Multi-disc multi-cylinder magnetorheological brake and control method thereof

Abstract

The invention provides a multi-disc and multi-cylinder type magnetorheological brake which comprises a composite magnetic circuit system formed by a left stator disc group, a right stator disc group and a middle stator cylinder group which are coaxially arranged, and an input shaft is fixedly connected with a multi-stage rotor disc and cylinder assembly in the circumferential direction. A double-coil reverse winding excitation structure is adopted, a left excitation coil and a right excitation coil drive a disc type magnetic circuit and a barrel type magnetic circuit, and magnetic field vector superposition of a middle magnetic area is achieved through magnetic circuit coupling. The rotor discs and the stator discs are alternately stacked to form an axial working gap, and the rotor cylinders and the stator cylinders are nested to form a radial working gap. The magnetic field intensity of a middle magnetic area is increased to 2.1 times of that of a single coil during double-coil reverse excitation; an epoxy resin coil rack is adopted to integrate supporting and sealing functions, and a framework oil seal is adopted to realize a dynamic sealing body. The device has the advantages of time-sharing cooperative power supply, fast dynamic response, high sealing reliability and the like, and is suitable for the field of high-precision motion control.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of liquid resistance brakes, and particularly relates to a multi-disc multi-cylinder magnetorheological brake and a control method thereof. BACKGROUND

[0002] Magnetorheological fluid is a new type of intelligent material with rheological properties, which is a black opaque suspension composed of nanoscale soft magnetic particles, dispersants and base liquid. Its rheological properties and physical state will change with the change of the applied magnetic field: the magnetorheological fluid presents a fluid state with good flowability when no external magnetic field is applied; and under the action of an external magnetic field, the soft magnetic particles in the magnetorheological fluid will connect to form a chain along the magnetic induction line, so that the magnetorheological fluid presents a solid-like state. Since the magnetorheological fluid can continuously and reversibly change between Newtonian fluid and solid-like state within milliseconds, it is widely used in the fields of automobiles, buildings, medical devices, aerospace, industrial manufacturing, sports equipment, etc.

[0003] Magnetorheological brake is an important direction of magnetorheological devices. By precisely adjusting the excitation current, the rheological properties of magnetorheological fluid can be used to realize precise control of the braking torque. According to the shape of the effective working area of the magnetorheological brake, the magnetorheological brake can be divided into disc-type magnetorheological brake and cylinder-type magnetorheological brake. The disc-type magnetorheological brake has obvious advantages in the field of precise motion control due to its small rotational inertia, high control precision and fast response speed; the cylinder-type magnetorheological brake can output higher braking torque under the same volume due to its larger effective working area. However, in the application scenarios with strict requirements on torque density and space constraints, the above two types of traditional structures often lead to a sharp increase in axial or radial size to meet the demand for large torque, which seriously restricts the integrated design of the system. SUMMARY

[0004] The purpose of the present application is to solve the problem of sharp increase in axial or radial size of the traditional structure, which seriously restricts the integrated design of the system, and a multi-disc multi-cylinder magnetorheological brake and a control method thereof are proposed.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: A multi-disc multi-cylinder magnetorheological brake, comprising an input shaft, a magnetorheological brake body fixedly connected to the input shaft, the magnetorheological brake body comprising a stator portion, a rotor portion and an excitation portion, the rotor portion being connected to the stator portion through a bearing, and the stator portion being located on the inner side of the rotor portion, the closed cavity formed between the rotor portion and the stator portion being the excitation portion, and the excitation portion being filled with magnetorheological fluid; The stator part comprises a right shell, a right stator disc set, an intermediate shell, a left shell, a left stator disc set, and a stator cylinder set; the intermediate shell is fixedly connected with the left shell and the right shell on both sides; the left shell and the right shell are rotatably connected with the output shaft through deep groove ball bearings; the right side of the right shell is connected with the right stator disc set; the left stator disc set is fixed to the inner side of the intermediate shell and the right side of the left shell; and the stator cylinder set is fixed to the inner side of the intermediate shell and the left side of the right stator disc set. The rotor part comprises a left rotor disc set, a right rotor disc set, and a rotor cylinder set which are connected to the input shaft through keys; the left rotor disc set and the rotor cylinder set are fixedly connected through screws. The excitation part comprises a right excitation coil set and a left excitation coil set which are fixedly installed on the inner walls of the right shell and the left shell.

[0006] Further, the right stator disc set comprises a right magnetic separation ring I, a right stator disc, and a right magnetic separation ring II which are arranged in sequence from right to left along the axial direction; the right magnetic separation ring I is fixedly connected with the right shell on one side; The left stator disc set comprises a left magnetic separation ring I, a left stator disc, and a left magnetic separation ring II which are arranged in sequence from left to right along the axial direction; the left magnetic separation ring I is fixedly connected with the left shell on one side; The stator cylinder set comprises a stator cylinder I and a stator cylinder II which are arranged in sequence from outside to inside along the radial direction; the intermediate shell and the stator cylinder I are separated from the stator cylinder II through a support cylinder.

[0007] Further, the left rotor disc set comprises a left magnetic separation ring, a left rotor disc II, and a left rotor disc I which are arranged in sequence from left to right along the axial direction; the left rotor disc II is fixedly connected with the support cylinder on one side; and the left stator disc is located between the left rotor disc I and the left rotor disc II; The right rotor disc set comprises a right rotor disc II, a right rotor disc I, and a right magnetic separation ring which are arranged in sequence from left to right along the axial direction; the right stator disc is located between the right rotor disc II and the right rotor disc I; The rotor cylinder set comprises a rotor cylinder I, a rotor cylinder II, and two support cylinders which are arranged in sequence from outside to inside along the radial direction; the left rotor disc II and the rotor cylinder II are separated from the rotor cylinder II through the support cylinder.

[0008] Further, the right excitation coil set comprises a right excitation coil and a right coil holder; the right excitation coil is wound on the right coil holder; the right shell, the right stator disc set, the stator cylinder set, and the intermediate shell are fixedly connected to form a groove, and the right excitation coil set is fixed in the groove; The left excitation coil set comprises a left excitation coil and a left coil holder; the left excitation coil is wound on the left coil holder; the left side of the left rotor disc set is provided with the left shell, the left shell, the left stator disc set, and the intermediate shell are fixedly connected to form a groove, and the left excitation coil set is placed in the groove.

[0009] Further, the winding directions of the left and right excitation coils are opposite; the coil frames of the left and right excitation coil groups are made of epoxy resin, which has the functions of structural support and sealing.

[0010] Further, the right sleeve is installed on the right side of the right rotor disc group and fixedly connected to the input shaft; the left sleeve is installed on the left side of the left rotor disc group and fixedly connected to the input shaft; the left housing and the left sleeve are provided with a mounting groove for mounting a skeleton oil seal, and the right housing and the right sleeve are provided with a mounting groove for mounting a skeleton oil seal.

[0011] Further, the stator part, the rotor part and the excitation part form left, right and middle magnetic zones; The left magnetic zone comprises the left housing, the left rotor disc I, the left stator disc, the left rotor disc II and the stator cylinder II which are alternately and sequentially stacked along the axial direction, forming four axially distributed cylindrical working gaps G1, G2, G3 and G4; The right magnetic zone comprises the right housing, the right rotor disc I, the right stator disc, the right rotor disc II and the stator cylinder II which are alternately and sequentially stacked along the axial direction, forming four axially distributed cylindrical working gaps G5, G6, G7 and G8; The middle magnetic zone comprises the middle housing, the rotor cylinder I, the stator cylinder I, the rotor cylinder II and the stator cylinder II which are coaxially nested along the radial direction, forming four radially distributed annular working gaps G9, G10, G11 and G12.

[0012] A control method of the multi-disc and multi-cylinder magnetorheological brake, comprising that when the left excitation coil is separately energized, the magnetic induction lines form a double closed loop: Path 1: the magnetic induction lines pass through the left housing, the middle housing, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12 and the stator cylinder II in sequence; Path 2: the magnetic induction lines pass through the left housing, the middle housing, the right housing, the working gap G8, the right rotor disc I, the working gap G7, the right stator disc, the working gap G6, the right rotor disc II, the working gap G5 and the stator cylinder II in sequence; The magnetic induction lines of the two paths converge at the stator cylinder II, then pass through the working gap G4, the left rotor disc II, the working gap G3, the left stator disc, the working gap G2, the left rotor disc I, the working gap G1 and finally the left housing in sequence to complete the magnetic circuit closure.

[0013] Further, when the right excitation coil is separately energized, the magnetic induction lines form a double closed loop: Path 1: the magnetic induction lines pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12, and the stator cylinder II from the right shell; Path 2: the magnetic induction lines pass through the middle shell, the left shell, the working gap G1, the left rotor disc I, the working gap G2, the left stator disc, the working gap G3, the left rotor disc II, the working gap G4, and the stator cylinder II from the right shell; The two paths of the magnetic induction lines converge at the stator cylinder II, and then pass through the working gap G5, the right rotor disc II, the working gap G6, the right stator disc, the working gap G7, the right rotor disc I, the working gap G8, and finally reach the right shell to complete the magnetic circuit closure.

[0014] Further, when the left excitation coil and the right excitation coil adopt the reverse excitation mode: The magnetic induction lines of the left excitation coil pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12, the stator cylinder II, the working gap G4, the left rotor disc II, the working gap G3, the left stator disc, the working gap G2, the left rotor disc I, the working gap G1, and finally reach the left shell to complete the magnetic circuit closure; the flow direction of the magnetic induction lines of the left excitation coil is clockwise; The magnetic induction lines of the right excitation coil pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12, the stator cylinder II, the working gap G5, the right rotor disc II, the working gap G6, the right stator disc, the working gap G7, the right rotor disc I, the working gap G8, and finally reach the right shell to complete the magnetic circuit closure; the flow direction of the magnetic induction lines of the right excitation coil is counterclockwise; The magnetic induction lines of the right excitation coil and the magnetic induction lines of the left excitation coil have the same magnetic field vector direction in the middle magnetic area.

[0015] The beneficial effects of the present application are: 1. Two excitation coils are adopted, and the time-sharing and collaborative power supply mode of the coils is supported, so that the safety is higher than that of a single coil structure.

[0016] 2. Based on the disc-cylinder composite structure innovation, the magnetic field utilization rate is improved under the premise of maintaining the constant size of the brake; 3. The output torque is improved through the axial-radial magnetic circuit coupling effect; 4. The magnetic field vector superposition effect is generated in the middle magnetic area by the collaborative excitation of the two coils, so that the output torque when the two coils work simultaneously is improved by 22.2% compared with the sum of the output torques when the two coils work separately. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 This is a cross-sectional view of the magnetorheological brake provided by the present invention; Figure 2 This is a schematic diagram of the stator, rotor, and excitation part of the magnetorheological brake provided by the present invention. Figure 3 This is a diagram showing the distribution of magnetic regions and working gaps provided by the present invention; Figure 4 This is a schematic diagram of the magnetic field distribution of the left excitation coil when it is working alone, provided by the present invention. Figure 5 This is a schematic diagram of the magnetic field distribution of the right excitation coil operating alone, provided by the present invention. Figure 6 This is a schematic diagram of the magnetic field distribution when two excitation coils are working simultaneously, provided by the present invention.

[0018] Reference numerals: 1-Input shaft; 2-Right end cover of bearing; 3-Right housing; 4-Right stator disk assembly, 4a-Right magnetic isolation ring I, 4b-Right stator disk, 4c-Right magnetic isolation ring II; 5-Right excitation coil assembly, 5a-Right excitation coil, 5b-Right coil frame; 6-Intermediate housing; 7-Rotor cylinder assembly, 7a-Rotor cylinder I, 7c-Rotor cylinder II, 7b-Support cylinder; 8-Left excitation coil assembly, 8a-Left excitation coil; 8b-Left coil frame; 9-Left housing; 10-Skeleton oil seal; 11-Left sleeve; 2-Deep groove ball bearing; 13-Bearing left end cover; 14-Left rotor disk assembly, 14a-Left magnetic isolation ring, 14b-Left rotor disk II, 14c-Left rotor disk I; 15-Left stator disk assembly, 15a-Left magnetic isolation ring I, 15b-Left stator disk, 15c-Left magnetic isolation ring II; 16-Stator cylinder assembly, 16a-Stator cylinder I; 16b-Stator cylinder II; 17-Right rotor disk assembly, 17a-Right rotor disk II, 17b-Right rotor disk I, 17c-Right magnetic isolation ring; 18-Right sleeve. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] The application principle of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1As shown, a multi-disc, multi-cylinder magnetorheological brake of this embodiment includes a magnetorheological brake body fixed to an input shaft 1. The magnetorheological brake body includes a stator part, a rotor part, and an excitation part. The rotor part and the stator part are connected by bearings, and the stator part is located inside the rotor part. The closed cavity formed between the rotor part and the stator part is the excitation part, which is filled with magnetorheological fluid.

[0022] The stator section includes a right housing 3, a right stator disk assembly 4, a middle housing 6, a left housing 9, a left stator disk assembly 15, and a stator cylinder assembly 16. The left housing 9 and the right housing 3 are fixedly connected to the left and right sides of the middle housing 6, with the left housing 9 located to the left of the right housing 3. Both the left housing 9 and the right housing 3 are rotatably connected to the output shaft 1 via deep groove ball bearings 12. The right stator disk assembly 4 is connected to the left side of the right housing 3. The left stator disk assembly 15 is fixedly connected to the inner side of the middle housing 6 and the right side of the left housing 9, with the left stator disk assembly 15 close to the left housing 9. The stator cylinder assembly 16 is fixedly connected to the inner side of the middle housing 6 and the left side of the right stator disk assembly 4.

[0023] The right stator disk assembly 4 includes a right magnetic isolation ring I4a, a right stator disk 4b, and a right magnetic isolation ring II4c arranged sequentially from right to left along the axial direction. One side of the right magnetic isolation ring I4a is fixedly connected to the right housing 3.

[0024] The left stator disk assembly 15 includes a left magnetic isolation ring I15a, a left stator disk 15b, and a left magnetic isolation ring II15c. One side of the left magnetic isolation ring I15a is fixedly connected to the right side of the left housing 9. The installation sequence along the axial direction from left to right is left magnetic isolation ring I15a, left stator disk 15b, and left magnetic isolation ring II15c.

[0025] The stator cylinder assembly 16 includes stator cylinder I16a and stator cylinder II16b. The stator cylinder assembly 16 is fixedly connected to the left side of the right stator disk assembly 4 and located inside the intermediate housing 6. The stator cylinders I16a and II16b are arranged radially from the outside to the inside. The intermediate housing 6, stator cylinders I16a and II16b are separated by support cylinders 7b with different radii to achieve structural support and positioning.

[0026] The rotor section includes a left rotor disk assembly 14, a right rotor disk assembly 17, and a rotor cylinder assembly 7, all connected to the input shaft 1 by a key. The left rotor disk assembly 14 and the rotor cylinder assembly 7 are fixedly connected by screws.

[0027] The left rotor disk assembly 14 includes a left magnetic isolation ring 14a, a left rotor disk II 14b, and a left rotor disk I 14c. The left rotor disk assembly 14 is fixedly installed at the left shoulder of the stepped shaft, and its installation sequence from right to left along the axial direction is: left rotor disk II 14b, left magnetic isolation ring 14a, and left rotor disk I 14c. One side of the left rotor disk II 14b is fixedly connected to the support cylinder 7b. The left stator disk 15b is located between the left rotor disk I 14c and the left rotor disk II 14b.

[0028] The right rotor disk assembly 17 includes right rotor disk II17a, right rotor disk I17b, and right magnetic isolation ring 17c. The right rotor disk assembly 17 is fixedly mounted on the output shaft 1, and its installation sequence from left to right along the axial direction is: right rotor disk II17a, right magnetic isolation ring 17c, and right rotor disk I17b. The right stator disk 4b is located between right rotor disk II17a and right rotor disk I17b.

[0029] The rotor cylinder assembly 7 includes rotor cylinder I7a, rotor cylinder II7c, and two support cylinders 7b with different radii. The rotor cylinder assembly 7 is fixedly installed on the outside of the left rotor disk II14b, with the installation sequence from outside to inside being rotor cylinder I7a and rotor cylinder II7c. The left rotor disk II14b, rotor cylinder II7c, and rotor cylinder II7c are separated from each other by the support cylinders 7b with different radii to achieve structural support and positioning.

[0030] The excitation section includes a right excitation coil group 5 and a left excitation coil group 8, which are fixedly installed on the inner walls of the left and right housings.

[0031] The right excitation coil assembly 5 includes a right excitation coil 5a and a right coil frame 5b. The right excitation coil 5a is wound on the right coil frame 5b. The right housing 3, the right stator disk assembly 4, the stator cylinder assembly 16, and the intermediate housing 6 are fixedly connected to form a groove, and the right excitation coil assembly 5 is fixed in the groove.

[0032] The left excitation coil assembly 8 includes a left excitation coil 8a and a left coil frame 8b. The left excitation coil 8a is wound on the left coil frame 8b. A left housing 9 is provided on the left side of the left rotor disk assembly 14. The left housing 9, the left stator disk assembly 15 and the intermediate housing 6 are fixedly connected to form a groove, and the left excitation coil assembly 8 is placed in the groove.

[0033] The left excitation coil 8a and the right excitation coil 5a are wound in opposite directions.

[0034] The rotor cylinder I7a, rotor cylinder II7c, and stator cylinder I16a are arranged in multiple evenly along the radial direction of the input shaft 1.

[0035] The left rotor disk I14c, left rotor disk II14b, left stator disk 15b, right rotor disk I17b, right rotor disk II17a, and right stator disk 4b are evenly arranged along the input shaft 1.

[0036] The right sleeve 18 is installed on the right side of the right rotor disk assembly 17 and is fixedly connected to the input shaft 1. The left sleeve 11 is installed on the left side of the left rotor disk assembly 14 and is fixedly connected to the input shaft 1.

[0037] An installation groove is provided between the left housing 9 and the left sleeve 11 for installing the skeleton oil seal 10. Similarly, there is also a skeleton oil seal on the right side of the magnetorheological brake. An installation groove is provided between the right housing 3 and the right sleeve 18 for installing the skeleton oil seal 10.

[0038] The right end cover 2 of the bearing is fixedly connected to the right side of the right housing 3, and the left end cover 13 of the bearing is fixedly connected to the left side of the left housing 9.

[0039] The right coil frame 5b and the left coil frame 8b are made of epoxy resin, which has the dual functions of structural support and sealing.

[0040] like Figure 3 As shown, the rotor section, stator section, and excitation section form a left magnetic region, a middle magnetic region, and a right magnetic region. The left magnetic region is located inside the left excitation coil group 8, outside the input shaft 1, on the right side of the left housing 9, and on the left side of the stator cylinder II 16b. The left magnetic region is formed by the alternating stacking of the left housing 9, left rotor disk I 14c, left stator disk 15b, left rotor disk II 14b, and stator cylinder II 16b, forming four parallel cylindrical working gaps G1, G2, G3, and G4 between each pair, and the working gaps are distributed along the axial direction.

[0041] Similarly, the right magnetic zone is located inside the right excitation coil group 5, outside the input shaft 1, on the left side of the right housing 3, and on the right side of the stator cylinder II16b. The right magnetic zone is formed by the alternating stacking of the right housing 3, the right rotor disk I17b, the right stator disk 4b, the right rotor disk II17a, and the stator cylinder II16b, with four parallel cylindrical working gaps G5, G6, G7, and G8 formed between the two end faces, and the working gaps are distributed along the axial direction.

[0042] The intermediate magnetic zone is located inside the intermediate housing 6, outside the stator cylinder II16b, to the right of the left excitation coil group 8, and to the left of the right excitation coil group 5. The intermediate magnetic zone is coaxially arranged by the intermediate housing 6, rotor cylinder I7a, rotor cylinder II7c, stator cylinder II16b, and stator cylinder I16a in an alternating nested manner, forming four coaxial annular working gaps G9, G10, G11, and G12 between each pair.

[0043] A control method for a multi-disc, multi-cylinder magnetorheological brake is as follows: (1) When the left excitation coil 8a is energized alone, the magnetic field lines form a double closed loop: like Figure 4 As shown, the left excitation coil 8a generates a magnetic field when energized alone. The magnetic field lines generated by the left excitation coil 8a form a closed loop according to two paths. Path 1: The magnetic field lines pass sequentially from the left shell through the middle shell 6, working gap G9, rotor cylinder I7a, working gap G10, stator cylinder I16a, working gap G11, rotor cylinder II7c, working gap G12, and stator cylinder II16b. Path 2: Starting from the left housing, the magnetic field lines pass sequentially through the middle housing 6, the right housing 3, the working gap G8, the right rotor disk I17b, the working gap G7, the right stator disk 4b, the working gap G6, the right rotor disk II17a, the working gap G5, and the stator cylinder II16b. The magnetic field lines of the two paths converge at the stator cylinder II16b, and then sequentially pass through the working gap G4, the left rotor disk II14b, the working gap G3, the left stator disk 15b, the working gap G2, the left rotor disk I14c, and the working gap G1, finally reaching the left housing 9 to complete the magnetic circuit closure.

[0044] (2) When the right excitation coil 5a is energized alone, the magnetic field lines form a double closed loop: like Figure 5 As shown, when the right excitation coil 5a is energized alone, the magnetic field lines generated by the right excitation coil 5a form a closed loop according to two paths. Path 1: from the right housing 3 through the intermediate housing 6, working gap G9, rotor cylinder I7a, working gap G10, stator cylinder I16a, working gap G11, rotor cylinder II7c, working gap G12, and stator cylinder II16b. Path 2: Starting from the right housing 3, passing through the middle housing 6, left housing 9, working gap G1, left rotor disk I14c, working gap G2, left stator disk 15b, working gap G3, left rotor disk II14b, working gap G4, stator cylinder II16b, the magnetic field lines of the two paths converge at stator cylinder II16b, then pass through working gap G5, right rotor disk II17a, working gap G6, right stator disk 4b, working gap G7, right rotor disk I17b, working gap G8, and finally to the right housing 3 to complete the magnetic circuit closure.

[0045] (3) When the left excitation coil 8a and the right excitation coil 5a adopt the reverse excitation mode, the middle magnetic region G9-G12 generates a superposition of directional magnetic fields: like Figure 6As shown, when the left excitation coil 8a and the right excitation coil 5a are simultaneously energized and in reverse excitation mode, a directional magnetic field superposition effect is formed in the middle magnetic region. Specifically, the magnetic field lines of the left excitation coil 8a flow along the left housing 9 sequentially through the middle housing 6, working gap G9, rotor cylinder I7a, working gap G10, stator cylinder I16a, working gap G11, rotor cylinder II7c, working gap G12, stator cylinder II16b, working gap G4, left rotor disk II14b, working gap G3, left stator disk 15b, working gap G2, left rotor disk I14c, working gap G1, and finally complete the magnetic circuit closure at the left housing 9. The direction of the magnetic field lines flowing through the left excitation coil 8a is clockwise. The magnetic field lines of the right excitation coil 5a flow along the right housing 3, sequentially passing through the intermediate housing 6, working gap G9, rotor cylinder I7a, working gap G10, stator cylinder I16a, working gap G11, rotor cylinder II7c, working gap G12, stator cylinder II16b, working gap G5, right rotor disk II17a, working gap G6, right stator disk 4b, working gap G7, right rotor disk I17b, working gap G8, finally reaching the right housing 3 to complete the magnetic circuit closure. The magnetic field lines of the right excitation coil 5a flow counterclockwise. The magnetic field vectors of both coils in the intermediate magnetic region are in the same direction, resulting in a combined magnetic induction intensity approximately 2.1 times that of a single coil, and a total braking torque increase of 22.2%. Simultaneously, the working gaps G1-G8 of the disc magnetic circuit partially cancel each other out in the stator disk region, maintaining the basic torque level and achieving high dynamic range torque graded control.

[0046] When the input shaft 1 rotates, it drives the left rotor disk I14c, left rotor disk II14b, right rotor disk I17b, right rotor disk II17a, and rotor cylinders I7a and II7c, which are fixed to the left rotor disk II14b by screws. If the left excitation coil 8a is energized alone at this time, the magnetic field lines will form a closed loop according to (1) of a multi-disc multi-cylinder magnetorheological brake control method, thereby performing braking; if the right excitation coil 5a is energized alone, the magnetic field lines will form a closed loop according to (2) of a multi-disc multi-cylinder magnetorheological brake control method, thereby performing braking; when the left excitation coil 8a and the right excitation coil 5a are energized at the same time and the reverse excitation mode is adopted, the magnetic field lines will form a closed loop according to (3) of a multi-disc multi-cylinder magnetorheological brake control method, thereby performing braking.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-disk multi-cylinder magnetorheological brake, characterized in that, The input shaft, the magnetorheological brake body fixed on the input shaft, the magnetorheological brake body comprising a stator part, a rotor part and an excitation part, the rotor part is connected with the stator part through a bearing, and the stator part is located inside the rotor part, the closed cavity formed between the rotor part and the stator part is the excitation part, and the closed cavity is filled with magnetorheological fluid; The stator part comprises a right shell, a right stator disc group, an intermediate shell, a left shell, a left stator disc group and a stator cylinder group; the intermediate shell is fixedly connected with the left shell and the right shell on both sides; the left shell and the right shell are rotatably connected with the output shaft through deep groove ball bearings; the right stator disc group is connected with the left side of the right shell; the left stator disc group is fixed to the inside of the intermediate shell and the right side of the left shell; and the stator cylinder group is fixed to the inside of the intermediate shell and the left side of the right stator disc group. The rotor part comprises a left rotor disc group, a right rotor disc group and a rotor cylinder group which are connected with the input shaft through keys; the left rotor disc group and the rotor cylinder group are fixedly connected through screws; The excitation part comprises a right excitation coil group and a left excitation coil group which are fixedly installed on the inner walls of the right shell and the left shell.

2. The multi-disc and multi-cylinder magnetorheological brake according to claim 1, wherein the right stator disc group comprises a right magnetic shielding ring I, a right stator disc and a right magnetic shielding ring II which are sequentially arranged from right to left along the axial direction; and the right magnetic shielding ring I is fixedly connected with the right shell on one side. The left stator disc group comprises a left magnetic shielding ring I, a left stator disc and a left magnetic shielding ring II which are sequentially arranged from left to right along the axial direction; and the left magnetic shielding ring I is fixedly connected with the left shell on one side. The stator cylinder group comprises a stator cylinder I and a stator cylinder II which are sequentially arranged from outside to inside along the radial direction; and the intermediate shell and the stator cylinder I are separated from the stator cylinder II through a support cylinder.

3. The multi-disc and multi-cylinder magnetorheological brake according to claim 1, wherein the left rotor disc group comprises a left magnetic shielding ring, a left rotor disc II and a left rotor disc I which are sequentially arranged from left to right along the axial direction; the left rotor disc II is fixedly connected with the support cylinder on one side; and the left stator disc is located between the left rotor disc I and the left rotor disc II. The right rotor disc group comprises a right rotor disc II, a right rotor disc I and a right magnetic shielding ring which are sequentially arranged from left to right along the axial direction; and the right stator disc is located between the right rotor disc II and the right rotor disc I. The rotor cylinder group comprises a rotor cylinder I, a rotor cylinder II and two support cylinders which are sequentially arranged from outside to inside along the radial direction; the left rotor disc II and the rotor cylinder II are separated from the rotor cylinder II through the support cylinder.

4. The multi-disc and multi-cylinder magnetorheological brake according to claim 1, wherein the right excitation coil group comprises a right excitation coil and a right coil holder; the right excitation coil is wound on the right coil holder; the right shell, the right stator disc group, the stator cylinder group and the intermediate shell are fixedly connected to form a groove; and the right excitation coil group is fixed in the groove. ​ ​ ​ The left excitation coil group comprises a left excitation coil and a left coil holder; the left excitation coil is arranged on the left coil holder; the left side of the left rotor disc group is provided with a left shell; the left shell, the left stator disc group and the middle shell are fixedly connected to form a recess, and the left excitation coil group is arranged in the recess.

5. The multi-disc multi-cylinder MRF brake according to claim 4, wherein, The winding directions of the left excitation coil and the right excitation coil are opposite; the coil holders of the left excitation coil group and the right excitation coil group are made of epoxy resin, which has the functions of structural support and sealing.

6. The multi-disc multi-cylinder MRF brake according to claim 1, wherein, The right sleeve is arranged on the right side of the right rotor disc group and is fixedly connected to the input shaft; the left sleeve is arranged on the left side of the left rotor disc group and is fixedly connected to the input shaft; the left shell and the left sleeve are provided with a mounting groove for mounting a skeleton oil seal, and the right shell and the right sleeve are provided with a mounting groove for mounting a skeleton oil seal.

7. A multi-disk multi-pad magnetorheological brake according to any one of claims 1-4, characterized in that, The stator part, the rotor part and the excitation part form a left magnetic area, a right magnetic area and a middle magnetic area; The left magnetic area comprises the left shell, the left rotor disc I, the left stator disc, the left rotor disc II and the stator cylinder II which are alternately and sequentially stacked along the axial direction, forming four axially distributed cylindrical working gaps G1, G2, G3 and G4; The right magnetic area comprises the right shell, the right rotor disc I, the right stator disc, the right rotor disc II and the stator cylinder II which are alternately and sequentially stacked along the axial direction, forming four axially distributed cylindrical working gaps G5, G6, G7 and G8; The middle magnetic area comprises the middle shell, the rotor cylinder I, the stator cylinder I, the rotor cylinder II and the stator cylinder II which are coaxially nested along the radial direction, forming four radially distributed annular working gaps G9, G10, G11 and G12.

8. A control method of a multi-disk multi-cylinder magnetorheological brake, characterized by, When the left excitation coil is powered alone, the magnetic induction lines form a double closed loop: Path 1: the magnetic induction lines pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12 and the stator cylinder II in sequence from the left shell; Path 2: the magnetic induction lines pass through the middle shell, the right shell, the working gap G8, the right rotor disc I, the working gap G7, the right stator disc, the working gap G6, the right rotor disc II, the working gap G5 and the stator cylinder II in sequence from the left shell; The magnetic induction lines of the two paths converge at the stator cylinder II, then pass through the working gap G4, the left rotor disc II, the working gap G3, the left stator disc, the working gap G2, the left rotor disc I, the working gap G1 in sequence, and finally reach the left shell to complete the magnetic circuit closure.

9. The control method of the multi-disk multi-pad MRF brake according to claim 8, characterized in that: When the right excitation coil is powered alone, the magnetic induction lines form a double closed loop: Path 1: the magnetic induction lines pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12 and the stator cylinder II from the right shell; Path 2: the magnetic induction lines pass through the middle shell, the left shell, the working gap G1, the left rotor disc I, the working gap G2, the left stator disc, the working gap G3, the left rotor disc II, the working gap G4, the stator cylinder II from the right shell; The two paths of magnetic induction lines converge at the stator cylinder II, then pass through the working gap G5, the right rotor disc II, the working gap G6, the right stator disc, the working gap G7, the right rotor disc I, the working gap G8, and finally reach the right shell to complete the magnetic circuit closure.

10. The control method of the multi-disk multi-pad MRF brake according to claim 8, characterized in that: When the left field coil and the right field coil adopt the reverse excitation mode: The magnetic induction lines of the left field coil pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12, the stator cylinder II, the working gap G4, the left rotor disc II, the working gap G3, the left stator disc, the working gap G2, the left rotor disc I, the working gap G1 in sequence along the left shell, and finally reach the left shell to complete the magnetic circuit closure; the flow direction of the magnetic induction lines of the left field coil is clockwise; The magnetic induction lines of the right field coil pass through the middle shell, the working gap G9, the rotor cylinder I, the working gap G10, the stator cylinder I, the working gap G11, the rotor cylinder II, the working gap G12, the stator cylinder II, the working gap G5, the right rotor disc II, the working gap G6, the right stator disc, the working gap G7, the right rotor disc I, the working gap G8 in sequence along the right shell, and finally reach the right shell to complete the magnetic circuit closure; the flow direction of the magnetic induction lines of the right field coil is counterclockwise; The magnetic field vector directions of the magnetic induction lines of the right field coil and the magnetic induction lines of the left field coil in the middle magnetic region are the same.

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