Drum-disc magnetorheological clutch based on energy recycling

Abstract

The present invention discloses a drum-disc magnetorheological clutch based on energy recycling, comprising a driving shaft, a driven housing, and a driven shaft, with a driving inner cylinder and a driven inner cylinder disposed within the driven housing. The driving inner cylinder has an annular groove disposed at its right end, and a sleeve is formed in the middle of the bottom of the driven inner cylinder. A magnetorheological fluid is filled in the gap between the driven and driving inner cylinders. Several shape memory alloy springs are distributed around the annular cavity of the driven inner cylinder. The edge of the driven inner cylinder is bent outward and extended to form a flange, which extends between the driven outer cylinder and the right end cap. Several return springs are disposed around the right end of the driven outer cylinder, and under the action of the return springs, the flange is engaged with the bottom of the clearance groove. The present invention combines the advantages of both drum-type and disk-type structures, converting the thermal energy and electromagnetic energy generated during operation into extrusion force to perform work. This not only increases heat dissipation and reduces the influence of temperature on the magnetorheological fluid, but also enhances the extrusion strengthening effect, improving the clutch's force transmission stability and energy efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of clutches, and in particular to a drum-disc type magnetorheological clutch based on energy recycling. Background Art

[0002] Magnetorheological fluid (MRF) is a new type of fluid with controllable flow properties. In the absence of an external magnetic field, MRF exhibits the properties of a low-viscosity Newtonian fluid. However, under the influence of an external magnetic field, MRF can reversibly transform from a liquid to a viscoplastic state in milliseconds. Based on these rheological properties, MRF is introduced as a working medium, utilizing its shear yield stress to achieve power transmission. Furthermore, the shear yield stress can be varied by adjusting the strength of the applied magnetic field, thereby varying the torque transmitted by the device. Due to the unique properties of MRF, it has broad application prospects in clutches and brakes.

[0003] For example, CN212360555 U discloses a multi-disc magnetorheological clutch based on electromagnetic force extrusion. It adopts a multi-disc structure to increase the working area of ​​the magnetorheological fluid, and effectively combines shape memory alloy and magnetorheological fluid into the clutch, effectively solving the problem of magnetorheological fluid performance degradation with increasing ambient temperature. At the same time, it rationally utilizes the extrusion strengthening effect of the magnetorheological fluid to improve the clutch torque. For example, CN206802225U discloses a shape memory alloy extruded magnetorheological fluid and friction combined transmission device. When the ambient temperature rises, the device can automatically connect to the power supply through the shape memory alloy switch. After the temperature of the device rises, the shape memory alloy spring generates an output force to push the driven pressure plate and the active right housing to generate pressure. The driven pressure plate can also squeeze the magnetorheological fluid, which can increase the performance of the magnetorheological fluid. For example, CN107763109A discloses a "temperature-controlled variable-surface magnetorheological transmission device". The shape memory alloy spring pushes the active plate to change the working surface of the magnetorheological fluid from one to two, which can transmit greater torque, and can automatically adjust the transmitted torque according to the real-time temperature, and ensure the stability of the transmission process.

[0004] The above-mentioned related research has greatly promoted the development of magnetorheological fluid in the field of transmission, but it is more about the continuous optimization and improvement of the device structure, while ignoring the problem that the heat generated by the device itself will reduce the mechanical properties of the magnetorheological fluid. However, the heat generated by the electric power loss of the excitation coil and the heat generated by the magnetorheological fluid working under high shear stress will increase the temperature of the clutch device. The material properties of magnetorheological fluid are easily affected by temperature. In high temperature environments, the performance of magnetorheological fluid will gradually decay or even fail as the temperature rises. Therefore, how to convert the energy generated during the working process into external force to generate extrusion pressure to enhance the extrusion strengthening effect, while increasing the heat dissipation capacity and making full use of the heat energy, thereby improving the clutch transmission performance, is of great significance to how to reduce the impact of the heat of the device itself on the performance and transmission performance of magnetorheological fluid. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to solve the problem that the existing magnetorheological fluid-based clutch is greatly affected by temperature and has poor stability, and to provide a drum-disc magnetorheological clutch based on energy recycling, which can make full use of the heat generated by the electric power loss of the excitation coil and the heat generated by the magnetorheological fluid under high shear stress, convert thermal energy and electromagnetic energy into external force work, and enhance the mechanical properties of the magnetorheological fluid, thereby enhancing heat dissipation and reducing the influence of temperature on the magnetorheological fluid, and enhancing the extrusion strengthening effect, improving the clutch transmission stability, and effectively improving the transmission performance and energy utilization of the magnetorheological clutch.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a drum-disc magnetorheological clutch based on energy recycling, comprising a driving shaft, a driven housing and a driven shaft, the driven housing comprising a left end cover, a driven outer cylinder and a right end cover connected in sequence, the right end of the driving shaft passes through the left end cover and extends into the driven housing, and is rotatably connected to the left end cover, and the driven shaft is fixedly connected to the right end cover; a coil groove is provided on the inner side of the driven outer cylinder near both ends, and an excitation coil is provided in the coil groove; it is characterized in that: an active inner cylinder and a driven inner cylinder are also provided in the driven housing; the active inner cylinder is sleeved on the active shaft and is connected to the active outer cylinder The driven shaft is fixedly connected and can rotate synchronously with the driving shaft. An annular groove coaxial with the driving inner cylinder is provided at the right end of the driving inner cylinder, so that a shaft sleeve is formed in the middle of the driving inner cylinder; the driven inner cylinder is made of an armature, and the middle part of its bottom is raised toward the inner side of the cylinder body to form a sleeve coaxial with the driven inner cylinder, and an annular cavity is formed between the sleeve and the side wall of the driven inner cylinder; the driven inner cylinder is located in the driving inner cylinder and is sleeved on the shaft sleeve through the sleeve, and a gap is formed between the outer wall of the driven inner cylinder and the inner wall of the driving inner cylinder; a sealing ring is provided between the right end of the driving inner cylinder and the driven inner cylinder, and the gap between the driven inner cylinder and the driving inner cylinder is filled with magnetorheological fluid;

[0007] Several shape memory alloy springs are distributed around the annular cavity of the driven inner cylinder; a spacer disk is also provided in the annular ring, and the shape memory alloy spring is located between the spacer disk and the barrel bottom of the driven inner cylinder, and its axis is parallel to the axis of the driven inner cylinder; the open end of the driven inner cylinder is bent outward and extended to form a flange, and the flange is located between the driven outer cylinder and the right end cover, and extends to the outside of the excitation coil; on the inner side of the right end cover, an annular give way groove is provided at the position corresponding to the flange, the flange is located in the give way groove, and there is a gap between the two sides of the flange and the right end of the driven outer cylinder and the bottom of the give way groove, so that the driven inner cylinder can move along its axial direction; at the right end of the driven outer cylinder, several return springs are provided around it, and the axis of the return spring is parallel to the axis of the driven outer cylinder. Under the action of the return spring, the flange fits with the bottom of the give way groove.

[0008] Furthermore, a magnetic isolation ring is provided inside the excitation coil, and the magnetic isolation ring seals the excitation coil in the coil slot.

[0009] Furthermore, the right end of the driven outer cylinder is provided with a spring accommodating groove corresponding to the return spring. The return spring is located in the spring accommodating groove, one end of which is fixedly connected to the bottom of the accommodating groove, and the other end is fixedly connected to the flange.

[0010] Furthermore, the return spring is located outside the excitation coil.

[0011] Furthermore, a liquid injection hole is provided at the left end of the active inner cylinder, which is connected to the gap between the driven inner cylinder and the active inner cylinder, and a liquid injection plug is provided in the liquid injection hole; on the inner side of the left end cover, an annular groove is provided corresponding to the position of the liquid injection plug, and the part of the liquid injection plug protruding from the active inner cylinder is located in the annular groove.

[0012] Furthermore, a transparent cover is provided on the outside of the left end cover. The transparent cover is sleeved on the driving shaft and fixedly connected to the left end cover.

[0013] Compared with the prior art, the present invention has the following advantages: after power is applied, the electromagnetic force generated by the excitation coil attracts the driven inner cylinder and drives the driven inner cylinder to move toward the left end cover. At the same time, the temperature-controlled shape memory alloy spring fully utilizes the heat generated by the electric power loss of the excitation coil and the heat generated by the magnetorheological fluid under high shear stress, and converts them into mechanical energy, further pushing the driven inner cylinder to move toward the left end cover, jointly squeezing the magnetorheological fluid and enhancing the mechanical properties of the magnetorheological fluid, thereby enhancing heat dissipation and reducing the influence of temperature on the magnetorheological fluid, and enhancing the extrusion strengthening effect, thereby improving the transmission stability of the clutch and effectively improving the transmission performance and energy utilization rate of the magnetorheological clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a schematic diagram of the decomposition structure of the present invention.

[0016] In the figure: 1-driving shaft; 2-driven shaft; 3-left end cover; 4-driven outer cylinder; 5-right end cover; 6-excitation coil; 7-driving inner cylinder; 8-driven inner cylinder; 9-sealing ring; 10-magnetorheological fluid; 11-shape memory alloy spring; 12-spacer disk; 13-flanged edge; 14-reset spring; 15-magnetic isolation ring; 16-liquid injection plug; 16-transparent cover. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example: See Figure 1 、 Figure 2 A drum-disc magnetorheological clutch based on energy recycling includes a driving shaft 1, a driven housing and a driven shaft 2. The driven housing includes a left end cover 3, a driven outer cylinder 4 and a right end cover 5 connected in sequence. The right end of the driving shaft 1 passes through the left end cover 3 and extends into the driven housing, and is rotatably connected to the left end cover 3 through a bearing. The driven shaft 2 is fixedly connected to the right end cover 5. On the inner side of the driven outer cylinder 4, a coil groove is provided near both ends, and an excitation coil 6 is provided in the coil groove. A magnetic isolation ring 15 is provided on the inner side of the excitation coil 6, and the magnetic isolation ring 15 encloses the excitation coil 6 in the coil groove. A transparent cover 17 is also provided on the outer side of the left end cover 3. The transparent cover 17 is sleeved on the driving shaft 1 and fixedly connected to the left end cover 3. A felt ring is provided between the transparent cover 17 and the driving shaft 1 to achieve the closure of the driven housing.

[0019] The driven housing also houses a driving inner cylinder 7 and a driven inner cylinder 8. The driving inner cylinder 7 is sleeved onto the driving shaft 1 and fixedly connected to it, rotating synchronously with it. The left end of the driving inner cylinder 7 has a shaft mounting groove along its axis, through which it is sleeved onto the driving shaft 1 and fixedly connected via a key. The right end of the driving inner cylinder 7 has an annular groove coaxial with the driving inner cylinder 7, forming a sleeve in the middle of the driving inner cylinder 7. The driven inner cylinder 8 is made of an armature, and the middle portion of its bottom rises inwardly, forming a sleeve coaxial with the driven inner cylinder 8. This sleeve forms an annular cavity with the sidewall of the driven inner cylinder 8. The driven inner cylinder 8 is located within the driving inner cylinder 7 and is sleeved onto the sleeve via this sleeve. A gap exists between the outer wall of the driven inner cylinder 8 and the inner wall of the driving inner cylinder 7 and the end of the sleeve. A sealing ring 9 is installed between the right end of the active inner cylinder 7 and the driven inner cylinder 8. The gap between the driven inner cylinder 8 and the active inner cylinder 7 is filled with magnetorheological fluid 10. A liquid injection hole is provided at the left end of the active inner cylinder 7. This injection hole communicates with the gap between the driven inner cylinder 8 and the active inner cylinder 7. A liquid injection plug 16 is installed in the injection hole. An annular groove is provided on the inside of the left end cap 3, corresponding to the position of the liquid injection plug 16. The portion of the liquid injection plug 16 that protrudes from the active inner cylinder 7 is located in this annular groove.

[0020] Several shape-memory alloy springs 11 are distributed around the annular cavity of the driven inner cylinder 8. A magnetic spacer disk 12 is also located within the annular cavity. The shape-memory alloy springs 11 are positioned between the magnetic spacer disk 12 and the bottom of the driven inner cylinder 8, with their axis parallel to the axis of the driven inner cylinder 8. A spring sleeve is located outside the shape-memory alloy springs 11. The right end of the sleeve passes through the magnetic spacer disk 12 and connects to the end cap. The left end is spaced from the bottom of the driven inner cylinder 8 to better guide the springs. The open end (right end) of the driven inner cylinder 8 is bent outward and extended to form a flange 13. This flange 13 is located between the driven outer cylinder 4 and the right end cap 5 and extends to the outside of the excitation coil. On the inside of the right end cap 5, an annular clearance groove is provided at the position corresponding to the flange 13. The flange 13 is located within this clearance groove, and clearance is provided between the flange 13 and the right end of the driven outer cylinder 4 and the bottom of the clearance groove on both sides, allowing the driven inner cylinder 8 to move axially. Several return springs 14 are arranged around the right end of the driven outer cylinder 4. The axis of each return spring 14 is parallel to the axis of the driven outer cylinder 4. One end of each return spring 14 is connected to the driven outer cylinder 4 and the other end is connected to the flange 13. Under the action of the return spring 14, the flange 13 is pressed against the bottom of the clearance groove. A spring receiving groove is provided at the right end of the driven outer cylinder 4, corresponding to the return spring 14. The return spring 14 is located within the spring receiving groove, with one end fixedly connected to the bottom of the groove and the other end fixedly connected to the flange 13. Preferably, the return spring 14 is located outside the excitation coil 6.

[0021] In this solution, the electromagnetic attraction force of the excitation coil 6 on the driven inner cylinder 8 is:

[0022]

[0023] Where μ0 is the magnetic permeability of vacuum or air; n is the number of turns of a single magnet coil; i is the current in the coil; S0 is the air gap area; δ s is the air gap thickness.

[0024] The thrust generated by the extension of the shape memory alloy spring 11 on the driven inner cylinder 8 is:

[0025]

[0026] Where, d is the spring wire diameter; D is the median diameter; n is the number of effective turns; λ is the axial expansion and contraction of the spring; G M is the elastic modulus of the martensite phase of the shape memory alloy; G A is the elastic modulus of the austenite phase of the shape memory alloy.

[0027] During operation, the active cylinder is connected to the active shaft 1 via a key. When the active shaft 1 rotates, the active cylinder rotates synchronously. At this time, the excitation coil 6 is de-energized and no electromagnetic field is generated. The magnetorheological fluid 10 between the active and driven cylinders is in a liquid state, exhibiting the properties of a low-viscosity Newtonian fluid, transmitting little or no torque. When the excitation coil 6 is energized, the electromagnetic field generated by the excitation coil 6 vertically penetrates the horizontal and vertical working gaps and the end working gaps of the magnetorheological fluid 10. The dispersed particles in the magnetorheological fluid 10 are instantly chained, transforming from a free-flowing liquid to a semi-solid or even solid state within milliseconds. This transmits a significant torque, driving the driven cylinder to rotate. Simultaneously, the energization of the excitation coil 6 generates an electromagnetic attraction on the driven cylinder, causing it to move toward the left end cap 3, squeezing the magnetorheological fluid 10 and generating a squeeze-strengthening effect, further increasing the transmitted torque. After a period of operation, the heat generated by the loss of electrical power in the excitation coil 6 and the heat generated by the MR fluid 10 under high shear stress raise the clutch device temperature, reducing the viscosity of the MR fluid 10 and leading to a decrease in the material's mechanical properties. This heat is transferred via the master and slave cylinders to the shape memory alloy spring 11, causing its thermal deformation to generate a restoring force that axially pushes the slave cylinder to squeeze the MR fluid 10. This squeeze enhances the mechanical properties of the MR fluid 10, compensating for the performance degradation caused by the temperature rise and improving rotational stability.

[0028] In this embodiment, a cylindrical gap is formed between the inner and outer walls of the annular groove of the active inner cylinder 7 and the driven inner cylinder 8, forming a double-cylinder structure. A disc-shaped gap is formed between the bottom of the annular groove and the bottom of the active inner cylinder 7. A disc-shaped gap is also formed between the sleeve end of the active inner cylinder 7 and the sleeve end of the driven inner cylinder 8. This creates a double-cylinder and double-disc gap across the entire clutch, forming a combined cylinder-disc structure. This significantly increases the volume of magnetorheological fluid 10 that can be accommodated, and the effective area of ​​the magnetorheological fluid 10 is also greatly increased, enabling greater torque transmission. Furthermore, when energized, the excitation coil 6 generates electromagnetic attraction, attracting the driven inner cylinder 8 and enhancing the squeeze-strengthening effect. Simultaneously, the heat generated by the excitation coil 6 acts on the shape memory alloy spring 11, converting the heat energy into work generated by the restoring force of the shape memory alloy spring 11. This not only increases heat dissipation but also enhances the squeeze-strengthening effect. This allows the energy generated during operation to be reused and converted into external force to produce work, improving energy utilization.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the technical solutions. Those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present invention that do not depart from the purpose and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A drum-disc magnetorheological clutch based on energy recycling, comprising a driving shaft, a driven housing, and a driven shaft. The driven housing comprises a left end cap, a driven outer cylinder, and a right end cap connected in sequence. The right end of the driving shaft passes through the left end cap and extends into the driven housing, where it is rotatably connected to the left end cap. The driven shaft is fixedly connected to the right end cap. A coil slot is provided on the inner side of the driven outer cylinder near each end, each containing an excitation coil. The invention is characterized in that: The driven housing is further provided with an active inner cylinder and a driven inner cylinder; the active inner cylinder is sleeved on the active shaft and fixedly connected to the active shaft and can rotate synchronously with the active shaft, and an annular groove coaxial with the active inner cylinder is provided at the right end of the active inner cylinder, so that a shaft sleeve is formed in the middle of the active inner cylinder; the driven inner cylinder is made of an armature, and the middle part of its bottom is raised toward the inner side of the cylinder to form a sleeve coaxial with the driven inner cylinder, and an annular cavity is formed between the sleeve and the side wall of the driven inner cylinder; the driven inner cylinder is located in the active inner cylinder and sleeved on the shaft sleeve through the sleeve, and a gap is provided between the outer wall of the driven inner cylinder and the inner wall of the active inner cylinder; a sealing ring is provided between the right end of the active inner cylinder and the driven inner cylinder, and the gap between the driven inner cylinder and the active inner cylinder is filled with magnetorheological fluid; Several shape memory alloy springs are distributed around the annular cavity of the driven inner cylinder; a spacer disk is also provided in the annular ring, and the shape memory alloy spring is located between the spacer disk and the barrel bottom of the driven inner cylinder, and its axis is parallel to the axis of the driven inner cylinder; the open end of the driven inner cylinder is bent outward and extended to form a flange, and the flange is located between the driven outer cylinder and the right end cover, and extends to the outside of the excitation coil; on the inner side of the right end cover, an annular give way groove is provided at the position corresponding to the flange, the flange is located in the give way groove, and there is a gap between the two sides of the flange and the right end of the driven outer cylinder and the bottom of the give way groove, so that the driven inner cylinder can move along its axial direction; at the right end of the driven outer cylinder, several return springs are provided around it, and the axis of the return spring is parallel to the axis of the driven outer cylinder. Under the action of the return spring, the flange fits with the bottom of the give way groove.

2. The drum-disc magnetorheological clutch based on energy recycling according to claim 1, characterized in that: A magnetic isolation ring is provided on the inner side of the excitation coil, and the magnetic isolation ring seals the excitation coil in the coil slot.

3. The drum-disc magnetorheological clutch based on energy recycling according to claim 1, characterized in that: The right end of the driven outer cylinder is provided with a spring accommodating groove corresponding to the return spring. The return spring is located in the spring accommodating groove, one end of which is fixedly connected to the bottom of the accommodating groove, and the other end is fixedly connected to the flange.

4. The drum-disc magnetorheological clutch based on energy recycling according to claim 1, characterized in that: The return spring is located outside the excitation coil.

5. The drum-disc type magnetorheological clutch based on energy recycling according to claim 1, characterized in that: At the left end of the active inner cylinder, there is a liquid injection hole, which is connected to the gap between the driven inner cylinder and the active inner cylinder, and a liquid injection screw plug is provided in the liquid injection hole; on the inner side of the left end cover, corresponding to the position of the liquid injection screw plug, there is an annular groove, and the part of the liquid injection screw plug protruding from the active inner cylinder is located in the annular groove.

6. The drum-disc magnetorheological clutch based on energy recycling according to claim 1, characterized in that: A transparent cover is also provided on the outside of the left end cover. The transparent cover is sleeved on the driving shaft and fixedly connected to the left end cover.

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