Rotor end ring fixing device of three-phase asynchronous motor

Abstract

The invention relates to the technical field of motors, in particular to a rotor end ring fixing device of a three-phase asynchronous motor, which comprises a rotor iron core, a plurality of copper bars are mounted on the rotor iron core, short circuit rings are mounted at the upper ends and the lower ends of the copper bars, and annular sleeve plates are arranged on the outer sides of the copper bars. The annular sleeve plate is arranged between the short circuit ring and the rotor core, a pressing ring is arranged in the short circuit ring and the adjacent annular sleeve plate, an annular groove is formed in the circumferential inner wall of the pressing ring, and metal plates are clamped on the inner wall of the annular groove in an equidistant distribution mode. Then the short circuit ring and the pressing ring are connected through the fixing screw, the stability of the short circuit ring is improved, the stress borne by the short circuit ring in the operation process is dispersed, the stress concentration of individual points is reduced, the fault risk is reduced, and the influence of thermal stress on the rotor end ring in the motor starting and stopping process is reduced through the elastic buffer mechanism.

Description

Technical Field

[0001] The invention relates to the technical field of electric motors, in particular to a rotor end ring fixing device for a three-phase asynchronous motor. Background Art

[0002] In the circulating water system, a circulating water pump motor is required to provide cooling water for the condenser, vacuum pump cooler, desulfurization system and other systems. After long-term use, the motor rotor cage rotor end ring (or short-circuit ring) may have problems such as loosening and breaking of the welding position between the cage bar and the short-circuit ring during operation. Therefore, a rotor end ring fixing device of a three-phase asynchronous motor is required to fix it.

[0003] In the circulating water system, the circulating water pump motor starts and stops frequently, with the highest number of starts and stops reaching dozens of times in a month, which causes changes in the thermal stress inside the motor and thus fatigue damage. Directly starting a heavy load at full voltage causes a large starting current of up to 5-7 times, with a starting current of 1000A and a starting time of 5-12s. During the starting process, the temperature rises very high, generating considerable thermal stress. The thermal stress will accelerate the cracking of the copper bar and the end ring, affecting the use of the motor. Therefore, a rotor end ring fixing device for a three-phase asynchronous motor is proposed. Summary of the invention

[0004] In view of the problem in the above or prior art that when the motor is frequently started and stopped, considerable thermal stress is generated, which accelerates the cracking of the copper bars and the end rings and affects the use of the motor, the present invention is proposed.

[0005] Therefore, an object of the present invention is to provide a rotor end ring fixing device for a three-phase asynchronous motor.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a rotor end ring fixing device for a three-phase asynchronous motor, comprising a rotor core, a plurality of copper bars are installed on the rotor core, short-circuit rings are installed at both upper and lower ends of the copper bars, an annular sleeve is arranged on the outside of the copper bars, the annular sleeve is between the short-circuit ring and the rotor core, a pressing ring is arranged inside the short-circuit ring and the adjacent annular sleeve, an annular groove is opened on the circumferential inner wall of the pressing ring, and metal plates are clamped on the inner wall of the annular groove at equal intervals.

[0007] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, a rotating shaft is installed at one end of the rotor core.

[0008] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, a plurality of rotor slots are opened on the circumferential outer wall of the rotor core, and the copper bars are all clamped on the inner walls of the corresponding rotor slots.

[0009] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, wherein: the surface of the annular sleeve plate is opened with a strip-shaped opening, and the copper strip is clamped on the inner wall of the strip-shaped opening.

[0010] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, wherein: a plurality of first fixing holes distributed equally are opened on the surface of the short-circuit ring, one end of the first fixing hole extends to the surface of the metal plate, a fixing screw is inserted into the interior of the first fixing hole, and one end of the fixing screw is against the surface of the metal plate.

[0011] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, a plurality of elastic buffer mechanisms are arranged inside the annular groove, and the elastic buffer mechanisms are located between two adjacent metal plates.

[0012] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, the elastic buffer mechanism includes a damping cylinder, which is installed on the surface of the annular sleeve, and the damping cylinder is located between two metal plates. A pressure rod is movably inserted on the top outer wall of the damping cylinder, and a buffer spring is wound around the circumferential outer wall of the damping cylinder and the pressure rod.

[0013] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, a clamping plate is fixedly installed on the surface of the pressure rod, and the clamping plate is slidably clamped on the opposite outer walls of the two metal plates.

[0014] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, wherein: an oil chamber 1 is arranged inside the damping cylinder, an oil chamber 2 is arranged inside the pressure rod, a piston valve is installed at the bottom end of the pressure rod, and the two ends of the piston valve are respectively connected to the oil chamber 1 and the oil chamber 2, and the interiors of the oil chamber 1 and the oil chamber 2 are filled with damping fluid.

[0015] As a preferred solution of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention, wherein: a plurality of second fixing holes distributed equally are opened on the surface of the short-circuit ring, the second fixing holes are located between two adjacent first fixing holes, and limiting rods are inserted on the circumferential inner walls of the second fixing holes, and the bottom ends of the limiting rods are located above the clamping plate.

[0016] The beneficial effects of the rotor end ring fixing device of the three-phase asynchronous motor of the present invention are as follows: as the outer diameter of the motor rotor increases, the centrifugal force to which the rotor end ring is subjected during high-speed rotation also increases. This centrifugal force may cause the fixing structure of the end ring to bear excessive stress. The present invention reinforces and supports the short-circuit ring through a pressure ring, then connects the short-circuit ring and the pressure ring through fixing screws, and arranges a metal plate reinforcement support inside the pressure ring, thereby improving the stability of the short-circuit ring and enhancing its reliability under various working conditions.

[0017] The motor is started and stopped frequently, and directly starting a heavy load at full voltage causes a starting current as high as 5 to 7 times larger, which in turn generates thermal stress and affects the rotor end ring. The present invention provides an elastic buffer mechanism. During the start and stop process of the motor, the elastic buffer mechanism is subjected to temperature changes, the buffer spring is compressed, and thermal stress is formed to compensate for the thermal stress of the rotor end ring itself. The buffer spring is compressed so that the pressure rod is pressed downward into the damping cylinder, and the damping fluid inside the oil chamber one and the oil chamber two flows through the piston valve, so that the elastic potential energy of the buffer spring compression is converted into the energy of the damping force, and the energy of the damping force is then converted into heat and slowly dissipated from the outer wall of the damping cylinder, thereby reducing the thermal stress of the rotor end ring and making the rotor end ring less likely to crack and loosen during use, thereby ensuring the normal use of the rotor end ring and reducing the loss of the motor during the start and stop process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 The figure is a schematic diagram of the overall structure of the rotor end ring fixing device of the three-phase asynchronous motor.

[0020] Figure 2 The figure is a schematic diagram of the rotor core structure of the rotor end ring fixing device of the three-phase asynchronous motor.

[0021] Figure 3 The figure is a schematic diagram of the short-circuit ring structure of the rotor end ring fixing device of the three-phase asynchronous motor.

[0022] Figure 4 The figure is a schematic diagram of the annular sleeve structure of the rotor end ring fixing device of the three-phase asynchronous motor.

[0023] Figure 5 It is a schematic diagram of the partial three-dimensional structure of the rotor end ring fixing device of the three-phase asynchronous motor.

[0024] Figure 6The present invention is a schematic cross-sectional structure diagram of an elastic buffer mechanism of a rotor end ring fixing device of a three-phase asynchronous motor.

[0025] In the figure: 100, rotor core; 101, rotating shaft; 102, rotor slot; 200, copper bar; 300, annular sleeve; 301, strip mouth; 400, short-circuit ring; 401, first fixing hole; 402, second fixing hole; 500, pressure ring; 501, annular groove; 502, metal plate; 503, fixing screw; 600, limit rod; 700, elastic buffer mechanism; 701, damping cylinder; 702, oil chamber one; 703, buffer spring; 704, clamping plate; 705, pressure rod; 706, oil chamber two; 707, piston valve. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0029] Example 1, reference Figures 1 to 5 , is the first embodiment of the present invention, which provides a rotor end ring fixing device for a three-phase asynchronous motor, including a rotor core 100, a plurality of copper bars 200 are installed on the rotor core 100, short-circuit rings 400 are installed at both upper and lower ends of the copper bars 200, an annular sleeve 300 is arranged on the outer side of the copper bars 200, the annular sleeve 300 is between the short-circuit ring 400 and the rotor core 100, a pressing ring 500 is arranged inside the short-circuit ring 400 and the adjacent annular sleeve 300, an annular groove 501 is opened on the circumferential inner wall of the pressing ring 500, and metal plates 502 are equidistantly distributed and clamped on the inner wall of the annular groove 501.

[0030] A pressure ring 500 and a metal plate 502 are provided on the inner side of the short-circuit ring 400, and the pressure ring 500 and the metal plate 502 are used to reinforce the rotor end ring, thereby improving the structural strength of the device, reducing failures caused by vibration and thermal expansion, and making the rotor end ring of the motor less likely to crack, thereby ensuring the normal use of the motor.

[0031] Specifically, a rotating shaft 101 is installed at one end of the rotor core 100 .

[0032] Specifically, a plurality of rotor slots 102 are formed on the circumferential outer wall of the rotor core 100 , and the copper bars 200 are all clamped on the inner walls of the corresponding rotor slots 102 .

[0033] Specifically, the surface of the annular sleeve 300 is provided with a strip-shaped opening 301 , and the copper strip 200 is clamped on the inner wall of the strip-shaped opening 301 .

[0034] The short-circuit ring 400 and the copper bar 301 form a squirrel cage motor, the rotor core 100 serves as a conductor, and the short-circuit ring 400 and the copper bar 301 form a closed conductive loop.

[0035] Example 2, reference Figure 3 and Figure 5 , which is the second embodiment of the present invention. Different from the previous embodiment, a plurality of first fixing holes 401 are opened on the surface of the short-circuit ring 400 and are evenly distributed. One end of the first fixing hole 401 extends to the surface of the metal plate 502. A fixing screw 503 is inserted into the inside of the first fixing hole 401, and one end of the fixing screw 503 is against the surface of the metal plate 502.

[0036] The short-circuit ring 400 is fixed to the metal plate 502 by fixing screws 503, thereby improving the structural strength of the device, reducing failures caused by vibration and thermal expansion, and making the rotor end ring of the motor less likely to crack.

[0037] Example 3, reference Figure 1 , Figure 3 and Figure 6 , which is the third embodiment of the present invention, is different from the previous embodiment in that a plurality of elastic buffer mechanisms 700 are disposed inside the annular groove 501 , and the elastic buffer mechanism 700 is located between two adjacent metal plates 502 .

[0038] The elastic buffer mechanism 700 is used to reduce the thermal stress on the rotor end ring during the start-stop process of the motor.

[0039] Furthermore, the elastic buffer mechanism 700 includes a damping cylinder 701, which is installed on the surface of the annular sleeve 300. The damping cylinder 701 is located between the two metal plates 502. A pressure rod 705 is movably inserted on the top outer wall of the damping cylinder 701, and a buffer spring 703 is wound around the circumferential outer wall of the damping cylinder 701 and the pressure rod 705.

[0040] During the start and stop process of the motor, the elastic buffer mechanism 700 senses the temperature change, causing the buffer spring 703 to compress, and then the pressure rod 705 to press into the damping cylinder 701, transforming the thermal stress and reducing the thermal stress on the rotor end ring.

[0041] Furthermore, a clamping plate 704 is fixedly mounted on the surface of the pressure rod 705 , and the clamping plate 704 is slidably clamped on the opposite outer walls of the two metal plates 502 .

[0042] When the pressure rod 705 is pressed downward, the clamping plate 704 slides stably on the outer walls of the two metal plates 502 to ensure the stability of the elastic buffer mechanism 700 .

[0043] Furthermore, an oil chamber 1 702 is provided inside the damping cylinder 701, an oil chamber 2 706 is provided inside the pressure rod 705, a piston valve 707 is installed at the bottom end of the pressure rod 705, and both ends of the piston valve 707 are respectively connected to the oil chamber 1 702 and the oil chamber 2 706, and the interiors of the oil chamber 1 702 and the oil chamber 2 706 are filled with damping liquid.

[0044] During the downward pressing process, the damping fluid inside the oil chamber 1 702 and the oil chamber 2 706 moves in the piston valve 707, so that the elastic potential energy of the buffer spring 703 is converted into the energy of the damping force.

[0045] Furthermore, a plurality of equally spaced second fixing holes 402 are formed on the surface of the short-circuit ring 400 . The second fixing holes 402 are located between two adjacent first fixing holes 401 . Limiting rods 600 are inserted into the circumferential inner walls of the second fixing holes 402 . The bottom ends of the limiting rods 600 are located above the clamping plate 704 .

[0046] The limiting rod 600 has the effect of blocking and limiting, preventing the clamping plate 704 from moving too much, thereby ensuring the stability of the pressing ring 500.

[0047] In summary, a rotor end ring fixing device for a three-phase asynchronous motor can enhance the structural stability of the device. The pressure exerted by the pressure ring 500 on the short-circuit ring 400 and fixedly connected thereto enhances the overall structural stability of the short-circuit ring 400 and reduces failures caused by vibration and thermal expansion. The uniform pressure distribution of the pressure ring 500 can disperse the stress to which the short-circuit ring 400 is subjected during operation, reduce stress concentration at individual points, and thus reduce the risk of failure. The elastic buffer mechanism 700 can facilitate reducing the influence of thermal stress on the rotor end ring during the start and stop of the motor.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A rotor end ring fixing device for a three-phase asynchronous motor, characterized in that: The invention comprises a rotor core (100), wherein a plurality of copper bars (200) are mounted on the rotor core (100), short-circuit rings (400) are mounted on both upper and lower ends of the copper bars (200), an annular sleeve (300) is arranged on the outer side of the copper bars (200), the annular sleeve (300) is between the short-circuit ring (400) and the rotor core (100), a pressing ring (500) is arranged inside the short-circuit ring (400) and the adjacent annular sleeve (300), an annular groove (501) is formed on the circumferential inner wall of the pressing ring (500), and metal plates (502) are equidistantly distributed and clamped on the inner wall of the annular groove (501).

2. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 1, characterized in that: A rotating shaft (101) is mounted on one end of the rotor core (100).

3. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 1 or 2, characterized in that: A plurality of rotor slots (102) are formed on the circumferential outer wall of the rotor core (100), and the copper bars (200) are all clamped on the inner walls of the corresponding rotor slots (102).

4. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 1, characterized in that: The surface of the annular sleeve (300) is provided with a strip-shaped opening (301), and the copper strip (200) is clamped on the inner wall of the strip-shaped opening (301).

5. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 1, characterized in that: The surface of the short-circuit ring (400) is provided with a plurality of first fixing holes (401) distributed at equal intervals, one end of the first fixing hole (401) extends toward the surface of the metal plate (502), a fixing screw (503) is inserted into the interior of the first fixing hole (401), and one end of the fixing screw (503) abuts against the surface of the metal plate (502).

6. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 5, characterized in that: A plurality of elastic buffer mechanisms (700) are arranged inside the annular groove (501), and the elastic buffer mechanisms (700) are located between two adjacent metal plates (502).

7. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 6, characterized in that: The elastic buffer mechanism (700) comprises a damping cylinder (701), which is mounted on the surface of the annular sleeve (300), and is located between two metal plates (502). A pressure rod (705) is movably inserted on the top outer wall of the damping cylinder (701), and a buffer spring (703) is wound around the circumferential outer walls of the damping cylinder (701) and the pressure rod (705).

8. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 7, characterized in that: A clamping plate (704) is fixedly mounted on the surface of the pressure rod (705), and the clamping plate (704) is slidably clamped on the opposite outer walls of the two metal plates (502).

9. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 8, characterized in that: An oil chamber 1 (702) is disposed inside the damping cylinder (701), an oil chamber 2 (706) is disposed inside the pressure rod (705), a piston valve (707) is installed at the bottom end of the pressure rod (705), and two ends of the piston valve (707) are respectively connected to the oil chamber 1 (702) and the oil chamber 2 (706).

10. The rotor end ring fixing device of a three-phase asynchronous motor according to claim 8 or 9, characterized in that: The surface of the short-circuit ring (400) is provided with a plurality of second fixing holes (402) distributed at equal intervals, the second fixing holes (402) are located between two adjacent first fixing holes (401), and limiting rods (600) are inserted into the circumferential inner walls of the second fixing holes (402), and the bottom ends of the limiting rods (600) are located above the clamping plate (704).

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