阅读说明：本技术 一种基于磁流变脂的双向力和力矩传动装置 (Bidirectional force and moment transmission device based on magnetorheological grease ) 是由 汪辉兴 王炅 于 2019-08-19 设计创作，主要内容包括：本发明公开了一种基于磁流变脂的双向力和力矩传动装置,包括杆轴、壳体、转盘、电磁线圈、磁流变脂、隔离圈、套筒、端盖和压缩弹簧。壳体为圆筒形,其上下两端通过端盖密封,上下端盖中心轴分别设置套筒,上下端盖的套筒从上至下贯穿设置杆轴,杆轴位于壳体的中部设置转盘,所述转盘开有凹槽,电磁线圈缠绕在该凹槽内部；所述转盘上下空间设置弹簧,所述压缩弹簧一端固定在端盖上,另一端与转盘表面接触配合；所述端盖、壳体、套筒、杆轴及转盘形成一个密封腔室,所述磁流变脂充满于该密封腔室。本发明能够在两个方向同时具有传力特性。(The invention discloses a bidirectional force and moment transmission device based on magnetorheological grease, which comprises a rod shaft, a shell, a turntable, an electromagnetic coil, the magnetorheological grease, an isolation ring, a sleeve, an end cover and a compression spring. The shell is cylindrical, the upper end and the lower end of the shell are sealed through end covers, the central shafts of the upper end cover and the lower end cover are respectively provided with a sleeve, the sleeves of the upper end cover and the lower end cover penetrate through a rod shaft from top to bottom, the rod shaft is positioned in the middle of the shell and is provided with a turntable, the turntable is provided with a groove, and the electromagnetic coil is wound in the groove; springs are arranged in the upper space and the lower space of the rotary table, one end of each compression spring is fixed on the end cover, and the other end of each compression spring is in contact fit with the surface of the rotary table; the end cover, the shell, the sleeve, the rod shaft and the turntable form a sealed cavity, and the magnetorheological grease is filled in the sealed cavity. The invention can simultaneously have force transmission characteristics in two directions.)

1. A bidirectional force and torque transmission device based on magnetorheological grease comprises

The shell (4) is cylindrical, the upper end and the lower end of the shell (4) are respectively sealed through an end cover (3), and a circular hole is formed in the center of the end cover (3);

the two sleeves (2) are respectively inserted into the round holes of the two end covers (3) and are in interference fit;

the rod shaft (1) is arranged in the shell (4), two ends of the rod shaft respectively extend out of the shell (4) from the sleeves (2), and the rod shaft (1), the shell (4), the two sleeves (2) and the two end covers (3) jointly form a sealed chamber;

the method is characterized in that:

a circle of annular boss is arranged in the middle of the rod shaft (1);

further comprising:

the inner ring of the rotary table (5) is provided with a circle of first grooves upwards from the bottom surface, the first grooves are clamped on the annular boss of the rod shaft (1) and fixedly connected, and a circle of second grooves are formed in the circumferential wall of the rotary table (5);

the electromagnetic coil (6), the electromagnetic coil (6) is twined in the second recess;

the isolation ring (10) is sleeved at the opening of the second groove to seal the opening of the second groove;

two compression springs (8), two compression springs (8) all set up in sealed cavity, and compression spring (8) one end is fixed on end cover (3), and the other end supports and carousel (5), and magnetorheological grease (7) are full of in sealed cavity.

2. The magnetorheological grease based two-way force and torque transmission device of claim 1, wherein: and a wiring terminal of the electromagnetic coil (6) extends out of the bidirectional force and moment transmission device based on the magnetorheological grease along the turntable (5) and the rod shaft (1) through a wire guide hole and is connected with an external direct-current power supply.

3. The magnetorheological grease based two-way force and torque transmission device of claim 1, wherein: still include a plurality of ring packing (9), embedding sealing washer (9) between end cover (3) and casing (4), embedding sealing washer (9) between end cover (3) and sleeve (2), embedding sealing washer (9) between sleeve (2) and pole axle (1).

4. The magnetorheological grease based two-way force and torque transmission device according to claim 1 or 3, wherein: the outer wall of the sleeve (2) is in interference fit with the inner wall of the end cover (3).

5. The magnetorheological grease based two-way force and torque transmission device according to claim 1 or 3, wherein: the outer wall of the rod shaft (1) and the inner wall of the sleeve (2) form clearance fit.

6. The magnetorheological grease based two-way force and torque transmission device according to claim 1 or claim, wherein: the turntable (5) and the shell (4) adopt low-carbon steel paramagnetic materials.

7. The magnetorheological grease based two-way force and torque transmission device according to claim 1 or claim, wherein: the end cover (3), the sleeve (2) and the rod shaft (1) are made of high-hardness aluminum alloy materials.

Technical Field

The invention belongs to power transmission equipment, and particularly relates to a bidirectional force and moment transmission device based on magnetorheological grease.

Background

The magnetorheological grease is composed of micron-sized ferromagnetic particles, base liquid and additives. Under the condition of zero magnetic field intensity, the magnetorheological grease is expressed as a Newton fluid with good fluidity and low viscosity, and under the condition of an external magnetic field, the magnetorheological grease is instantaneously (in millisecond magnitude) transited to a Bingham fluid with high viscosity and low fluidity. Research shows that the shearing yield stress of the magnetorheological grease can reach 50-100 KP, the working temperature range is-40-150 ℃, and the reversible cycle change frequency of the magnetorheological grease is about 300 ten thousand, so that the magnetorheological device has the characteristics of long service life, quick response, wide working temperature range and the like.

The magnetorheological grease has wide application prospect in multiple engineering fields of vibration reduction and inhibition, mechanical transmission, precision machining, sealing and the like due to the excellent rheological property of the magnetorheological grease, wherein the development of a magnetorheological force transmission device by taking the magnetorheological grease as a force transmission medium is an important branch of the research on the application technology of the magnetorheological grease.

Currently, magnetorheological dampers can be classified into piston-type magnetorheological dampers and rotary-type magnetorheological dampers according to their operating modes. The piston type magnetorheological damper is early in research, and the research on the structural design and the mechanical model of the piston type magnetorheological damper is mature. However, in some applications, such as rehabilitation robots, speed change and braking/transmission systems, etc., the damper is required to provide continuously rotating controllable damping force/torque, so that the research on the force transmission function of the integrated piston type magnetorheological damper and the force transmission function of the rotary type magnetorheological damper has important application significance.

Working in shear mode, the shear force of magnetorheological grease can be described by Bingham model, and is expressed as follows:

in the formula: τ is the shear stress of the fluid; tau is_yIs the magneto-shear yield stress; mu is the viscosity of the liquid after yielding (the actually measured slope of the shear stress after yielding) independent of the magnetic field strength;fluid shear rate.

Disclosure of Invention

The invention aims to provide a bidirectional force and moment transmission device based on magnetorheological grease, which integrates the force and moment transmission functions into one device, and two compression springs are added into the device, so that the restoring force in two directions is generated, and the device can simultaneously have the force transmission characteristic in two directions, and finally, a force or moment transmission device can be obtained.

The technical solution for realizing the purpose of the invention is as follows: a bidirectional force and moment transmission device based on magnetorheological grease comprises a rod shaft, a shell, a rotary table, an electromagnetic coil, the magnetorheological grease, an isolation ring, two sleeves, two end covers and two compression springs.

The shell is cylindrical, the upper end and the lower end of the shell are sealed through end covers respectively, a round hole is formed in the center of each end cover, and the two sleeves are inserted into the round holes of the two end covers respectively and are in interference fit. The rod shaft is arranged in the shell, two ends of the rod shaft respectively extend out of the shell from the sleeves, and the rod shaft, the shell, the two sleeves and the two end covers jointly form a sealed cavity.

The middle part of the rod shaft is provided with a circle of annular boss, the inner ring of the turntable is upwards provided with a circle of first groove from the bottom surface, the first groove is clamped on the annular boss of the rod shaft and is fastened by screws, the cross section area of a magnetic circuit of the rotating shaft is reduced by adopting the design of the first groove and the annular boss, and then the magnetic flux density in the turntable is increased, so that the torque and the force of the whole transmission device are improved. A circle of second grooves are formed in the circumferential wall of the rotary table, the electromagnetic coil is wound in the second grooves, a wiring terminal of the electromagnetic coil extends out of the bidirectional force and torque transmission device based on the magnetorheological grease along the rotary table and the rod shaft through a wire guide hole and is connected with an external direct-current power supply, and the isolation ring is sleeved at the opening of the second grooves to seal the opening of the second grooves.

Two compression springs are arranged in the sealed cavity, one end of each compression spring is fixed on the end cover, the other end of each compression spring abuts against the rotary table, and magnetorheological grease is filled in the sealed cavity; the end cover, the shell, the sleeve, the rod shaft and the turntable form a sealed cavity, the sealed cavity is filled with the magnetorheological grease, and the isolation ring isolates the magnetorheological grease from the electromagnetic coil.

Compared with the prior art, the invention has the remarkable advantages that:

(1) the turntable can move up and down and rotate circumferentially along with the shaft rod, so that the device can integrate force and moment transmission functions together, and can transmit axial force and moment.

(2) Two compression springs are adopted to generate restoring forces in two directions, so that the invention can simultaneously have force transmission characteristics in two directions, and finally a force or torque transmission device can be obtained.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a magnetorheological grease based bidirectional force and torque transmission device of the present invention.

FIG. 2 is a schematic view of the dynamic rotation of the present invention.

FIG. 3 is a graph of yield stress versus magnetic induction according to the present invention.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

With reference to fig. 1, the bidirectional force and torque transmission device based on magnetorheological grease of the present invention includes a rod shaft 1, a housing 4, a turntable 5, an electromagnetic coil 6, magnetorheological grease 7, an isolation ring 10, two sleeves 2, two end caps 3, and two compression springs 8.

The shell 4 is cylindrical, the upper end and the lower end of the shell are sealed through the end covers 3 respectively, a circular hole is formed in the center of each end cover 3, and the two sleeves 2 are inserted into the circular holes of the two end covers 3 respectively and are in interference fit. The rod shaft 1 is arranged in the shell 4, two ends of the rod shaft respectively extend out of the shell 4 from the sleeves 2, and the rod shaft 1, the shell 4, the two sleeves 2 and the two end covers 3 form a sealed chamber together.

The middle of the rod shaft 1 is provided with a circle of annular boss, the inner ring of the turntable 5 is upwards provided with a circle of first groove from the bottom surface, the first groove is clamped on the annular boss of the rod shaft 1 and is fastened through screws, the cross section area of a magnetic circuit of the rotating shaft is reduced by adopting the design of the first groove and the annular boss, and then the magnetic flux density inside the turntable 5 is increased, so that the torque and the force of the whole transmission device are improved. A circle of second grooves are formed in the circumferential wall of the rotary disc 5, the electromagnetic coil 6 is wound in the second grooves, a wiring terminal of the electromagnetic coil 6 extends out of the bidirectional force and torque transmission device based on the magnetorheological grease along the rotary disc 5 and the rod shaft 1 through a wire hole and is connected with an external direct-current power supply, and the isolation ring 10 is sleeved at the opening of the second grooves to seal the opening of the second grooves.

Two compression springs 8 are arranged in the sealed cavity, one end of each compression spring 8 is fixed on the end cover 3, the other end of each compression spring 8 abuts against the rotary table 5, and the sealed cavity is filled with magnetorheological grease 7; the end cover 3, the shell 4, the sleeve 2, the rod shaft 1 and the turntable 5 form a sealed cavity, the magnetorheological grease 7 is filled in the sealed cavity, and the isolation ring 10 isolates the magnetorheological grease 7 from the electromagnetic coil 6.

The bidirectional force and moment transmission device based on the magnetorheological grease further comprises a plurality of annular sealing rings 9, the sealing rings 9 are embedded between the end cover 3 and the shell 4, and the end cover 3 is fixedly connected with the shell 4 through bolts 11. A sealing ring 9 is embedded between the end cover 3 and the sleeve 2, and the outer wall of the sleeve 2 is in interference fit with the inner wall of the end cover 3. A sealing ring 9 is embedded between the sleeve 2 and the rod shaft 1, and the outer wall of the rod shaft 1 and the inner wall of the sleeve 2 form clearance fit.

The turntable 5 and the shell 4 are made of low-carbon steel paramagnetic materials, and the end cover 3, the sleeve 2 and the rod shaft 1 are made of high-hardness aluminum alloy materials.

The yield stress is related to the magnetic induction as follows:

τ_y＝αH^β

τ_yfor shear yield stress, H is the magnetic field strength, and alpha and beta are coefficients.

The working process is as follows:

with reference to fig. 1 and 2, the current flowing into the electromagnetic coil 6 is controlled according to the user's needs, magnetic flux with a certain intensity is generated in the rotary disc 5, the magnetorheological grease 7 and the shell 4, the magnetorheological grease 7 generates a rheological phenomenon and has a certain yield stress, when an external force or a moment acts on the rod shaft 1, the rod shaft 1 moves or rotates under the action of the force or the moment, and then the rotary disc 5 is driven to move or rotate, and the magnetorheological grease 7 with a certain yield stress generates a blocking effect on the force or the moment, so that the force or the moment is transmitted. From fig. 3, the relationship between yield stress and magnetic induction is exponential, and as shown in fig. 3, the magnetic flux tends to saturate as the current increases.

The invention is used in the following similar occasions, such as a rehabilitation robot, a speed change and brake/transmission system and the like, and the damper is required to provide continuously rotating controllable damping force/moment, so the research of integrating the force transmission function of the piston type magnetorheological damper and the force transmission moment function of the rotary type magnetorheological damper has important application significance.