AU2016236722A1

AU2016236722A1 - Magneto-rheological technology based overload protection device for torque shaft of electric motor in coal mining machine

Info

Publication number: AU2016236722A1
Application number: AU2016236722A
Authority: AU
Inventors: Jingjing Liu; Xinhua Liu; Junquan PENG; Yankun REN; Chao TAN; Dongdong Wang; Lifeng Wang; Zhongbin WANG; Qiuxiang ZHANG
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2015-03-23
Filing date: 2016-01-20
Publication date: 2017-04-13
Anticipated expiration: 2036-01-20
Also published as: CN104779753A; WO2016150242A1; AU2016236722B2

Abstract

A magneto-rheological technology-based overload protection device for the torque shaft of the electric motor in a coal mining machine comprises a cutting part gear (3), bearings (2) installed at either end of the cutting part gear (3), a shaft coupling (4), a cutting part shell (6), a motor (8), a torque shaft II (1), a torque shaft I (7) and a magneto-rheological fluid overload protection device (5). One end of the torque shaft II (1) is connected with the cutting part gear (3) by means of a splined connection, the other end is connected with the magneto-rheological fluid overload protection device (5) via the shaft coupling (4). One end of the torque shaft I (7) is connected with the rotor (9) of the motor by means of a splined connection, the other end is connected with the magneto-rheological fluid overload protection device (5) via the shaft coupling (4). The magneto-rheological fluid overload protection device (5) is fixed on the cutting part shell (6) by a connecting piece (13). The overload protection device can automatically recover in case of overload without destroying any structure and replacing any component, thereby saving the time, improving the operating efficiency and reducing the production cost.

Description

A TORQUE SHAFT OVERLOAD PROTECTION DEVICE FOR COAL MACHINE MOTOR BASED ON MAGNET-ORHEOLOGICAL TECHOLOGY

TECHNICAL FIELD

[1] The present invention relates to an overload protection device for coal machine, in particular, to a torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology, belonging to the coal machine technical field.

BACKGROUND

Coal machine is typically designed to the form of a torque shaft at the cutting motor, which not only transmits power between the cutting motor and mechanical transmission system, but also functions as an overload protection. Currently, the basic structure for cutting motor torque shaft of a coal machine is a hollow outer spline shaft, and one side of the shaft is provided with a U-shaped or V-shaped unloading groove to yield notch effect. The torque shaft is mainly damaged by torsion failure, and usually when the cutting part is overloaded, the torque shaft is fractured at the unloading groove to then be changed with a new torque shaft. This causes two problems, one of which is difficulty in changing, heavy workload in changing when fractured, hard to withdraw the fractured shaft body, reducing effect of the coal machine; the other is high cost, i.e. a new torque shaft needs to change after it is scrapped when fractured and a single cost between the thousands to tens of thousands of dollars increases the operating costs of the coal machine.

SUMMARY

[3] To solve above problems existing in prior art, the present invention provides a torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology, which can achieve automatic recovery from overload without damaging any structures and a need to change any elements, thereby saving time, improving working efficiency and saving cost.

[4] To achieve above purpose, the technical solution employed by the present invention is: The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology comprises a cutting gear, a bearing mounted on two ends of the cutting gear, a coupling, a cutting casing and a motor, and further comprises a torque shaft II, a torque shaft I and an overload protection device for magneto-rheological (MR) fluid; one end of the torque shaft II is spline-connected with the cutting gear, the other end is connected with the overload protection device for magneto-rheological (MR) fluid by the coupling; one end of the torque shaft I is spline-connected with the motor, the other end is connected with the overload protection device for magneto-rheological (MR) fluid by the coupling; the overload protection device for magneto-rheological (MR) fluid is secured on the cutting casing by connectors.

[5] Preferably, the overload protection device for magneto-rheological (MR) fluid is mainly constituted by a casing, an output shaft, a bearing seat, an active rotor, a driven rotor I, a driven rotor II and an input shaft; the casing is constituted by a left casing and a right casing, the bearing seat is secured on the left, right casing by connectors, the output shaft and input shaft runs through the left and right casing respectively and parts of the output shaft and input shaft outside the casing is mounted on the bearing seat by the bearing, the active rotor is positioned between the driven rotor I and the driven rotor II, an operation gap for magneto-rheological (MR) fluid remains between the active rotor and the driven rotor I, driven rotor II; the active rotor is connected with the input shaft, the driven shaft I is connected with the output shaft, and the driven rotor II is secured with the driven rotor I by connectors; [6] A permanent magnet is further mounted on the casing, and the permanent magnet is located in the middle of the upper and lower sides of the driven rotor I, where the magnetic field produced by the permanent magnet through the left, right casing runs to and a magnetic field perpendicular to the casing side the is formed on the operating interface between the two casings.

[7] Further, an oil seal is provided between the driven rotor II and the input shaft.

[8] Preferably, the operation gap for the magneto-rheological (MR) fluid of the overload protection device for magneto-rheological (MR) fluid is lmm~3mmo [9] Preferably, the active rotor is connected with the input shaft and the driven rotor is connected with the output shaft, by way of welding.

[10] Preferably, the permanent magnet is made of NdFeB permanent magnetic material with high performance.

[11] Preferably, the connectors are bolts or screws.

[12] Preferably, the coupling is a spline coupling.

Advantageous Effects [13] Compared with the prior art, the present invention is provided with an independent overload protection device for magneto-rheological (MR) fluid and makes the torque shaft into two connected by the overload protection device for magneto-rheological (MR) fluid, the torque shaft is still connected with the motor and the cutting gear by the spline. In normal operation, the torque shaft drives the main driven rotor of the overload protection device for magneto-rheological (MR) fluid to rotate simultaneously, when the cutting part is overloaded, the main driven rotor slip of the overload protection device for magneto-rheological (MR) fluid is operated to make the torque shaft connected with the motor rotate within a rated working range for achieving the purpose of protecting other transmission elements of coal machine, and when the coal machine is adjusted to a normal condition, the overload protection device for magneto-rheological (MR) fluid may again achieve simultaneous rotation automatically. When the cutting part is overloaded, the torque shaft may not be damaged and instead recover automatically; the torque shaft may move outwardly after releasing the limit spring for preserving its original clutch function. The present invention may not cause damage, need not to change torque shaft, and operate safely and reliably, easy to maintenance, and reduce the production cost effectively to promote the yield. The present invention has a simple structure, an easy fabrication and low manufacture cost.

BRIEF DESCRIPTION OF THE DRAWINGS

[14] Fig. 1 is a structural schematic view of the invention; [15] Fig. 2 is a structure diagram of the overload protection device for magneto-rheological (MR) fluid of the invention; [16] In figures: 1, torque shaft, 2, bearing, 3, cutting gear, 4, coupling, 5, overload protection device for magneto-rheological (MR) fluid , 6, cutting casing, 7, torque shaft I, 8, motor, 9, motor rotor, 10, output shaft, 12, bearing seat, 13, connector, 14, left casing, 15, active rotor, 16, permanent magnet, 17, right casing, 18, driven rotor I, 19, driven rotor II, 21, oil seal, 22, input shaft.

DETAILED DESCRIPTION

[17] The invention will be further described in combination with embodiments.

[18] As shown in Fig. 1, the overload protection device based on magneto-rheological technology for torque shaft of coal machine motor in the present invention comprises a cutting gear 3, a bearing 2 mounted on two ends of the cutting gear 3, a coupling 4, a cutting casing 6 and a motor 8, and further comprises a torque shaft II 1, a torque shaft I 7 and a overload protection device for magneto-rheological (MR) fluid 5; one end of the torque shaft Π 1 is connected with the spline of the cutting gear 3, the other end is connected with the overload protection device for magneto-rheological (MR) fluid 5 by the coupling 4; one end of the torque shaft 17 is spline-connected with the motor rotor 9 of the motor 8, the other end is connected with the overload protection device for magneto-rheological (MR) fluid 5 by the coupling 4; the overload protection device for magneto-rheological (MR) fluid 5 is secured on the cutting casing 6 by connectors 13.

[19] As shown in Fig. 2, being the first preferable solution for above solutions in the present invention, the overload protection device for magneto-rheological (MR) fluid 5 is mainly constituted by a casing, an output shaft 10, a bearing seat 12, an active rotor 15, a driven rotor I 18, a driven rotor II 19 and an input shaft 22; the casing is constituted by a left casing 14 and a right casing 17, the bearing seat 12 is secured on the left, right casing 14, 17 by connectors 13, the output shaft W and input shaft 22 runs through the left and right casing 14, 17 respectively and parts of the output shaft 10 and input shaft 22 outside the casing is mounted on the bearing seat 12 by the bearing 2, the active rotor 15 is positioned between the driven rotor 118 and the driven rotor II 19 or the active rotor 15 may also be located on any locations between two driven rotors, but a better effective magnetic field may be generated in the middle, an operating gap for magneto-rheological (MR) fluid remains between the active rotor 15 and the driven rotor 118, driven rotor II 19; the active rotor 15 is connected with the input shaft 22, the driven shaft I 18 is connected with the output shaft 10, and the driven rotor II 19 is secured with the driven rotor I 18 by connectors 13; [20] A permanent magnet is further mounted on the casing: 16, and the permanent magnet: 16 is located in the middle of the upper and lower sides of the driven rotor 118, the magnetic field produced by the permanent magnet: 16 runs through the left, right casing 14, 17 and forms a magnetic field perpendicular to the casing side on the operating interface between the two casings.

[21] The above technical solution may provide protection when the active rotor and driven rotor run slippingly in a short time upon an overload on the torque shaft, it recovers simultaneous operation in normal condition, which effectively protects the torque shaft and thereby prolonging the service of the torque shaft. In addition, the present invention fabricates it into an independent structure, which is secured to the coal machine casing 6 by its casing, in order to be convenient for mounting the overload protection device.

[22] As an improvement of the present invention for above technical solutions, an oil seal 21 is provided between the driven rotor II19 and the input shaft 22 to effectively avoid the leakage of the magneto-rheological (MR) fluid and further ensure safety and reliability of the device during operation.

[23] As a second preferable solution of the present invention for above technical solutions, the gap of the overload protection device for magneto-rheological (MR) fluid 5 is lmm~3mm, which in practical may be selected as 1mm, 2mm or 3mm by the operator according to the needs of the scene, and of course be also selected as any one of lmm~3mm. Since a small operation gap requires manufacturing accuracy of the active disk and difficulty in assembly while reducing the fluidity of the magneto-rheological (MR) fluid and a large operation gap results in an increase in magnetic reluctance, decrease of magnetic intensity and hence drop of the transferring torque, it is the most appropriate to choose an operation gap of lmm-3mm that not only has not a high requirement for manufacturing accuracy of the active disk but also causes a decrease of the magnetic intensity.

[24] As a third preferable solution of the present invention for above technical solutions, welding connection employed between the active rotor 15 and the input shaft 22, the driven rotor 118 and the output shaft 10 has a better stability, is not easy to be released or damaged and further effectively protects the reliability of the device during operation.

[25] As a fourth preferable solution of the present invention for above technical solutions, the permanent magnet: 16 made of the permanent magnetic material of NdFeB with high performance has no power consumption, little magnetic remainder, long service, and decreased the production cost.

[26] As a fifth preferable solution of the present invention for above technical solutions, the connectors 13 being bolts or screws are easy to detach and assemble while convenient for changing components.

[27] As the spline-connection has a larger torque, the coupling 4 is preferably a spline coupling, which has a better transfer effect.

[28] At the operation interface, the magnetic field generated from the permanent magnet: 16 transfers through the left casing 14, the right casing 17, the driven rotor 118, the driven rotor II19 and the active rotor 15 to the operation gap of the magneto-rheological (MR) fluid. Power generated from the motor 8 is transferred to the torque shaft I 7 by the spline, then transferred to the overload protection device for magneto-rheological (MR) fluid 5 through the spline coupling, and further transferred to the torque shaft II 1 through another spline coupling, thereafter transferred to the cutting gear 3 through the spline. After being transferred to the input shaft 22, the active rotor 15 of the overload protection device for magneto-rheological (MR) fluid 5, the power is transferred to the driven 118, driven rotor II 19 and output shaft 10 by the magneto-rheological (MR) fluid in the magneto-rheological (MR) fluid operation gap for exiting. During normal operation, the magneto-rheological fluid can withstand the transferred torque so as to achieve a simultaneous rotation of the active rotor 15 with the driven rotor 118 and the driven rotor II19, but when overloaded, the magneto-rheological fluid cannot withstand the transferred torque, a slip may be generated between the active rotor 15 and the driven rotor 118, the driven rotor II19 while the motor 8 is still rotating within the rated operation range, thereby protecting other transmission elements of the coal machine, prolonging the service of the service and reducing the production cost.

Claims

CLAIMS [Claim 1] A torque shaft overload protection device for coal machine motor based on magneto- rheological (MR) technology in the present invention comprising a cutting gear (3), a bearing (2) mounted on two ends of the cutting gear (3), a coupling (4), a cutting casing (6) and a motor (8), characterized by further comprising a torque shaft II (1), a torque shaft I (7) and a overload protection device for magneto-rheological (MR) fluid (5); one end of the torque shaft II (1) is spline-connected with the cutting gear (3), the other end is connected with the overload protection device for magneto-rheological (MR) fluid (5) by the coupling (4); one end of the torque shaft I (7) is spline-connected with the motor rotor (9) of the motor (8), the other end is connected with the overload protection device for magneto-rheological (MR) fluid (5) by the coupling (4); the overload protection device for magneto-rheological (MR) fluid (5) is secured on the cutting casing (6) by connectors (13). [Claim
2] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 1, characterized in that, the overload protection device for magneto-rheological (MR) fluid (5) is mainly constituted by a casing, an output shaft (10), a bearing seat (12), an active rotor (15), a driven rotor I (18), a driven rotor II (19) and an input shaft (22); the casing is constituted by a left casing (14) and a right casing (17), the bearing seat (12) is secured on the left, right casing (14), (17) by connectors (13), the output shaft (10) and input shaft (22) runs through the left and right casing (14), (17) respectively and parts of the output shaft (10) and input shaft (22) outside the casing is mounted on the bearing seat (12) by the bearing (2) respectively, the active rotor (15) is positioned between the driven rotor I (18) and the driven rotor II (19), an operation gap for magneto-rheological fluid remains between the active rotor (15) and the driven rotor 1(18), driven rotor II (19); the active rotor (15) is connected with the input shaft (22), the driven shaft I (18) is connected with the output shaft (10), and the driven rotor II (19) is secured with the driven rotor I (18) by connectors (13); A permanent magnet is further mounted on the casing (16), and the permanent magnet (16) is located in the middle of the upper and lower sides of the driven rotor I (18), the magnetic field produced by the permanent magnet (16) runs through the left, right casing (14), (17) and forms a magnetic field perpendicular to the casing side on the operating interface between the two casings. [Claim
3] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 2, characterized in that, an oil seal (21) is provided between the driven rotor II (19) and the input shaft (22). [Claim
4] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 2, characterized in that, the operation gap for the magneto-rheological fluid of the overload protection device for magneto-rheological (MR) fluid (5) is lmm^Smin·. . [Claim
5] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 3, characterized in that, the active rotor (15) is connected with the input shaft (22) and the driven rotor I (18) is connected with the output shaft (10), by way of welding. [Claim
6] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to any one of Claim 2 ~ 5, characterized in that, the permanent magnet (16) is made of NdFeB permanent magnetic material with high performance. [Claim
7] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 6, characterized in that, the connectors (13) are bolts or screws. [Claim
8] The torque shaft overload protection device for coal machine motor based on magneto-rheological (MR) technology according to Claim 7, characterized in that, the coupling (4) is a spline coupling.