An automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor

Abstract

This invention discloses an automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor, comprising a support frame, an automatic brush-lifting system, a slip ring and rotor winding short-circuiting system, and a control system. The support frame is mounted on the base of the three-phase wound-rotor asynchronous motor; the automatic brush-lifting system is installed on the upper part of the support frame; the slip ring and rotor winding short-circuiting system is installed on the shaft of the three-phase wound-rotor asynchronous motor; and the control system is installed on the support frame and connected to the automatic brush-lifting system. This invention can automatically realize the contact and separation of the main carbon brush and the main slip ring of the three-phase wound-rotor asynchronous motor, ensuring that the main carbon brush is engaged only during motor startup and disengaged after startup. Therefore, it greatly extends the service life of the main carbon brush and the main slip ring, improves the reliability of the three-phase wound-rotor asynchronous motor, and reduces the number of repairs, failure rate, and maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and in particular to an automatic brush-type slip ring device for a three-phase wound asynchronous motor. Background Technology

[0002] When starting a three-phase wound-rotor induction motor, the rotor winding is typically connected to an external starting circuit via slip rings and carbon brushes to alter the motor's starting characteristic curve, thereby increasing the starting torque and reducing the starting current. However, in traditional three-phase wound-rotor induction motors, the carbon brushes and slip rings remain in constant contact after starting, resulting in prolonged friction between them during operation. This significantly impacts the lifespan of the slip ring system and carbon brushes, and also increases the motor's failure rate.

[0003] For the reasons mentioned above, it is necessary to improve the traditional three-phase wound-rotor asynchronous motor, which suffers from problems such as the inability of the carbon brush and slip ring to separate after starting, resulting in short service life of the slip ring system and carbon brush, and high motor failure rate. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor that features a simple structure and enables separation of the main carbon brush and slip ring.

[0005] The technical solution of this invention to solve the above problems is: an automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor, comprising a support frame, an automatic brush-lifting system, a slip ring and rotor winding short-circuiting system, and a control system. The support frame is mounted on the frame of the three-phase wound-rotor asynchronous motor; the automatic brush-lifting system is installed on the upper part of the support frame; the slip ring and rotor winding short-circuiting system is installed on the shaft of the three-phase wound-rotor asynchronous motor; the control system is installed on the support frame and is connected to the automatic brush-lifting system.

[0006] The aforementioned automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor includes an automatic brush-lifting system comprising a brush-lifting torque motor with a reducer, a gear shaft, a gear transmission variable diameter system, a conductive ring, and a tensioning bolt system. The gear transmission variable diameter system includes a front support plate, a rear support plate, a small gear, a large gear, a turntable, and a crossbar. The front and rear support plates serve as fixing components, each with several radial guide grooves distributed around the same axis and along the radius of that axis. The front and rear support plates are positioned opposite each other and fastened together by the tensioning bolt system. Two turntables are symmetrically arranged on the opposite side of the front and rear support plates, each with a large gear beside it. The large gear and the corresponding turntable are fastened together as a disc-shaped rotating component, with the rotation axis of the disc-shaped rotating component coaxial with the first center hole on the front support plate and the second center hole on the rear support plate. The turntables are designed with the same number of arc-shaped grooves as the radial guide grooves. Several roller mechanisms are also installed on the turntables, with the first center hole on the front support plate and the second center hole on the rear support plate being coaxial with the first center hole on the front support plate and the second center hole on the rear support plate. The second center hole on the support plate is provided with circumferential guide grooves. The rollers of the roller mechanism constrain the turntable so that it can only rotate around the circumferential guide grooves provided on the front and rear support plates. The brush lifting torque motor is installed on the rear support plate. The brush lifting torque motor is connected to a small gear through a gear shaft. The small gear meshes with a large gear. One end of the gear shaft connected to the small gear can be manually operated with a hand crank. The same number of crossbars as the radial guide grooves are installed between the radial guide grooves on the front and rear support plates. The diameter of the main body of each crossbar is larger than the groove width of the radial guide groove. Each crossbar is equipped with 3 main carbon brushes and several auxiliary carbon brushes. Each main carbon brush is connected to a conductive ring through a wire. The conductive ring is connected to an external starting circuit through a cable. The two ends of the main body of each crossbar that contact the radial guide grooves on the front and rear support plates are rectangular block structures. The function of these rectangular block structures is to guide the crossbar so that it can only move along the radial guide grooves. The two ends of the main body of each crossbar are provided with cylindrical bosses. Bearings are installed at the contact points between the cylindrical bosses and the arc grooves on the turntable.

[0007] The aforementioned automatic brush-type slip ring device for a three-phase wound-rotor asynchronous motor includes a tension bolt system comprising four tie rods arranged in a square between a front support plate and a rear support plate. Each tie rod has symmetrically arranged studs at both ends, which pass through the front and rear support plates respectively and are secured to them by washers and nuts. Three conductive rings are evenly spaced and fitted onto the four tie rods. A support top plate is also provided between the front and rear support plates to enhance the stability of the connection and fastening. Both ends of the support top plate are fixedly connected to the front and rear support plates respectively. Mounting bends are provided at the bottom of both the front and rear support plates, which are then fixed to the support frame via corresponding mounting bends.

[0008] The aforementioned automatic brush-type slip ring device for a three-phase wound asynchronous motor has a spring pull plate on the turntable, and a tension spring is installed between the spring pull plate and the screws on the front support plate.

[0009] The above-mentioned automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor has an electromagnet locking mechanism installed on the automatic brush-lifting system. When the carbon brush position detection switch detects that the main carbon brush and the main slip ring are in contact, the large gear is locked to ensure that the main carbon brush and the main slip ring are always in good contact during the start-up process of the three-phase wound-rotor asynchronous motor. When the main carbon brush and the main slip ring need to be separated, the electromagnetic locking mechanism is released.

[0010] The aforementioned automatic brush-type slip ring device for a three-phase wound-rotor asynchronous motor includes a main slip ring system and a secondary slip ring and rotor winding short-circuiting system. The main slip ring system comprises a bushing wrapped with insulating material, three main slip rings, several conductive rods, and several conductive plates. The three main slip rings are evenly distributed on the bushing, and the main slip rings are interference-fitted with the bushing. The bushing is mounted on the shaft of the three-phase wound-rotor asynchronous motor. Each main slip ring has two symmetrically distributed conductive rods. The corresponding conductive rods are connected together by conductive sheets; the three main slip rings are respectively connected to one phase rotor winding of a three-phase wound-rotor asynchronous motor through corresponding conductive rods; the conductive sheets are made of copper, and the contact parts with the conductive rods are machined with grooves; the main body of the conductive rod is made of copper, the outer cylindrical part is wrapped with insulating material, threaded holes are machined at both ends, and the contact parts with the conductive sheets are provided with groove planes that cooperate with the grooves; the auxiliary slip rings and rotor winding short-circuiting system include several auxiliary slip rings, a rotor winding short-circuiting system, and auxiliary slip ring conductive rods.

[0011] The aforementioned automatic brush-lifting slip ring device for a three-phase wound asynchronous motor has a carbon brush position detection switch installed on the front support plate. The position of the large gear is detected by the carbon brush position detection switch, thereby obtaining the position status information of the main carbon brush and the main slip ring, thus realizing feedback control.

[0012] The aforementioned automatic brush-type slip ring device for a three-phase wound asynchronous motor has a stop structure on the bushing. The auxiliary slip ring and rotor winding short-circuit system are positioned with the main slip ring system through the stop structure and connected by bolts.

[0013] The aforementioned automatic brush-type slip ring device for a three-phase wound asynchronous motor further includes a main cable support frame, which is made of insulating material. The rotor winding cables of the three-phase wound asynchronous motor are supported and fixed by the main cable support frame, and each cable passes through the corresponding notch on the main cable support frame and is then connected to the corresponding conductive rod.

[0014] The aforementioned automatic brush-lifting slip ring device for a three-phase wound asynchronous motor has a protective cover on the support frame. The protective cover covers the outside of the automatic brush-lifting system, slip ring, and rotor winding short-circuiting system. The protective cover has a door and an observation window.

[0015] The beneficial effects of this invention are as follows: This invention provides an automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor. This device can automatically realize the contact and separation of the main carbon brush and the main slip ring of the three-phase wound-rotor asynchronous motor. When the three-phase wound-rotor asynchronous motor starts, the main carbon brush and the main slip ring are in contact, connecting to the external starting circuit. After starting, the rotor winding of the three-phase wound-rotor asynchronous motor is short-circuited, and then the main carbon brush and the main slip ring are separated, disconnecting the external starting circuit. Since the main carbon brush is only connected during the motor starting process and disconnected after the motor starts, the service life of the main carbon brush and the main slip ring is greatly extended, the reliability of the three-phase wound-rotor asynchronous motor is improved, and the number of repairs, failure rate and maintenance cost of the three-phase wound-rotor asynchronous motor are reduced. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a structural diagram of an automatic brush lifting system.

[0018] Figure 3 This is a structural diagram of the crossbar.

[0019] Figure 4 This is a schematic diagram of the slip ring and rotor winding short-circuit system.

[0020] Figure 5 This is a schematic diagram of the main slip ring system.

[0021] Figure 6 This is a schematic diagram of the main slip ring.

[0022] Figure 7 This is a schematic diagram of the conductive rod.

[0023] Figure 8 This is a schematic diagram of the conductive sheet.

[0024] Figure 9 This is a schematic diagram illustrating the installation effect of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1As shown, an automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor includes a support frame 1, an automatic brush-lifting system 2, a slip ring and rotor winding short-circuiting system 3, and a control system 5. The support frame 1 is secured to the base of the three-phase wound-rotor asynchronous motor 6 by multiple double-ended studs 101. The automatic brush-lifting system 2 is mounted on the upper part of the support frame 1. The slip ring and rotor winding short-circuiting system 3 is mounted on the shaft of the three-phase wound-rotor asynchronous motor 6. The control system 5 is mounted on the support frame 1 and connected to the automatic brush-lifting system 2. A protective cover 4 is provided on the support frame 1, covering the automatic brush-lifting system 2 and the slip ring and rotor winding short-circuiting system 3. The protective cover 4 is provided with a door 401 and an observation window 402.

[0027] like Figure 2As shown, the automatic brush lifting system 2 includes a brush lifting torque motor 205 with a reducer, a gear shaft 206, a gear transmission variable diameter system, a conductive ring 208, and a tensioning bolt system; the gear transmission variable diameter system includes a front support plate 201, a rear support plate 202, a pinion 210, a large gear 211, a turntable 212, and a crossbar 207; the front support plate 201 and the rear support plate 202 serve as fixing components, and both the front support plate 201 and the rear support plate 202 are designed with a plurality of radial guide grooves 2011 arranged around the same axis and distributed along the radius of that axis; the front support plate 201 and the rear support plate 202... Support plates 202 are arranged opposite each other and fastened together by a tension bolt system; two turntables 212 are symmetrically arranged on the opposite side of the front support plate 201 and the rear support plate 202, and a large gear 211 is provided next to each turntable 212. The large gear 211 and the corresponding turntable 212 are fastened together as a disc-shaped rotating component. The rotation axis of the disc-shaped rotating component is coaxial with the first center hole 2014 on the front support plate 201 and the second center hole on the rear support plate 202; the turntable 212 is designed with the same number of arc-shaped grooves 2121 as the radial guide grooves 2011; the turntable 212 is also equipped with There are several roller mechanisms 214. The first center hole 2014 on the front support plate 201 and the second center hole on the rear support plate 202 are both provided with circumferential guide grooves 2012. The rollers of the roller mechanisms 214 constrain the turntable 212 so that it can only rotate around the circumferential guide grooves 2012 provided on the front support plate 201 and the rear support plate 202. A brush-lifting torque motor 205 is mounted on the rear support plate 202. The brush-lifting torque motor 205 is connected to a small gear 210 through a gear shaft 206. The small gear 210 meshes with a large gear 211. One end of the gear shaft 206 connected to the small gear 210 allows... The machine is manually operated by a hand crank 215; the same number of crossbars 207 as the radial guide grooves 2011 are installed between the radial guide grooves 2011 on the front support plate 201 and the rear support plate 202. The main body of the crossbar 207 is made of insulating material, preferably epoxy glass cloth laminate; the diameter of the main body of each crossbar 207 is larger than the groove width of the radial guide groove 2011; each crossbar 207 is equipped with 3 main carbon brushes 2071 and several auxiliary carbon brushes 2072. Each main carbon brush 2071 is connected to a conductive ring 208 through a wire. The conductive ring 208 is connected to an external starting circuit through a cable.

[0028] like Figure 3 As shown, the two ends of the main body of each crossbar 207 that contact the radial guide grooves 2011 on the front support plate 201 and the rear support plate 202 are rectangular block structures. The function of the rectangular block structure is to guide, so that the crossbar 207 can only move along the radial guide grooves 2011. The two ends of the main body of each crossbar 207 are provided with cylindrical bosses 2073. Bearings 217 are installed at the contact points between the cylindrical bosses 2073 and the arc grooves 2121 on the turntable 212. The purpose is to reduce friction at this point and improve service life.

[0029] The tensioning bolt system includes four tie rods 204, which are arranged in a square between the front support plate 201 and the rear support plate 202. Each tie rod 204 has studs symmetrically arranged at both ends. The studs at both ends of the tie rod 204 pass through the front support plate 201 and the rear support plate 202 respectively, and are fastened to the front support plate 201 and the rear support plate 202 by washers and nuts 216. Three conductive rings 208 are equally spaced and sleeved on the four tie rods 204. A support top plate 203 is also provided between the front support plate 201 and the rear support plate 202 to enhance the stability of the connection and fastening. The two ends of the support top plate 203 are fixedly connected to the front support plate 201 and the rear support plate 202 respectively. The bottom of the front support plate 201 and the rear support plate 202 are provided with mounting bends 2021, and the front support plate 201 and the rear support plate 202 are fixed to the support frame 1 by the corresponding mounting bends 2021.

[0030] The turntable 212 is equipped with a spring pull plate 213. A suitable tension spring is installed between the spring pull plate 213 and the screw 2013 on the front support plate 201. The function of this tension spring is to increase the motion damping of the system. After the carbon brush and the main slip ring are separated to the maximum distance and the brush lifting torque motor 205 is de-energized, this tension spring is used to maintain the relatively stable position of the turntable 212 and keep the main carbon brush 2071 separated from the main slip ring 3011 in a stable state.

[0031] like Figures 4-8 As shown, the slip ring and rotor winding short-circuiting system 3 includes a main slip ring system 301, a secondary slip ring and rotor winding short-circuiting system 302, and a main cable support frame 303. The main slip ring system 301 includes a bushing 3014 wrapped with insulating material, three main slip rings 3011, conductive rods 3012, and conductive plates 3013. The three main slip rings 3011 are evenly distributed on the bushing 3014, and the spacing must meet the electrical distance requirements. The main slip rings 3011 and the bushing 3014 are interference-fitted, and the bushing 3014 is mounted on the shaft of the three-phase wound-rotor asynchronous motor 6. Two conductive rods 3012 are symmetrically distributed on each main slip ring 3011, and the main slip rings 3011 and the corresponding conductive rods 3012 are connected together through conductive plates 3013. The three main slip rings 3011 are respectively connected to one phase rotor winding of the three-phase wound-rotor asynchronous motor 6 through the corresponding conductive rods 3012.

[0032] A carbon brush position detection switch 209 is installed on the front support plate 201. The position of the large gear 211 is detected by the carbon brush position detection switch 209, thereby obtaining the position status information of the main carbon brush and the main slip ring 3011, thus realizing feedback control.

[0033] The conductive sheet 3013 is made of copper, and a groove 30131 is machined at the contact part with the conductive rod 3012; the main body of the conductive rod 3012 is made of copper, the outer cylindrical part is wrapped with insulating material, and threaded holes 30121 are machined at both ends. A groove plane 30122 that mates with the groove 30131 is provided at the contact part with the conductive sheet 3013; the auxiliary slip ring and rotor winding short-circuit system 302 includes several auxiliary slip rings 3021, a rotor winding short-circuit system 3022, and auxiliary slip ring conductive rods 3023.

[0034] The main cable support frame 303 is made of insulating material; the rotor winding cable of the three-phase wound asynchronous motor 6 is supported and fixed by the main cable support frame 303, and each cable passes through the corresponding notch 305 on the main cable support frame 303 and is then connected to the corresponding conductive rod 3012.

[0035] The bushing 3014 is provided with a stop structure 304. The auxiliary slip ring and rotor winding short-circuit system 302 and the main slip ring system 301 are positioned by the stop structure 304 and connected by bolts.

[0036] The automatic brush lifting system 2 is equipped with an electromagnetic locking mechanism. When the carbon brush position detection switch 209 detects that the main carbon brush and the main slip ring 3011 are in contact, the large gear 211 is locked to ensure that the main carbon brush and the main slip ring 3011 are always in good contact during the starting process of the three-phase wound asynchronous motor 6. When the main carbon brush and the main slip ring 3011 need to be separated, the electromagnetic locking mechanism is released.

[0037] The method of using this invention includes the following steps: 1. Before starting the three-phase wound-rotor asynchronous motor 6, the main circuit of the rotor winding short-circuit system 3022 is normally closed, and the main carbon brush 2071 and the main slip ring 3011 are in a separated state. At this time, the rotor winding of the three-phase wound-rotor asynchronous motor 6 is in an internal short-circuit state through the rotor winding short-circuit system 3022. When the three-phase wound-rotor asynchronous motor 6 needs to be started, the control system 5 first makes the brush lifting torque motor 205 with a reducer in the automatic brush lifting system 2 rotate forward, driving the gear shaft 206 to drive the gear diameter changing system to operate, so that the main carbon brush 2071 contacts the main slip ring 3011 and the auxiliary carbon brush 2072 contacts the auxiliary slip ring 3021. After the carbon brush moves to the position, the carbon brush position detection switch 209 gives a feedback signal, and the rotor winding short-circuit system 3022 is activated to disconnect its main circuit. At this time, the brush lifting torque motor 205 with a reducer continues to run in a stalled state, and the rotor winding of the three-phase wound-rotor asynchronous motor 6 is stably connected to the external starting circuit through the main slip ring system 301.

[0038] 2. The three-phase wound-rotor asynchronous motor 6 is started upon power-on.

[0039] 3. After the three-phase wound-rotor asynchronous motor 6 completes its startup and sends a feedback signal, the rotor winding short-circuiting system 3022 activates again to short-circuit its main circuit. At this time, the rotor winding of the three-phase wound-rotor asynchronous motor 6 is short-circuited through the rotor winding short-circuiting system 3022. The external starting circuit is now short-circuited and there is basically no current flowing through it. At the same time, the control system 5 controls the brush lifting torque motor 205 with the reducer to reverse, driving the gear diameter changing system to reverse, causing the main carbon brush 2071 to separate from the main slip ring 3011 and the auxiliary carbon brush 2072 to separate from the auxiliary slip ring 3021. After separation, once the separation is complete, the control system 5 controls the brush lifting torque motor 205 with the reducer to de-energize and stop rotating. At this time, the tension spring installed between the spring pull plate 213 and the screw 2013 on the front support plate 201 shortens its extension length but still remains in a stretched state. Through this spring tension, the position of the turntable 212 can be kept relatively stable, thereby ensuring that the main carbon brush 2071 is reliably separated from the main slip ring 3011 and the auxiliary carbon brush 2072 is also reliably separated from the auxiliary slip ring 3021. After this, the three-phase wound-rotor asynchronous motor 6 operates under rated conditions.

Claims

1. An automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor, comprising a support frame, an automatic brush-lifting system, slip rings and a rotor winding short-circuiting system, and a control system, characterized in that: The support frame is mounted on the base of the three-phase wound asynchronous motor; the automatic brush lifting system is installed on the upper part of the support frame; the slip ring and rotor winding short-circuiting system is installed on the shaft of the three-phase wound asynchronous motor; the control system is installed on the support frame and is connected to the automatic brush lifting system. The automatic brush lifting system includes a brush lifting torque motor with a reducer, a gear shaft, a gear transmission variable diameter system, a conductive ring, and a tensioning bolt system. The gear transmission variable diameter system includes a front support plate, a rear support plate, a small gear, a large gear, a turntable, and a crossbar. The front and rear support plates serve as fixing components, each with several radial guide grooves distributed around the same axis and along the radius of that axis. The front and rear support plates are arranged opposite each other and fastened together by the tensioning bolt system. Two turntables are symmetrically arranged on the opposite side of the front and rear support plates, each with a large gear next to it. The large gear and the corresponding turntable are fastened together as a disc-shaped rotating component, with the rotation axis of the disc-shaped rotating component coaxial with the first center hole on the front support plate and the second center hole on the rear support plate. The turntables have the same number of arc-shaped grooves as the radial guide grooves. Several roller mechanisms are also installed on the turntables, with the first center hole on the front support plate and the second center hole on the rear support plate circumferentially... Each component is equipped with circumferential guide grooves. The rollers of the roller mechanism constrain the turntable, allowing it to rotate only around the circumferential guide grooves on the front and rear support plates. A brush-lifting torque motor is mounted on the rear support plate, connected to a small gear via a gear shaft. The small gear meshes with a large gear, and one end of the gear shaft connected to the small gear can be manually operated using a hand crank. Crossbars, the same number as the radial guide grooves, are installed between the radial guide grooves on the front and rear support plates. The diameter of the main body of each crossbar is larger than the width of the radial guide groove. Each crossbar is equipped with three main carbon brushes and several auxiliary carbon brushes. Each main carbon brush is connected to a conductive ring via a wire, and the conductive ring is connected to an external starting circuit via a cable. The two ends of the main body of each crossbar that contact the radial guide grooves on the front and rear support plates are rectangular block structures. These rectangular block structures serve as guides, ensuring that the crossbar can only move along the radial guide grooves. Each crossbar has cylindrical bosses at both ends, with bearings installed where the cylindrical bosses contact the arc-shaped grooves on the turntable.

2. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 1, characterized in that: The tensioning bolt system includes four tie rods arranged in a square between the front and rear support plates. Each tie rod has studs symmetrically installed at both ends, which pass through the front and rear support plates respectively and are fastened to them by washers and nuts. Three conductive rings are evenly spaced and fitted onto the four tie rods. A support top plate is also provided between the front and rear support plates to enhance the stability of the connection and fastening. The two ends of the support top plate are fixedly connected to the front and rear support plates respectively. The bottom of both the front and rear support plates are provided with mounting bends, which fix the front and rear support plates to the support frame.

3. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 1, characterized in that: The turntable is equipped with a spring pull plate, and a tension spring is installed between the spring pull plate and the screws on the front support plate.

4. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 1, characterized in that: The automatic brush lifting system is equipped with an electromagnet locking mechanism. When the carbon brush position detection switch detects that the main carbon brush and the main slip ring are in contact, the large gear is locked to ensure that the main carbon brush and the main slip ring are always in good contact during the starting process of the three-phase wound asynchronous motor. When the main carbon brush and the main slip ring need to be separated, the electromagnet locking mechanism is released.

5. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 2, characterized in that: The slip ring and rotor winding short-circuiting system includes a main slip ring system and a secondary slip ring and rotor winding short-circuiting system. The main slip ring system includes a bushing wrapped with insulating material, three main slip rings, several conductive rods, and several conductive plates. The three main slip rings are evenly distributed on the bushing, and the main slip rings and the bushing are interference-fitted. The bushing is mounted on the shaft of a three-phase wound-rotor asynchronous motor. Two conductive rods are symmetrically distributed on each main slip ring, and the main slip rings and corresponding conductive rods are connected together by conductive plates. The three main slip rings are respectively connected to one phase rotor winding of the three-phase wound-rotor asynchronous motor through corresponding conductive rods. The conductive plates are made of copper, and the contact parts with the conductive rods are machined with grooves. The main body of the conductive rod is made of copper, the outer cylindrical part is wrapped with insulating material, and threaded holes are machined at both ends. The contact parts with the conductive plates are provided with groove planes that mate with the grooves. The secondary slip ring and rotor winding short-circuiting system includes several secondary slip rings, a rotor winding short-circuiting system, and secondary slip ring conductive rods.

6. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 5, characterized in that: A carbon brush position detection switch is installed on the front support plate. The position of the large gear is detected by the carbon brush position detection switch, thereby obtaining the position status information of the main carbon brush and the main slip ring, thus realizing feedback control.

7. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 5, characterized in that: The bushing is provided with a stop structure. The auxiliary slip ring and rotor winding short-circuit system are positioned with the main slip ring system through the stop structure and are connected by bolts.

8. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 1, characterized in that: The slip ring and rotor winding short-circuiting system also includes a main cable support frame, which is made of insulating material. The rotor winding cables of the three-phase wound asynchronous motor are supported and fixed by the main cable support frame, and each cable passes through the corresponding notch on the main cable support frame and is then connected to the corresponding conductive rod.

9. The automatic brush-lifting slip ring device for a three-phase wound-rotor asynchronous motor according to claim 1, characterized in that: The support frame is equipped with a protective cover, which covers the outside of the automatic brush lifting system, slip ring and rotor winding short-circuiting system. The protective cover is equipped with a door and an observation window.

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