Large-torque ultrathin permanent magnet brake

Abstract

The invention discloses a large-torque ultrathin permanent magnet brake and belongs to the technical field of permanent magnet brake production, the large-torque ultrathin permanent magnet brake comprises an outer groove disc, an inner groove disc, an electromagnetic coil, a retainer and a permanent magnet, the outer groove disc comprises an outer cylinder and an outer disc, the inner wall of the outer disc and the outer wall of one end of the outer cylinder are connected and integrally formed, and the inner groove disc comprises an inner cylinder and an inner disc; the inner wall of the inner disc and the outer wall of one end of the inner cylinder are connected and integrally formed, the part, close to the center position, of the surface of one side of the inner disc is the cavity wall surface of one side of the coil inner cavity, and the permanent magnet and the annular retainer are located between the part, close to the edge position, of the surface of one side of the inner disc and the outer disc. The purposes of remarkably increasing the braking torque and reducing the coil function and temperature rise on the premise that the axial size of the brake is not increased are achieved, finally the purposes of large torque, small power, small temperature rise and ultra-thin (namely extremely-small axial size) functions are achieved, and the application requirements of humanoid robots and other products with extremely-small axial size requirements are met.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet brake manufacturing technology, specifically relating to a high-torque ultra-thin permanent magnet brake. Background Technology

[0002] A permanent magnet brake is a type of brake that uses a permanent magnet to attract an armature to achieve braking, and uses an electromagnet to counteract the attraction of the permanent magnet to release the brake. It is widely used in emerging industries such as robotics and low-altitude aircraft.

[0003] The basic structure of a traditional permanent magnet brake includes an outer grooved disc, an inner grooved disc, an electromagnetic coil, an armature, leaf springs, a cage, and a permanent magnet. The outer grooved disc is integrally formed by connecting an annular outer cylinder and an annular inner disc. One end of the inner wall of the annular outer cylinder is connected to the outer wall of the annular inner disc. The inner grooved disc is integrally formed by connecting an annular inner cylinder and an annular outer disc. One end of the outer wall of the annular inner cylinder is connected to the inner wall of the annular outer disc. The annular outer cylinder of the outer grooved disc is located outside the annular inner cylinder of the inner grooved disc. The electromagnetic coil is placed inside a ring-shaped coil cavity formed by the outer and inner grooved discs. The annular cage is located axially within the annular inner disc of the outer grooved disc and the inner grooved disc of the brake. Between the inner grooved disc and the outer annular disc, the cage and the inner annular disc of the outer grooved disc are located between the outer annular disc of the inner grooved disc and the electromagnetic coil. The permanent magnet is mounted on the cage (in order to facilitate installation and adjustment of the permanent magnet force, multiple independent permanent magnets are generally evenly mounted on the cage). The armature is close to the same end of the outer annular cylinder of the outer grooved disc and the inner annular cylinder of the inner grooved disc, and the braking function is achieved by contacting and rubbing with the outer annular cylinder of the outer grooved disc. The leaf spring is mounted on the armature, and the leaf spring is provided with a connection hole for connecting with the rotating flange of the equipment. The outer annular disc of the inner grooved disc is provided with a connection screw hole near the outer edge for connecting with the fixed parts of the equipment. In application, the inner grooved plate is connected to the fixed component of the equipment, and the leaf spring is connected to the rotating flange of the equipment. During operation, the electromagnetic coil is energized, generating an electromagnetic field with the same or similar intensity as the permanent magnetic field of the permanent magnet. At this time, the armature is separated from the annular outer cylinder of the outer grooved plate under the action of the leaf spring, ensuring that the rotating flange of the equipment and the shaft connected to it can rotate freely, and the permanent magnet brake is in the released braking state. When the electromagnetic coil is de-energized, the electromagnetic field disappears, and the permanent magnetic attraction generated by the permanent magnetic field of the permanent magnet attracts the armature, causing it to come into close contact with the end of the annular outer cylinder of the outer grooved plate. Strong friction is generated, causing the armature speed to decrease rapidly until it stops. At this time, the armature, the rotating flange of the equipment, and the shaft connected to it cannot rotate, and the permanent magnet brake is in the braking state. The structure of the above-mentioned conventional permanent magnet brake can be referred to the utility model patent document with authorization announcement number "CN 223549686 U", which is not shown in the drawings of this application.

[0004] The aforementioned traditional permanent magnet brakes have the following drawbacks: First, the cage and permanent magnet are distributed axially with the electromagnetic coil in the brake. This structure inevitably causes the cage and permanent magnet to occupy the axial dimension of the brake, compressing the axial installation space of the electromagnetic coil. Either the axial dimension of the brake can be increased to meet the torque requirements, which may prevent its application in products such as humanoid robots where the axial dimension requirements are extremely small, or the number of turns or diameter of the electromagnetic coil can be reduced to meet the axial dimension requirements, which may result in insufficient torque or extremely high current density and temperature rise of the electromagnetic coil, reducing the service life of the electromagnetic coil and the braking effect of the brake. Therefore, it is impossible to have both high torque (requiring the electromagnetic coil to occupy a large space to generate a large electromagnetic field) and ultra-thin brake (i.e., sufficiently small axial dimension), which limits its application in products such as humanoid robots where the axial dimension requirements are extremely small. Second, the permanent magnet is located on the side of the electromagnetic coil away from the armature, resulting in greater magnetic loss. More permanent magnets are needed to obtain greater torque. Due to the large number of permanent magnets, the electromagnetic coil requires a large magnetomotive force to counteract the permanent magnet force, which requires a large power of the electromagnetic coil and reduces product reliability. Third, the annular inner disk of the outer groove disk and the annular outer disk of the inner groove disk, as well as the armature and leaf spring, are all connected by screws. Because the screw length is standard, it is impossible to make its axial dimension extremely small as needed, which will also increase the axial dimension of the brake. This is also a significant defect in robot joint modules and low-altitude aircraft where the axial dimension requirement is extremely small. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-thin permanent magnet brake that combines the advantages of extremely small axial dimensions and large torque in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions: A high-torque ultrathin permanent magnet brake includes an outer grooved disc, an inner grooved disc, an electromagnetic coil, a cage, and a permanent magnet. The outer grooved disc includes an outer cylinder coaxial with the ultrathin permanent magnet brake and in a cylindrical shape. The inner grooved disc includes an inner cylinder coaxial with the ultrathin permanent magnet brake and in a cylindrical shape. The outer cylinder is located outside the inner cylinder. The electromagnetic coil is placed in a coil cavity between the outer cylinder and the inner cylinder. The outer grooved disc also includes an outer disc coaxial with the ultrathin permanent magnet brake and in an annular shape. The inner wall of the outer disc is connected to and integrally formed with one end of the outer wall of the outer cylinder. The inner grooved disc also includes an inner disc coaxial with the ultrathin permanent magnet brake and in an annular shape. The inner wall of the inner disc is connected to and integrally formed with one end of the outer wall of the inner cylinder. A portion of one side surface of the inner disc near the center is the cavity wall surface of one side of the coil cavity. The permanent magnet and the annular cage are located between the outer disc and a portion of one side surface of the inner disc near the edge.

[0007] Preferably, in order to reliably position the permanent magnets and facilitate assembly, a retaining ring is provided in the inner disk at a position inside the ring formed by the multiple permanent magnets, protruding towards the outer disk. The retainer is located outside the ring formed by the multiple permanent magnets, and the multiple permanent magnets are located between the retaining ring and the retainer.

[0008] Preferably, in order to achieve braking and de-braking functions and facilitate connection with the rotating flange of the equipment, the ultra-thin permanent magnet brake further includes an armature and a leaf spring. The armature is close to the same end of the outer cylinder and the inner cylinder, away from the inner disc and close to the electromagnetic coil. The leaf spring is installed on the side of the armature away from the outer cylinder, and the leaf spring is provided with a plurality of leaf spring connection holes evenly distributed along the circumferential direction.

[0009] Preferably, in order to further reduce the axial dimension of the brake, the outer disc and the inner disc, and the leaf spring and the armature are connected by a plurality of rivets.

[0010] Preferably, in order to facilitate the positioning of the cage, the cage is provided with a through hole and the corresponding rivet passes through the through hole.

[0011] Preferably, depending on actual installation and application needs, the surface planes of the inner disk are all located on the same plane, and the permanent magnet, the cage, and the outer disk are all far away from the armature; or, the annular region in the inner disk corresponding to the outer disk is continuously bent at 90° towards the armature to form a "Z"-shaped structure, the permanent magnet, the cage, and the outer disk are all close to the armature, and part of the surface of the "Z"-shaped structure in the inner disk and the inner wall surface of the inner cylinder are both the cavity wall surface of one side of the coil cavity.

[0012] Preferably, in order to facilitate the connection of the inner disk to the fixed parts of the device, the inner disk is provided with a plurality of inner disk connection holes evenly distributed in the circumferential direction near the edge.

[0013] The beneficial effects of this invention are as follows: This invention improves upon the traditional location of the outer disc of the outer groove plate by placing it on the outside of the outer cylinder, and positions the cage and permanent magnet on the outside of the outer cylinder. This utilizes the axial space originally occupied by the cage and permanent magnet as part of the coil's inner cavity, significantly increasing the axial dimension of the coil's inner cavity. This achieves a significant increase in braking torque, reduced coil capacity, and lower temperature rise without increasing the brake's axial dimension. Ultimately, it achieves a combination of high torque, low power, low temperature rise, and ultra-thin (i.e., extremely small axial dimension) functionality, meeting the application requirements of humanoid robots and other products with extremely small axial dimension requirements. Although this invention increases the radial dimension of the brake, the axial dimension of the radially convex portion formed by the cage, permanent magnet, and corresponding parts of the outer and inner discs is relatively small. Therefore, the radially protruding part can move arbitrarily within the corresponding axial region of the brake as needed. This structure perfectly meets the application requirements in products such as humanoid robots (for example, placing the radially protruding part in the gap between the motor and encoder of the integrated joint module of the humanoid robot). At the same time, the permanent magnet can be located close to the armature, thereby reducing the loss of permanent magnet force, reducing the number of permanent magnets, reducing the power of the electromagnetic coil, reducing the temperature rise, and improving the reliability of the product. By improving the traditional screw connection structure between the outer and inner discs and between the leaf spring and the armature to a riveted connection structure, the axial dimension of the brake is further reduced, better meeting the application requirements of the brake in products such as humanoid robots and low-altitude aircraft where the axial dimension requirements are extremely small. Attached Figure Description

[0014] Figure 1 This is a three-dimensional exploded view of the high-torque ultra-thin permanent magnet brake described in Embodiment 1 of the present invention before assembly; Figure 2 This is a perspective view of the assembled high-torque ultra-thin permanent magnet brake described in Embodiment 1 of the present invention; Figure 3 This is a front sectional view of the assembled high-torque ultra-thin permanent magnet brake described in Embodiment 1 of the present invention; Figure 4 This is a front sectional view of the assembled high-torque ultra-thin permanent magnet brake described in Embodiment 2 of the present invention.

[0015] In the diagram, 1-leaf spring connecting hole, 2-leaf spring, 3-rivet, 4-armature, 5-electromagnetic coil, 6-lead wire, 7-outer cylinder, 8-outer grooved plate, 9-outer disc, 10-permanent magnet, 11-cage, 12-inner cylinder, 13-inner grooved plate, 14-inner disc, 15-retaining ring, 16-inner disc connecting hole, 17-coil inner cavity, 18-epoxy resin. Detailed Implementation

[0016] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1:

[0017] like Figures 1-3 As shown, a high-torque ultra-thin permanent magnet brake includes an outer grooved disc 8, an inner grooved disc 13, an electromagnetic coil 5, a retainer 11, and a permanent magnet 10. The outer grooved disc 8 includes an outer cylinder 7 that is coaxial (vertical in the figure) with the ultra-thin permanent magnet brake and is cylindrical. The inner grooved disc 13 includes an inner cylinder 12 that is coaxial with the ultra-thin permanent magnet brake and is cylindrical. The outer cylinder 7 is located outside the inner cylinder 12. The electromagnetic coil 5 is placed in the coil cavity 17 between the outer cylinder 7 and the inner cylinder 12. The outer grooved disc 8 also includes components coaxial with the ultra-thin permanent magnet brake. The outer disk 9 is axially oriented and circular. The inner wall of the outer disk 9 is connected to one end of the outer wall of the outer cylinder 7 and is integrally formed. The inner groove disk 13 also includes an inner disk 14 that is coaxially oriented and circular with the ultra-thin permanent magnet brake. The inner wall of the inner disk 14 is connected to one end of the outer wall of the inner cylinder 12 and is integrally formed. The part of one side surface of the inner disk 14 near the center position is the side cavity wall surface of the coil cavity 17. The permanent magnet 10 and the circular retainer 11 are located between the outer disk 9 and the part of one side surface of the inner disk 14 near the edge position.

[0018] like Figures 1-3 As shown, this embodiment also discloses the following more optimized structures: In order to reliably position the permanent magnet 10 and facilitate assembly, a retaining ring 15 is provided in the inner disk 14 at the position inside the ring formed by the multiple permanent magnets 10, which protrudes towards the outer disk 9. The retainer 11 is located outside the ring formed by the multiple permanent magnets 10, and the multiple permanent magnets 10 are located between the retaining ring 15 and the retainer 11.

[0019] In order to realize the braking and releasing functions and facilitate connection with the rotating flange of the equipment, the ultra-thin permanent magnet brake also includes an armature 4 and a leaf spring 2. The armature 4 is close to the same end of the outer cylinder 7 and the inner cylinder 12 and away from the inner plate 14 and close to the electromagnetic coil 5. The leaf spring 2 is installed on the side of the armature 4 away from the outer cylinder 7. The leaf spring 2 is provided with a plurality of leaf spring connecting holes 1 evenly distributed along the circumferential direction.

[0020] To further reduce the axial dimension of the brake, the outer disc 9 and the inner disc 14, as well as the leaf spring 2 and the armature 4, are connected by multiple rivets 3.

[0021] To facilitate the positioning of the retainer 11, the retainer 11 is provided with a through hole through which the corresponding rivet 3 passes.

[0022] According to actual installation and application requirements, the surface plane of the inner disk 14 is located on the same plane, and the permanent magnet 10, the cage 11 and the outer disk 9 are all far away from the armature; To facilitate the connection of the inner plate 14 to the fixed parts of the equipment, the inner plate 14 is provided with a plurality of inner plate connection holes 16 evenly distributed in the circumferential direction near the edge.

[0023] Figures 1-3 The diagram also shows a lead wire 6 (in Embodiment 2 below) connected to the electromagnetic coil 5 and passing through the corresponding through hole on the outer cylinder 7. Figure 4 Also shown). Figure 3 The diagram also shows an epoxy resin 18 (as described in Example 2 below) disposed within the inner cavity 17 of the coil and used to fix the electromagnetic coil 5. Figure 4 (As also shown), these are all conventional structures.

[0024] like Figures 1-3 As shown, in application, the inner groove plate 13 is installed on the fixed part (not shown in the figure, such as the robot joint internal housing mounting plate) of the device (not shown in the figure, such as a humanoid robot) through multiple inner plate connecting holes 16 on the inner plate 14 and mounting screws (not shown in the figure). The leaf spring 2 is connected to the rotating flange of the device (not shown in the figure, connected to the rotating shaft of the device) through the connector (not shown in the figure) and multiple leaf spring connecting holes 1.

[0025] When in operation, the electromagnetic coil 5 is energized and generates an electromagnetic field with the same or similar intensity as the permanent magnetic field of the permanent magnet 10. At this time, the armature 4 is separated from the outer cylinder 7 of the outer groove plate 8 under the action of the leaf spring 2 (and is also necessarily separated from the inner cylinder 12 of the inner groove plate 13), ensuring that the rotating flange of the equipment and the shaft connected to it can rotate freely, and the permanent magnet brake is in the released braking state. When the electromagnetic coil 5 is de-energized, the electromagnetic field disappears, and the permanent magnetic attraction generated by the permanent magnetic field of the permanent magnet 10 attracts the armature 4 to make it closely contact the end of the outer cylinder 7 of the outer groove plate 8 (under normal circumstances, the armature 4 does not contact the inner cylinder 12 of the inner groove plate 13), generating strong friction that rapidly reduces the rotation speed of the armature 4 until it stops. At this time, the armature 4 and the rotating flange of the equipment and the shaft connected to it cannot rotate, and the permanent magnet brake is in the braking state.

[0026] Implementation: 2:

[0027] like Figure 4 As shown, compared with the structure of Embodiment 1, the difference in this embodiment is that the annular region in the inner disk 14 corresponding to the outer disk 9 is continuously bent at 90° towards the armature 4 to form a "Z"-shaped structure. The permanent magnet 10, the cage 11, and the outer disk 9 are all close to the armature 4. Part of the surface of the "Z"-shaped structure in the inner disk 14 and the inner wall surface of the inner cylinder 12 are both the surface of one side of the cavity wall of the coil cavity 17. At the same time, because the permanent magnet 10 is closer to the armature 4, the permanent magnetic force is greater. Under the premise of keeping the braking torque unchanged, the number of permanent magnets 10 in this embodiment is less than that in Embodiment 1. Based on this, the permanent magnet 10, the cage 11, and the outer disk 9 can also be located in a position between Embodiment 1 and Embodiment 2, depending on actual needs. The working principle in the application of this Embodiment 1 is the same as that in Embodiment 1, and will not be repeated here.

[0028] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of the patent of the present invention.

Claims

1. A high-torque ultra-thin permanent magnet brake, comprising an outer grooved disc, an inner grooved disc, an electromagnetic coil, a cage, and a permanent magnet, wherein the outer grooved disc includes an outer cylinder coaxial with and cylindrical in shape with respect to the ultra-thin permanent magnet brake, the inner grooved disc includes an inner cylinder coaxial with and cylindrical in shape with respect to the ultra-thin permanent magnet brake, the outer cylinder is located outside the inner cylinder, and the electromagnetic coil is disposed within a coil cavity between the outer cylinder and the inner cylinder, characterized in that: The outer groove disk also includes an outer disk that is coaxial with the ultra-thin permanent magnet brake and is circular. The inner wall of the outer disk is connected to one end of the outer wall of the outer cylinder and is integrally formed. The inner groove disk also includes an inner disk that is coaxial with the ultra-thin permanent magnet brake and is circular. The inner wall of the inner disk is connected to one end of the outer wall of the inner cylinder and is integrally formed. The portion of one side surface of the inner disk near the center position is the side cavity wall surface of the coil cavity. The permanent magnet and the circular retainer are located between the portion of one side surface of the inner disk near the edge position and the outer disk.

2. The high-torque ultra-thin permanent magnet brake according to claim 1, characterized in that: The inner disk has a retaining ring located inside the ring formed by the multiple permanent magnets, which protrudes towards the outer disk. The retainer is located outside the ring formed by the multiple permanent magnets, and the multiple permanent magnets are located between the retaining ring and the retainer.

3. The high-torque ultra-thin permanent magnet brake according to claim 1 or 2, characterized in that: The ultra-thin permanent magnet brake also includes an armature and a leaf spring. The armature is close to the same end of the outer cylinder and the inner cylinder, away from the inner disc and close to the electromagnetic coil. The leaf spring is installed on the side of the armature away from the outer cylinder. The leaf spring is provided with a plurality of leaf spring connecting holes evenly distributed along the circumferential direction.

4. The high-torque ultra-thin permanent magnet brake according to claim 3, characterized in that: The outer disk and the inner disk, as well as the leaf spring and the armature, are connected by multiple rivets.

5. The high-torque ultra-thin permanent magnet brake according to claim 4, characterized in that: The retainer has a through hole through which the corresponding rivet passes.

6. The high-torque ultra-thin permanent magnet brake according to claim 3, characterized in that: The surfaces of the inner disk are all located on the same plane, and the permanent magnet, the cage, and the outer disk are all far away from the armature; or, the annular region in the inner disk corresponding to the outer disk is continuously bent at 90° towards the armature to form a "Z" shaped structure, and the permanent magnet, the cage, and the outer disk are all close to the armature, and part of the surface of the "Z" shaped structure in the inner disk and the inner wall surface of the inner cylinder are both the cavity wall surface of one side of the coil cavity.

7. The high-torque ultra-thin permanent magnet brake according to claim 3, characterized in that: The inner disk has multiple inner disk connection holes evenly distributed along the circumference near the edge.

Images