Magnetorheological brake with multiple extrusion positions

Abstract

The invention provides a multi-extrusion magnetorheological brake. The multi-extrusion magnetorheological brake comprises a shell, a brake shaft, a brake disc, a magnetism isolating ring, a plurality of sliding blocks, a plurality of elastic pieces, two magnet exciting coils, magnetorheological fluid and a flow adjusting assembly. The brake shaft is rotationally connected to the shell; the brake disc is fixed on the brake shaft; the magnetism isolating ring is arranged in the shell, a plurality of sliding cavities are formed in the magnetism isolating ring, and a fluid channel communicating the sliding cavities is arranged between every two adjacent sliding cavities. The sliding block is arranged in the sliding cavity in a sliding manner; the two opposite ends of the elastic piece are elastically propped against the sliding block and the cavity wall of the sliding cavity respectively; the two magnet exciting coils are arranged on the two opposite sides of the magnetism isolating ring respectively. The magnetorheological fluid is arranged in the shell and flows in the sliding cavity and the fluid channel; the flow adjusting assembly comprises a moving disc arranged outside the shell and a plurality of adjusting rods fixedly connected with the moving disc, notches are formed in the adjusting rods, the adjusting rods are in sliding connection with the shell, and one end of each adjusting rod is arranged in the fluid channel to seal the fluid channel. The power-off protection function is achieved, and potential safety hazards can be reduced.

Description

Technical Field

[0001] The present invention relates to a brake, and more particularly to a magnetorheological brake with multiple squeezes. Background Art

[0002] A magnetorheological brake is a device that uses the viscous characteristics of magnetorheological fluid to achieve braking. Its working principle is to change the magnetic field intensity to cause the magnetorheological fluid to undergo plastic flow, thereby achieving braking of the piston. This braking method has the advantages of fast response speed, large braking force, and small wear. The working principle of the magnetorheological brake is also reflected in its ability to automatically adjust the friction coefficient to adapt to different working conditions. When the braking system requires a greater braking force, the magnetorheological fluid becomes "harder", thereby increasing the braking force; conversely, when the braking system requires a smaller braking force, the magnetorheological fluid becomes "softer", thereby reducing the braking force. This adaptive performance enables the magnetorheological brake to maintain good braking performance under various working conditions. Another advantage of the magnetorheological brake is its good heat dissipation performance. Since the working temperature of the magnetorheological fluid is independent of the ambient temperature, excessive heat accumulation does not occur during use, thus avoiding performance degradation caused by overheating. In addition, the magnetorheological brake also has a long service life and low maintenance cost, making it widely used in the fields of automobiles, aviation, and medical treatment.

[0003] Chinese Patent Application Publication No. CN115853930A discloses a magnetorheological brake. The magnetorheological brake uses a T-shaped brake disc. Grooves are provided on the outer peripheral surface of the T-shaped brake disc, and the grooves extend along the circumferential direction of the T-shaped brake disc. At the same time, a convex platform matching the grooves is provided on the inner peripheral surface of the locking ring; there is a first gap between the outer peripheral surface of the T-shaped brake disc and the inner peripheral surface of the locking ring, and there is also a second gap between the first end face and the second end face and the housing. One end of the second gap is sealed by a sealing ring, and the other end of the second gap communicates with the first gap. The first gap and the second gap are filled with magnetorheological fluid. It can not only effectively save the use of magnetorheological fluid, but also improve the braking torque of the magnetorheological brake without changing the braking area of the brake disc through the improvement of the brake disc structure. However, in the existing magnetorheological brakes, usually only when an electric current is passed through the excitation coil can the magnetorheological fluid undergo a rheological effect under the action of the magnetic field, and then cooperate with the brake disc to achieve braking. If the excitation coil accidentally loses power during the braking process, its magnetic field disappears and the magnetorheological fluid cannot cooperate with the brake disc to achieve braking, resulting in the brake shaft of the existing magnetorheological brake still being able to rotate after being subjected to an external force and unable to maintain the braking state, which may cause potential safety hazards. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems presented in the above-mentioned background art, and provides a magnetorheological brake with multiple squeezes, which enables the magnetorheological brake to have a power-off protection function and reduces potential safety hazards.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A magnetorheological brake with multiple squeezes, comprising:

[0007] A housing, an accommodation cavity is formed inside the housing;

[0008] A brake shaft, the brake shaft is rotatably connected to the housing;

[0009] A brake disc, the brake disc is accommodated in the accommodation cavity and fixedly sleeved on the brake shaft;

[0010] A magnetic isolation ring, the magnetic isolation ring is fixed in the accommodation cavity and disposed around the outer side of the brake disc. A plurality of sliding cavities are provided inside the magnetic isolation ring. The plurality of sliding cavities are circumferentially spaced along the magnetic isolation ring, and one end of the sliding cavity facing the brake disc communicates with the accommodation cavity. A fluid passage communicating the adjacent two sliding cavities is provided between the adjacent two sliding cavities;

[0011] A plurality of sliders, the plurality of sliders are respectively slidably disposed in the plurality of sliding cavities;

[0012] A plurality of elastic members, the plurality of elastic members are respectively disposed in the plurality of sliding cavities and located at one end of the corresponding slider away from the brake disc. The opposite ends of the elastic member are elastically abutted against the corresponding slider and the cavity wall of the corresponding sliding cavity respectively, so that the slider remains in contact with the outer peripheral surface of the brake disc;

[0013] Two excitation coils, both of the two excitation coils are fixed in the accommodation cavity and are respectively disposed on opposite sides of the magnetic isolation ring along the axial direction of the brake shaft. The excitation coils are disposed around the outer side of the brake disc;

[0014] Magnetorheological fluid, flowing in the accommodation cavity, the plurality of sliding cavities and the fluid passage; and

[0015] The flow rate regulating assembly includes a moving disk disposed outside the housing and a plurality of regulating rods fixedly connected to the moving disk. One of the regulating rods is provided between two adjacent sliding cavities. A notch is provided on the regulating rod. The plurality of regulating rods are all slidably connected to the housing, and the free ends of the regulating rods are disposed in the fluid channels between the corresponding adjacent two sliding cavities to close the fluid channels. When the exciting coil is energized, the moving disk can drive the regulating rods to move, so that the notches of the regulating rods are aligned with the fluid channels, thereby enabling the two adjacent sliding cavities to communicate with each other.

[0016] Further, the outer peripheral surface of the brake disk is connected by a plurality of first convex arc surfaces and a plurality of first concave arc surfaces. The plurality of first convex arc surfaces are evenly spaced along the circumferential direction of the brake disk, and each of the first concave arc surfaces connects two adjacent first convex arc surfaces; the free end of at least one slider extends into the space formed by enclosing the first concave arc surface under the action of the corresponding elastic member.

[0017] Further, a plurality of second concave arc surfaces are spaced on the inner circumferential surface of the magnetic isolation ring, and one of the sliding cavities is provided between two adjacent second concave arc surfaces.

[0018] Further, a second convex arc surface is provided at one end of the slider facing the brake disk. Under the elastic force of the elastic member, the second convex arc surface elastically abuts against the outer peripheral surface of the brake disk; a permanent magnet is fixed at one end of the slider close to the brake disk.

[0019] Further, the flow rate regulating assembly further includes a plurality of reset members, and the plurality of reset members are respectively provided corresponding to the plurality of regulating rods. The opposite ends of each reset member elastically abut against the cavity wall of the sliding cavity and the regulating rod respectively, so as to drive the regulating rod to reset and close the fluid channel when the exciting coil is de-energized.

[0020] Further, a fixing groove is recessed at the free end of the regulating rod, and one end of the reset member for connecting with the regulating rod is inserted into the fixing groove and elastically abuts against the groove wall of the fixing groove.

[0021] Further, a plurality of grooves are recessed on both opposite end faces of the brake disk. The plurality of grooves are spaced along the circumferential direction of the brake disk, and each groove has an arc-shaped structure.

[0022] Further, one end of the slider away from the brake disc is provided with a communication groove. The communication groove penetrates the slider along the circumferential direction of the brake disc and penetrates one end of the slider away from the brake disc, so that the sliding cavity is kept in communication with two fluid channels respectively located on both sides of the sliding cavity through the communication groove; on opposite groove walls of the communication groove along the axial direction of the brake shaft, a groove is correspondingly recessed, and the grooves on the opposite groove walls of the communication groove enclose to form a mounting hole, and one end of the elastic member extends into the mounting hole and elastically abuts against the hole wall of the mounting hole.

[0023] Further, a positioning groove for positioning the adjusting rod is provided on each fluid channel, and one end of the adjusting rod away from the moving disc is slidably inserted into the positioning groove.

[0024] Further, the housing includes an annular shell body and two end shells respectively fixedly connected to opposite ends of the shell body. The two end shells and the shell body enclose to form the receiving cavity; the brake shaft is rotatably connected to the end shell through a bearing assembly; the magnetic isolation ring is fixed on the inner wall of the shell body; the two excitation coils are respectively fixed on the inner walls of the two end shells; the adjusting rod is slidably connected to one of the end shells.

[0025] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0026] For the multi-extrusion magnetorheological brake of the present invention, when the excitation coil is powered off, the fluid channel between the corresponding adjacent two sliding cavities is closed by the free end of the adjusting rod, so that the magnetorheological fluid in the sliding cavity cannot flow into the adjacent sliding cavity. Since generally liquids are incompressible, at this time, the slider cannot move away from the brake disc under the action of an external force. Thus, the rotation of the brake shaft is locked through the cooperation between the slider and the brake disc, and further, the magnetorheological brake has a power-off protection function, reducing potential safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a perspective view of a multi-extrusion magnetorheological brake according to a preferred embodiment of the present invention;

[0028] Figure 2 is Figure 1 an exploded view of the shown magnetorheological brake;

[0029] Figure 3 is Figure 2 a structural diagram from another perspective;

[0030] Figure 4 is a perspective view of the brake disc of the magnetorheological brake according to a preferred embodiment of the present invention;

[0031] Figure 5 Stereogram of the magnetic isolation ring and slider of the magnetorheological brake according to the preferred embodiment of the present invention;

[0032] Figure 6 Structural diagram of two exciting coils of the magnetorheological brake according to the preferred embodiment of the present invention;

[0033] Figure 7 Stereogram of the slider of the magnetorheological brake according to the preferred embodiment of the present invention;

[0034] Figure 8 Stereogram of the adjusting rod of the magnetorheological brake according to the preferred embodiment of the present invention;

[0035] Figure 9 is Figure 1 front view of the shown magnetorheological brake;

[0036] Figure 10 is Figure 9 cross-sectional view along line A-A;

[0037] Figure 11 is Figure 10 enlarged view at I;

[0038] Figure 12 is Figure 9 cross-sectional view along line B-B;

[0039] Figure 13 is Figure 12 enlarged view at II, at this time the notch of the adjusting rod communicates with the fluid channel;

[0040] Figure 14 is Figure 13 state diagram when the adjusting rod closes the fluid channel;

[0041] Figure 15 is Figure 1 side view of the shown magnetorheological brake;

[0042] Figure 16 is Figure 15 cross-sectional view along line C-C;

[0043] Figure 17 Magnetic induction line distribution diagram of the magnetorheological brake according to the preferred embodiment of the present invention when the moving disk abuts against the outer side of the end shell;

[0044] Figure 18 Magnetic induction line trend distribution diagram of the magnetorheological brake according to the preferred embodiment of the present invention when the moving disk abuts against the outer side of the end shell;

[0045] Description of main component symbols

[0046] 10. Housing; 11. Receiving cavity; 13. Shell; 15. End shell; 151. Rotation hole; 153. Installation groove; 154. Interpenetration hole; 16. Sealing ring; 20. Brake shaft; 21. Bearing assembly; 211. Bearing part; 213. Bearing cover; 23, 96. Skeleton oil seal; 25. Flange; 30. Brake disc; 32. Brake groove; 34. First convex arc surface; 36. First concave arc surface; 40. Magnetic isolation ring; 42. Second concave arc surface; 44. Sliding cavity; 46. Fluid channel; 47. Positioning groove; 50. Slide block; 52. Second convex arc surface; 54. Communication groove; 56. Groove; 57. Installation hole; 58. Permanent magnet; 59. Installation slot; 60. Elastic member; 70. Excitation coil; 90. Flow regulation assembly; 91. Moving disk; 93. Adjusting rod; 931. Notch; 932. Fixed groove; 95. Reset member. Detailed implementation manners

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0048] It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0050] Please also refer to Figures 1 to 5 As shown in [specific figure reference], a multi-point extrusion magnetorheological brake provided by a preferred embodiment of the present invention includes a housing 10, a brake shaft 20, a brake disc 30, a magnetic isolation ring 40, a plurality of slide blocks 50, a plurality of elastic members 60, two excitation coils 70, a magnetorheological fluid (not shown in the figure), and a flow regulation assembly 90.

[0051] Please refer toFigures 9 to 11 Inside the outer shell 10, a receiving cavity 11 is formed around the inner periphery. In this embodiment, the outer shell 10 includes an annular housing 13 and two end caps 15 respectively fixedly connected to opposite ends of the housing 13. The two end caps 15 and the housing 13 enclose to form the receiving cavity 11. Rotation holes 151 are respectively formed through the substantially central positions of the two end caps 15. An installation groove 153 is recessed on the inner wall of each end cap 15. The installation groove 153 communicates with the receiving cavity 11 and is used for embedding the excitation coil 70. In addition, to further improve the sealing performance of the outer shell 10, in this embodiment, a sealing ring 16 is also provided at the connection between the end cap 15 and the housing 13.

[0052] The brake shaft 20 is rotatably connected to the outer shell 10; in this embodiment, the brake shaft 20 passes through the rotation holes 151 of the two end caps 15 and is rotatably connected to the two end caps 15 through two bearing assemblies 21 respectively. The two bearing assemblies 21 are respectively installed on the outer end faces of the two end caps 15. Each bearing assembly 21 includes a bearing portion 211 and a bearing cover 213. The bearing portion 211 is sleeved on the brake shaft 20, so that the brake shaft 20 is rotatably connected to the end cap 15 through the bearing portion 211. The bearing cover 213 is sleeved on the brake shaft 20 and covers the outside of the bearing portion 211, thereby protecting the bearing portion 211 and preventing external impurities, etc. from entering the bearing portion 211 and affecting the rotation of the brake shaft 20. The structure of the bearing portion 211 belongs to the prior art. For example, ball bearings or roller bearings in the prior art can be used, etc. In addition, in this embodiment, a skeleton oil seal 23 is also provided between the end cap 15, the brake shaft 20 and the bearing cover 213 to further improve the sealing performance of the outer shell 10.

[0053] The brake disc 30 is received in the receiving cavity 11 and fixedly sleeved on the brake shaft 20. Specifically, a flange 25 is convexly formed on the outer peripheral surface of the brake shaft 20. The brake disc 30 is sleeved on the brake shaft 20 and fixedly connected to the flange 25 of the brake shaft 20 through connecting members such as screws. In addition, in this embodiment, a plurality of brake grooves 32 are recessed on two opposite end faces of the brake disc 30. The plurality of brake grooves 32 are circumferentially spaced apart along the brake disc 30. Each brake groove 32 has an arc-shaped structure, which can increase its contact area with the magnetorheological fluid and further improve the braking effect. The outer peripheral surface of the brake disc 30 is connected by a plurality of first convex arc surfaces 34 and a plurality of first concave arc surfaces 36. The plurality of first convex arc surfaces 34 are evenly circumferentially spaced apart along the brake disc 30. The first convex arc surfaces 34 protrude in a direction away from the center of the brake disc 30; each first concave arc surface 36 connects two adjacent first convex arc surfaces 34, and the first concave arc surface 36 is recessed in a direction towards the center of the brake disc 30.

[0054] The magnetic isolation ring 40 is fixed within the receiving cavity 11 and is disposed around the outer side of the brake disc 30. In the present embodiment, the magnetic isolation ring 40 can be fixed to the inner wall of the housing 13 and / or the inner walls of the end housings 15 by means of bonding or the like. Please also refer to Figure 15 and Figure 16 , and a plurality of second concave arc surfaces 42 are provided at intervals on the inner circumferential surface of the magnetic isolation ring 40. A plurality of sliding cavities 44 are provided within the magnetic isolation ring 40. The plurality of sliding cavities 44 are arranged at intervals along the circumferential direction of the magnetic isolation ring 40, and one end of each sliding cavity 44 facing the brake disc 30 communicates with the receiving cavity 11. In the present embodiment, one sliding cavity 44 is provided between two adjacent second concave arc surfaces 42. The length direction of the sliding cavity 44 is parallel to the radial direction of the brake disc 30, and the end of the sliding cavity 44 away from the brake disc 30 is a closed end. A fluid passage 46 communicating the two adjacent sliding cavities 44 is provided between two adjacent sliding cavities 44. In the present embodiment, a positioning groove 47 is further provided on each fluid passage 46. The positioning groove 47 extends along the axial direction of the brake shaft 20 and penetrates one end surface of the magnetic isolation ring 40. The magnetic isolation ring 40 is made of a magnetic isolation material.

[0055] A plurality of sliders 50 are respectively slidably disposed in the plurality of sliding cavities 44, and the slidable direction of the slider 50 is parallel to the length direction of the corresponding sliding cavity 44. One end of the slider 50 facing the brake disc 30 is provided with a second convex arc surface 52 protruding towards the brake disc 30. Please also refer to Figure 7 , and a communication groove 54 is provided at one end of the slider 50 away from the brake disc 30. The communication groove 54 penetrates the opposite two sides of the slider 50 along the circumferential direction of the brake disc 30 and penetrates one end of the slider 50 away from the brake disc 30, so that the corresponding sliding cavity 44 is kept in communication with the two fluid passages 46 respectively located on both sides of the sliding cavity 44 through the communication groove 54, avoiding blocking the communication between the sliding cavity 44 and the fluid passage 46 due to the presence of the slider 50. A groove 56 is correspondingly recessed on the opposite two groove walls of the communication groove 54 along the axial direction of the brake shaft 20. The grooves 56 on the opposite two groove walls of the communication groove 54 enclose to form a mounting hole 57. The mounting hole 57 is parallel to the length direction of the sliding cavity 44, and the mounting hole 57 is used for mounting the elastic member 60. In the present embodiment, two mounting holes 57 are provided on each slider 50. It can be understood that the number of the mounting holes 57 can also be set to other numbers according to actual needs. The slider 50 is made of a magnetic isolation material.

[0056] A plurality of elastic members 60 are respectively disposed in a corresponding plurality of sliding cavities 44 and are located at one end of the corresponding slider 50 away from the brake disc 30. The opposite ends of the elastic member 60 are elastically abutted against the corresponding slider 50 and the wall of the corresponding sliding cavity 44 respectively, so that the slider 50 remains in contact with the outer peripheral surface of the brake disc 30. Specifically, under the action of the elastic force of the elastic member 60, the second convex arc surface 52 of the slider 50 is elastically abutted against the outer peripheral surface of the brake disc 30. In the present embodiment, the elastic member 60 is a spring, and two elastic members 60 are provided corresponding to each slider 50. One ends of the two elastic members 60 respectively extend into two mounting holes 57 of the corresponding slider 50 and are elastically abutted against the hole walls of the corresponding mounting holes 57, and the other ends of the two elastic members 60 are abutted against the groove walls of the corresponding sliding cavity 44. The telescopic direction of the elastic member 60 is parallel to the length direction of the corresponding sliding cavity 44. In the present embodiment, a permanent magnet 58 is further fixed to one end of the slider 50 close to the brake disc 30. Specifically, a mounting groove 59 is concavely provided at one end of the slider 50 close to the brake disc 30. The mounting groove 59 is provided on the side surface of the slider 50 facing the end shell 15, and the permanent magnet 58 is fixed in the mounting groove 59. Preferably, the permanent magnet 58 can adopt an N52 permanent magnet.

[0057] Please refer to Figure 6 at the same time. Both excitation coils 70 are fixed in the receiving cavity 11 and are respectively disposed on opposite sides of the magnetic isolation ring 40 along the axial direction of the brake shaft 20. The excitation coils 70 are disposed around the outside of the brake disc 30. In the present embodiment, the two excitation coils 70 are respectively fixed on the inner walls of the two end shells 15. Specifically, the excitation coils 70 are generally annular, and the two excitation coils 70 are respectively fixed in the mounting grooves 153 of the two end shells 15.

[0058] The magnetorheological fluid is arranged to flow in the receiving cavity 11, a plurality of sliding cavities 44 and the fluid channels 46.

[0059] The flow rate adjusting assembly 90 includes a moving disk 91 disposed outside the housing 10 and a plurality of adjusting rods 93 fixedly connected to the moving disk 91. In the present embodiment, the moving disk 91 is generally in the shape of an annular plate. The moving disk 91 is disposed outside one of the end shells 15 and is disposed around the outer periphery of the bearing cover 213 on the corresponding end shell 15. One ends of the plurality of adjusting rods 93 are fixed on the same side of the moving disk 91. Please refer to Figure 8 at the same time. In the present embodiment, an adjusting rod 93 is provided between two adjacent sliding cavities 44. A notch 931 is provided on the adjusting rod 93. The plurality of adjusting rods 93 are all slidably connected to the housing 10, and the free ends of the adjusting rods 93 are disposed in the fluid channel 46 between the corresponding two adjacent sliding cavities 44 to close the fluid channel 46. Specifically, please refer to Figures 12 to 14 at the same time. A plurality of insertion holes 154 are provided on the end shell 15 close to the moving disk 91 corresponding to the plurality of adjusting rods 93 ( Figure 2) The length direction of the insertion holes 154 is parallel to the axial direction of the brake shaft 20. A plurality of adjusting rods 93 are respectively inserted into the fluid channels 46 between the corresponding adjacent two sliding cavities 44 through a plurality of insertion holes 154, and one end of the adjusting rod 93 away from the moving disk 91 is slidably inserted into the positioning groove 47 of the corresponding fluid channel 46. At this time, the corresponding fluid channel 46 is closed by the adjusting rod 93, so that the adjacent two sliding cavities 44 are not communicated. The moving disk 91 can drive the adjusting rod 93 to move when the excitation coil 70 is energized, so that the notch 931 of the adjusting rod 93 is aligned with the fluid channel 46, thereby enabling the adjacent two sliding cavities 44 to communicate. In the present embodiment, the notch 931 is recessed in the circumferential direction on the circumferential wall of the adjusting rod 93. When the excitation coil 70 is energized, the moving disk 91 is attracted by the excitation coil 70 and moves toward the end housing 15 until the notch 931 is aligned with the fluid channel 46, thereby enabling the adjacent two sliding cavities 44 to communicate. In addition, in order to improve the sealing performance of the housing 10, a skeleton oil seal 96 is further installed between the adjusting rod 93 and the end housing 15 to prevent the magnetorheological fluid from leaking from the insertion holes 154.

[0060] In the present embodiment, the flow rate adjusting assembly 90 further includes a plurality of reset members 95, and the plurality of reset members 95 are respectively arranged corresponding to the plurality of adjusting rods 93. The opposite ends of each reset member 95 are elastically abutted against the wall of the sliding cavity 44 and the adjusting rod 93 respectively, so as to drive the adjusting rod 93 to reset and close the fluid channel 46 when the excitation coil 70 is de-energized. Specifically, in the present embodiment, the reset member 95 is a spring. A fixing groove 932 is recessed at the free end of the adjusting rod 93. One end of the reset member 95 for connecting with the adjusting rod 93 is inserted into the fixing groove 932 and elastically abutted against the groove wall of the fixing groove 932; the telescopic direction of the reset member 95 is parallel to the axial direction of the brake shaft 20. When the excitation coil 70 is energized, the moving disk 91 is attracted by the excitation coil 70 and moves toward the end housing 15 and compresses the reset member 95; when the excitation coil 70 is de-energized, the elastic restoring force of the reset member 95 drives the adjusting rod 93 to move away from the end housing 15 to reset, and then closes the corresponding fluid channel 46 through the adjusting rod 93.

[0061] During use, in the non-braking working condition, the brake shaft 20 of the multi-extrusion magnetorheological brake is not connected to the equipment to be braked, such as an automobile, a rehabilitation medical device, etc., and the magnetorheological brake does not participate in the work.

[0062] When it is necessary to brake the equipment, the brake shaft 20 of the magnetorheological brake is connected to the equipment to be braked, such as an automobile, a rehabilitation medical device, etc. When the brake shaft 20 rotates, it drives the brake disk 30 to rotate together; at the same time, the excitation coil 70 is energized to generate an adjustable magnetic field in the working gap filled with the magnetorheological fluid ( Figures 17 - 18). When the excitation coil 70 is energized to generate a magnetic field, the excitation coil 70 generates suction, causing the movable disk 91 to move toward the end shell 15 and compress the reset member 95 until the movable disk 91 abuts against the outer side of the end shell 15. At this time, the notch 931 of the adjustment rod 93 that moves with the movable disk 91 is aligned with the fluid channel 46, so that the two adjacent sliding chambers 44 are connected, and the magnetorheological fluid can flow between the multiple sliding chambers 44, so as not to hinder the telescopic movement of the slider 50 in the corresponding sliding chamber 44. When the brake disc 30 rotates, the slider 50 is subjected to the pressure of the brake disc 30, and under the action of the elastic member 60, it can perform telescopic movement relative to the brake disc 30. When the excitation coil 70 is energized, the adjustable magnetic field generated acts on the magnetorheological fluid, forming a chain structure between its particles, thereby increasing its viscosity, thereby generating a certain braking force on the rotating brake disc 30. By adjusting the current passing through the excitation coil 70, magnetic fields of different sizes are generated to change the viscosity of the magnetorheological fluid. The magnetorheological fluid changes its form and transforms into a quasi-solid state. The generated torque is transmitted to the brake shaft 20, thereby obtaining the required braking force. In addition, the elastic member 60 allows multiple sliders 50 to press against the outer peripheral surface of the brake disc 30, which can further increase the braking torque.

[0063] When the device is braked, if the excitation coil 70 is accidentally powered off, the elastic restoring force of the reset member 95 drives the movable disk 91 to move away from the end shell 15 to reset, so that the notch 931 of the adjustment rod 93 is offset from the corresponding fluid channel 46, and then the corresponding fluid channel 46 is closed by the adjustment rod 93, so that the magnetorheological fluid in the sliding cavity 44 cannot flow to the adjacent sliding cavity 44. Since the liquid is generally incompressible, at this time, the slider 50 cannot move away from the brake disc 30 under the action of external force, so that the rotation locking of the brake shaft 20 is achieved through the cooperation between the slider 50 and the brake disc 30, so that the magnetorheological brake has a power-off protection function, reducing safety hazards.

[0064] In addition, in the multi-point extruded magnetorheological brake of the embodiment of the present invention, the outer peripheral surface of the brake disc 30 is connected by a plurality of first convex arc surfaces 34 and a plurality of first concave arc surfaces 36. When the excitation coil 70 is powered off, the free end of at least one slider 50 extends into the space enclosed by the first concave arc surfaces 36 under the action of the corresponding elastic member 60, thereby further improving the stability of the slider 50 in rotating the brake disc 30 and the brake shaft 20 through the cooperation between the slider 50 and the first concave arc surfaces 36.

[0065] Existing magnetorheological brakes mainly use the shear mode to achieve braking during braking. The single braking form results in a small braking torque for the magnetorheological brake. Most existing magnetorheological brakes increase the braking area of the brake disc 30 to increase the braking torque, leading to an increase in the overall volume of the magnetorheological brake and making it difficult to meet the braking requirements of current miniaturized devices. In the magnetorheological brake with multiple squeezes according to the embodiments of the present invention, a number of second concave arcs 42 are also provided at intervals on the inner peripheral surface of the magnetic isolation ring 40. When the brake disc 30 rotates, the number of second concave arcs 42 cooperate with the outer peripheral surface of the brake disc 30 formed by a number of first convex arcs 34 and a number of first concave arcs 36, capable of changing the gap for the magnetorheological fluid to flow between the brake disc 30 and the magnetic isolation ring 40. When the flow gap of the magnetorheological fluid changes, the flow velocity of the magnetorheological fluid at different gaps changes, generating a flow velocity difference. The magnetorheological fluid is squeezed in the area with a slow flow velocity, and the working mode of the magnetorheological fluid changes from a single shear type to a shear - extrusion hybrid type. The shear yield stress of the magnetorheological fluid can be greatly improved by being squeezed, so as to increase the braking torque without changing the braking area.

[0066] In the magnetorheological brake with multiple squeezes according to the embodiments of the present invention, a second convex arc 52 is provided at one end of the slider 50 facing the brake disc 30. When the brake disc 30 rotates with the brake shaft 20, the outer peripheral surface of the brake disc 30 contacts the second convex arc 52 of the slider 50, capable of reducing wear; however, it will cause the contact between the outer peripheral surface of the brake disc 30 and the second convex arc 52 to be point - to - point contact, which is prone to stress concentration at the contact position between the two. And when the excitation coil 70 is powered off, the contact between the outer peripheral surface of the brake disc 30 and the second convex arc 52 is a direct hard contact, resulting in easy damage at the contact position between the two. In the embodiments of the present invention, a permanent magnet 58 is added at one end of the slider 50 close to the brake disc 30. Through the magnetic force of the permanent magnet 58, the magnetorheological fluid is locally solidified between the outer peripheral surface of the brake disc 30 and the slider 50, making the contact between the brake disc 30 and the slider 50 a soft contact, thereby preventing or reducing the damage of the brake disc 30 and the slider 50 due to excessive stress.

[0067] In the magnetorheological brake with multiple squeezes according to the embodiments of the present invention, the flow rate adjustment assembly 90 further includes a number of reset members 95. The number of reset members 95 corresponds to a number of adjusting rods 93 respectively. The opposite ends of each reset member 95 are elastically abutted against the wall of the sliding cavity 44 and the adjusting rod 93 respectively, so as to drive the adjusting rod 93 to reset and close the fluid passage 46 when the excitation coil 70 is powered off, achieving power - off protection.

[0068] In the multi-extrusion magnetorheological brake according to the embodiment of the present invention, a braking groove 32 is provided on the end surface of the brake disc 30, so as to form a contact surface with surface texture on the brake disc 30. Under the action of a magnetic field, the shear stress between the particle chains formed after the magnetorheological fluid is magnetized and the contact surface with surface texture is significantly increased, thereby increasing the braking torque of the brake.

[0069] It can be understood that in other embodiments, the shapes of the housing 10, the brake shaft 20, etc. can be adjusted as needed, and the present invention is not limited thereto.

[0070] It can be understood that in other embodiments, only one end of the brake shaft 20 may extend into the housing 10 and be rotatably connected to the housing 10.

[0071] The above description is a detailed description of the preferred and feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications made under the technical spirit disclosed by the present invention shall fall within the scope of the patent covered by the present invention.

Claims

1. A magnetorheological brake with multiple squeezes, characterized in that Comprising: A housing (10), with a receiving cavity (11) formed inside the housing (10); A brake shaft (20), rotatably connected to the housing (10); A brake disc (30), received in the receiving cavity (11) and fixedly sleeved on the brake shaft (20); A magnetic isolation ring (40), fixed inside the receiving cavity (11) and disposed around the outside of the brake disc (30). A plurality of sliding cavities (44) are provided inside the magnetic isolation ring (40). The plurality of sliding cavities (44) are arranged at intervals along the circumferential direction of the magnetic isolation ring (40), and one end of each sliding cavity (44) facing the brake disc (30) communicates with the receiving cavity (11). A fluid passage (46) communicating the adjacent two sliding cavities (44) is provided between the adjacent two sliding cavities (44); A plurality of sliders (50), respectively slidably disposed in the plurality of sliding cavities (44); A plurality of elastic members (60), respectively disposed in the plurality of sliding cavities (44) and located at one end of the corresponding slider (50) away from the brake disc (30). The opposite ends of the elastic member (60) are respectively elastically abutted against the corresponding slider (50) and the wall of the corresponding sliding cavity (44), so that the slider (50) remains in contact with the outer peripheral surface of the brake disc (30); Two excitation coils (70), both fixed inside the receiving cavity (11) and respectively disposed on opposite sides of the magnetic isolation ring (40) along the axial direction of the brake shaft (20). The excitation coils (70) are disposed around the outside of the brake disc (30); Magnetorheological fluid, flowing in the receiving cavity (11), the plurality of sliding cavities (44) and the fluid passage (46); and A flow rate adjusting assembly (90), including a moving disc (91) disposed outside the housing (10) and a plurality of adjusting rods (93) fixedly connected to the moving disc (91). One adjusting rod (93) is provided between the adjacent two sliding cavities (44). A notch (931) is provided on the adjusting rod (93). The plurality of adjusting rods (93) are all slidably connected to the housing (10), and the free end of the adjusting rod (93) is disposed in the fluid passage (46) between the corresponding adjacent two sliding cavities (44) to block the fluid passage (46). When the excitation coil (70) is energized, the moving disc (91) can drive the adjusting rod (93) to move, so that the notch (931) of the adjusting rod (93) is aligned with the fluid passage (46), thereby communicating the adjacent two sliding cavities (44).

2. The multi-point extrusion magnetorheological brake according to claim 1, wherein The outer peripheral surface of the brake disc (30) is connected by a plurality of first convex arc surfaces (34) and a plurality of first concave arc surfaces (36). The plurality of first convex arc surfaces (34) are evenly distributed at intervals along the circumferential direction of the brake disc (30). Each first concave arc surface (36) connects the adjacent two first convex arc surfaces (34). The free end of at least one slider (50) extends into the space formed by the surrounding of the first concave arc surface (36) under the action of the corresponding elastic member (60).

3. The multi-point extrusion magnetorheological brake according to claim 2, wherein A plurality of second concave arc surfaces (42) are provided at intervals on the inner peripheral surface of the magnetic isolation ring (40). A sliding cavity (44) is provided between the adjacent two second concave arc surfaces (42).

4. The multi-point extrusion magnetorheological brake according to claim 3, wherein, One end of the slider (50) facing the brake disc (30) is provided with a second convex arc surface (52), which elastically abuts against the outer peripheral surface of the brake disc (30) under the elastic force of the elastic member (60); a permanent magnet (58) is fixed to one end of the slider (50) close to the brake disc (30).

5. The multi-point extrusion magnetorheological brake according to claim 1, characterized in that, The flow rate adjusting assembly (90) further includes a plurality of reset members (95), and the plurality of reset members (95) are respectively arranged corresponding to the plurality of adjusting rods (93). Opposite ends of each reset member (95) elastically abut against the wall of the sliding cavity (44) and the adjusting rod (93) respectively, so as to drive the adjusting rod (93) to reset and then close the fluid passage (46) when the exciting coil (70) is powered off.

6. The multi-point extrusion magnetorheological brake according to claim 5, characterized in that, A fixing groove (932) is recessed at the free end of the adjusting rod (93), and one end of the reset member (95) for connecting with the adjusting rod (93) is inserted into the fixing groove (932) and elastically abuts against the groove wall of the fixing groove (932).

7. The multi-point extrusion magnetorheological brake according to claim 1, characterized in that, A plurality of grooves (56) are recessed on two opposite end faces of the brake disc (30), and the plurality of grooves (56) are distributed at intervals along the circumferential direction of the brake disc (30), and each groove (56) has an arc-shaped structure.

8. The multi-point extrusion magnetorheological brake according to claim 1, wherein One end of the slider (50) far from the brake disc (30) is provided with a communication groove (54), the communication groove (54) penetrates the slider (50) along the circumferential direction of the brake disc (30) and the communication groove (54) penetrates one end of the slider (50) far from the brake disc (30), so that the sliding cavity (44) is kept in communication with the two fluid passages (46) respectively located on both sides of the sliding cavity (44) through the communication groove (54); a groove (56) is correspondingly recessed on opposite groove walls of the communication groove (54) along the axial direction of the brake shaft (20), and the grooves (56) on the opposite groove walls of the communication groove (54) enclose to form a mounting hole (57), and one end of the elastic member (60) extends into the mounting hole (57) and elastically abuts against the hole wall of the mounting hole (57).

9. The multi-point extrusion magnetorheological brake according to claim 1, characterized in that, A positioning groove (47) for positioning the adjusting rod (93) is provided on each fluid passage (46), and one end of the adjusting rod (93) far from the moving disc (91) is slidably inserted into the positioning groove (47).

10. The multi-point extrusion magnetorheological brake according to claim 1, wherein The housing (10) includes an annular housing body (13) and two end housings (15) respectively fixedly connected to opposite ends of the housing body (13), and the two end housings (15) and the housing body (13) enclose to form a receiving cavity (11); the brake shaft (20) is rotatably connected to the end housing (15) through a bearing assembly (21); the magnetic isolation ring (40) is fixed to the inner wall of the housing body (13); the two exciting coils (70) are respectively fixed to the inner walls of the two end housings (15); the adjusting rod (93) is slidably connected to one of the end housings (15).

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