufacturing running drum and framework
JP2024004810A
Disk brake
WO2015151618A1