A motor startup process protection device

Abstract

The present application discloses a protection device for the starting process of an electric motor in the field of motor protection. Through the cooperation between the coupling device and the protection device, when the starting resistance of the equipment shaft is greater than the designed value, the deformation amount of the buffer rubber pad squeezed by the first clamping block is greater than the designed value. At this time, the relative rotation amount between the first shaft sleeve and the second shaft sleeve is too large, which forces the airbag to undergo excessive torsion. At this time, the gas in the airbag is twisted, the air pressure increases, and the increased air pressure is transmitted to the cylinder, causing the push rod to displace, and then driving the axial slip ring to displace against the elastic force of the tension spring, so that the first ratchet ring is disengaged from the second ratchet ring, and then the power transmission between the electric motor and the equipment shaft is quickly cut off, making the electric motor run idly, achieving timely protection of the electric motor, preventing it from being damaged by overload, with timely and effective protection, having market prospects, and being suitable for popularization and application.

Description

Technical Field

[0001] This application relates to the field of motor protection, and particularly relates to a protection device for the motor starting process. Background Art

[0002] The starting process of a motor is an important process during the motor operation, especially the starting process of an AC asynchronous motor and the asynchronous starting process of a pumped-storage motor when it operates as a motor. The excessive current during the asynchronous starting process of a motor is a drawback that the motor itself cannot overcome. The excessive current during the motor starting process can not only cause excessive voltage drop in the power grid, affecting the normal operation of other motors and electrical equipment connected to the power grid, but also subject the motor itself to a large electromagnetic force impact and pose a risk of overheating the motor windings, thus affecting the operating safety of the motor. Therefore, people always hope that if a fault occurs during the motor starting process, the protection device can be immediately activated to prevent the motor from being damaged.

[0003] The motor comprehensive protector mainly functions to cut off the working power supply in time when the motor experiences phase loss and overcurrent operation, protecting the motor from damage. However, most of the existing motor comprehensive protectors monitor and protect from the current input side. Such protectors ignore the faults on the shaft side of the equipment. When the resistance of the equipment shaft is too large at the initial stage of starting, the motor will also be overloaded at the moment of starting, causing damage to the motor, which has certain potential safety hazards. For this reason, we propose a protection device for the motor starting process to solve the above problems. Summary of the Invention

[0004] The purpose of this application is to design a protection device that automatically cuts off the power transmission when the motor is overloaded, causing the motor to rotate idly, so as to prevent the phenomenon of motor overload damage. Compared with the prior art, a protection device for the motor starting process is provided. Through a coupling device arranged at the output end of the motor and a protection device arranged on the equipment shaft, the coupling device includes a first shaft sleeve sleeved on the output end of the motor, and a plurality of first blocks evenly arranged at equal angles are fixed on the side of the first shaft sleeve away from the motor;

[0005] The protection device includes a second shaft sleeve sleeved on the equipment shaft. An axial sliding ring is slidably connected along the axial direction on the outer side of the second shaft sleeve. A plurality of limiting sliding grooves are evenly arranged at equal angles on the inner side of the axial sliding ring. Limiting sliding rods matching the limiting sliding grooves one by one are arranged on the outer wall of the second shaft sleeve. A rotating ring is rotatably connected to the side of the second shaft sleeve away from the equipment shaft. A limiting bearing seat is arranged on the inner side of the rotating ring. A limiting shaft corresponding to the limiting bearing seat is fixed at the end of the second shaft sleeve;

[0006] On one side of the rotating ring, a plurality of second clamping blocks are fixedly arranged at equal angular intervals. The second clamping blocks are in one-to-one correspondence with the first clamping blocks, and a buffer rubber pad is clamped between the second clamping blocks and the first clamping blocks. On the other side of the rotating ring, a first ratchet ring is fixedly arranged. On one side of the axial sliding ring, a second ratchet ring meshing with the first ratchet ring is provided;

[0007] An airbag is arranged between the first shaft sleeve and the second shaft sleeve. Both ends of the airbag are fixedly connected with the first shaft sleeve and the second shaft sleeve through connecting seats respectively. A cylinder is arranged in the limiting sliding rod. A push rod matching with the cylinder is fixedly arranged on the inner side of the axial sliding ring. A piston is fixedly arranged at the end of the push rod. The cylinder is communicated with the airbag. A tension spring is also clamped between the axial sliding ring and the second shaft sleeve.

[0008] When the starting resistance of the equipment shaft is the designed value, the motor can squeeze the buffer rubber pad through the first clamping block of the first shaft sleeve to deform appropriately, and then sequentially push the second clamping block, the first ratchet ring, the second ratchet ring and the second shaft sleeve to achieve the power transmission of the equipment shaft. When the starting resistance of the equipment shaft is greater than the designed value, the deformation amount of the buffer rubber pad squeezed by the first clamping block is greater than the designed value. At this time, the relative rotation amount between the first shaft sleeve and the second shaft sleeve is too large, which forces the airbag to twist too much. At this time, the gas in the airbag is twisted and the air pressure increases, and the increased air pressure is transmitted to the cylinder, causing the push rod to displace, and then driving the axial sliding ring to displace against the elastic force of the tension spring, so that the first ratchet ring and the second ratchet ring are disengaged, and then the power transmission between the motor and the equipment shaft is quickly cut off, making the motor run idle, achieving timely protection of the motor, preventing it from being damaged by overload, with timely and effective protection, having a market prospect and being suitable for popularization and application.

[0009] Further, the tension spring has an elastic force to drive the axial sliding ring to approach the rotating ring. In the free state of the tension spring, the first ratchet ring and the second ratchet ring are engaged with each other.

[0010] Further, the tooth ends of the first ratchet ring and the second ratchet ring are both flexible structures. When the first ratchet ring rotates clockwise along the output end of the motor, it has a one-way resistance to drive the second ratchet ring to rotate synchronously.

[0011] Further, the thickness of the buffer rubber pad is equal to the relative distance between adjacent first clamping blocks and second clamping blocks, and the maximum compression deformation amount of the buffer rubber pad can be replaced according to the output torque of the motor.

[0012] Further, when the compression deformation amount of the buffer rubber pad is half of the relative gap between the first clamping block and the second clamping block, the air pressure generated by the torsion of the airbag is less than the elastic force of the tension spring.

[0013] Further, when the compression deformation amount of the buffer rubber pad is greater than half of the relative gap between the first clamping block and the second clamping block, the air pressure generated by the torsion of the airbag is greater than the elastic force of the tension spring.

[0014] Further, the airbag is filled with saturated gas, and the airbag is a rubber structure with a low elastic coefficient. The airbag does not expand after being filled with saturated gas.

[0015] Further, the protective air pressure filled in the airbag is equal to the elastic force of the tension spring.

[0016] Further, limiting blocks are fixed inside both the first shaft sleeve and the second shaft sleeve, and limiting slots matching the limiting blocks are provided on the output end of the motor and the equipment shaft.

[0017] Further, the cylinders are arranged at intervals on the limiting slide rod, that is, the number of cylinders is one-half of the number of limiting slide rods.

[0018] Compared with the prior art, the advantages of the present application are as follows:

[0019] (1) Through the mutual cooperation between the coupling device with the first shaft sleeve and the first clamping block and the protection device with the second shaft sleeve, the limiting slide rod, the cylinder, the limiting shaft, the rotating ring, the second clamping block, the first ratchet ring, the limiting bearing seat, the axial sliding ring, the second ratchet ring, the push rod, the limiting chute, and the tension spring, when the starting resistance of the equipment shaft is the designed value, the motor can squeeze the buffer rubber pad through the first clamping block of the first shaft sleeve to cause appropriate deformation, and then sequentially push the second clamping block, the first ratchet ring, the second ratchet ring, and the second shaft sleeve to achieve the power transmission of the equipment shaft. When the starting resistance of the equipment shaft is greater than the designed value, the deformation amount of the buffer rubber pad squeezed by the first clamping block is greater than the designed value. At this time, the relative rotation amount between the first shaft sleeve and the second shaft sleeve is too large, that is, it forces the airbag to twist too much. At this time, the gas in the airbag is twisted and the air pressure increases, and the increased air pressure is transmitted to the cylinder, causing the push rod to displace, and then driving the axial sliding ring to displace against the elastic force of the tension spring, so that the first ratchet ring and the second ratchet ring are disengaged, and then quickly cut off the power transmission between the motor and the equipment shaft, making the motor idle, achieving timely protection of the motor, preventing it from being damaged by overload, with timely and effective protection, having market prospects, and being suitable for popularization and application.

[0020] (2) Through the structural design of the first ratchet ring and the second ratchet ring with flexible tooth ends, when the motor drives clockwise with a normal torque, the first ratchet ring and the second ratchet ring are aligned, and then the purpose of driving the equipment shaft to rotate is achieved. When the motor has a misoperation of counterclockwise reverse rotation, the first ratchet ring and the second ratchet ring do not have an alignment resistance. At the same time, the rotation of the first ratchet ring will, through the one-way resistance of the ratchet teeth, push the second ratchet ring to displace against the tension spring, and then achieve the protection effect of preventing reverse rotation. At the same time, when the resistance of the equipment shaft is too large and the second ratchet ring actively moves away from the first ratchet ring, the flexible tooth ends can be used for a smooth process to prevent the second ratchet ring and the first ratchet ring from engaging when they are disengaged, effectively protecting the service life of the first ratchet ring and the second ratchet ring.

[0021] (3) Through the structural design of replaceable buffer rubber pads, the triggering condition of the protection device can be adjusted to meet the protection requirements of different torque motors, improving the adaptability. At the same time, when the resistance transmitted by the equipment shaft is within the designed range, power transmission can be achieved by the first block and the second block squeezing the buffer rubber pads. Combining with the deformation of the buffer rubber pads, soft start of the motor can also be realized, further enhancing the protection of the motor.

[0022] (4) Through the design of the first shaft sleeve and the second shaft sleeve with limit blocks and the output end of the motor and the equipment shaft with limit slots, the first shaft sleeve and the second shaft sleeve are tightly sleeved with the output end of the motor and the equipment shaft, and relative rotation in the circumferential direction is not likely to occur, improving the transmission stability of the driving force.

[0023] (5) Through the design of the number of cylinders and limit slide bars, some limit slide bars are of solid structure, thus effectively improving the circumferential structural connection strength between the axial slip ring and the second shaft sleeve, making deformation less likely to occur and increasing the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of the present application;

[0025] Figure 2 is a front structural schematic diagram of the coupling device and the protection device proposed in the present application;

[0026] Figure 3 is a side structural schematic diagram of the coupling device and the protection device proposed in the present application;

[0027] Figure 4 is an exploded structural schematic diagram of the coupling device proposed in the present application;

[0028] Figure 5 is an exploded structural schematic diagram of the protection device proposed in the present application;

[0029] Figure 6 is a structural schematic diagram of the second shaft sleeve proposed in the present application;

[0030] Figure 7 is a structural schematic diagram of the axial slip ring proposed in the present application;

[0031] Figure 8 is a sectional structural schematic diagram of the coupling device and the protection device proposed in the present application;

[0032] Figure 9 is an internal structural schematic diagram of the protection device under normal working conditions proposed in the present application;

[0033] Figure 10 is an internal structural schematic diagram of the protection device under abnormal working conditions proposed in the present application.

[0034] Description of reference numerals in the figure:

[0035] Motor 1, equipment shaft 2, coupling device 3, first bushing 31, first clamping block 32, protection device 4, second bushing 41, limit slide bar 411, cylinder 412, limit shaft 413, rotating ring 42, second clamping block 421, first ratchet ring 422, limit bearing seat 423, axial slip ring 43, second ratchet ring 431, push rod 432, limit chute 433, tension spring 44, limit block 5, buffer rubber pad 6, airbag 7, connecting seat 71. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0037] Embodiment 1:

[0038] The present application discloses a protection device for the starting process of a motor. Please refer to Figure 1-10 , which includes a coupling device 3 provided at the output end of the motor 1 and a protection device 4 provided on the equipment shaft 2. The coupling device 3 includes a first bushing 31 sleeved on the output end of the motor 1, and a plurality of first clamping blocks 32 evenly arranged at equal angles are fixed on the side of the first bushing 31 away from the motor 1;

[0039] The protection device 4 includes a second bushing 41 sleeved on the equipment shaft 2. An axial slip ring 43 is slidably connected along the axial direction on the outer side of the second bushing 41. A plurality of limit chutes 433 are evenly arranged at equal angles on the inner side of the axial slip ring 43. Limit slide bars 411 matching the limit chutes 433 one by one are provided on the outer wall of the second bushing 41. A rotating ring 42 is rotatably connected to the side of the second bushing 41 away from the equipment shaft 2. A limit bearing seat 423 is provided on the inner side of the rotating ring 42, and a limit shaft 413 corresponding to the limit bearing seat 423 is fixed at the end of the second bushing 41;

[0040] A plurality of second clamping blocks 421 evenly arranged at equal angles are fixed on one side of the rotating ring 42. The second clamping blocks 421 match the first clamping blocks 32 one by one. A buffer rubber pad 6 is clamped between the second clamping blocks 421 and the first clamping blocks 32. A first ratchet ring 422 is fixed on the other side of the rotating ring 42, and a second ratchet ring 431 meshing with the first ratchet ring 422 is provided on one side of the axial slip ring 43;

[0041] An airbag 7 is provided between the first bushing 31 and the second bushing 41. Both ends of the airbag 7 are fixedly connected to the first bushing 31 and the second bushing 41 through connecting seats 71 respectively. A cylinder 412 is provided inside the limit slide bar 411. A push rod 432 matching the cylinder 412 is fixedly installed on the inner side of the axial sliding ring 43. A piston is fixedly installed at the end of the push rod 432. The cylinder 412 is communicated with the airbag 7. A tension spring 44 is clamped between the axial sliding ring 43 and the second bushing 41.

[0042] Through the mutual cooperation between the coupling device 3 with the first bushing 31 and the first clamping block 32 and the protection device 4 with the second bushing 41, the limit slide bar 411, the cylinder 412, the limit shaft 413, the rotating ring 42, the second clamping block 421, the first ratchet ring 422, the limit bearing seat 423, the axial sliding ring 43, the second ratchet ring 431, the push rod 432, the limit chute 433, and the tension spring 44 in the present invention, when the starting resistance of the equipment shaft 2 is the designed value, the motor 1 can cause an appropriate deformation of the buffer rubber pad 6 by squeezing the first clamping block 32 of the first bushing 31, and then sequentially push the second clamping block 421, the first ratchet ring 422, the second ratchet ring 431 and the second bushing 41 in sequence to achieve the power transmission of the equipment shaft 2. When the starting resistance of the equipment shaft 2 is greater than the designed value, the deformation amount of the buffer rubber pad 6 squeezed by the first clamping block 32 is greater than the designed value. At this time, the relative rotation amount between the first bushing 31 and the second bushing 41 is too large, that is, it forces the airbag 7 to undergo excessive torsion. At this time, the gas in the airbag 7 is twisted, the air pressure increases, and the increased air pressure is transmitted to the cylinder 412, causing the push rod 432 to displace, and then driving the axial sliding ring 43 to displace against the elastic force of the tension spring 44, so that the first ratchet ring 422 is disengaged from the second ratchet ring 431, and then quickly cuts off the power transmission between the motor 1 and the equipment shaft 2, making the motor 1 idle, achieving timely protection of the motor 1 to prevent it from being damaged by overload, with timely and effective protection, having market prospects and being suitable for popularization and application.

[0043] It should be noted that in this embodiment, the tension spring 44 has an elastic force that drives the axial sliding ring 43 to approach the rotating ring 42. In the free state of the tension spring 44, the first ratchet ring 422 and the second ratchet ring 431 are engaged with each other. The tooth ends of both the first ratchet ring 422 and the second ratchet ring 431 are flexible structures. When the first ratchet ring 422 rotates clockwise along the output end of the motor 1, it has a one-way resistance that drives the second ratchet ring 431 to rotate synchronously.

[0044] Through the structural design of the first ratchet ring 422 with flexible tooth ends and the second ratchet ring 431, when the motor 1 drives clockwise with a normal torque, the first ratchet ring 422 and the second ratchet ring 431 are engaged, thereby achieving the purpose of driving the rotation of the equipment shaft 2. When the motor 1 has a misoperation of counterclockwise reverse rotation, the first ratchet ring 422 and the second ratchet ring 431 do not have an engagement resistance. At the same time, the rotation of the first ratchet ring 422 will, through the one-way blocking action of the ratchets, push the second ratchet ring 431 to overcome the displacement of the tension spring 44, thereby achieving the protective effect of preventing reverse rotation. At the same time, when the resistance of the equipment shaft 2 is too large and the second ratchet ring 431 actively moves away from the first ratchet ring 422, the flexible tooth ends can be used to smooth the process, so as to prevent the occurrence of tooth jamming when the second ratchet ring 431 and the first ratchet ring 422 are disengaged, effectively protecting the service life of the first ratchet ring 422 and the second ratchet ring 431.

[0045] Further, please refer to Figure 1-10 , the thickness of the buffer rubber pad 6 is equal to the relative spacing between the adjacent first clamping block 32 and the second clamping block 421. The maximum compression deformation amount of the buffer rubber pad 6 can be replaced according to the output torque of the motor 1. When the compression deformation amount of the buffer rubber pad 6 is half of the relative gap between the first clamping block 32 and the second clamping block 421, the air pressure generated by the torsion of the airbag 7 is less than the elastic force of the tension spring 44. When the compression deformation amount of the buffer rubber pad 6 is greater than half of the relative gap between the first clamping block 32 and the second clamping block 421, the air pressure generated by the torsion of the airbag 7 is greater than the elastic force of the tension spring 44.

[0046] Through the structural design of the replaceable buffer rubber pad 6, the triggering condition of the protection device 4 can be adjusted to meet the protection use of motors 1 with different torques, increasing the adaptability. At the same time, when the resistance transmitted by the equipment shaft 2 is within the design range, the power transmission can be realized by the first clamping block 32 and the second clamping block 421 squeezing the buffer rubber pad 6. Combining with the deformation amount of the buffer rubber pad 6, the soft start of the motor can also be realized, further enhancing the protection of the motor.

[0047] Specifically, please refer to Figure 1-10 , the airbag 7 is filled with saturated gas. The airbag 7 is a rubber structure with a low elastic coefficient. The airbag 7 does not expand after being filled with saturated gas. The protection air pressure filled in the airbag 7 is equal to the elastic force of the tension spring 44.

[0048] Specifically, limit blocks 5 are fixedly arranged inside both the first shaft sleeve 31 and the second shaft sleeve 41. Limit slots matching the limit blocks 5 are arranged on both the output end of the motor 1 and the equipment shaft 2.

[0049] Through the design of the first bushing 31 and the second bushing 41 with limit blocks 5, the output end of the motor 1 with a limit slot, and the equipment shaft 2, the first bushing 31 and the second bushing 41 are tightly sleeved with the output end of the motor 1 and the equipment shaft 2, and it is not easy to have relative rotation in the circumferential direction, improving the transmission stability of the driving force.

[0050] Specifically, please refer to Figure 1-10 , the cylinders 412 are arranged at intervals on the limit slide bars 411, that is, the number of cylinders 412 is one-half of the number of limit slide bars 411.

[0051] Through the design of the number of cylinders 412 and limit slide bars 411, part of the limit slide bars 411 are of solid structure, thus effectively improving the circumferential structural connection strength between the axial slip ring 43 and the second bushing 41, not easy to deform, and increasing the service life.

[0052] The above is only the preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application, according to the technical solution of the present application and its improved concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present application.

Claims

1. A protection device for the starting process of an electric motor, comprising a coupling device (3) arranged at the output end of the electric motor (1) and a protection device (4) arranged on the equipment shaft (2), characterized in that, The coupling device (3) includes a first bushing (31) sleeved on the output end of the motor (1), and a plurality of first clamping blocks (32) evenly arranged at equal angles are fixed on the side of the first bushing (31) away from the motor (1); The protection device (4) includes a second bushing (41) sleeved on the equipment shaft (2). An axial sliding ring (43) is slidably connected along the axial direction on the outer side of the second bushing (41). A plurality of limiting sliding grooves (433) are evenly arranged at equal angles on the inner side of the axial sliding ring (43). A limiting sliding rod (411) matching the limiting sliding grooves (433) one by one is arranged on the outer wall of the second bushing (41). A rotating ring (42) is rotatably connected to the side of the second bushing (41) away from the equipment shaft (2). A limiting bearing seat (423) is arranged on the inner side of the rotating ring (42). A limiting shaft (413) corresponding to the limiting bearing seat (423) is fixed at the end of the second bushing (41); A plurality of second clamping blocks (421) evenly arranged at equal angles are fixed on one side of the rotating ring (42). The second clamping blocks (421) are matched with the first clamping blocks (32) one by one. A buffer rubber pad (6) is clamped between the second clamping blocks (421) and the first clamping blocks (32). A first ratchet ring (422) is fixed on the other side of the rotating ring (42). A second ratchet ring (431) meshing with the first ratchet ring (422) is arranged on one side of the axial sliding ring (43); An airbag (7) is arranged between the first bushing (31) and the second bushing (41). The two ends of the airbag (7) are respectively fixedly connected with the first bushing (31) and the second bushing (41) through connecting seats (71). A cylinder (412) is arranged in the limiting sliding rod (411). A push rod (432) matching the cylinder (412) is fixed on the inner side of the axial sliding ring (43). A piston is fixed at the end of the push rod (432). The cylinder (412) is communicated with the airbag (7). A tension spring (44) is also clamped between the axial sliding ring (43) and the second bushing (41).

2. The protection device for the motor starting process according to claim 1, characterized in that, The tension spring (44) has an elastic force to drive the axial sliding ring (43) to approach the rotating ring (42). In the free state of the tension spring (44), the first ratchet ring (422) and the second ratchet ring (431) are engaged with each other.

3. A motor starting process protection device according to claim 1, characterized in that, The tooth ends of the first ratchet ring (422) and the second ratchet ring (431) are both flexible structures. When the first ratchet ring (422) rotates clockwise along the output end of the motor (1), it has a one-way resistance to drive the second ratchet ring (431) to rotate synchronously.

4. A protection device for the starting process of an electric motor according to claim 1, characterized in that, The thickness of the buffer rubber pad (6) is equal to the relative distance between adjacent first clamping blocks (32) and second clamping blocks (421). The maximum compression deformation amount of the buffer rubber pad (6) can be replaced according to the output torque of the motor (1).

5. The protection device for the motor starting process according to claim 4, characterized in that, When the compression deformation amount of the buffer rubber pad (6) is half of the relative gap between the first clamping block (32) and the second clamping block (421), the air pressure generated by the torsion of the airbag (7) is less than the elastic force of the tension spring (44).

6. The protection device for the motor starting process according to claim 4, characterized in that, When the compression deformation amount of the buffer rubber pad (6) is greater than half of the relative gap between the first clamping block (32) and the second clamping block (421), the air pressure generated by the torsion of the airbag (7) is greater than the elastic force of the tension spring (44).

7. A motor starting process protection device according to claim 1, characterized in that, The airbag (7) is filled with a saturated gas, the airbag (7) is a rubber structure with a low elastic coefficient, and the airbag (7) does not expand after being filled with the saturated gas.

8. A protection device for the starting process of an electric motor according to claim 1, characterized in that, The protective air pressure filled in the airbag (7) is equal to the elastic force of the tension spring (44).

9. The protection device for the motor starting process according to claim 1, characterized in that Limit blocks (5) are fixedly arranged in both the first shaft sleeve (31) and the second shaft sleeve (41), and limit slots matching the limit blocks (5) are arranged on the output end of the motor (1) and the equipment shaft (2).

10. A motor starting process protection device according to claim 1, characterized in that, The cylinders (412) are arranged at intervals on the limit slide rods (411), that is, the number of the cylinders (412) is half of the number of the limit slide rods (411).

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