阅读说明：本技术 泵体组件、涡旋压缩机 (Pump body subassembly, scroll compressor ) 是由 毕远航 徐嘉 刘雷 曲成林 蒋云鹏 杨诚 于 2021-09-01 设计创作，主要内容包括：本发明提供一种泵体组件、涡旋压缩机,其中的泵体组件,包括上支架、曲轴、动涡旋盘、静涡旋盘,所述上支架套装于所述曲轴的外周,所述曲轴上构造有中心油道,所述上支架上构造有储油腔,所述中心油道能够将压缩机机壳底部油池中的润滑油输送至所述储油腔内,还包括泵油组件,所述上支架上还构造有第一输油通道,所述泵油组件能够将所述储油腔内的润滑油经由所述第一输油通道输送至所述动涡旋盘与所述静涡旋盘的摩擦位置。根据本发明,通过单独设置所述泵油组件,将所述储油腔内的润滑油泵送至所述摩擦位置,从而保证了所述泵体组件中的摩擦副能够被充分润滑,从而提升压缩机的整机性能及系统可靠性,同时也能够降低压缩机的运行噪音。(The invention provides a pump body assembly and a scroll compressor, wherein the pump body assembly comprises an upper bracket, a crankshaft, a movable scroll and a fixed scroll, the upper bracket is sleeved on the periphery of the crankshaft, a central oil duct is formed on the crankshaft, an oil storage cavity is formed on the upper bracket, the central oil duct can convey lubricating oil in an oil pool at the bottom of a compressor shell into the oil storage cavity, the pump body assembly also comprises an oil pumping assembly, a first oil conveying channel is formed on the upper bracket, and the oil pumping assembly can convey the lubricating oil in the oil storage cavity to the friction position of the movable scroll and the fixed scroll through the first oil conveying channel. According to the invention, the lubricating oil in the oil storage cavity is pumped to the friction position by independently arranging the oil pumping assembly, so that the friction pair in the pump body assembly can be fully lubricated, the overall performance and the system reliability of the compressor are improved, and the running noise of the compressor can be reduced.)

1. The pump body assembly comprises an upper support (1), a crankshaft (2), a movable scroll (3) and a fixed scroll (4), wherein the upper support (1) is sleeved on the periphery of the crankshaft (2), a central oil duct (21) is constructed on the crankshaft (2), an oil storage cavity (11) is constructed on the upper support (1), lubricating oil in an oil pool at the bottom of a compressor shell (100) can be conveyed into the oil storage cavity (11) through the central oil duct (21), the pump body assembly is characterized by further comprising an oil pumping assembly, a first oil conveying channel is further constructed on the upper support (1), and the lubricating oil in the oil storage cavity (11) can be conveyed to the friction position of the movable scroll (3) and the fixed scroll (4) through the first oil conveying channel by the oil pumping assembly.

2. Pump body assembly according to claim 1, characterized in that the oil pumping assembly comprises a rotary drive (51), a piston rod (52), the rotary driving member (51) is sleeved on the crankshaft (2) to rotate along with the rotation of the crankshaft (2), the first oil delivery channel comprises a first oil channel (61), one end of the piston rod (52) is inserted into the first oil channel (61), the other end of the piston rod (52) is connected with the rotary driving piece (51), the piston rod (52) is capable of being driven by the rotary drive (51) to reciprocate linearly in the extending direction of the first oil passage (61) when the rotary drive (51) rotates, so as to suck the lubricating oil in the oil storage chamber (11) into the first oil delivery channel and press the lubricating oil entering the first oil delivery channel into the friction position.

3. The pump block assembly according to claim 2, wherein the rotary drive member (51) includes a connection pad (511) and a flange (512) at a side of the connection pad (511) facing the upper bracket (1), a height of the flange (512) smoothly changes between a preset maximum height and a preset minimum height in a circumferential direction of the connection pad (511), the rotary drive member (51) is sleeved with the crankshaft (2) through the connection pad (511), and the other end of the piston rod (52) is connected with a first end face of the flange (512) facing the upper bracket (1).

4. The pump body assembly according to claim 3, characterized in that the other end of the piston rod (52) is configured with a sliding slot (521), the first end face being inside the sliding slot (521).

5. The pump body assembly according to claim 4, characterized in that a sliding member (513) is provided between the runner (521) and the flange (512).

6. The pump body assembly according to claim 3, characterized in that said coupling disc (511) is provided with an oil drain hole (514); and/or a balance block (515) is arranged on the connecting disc (511).

7. The pump block assembly according to claim 2, characterized in that it further comprises a piston rod holder (53) fixedly connected to said upper bracket (1) and having a through hole formed therein, said piston rod (52) passing through said through hole and being movable along the axial direction of said through hole; and/or the one end of the piston rod (52) is sleeved with a sealing ring (54).

8. The pump body assembly according to claim 2, wherein the first oil delivery channel further comprises a second oil passage (62), one end of the second oil passage (62) is communicated with the first oil passage (61), the other end of the second oil passage (62) is communicated with the oil storage chamber (11), and a first one-way valve (71) is arranged in the second oil passage (62) to ensure that lubricating oil in the oil storage chamber (11) enters the first oil delivery channel in a one-way manner.

9. The pump body assembly according to claim 8, wherein the first oil delivery passage further includes a third oil passage (63), one end of the third oil passage (63) communicates with the first oil passage (61), and the other end of the third oil passage (63) communicates with a second oil delivery passage (64) provided on the fixed scroll (4).

10. The pump block assembly according to claim 9, characterized in that a second one-way valve (72) is arranged in the third oil channel (63) to ensure one-way entry of the lubricating oil in the first oil delivery channel into the second oil delivery channel (64); and/or the second oil delivery passage (64) is communicated with a buffer space (200), and the buffer space (200) is a space between the top of the compressor shell (100) and the fixed scroll (4).

11. The pump body assembly according to any one of claims 1 to 10, wherein the upper bracket (1) is further configured with a first air flow passage, a gas-liquid separation component is arranged in the first air flow passage, the mixed air flow in the buffer space (200) can enter the first air flow passage, the separation of the lubricating oil and the refrigerant air flow is realized under the action of the gas-liquid separation component, and the separated air flow is discharged through an exhaust port of the compressor casing (100).

12. The pump block assembly according to claim 11, wherein a third oil delivery channel (65) is further formed in the upper bracket (1), and the lubricating oil separated in the first air flow channel can enter the oil storage chamber (11) through the third oil delivery channel (65).

13. The pump body assembly according to claim 11, wherein the gas-liquid separation member includes a filter assembly (81) and an air pipe (82), the filter assembly (81) and the air pipe (82) are respectively located upstream and downstream of a flow direction of the refrigerant air flow, and an inlet of the air pipe (82) has a height higher than an outlet of the first air flow passage.

14. A scroll compressor including a pump body assembly according to any one of claims 1 to 13.

Technical Field

The invention belongs to the technical field of compressor manufacturing, and particularly relates to a pump body assembly and a scroll compressor.

Background

The scroll compressor mainly comprises six major components of a static scroll, a movable scroll, an upper support, a lower support, a cross slip ring and a crankshaft, in order to ensure that the compressor can stably and reliably operate, friction pairs among all parts must be effectively lubricated, and particularly all friction pairs generated between the movable and static scrolls of the compressor are caused by the following reasons: 1. from the angle of theoretical analysis, the area occupation ratio of the end face friction pair of the movable vortex disc and the fixed vortex disc is the largest, and the movable vortex disc and the fixed vortex disc are lubricated and sealed by an oil film under the action of a plurality of forces such as radial force, axial force and tangential gas force, so that whether the movable vortex disc and the fixed vortex disc are effectively lubricated is crucial; 2. from the angle of dissection of the actual after-sale abnormal machine, the problem of the abnormal machine is that the abnormal problem occurs to the movable and static discs with high probability, most of the abnormal phenomena of the movable and static discs are oil shortage, the end faces of the movable disc and the tooth tops and the tooth bottoms of the movable disc are abraded in a large area, a phosphorization layer of the movable disc falls off, and the end faces of the movable disc can be thinned by hundreds of microns in a whole in severe condition. In conclusion, the friction pair between the movable disc and the static disc is well lubricated, and the compressor can stably and reliably run with high probability. In order to effectively lubricate the movable and static discs, the end faces of the movable and static discs and the refrigerating oil (namely lubricating oil) in a cavity formed by the end faces are enough, but in the running process of the compressor, a refrigerant enters the cavity compressor to be fully mixed with enough lubricating oil, the refrigerant is discharged out of the compressor and enters the multi-split system to carry out refrigerating and heating circulation, the oil carrying rate is increased, and then a long connecting pipe is arranged, the lubricating oil cannot flow back into the compressor, so that the oil shortage in a single machine of the compressor can be caused, each friction pair cannot be well lubricated, the compressor is abnormal, and the performance, the noise and the reliability of the whole system cannot meet the requirements.

Scroll compressor utilizes the oil pump to carry out the fuel feeding, and under the drive of motor, the bent axle drives the oil pump rotation and inhales oil, and lubricating oil reaches the bent axle top along bent axle axial through hole upward movement, and lubricating oil lubrication driving disc bearing gets into the back pressure chamber, and back pressure chamber oil bath is full of the back, and two tunnel movements of lubricated oil content branch: get into the cavity all the way, the quiet vortex dish of lubricated slip flows back to the sheet metal component along the inside radial passage that is equipped with of upper bracket all the way to get back to in the middle of the compressor bottom oil bath (green arrow in the figure shows), oil mass is sufficient in the compressor is guaranteed in this circulation. Fig. 1 below is an internal oil passage diagram of the scroll compressor.

The compressor is equivalent to the heart part in the whole refrigerating system, and whether the compressor is reliable or not determines the service life and the performance index of the matching system. The influence of the oil supply quantity and the oil circulation rate of the compressor on the performance, the noise and the reliability of single machine and system matching becomes a competitive key technical parameter in the industry, and the reliability of the compressor can be greatly improved by increasing the oil quantity of the end face and the inner part of the movable and static discs and reducing the oil circulation rate of the compressor under the high-frequency operation of the compressor. The first phenomenon: along with the increase of the rotating speed of the compressor, the relative movement speed of the movable and static discs is high, the temperature of the end face and the inner part of the cavity is high, more lubricating oil is required to be lubricated in a large area, and a large amount of heat in the compression cavity is taken away, so that the friction pair between the movable and static discs is well lubricated, the deformation of the movable and static discs is reduced, and the compressor can run stably and reliably. A second phenomenon: sufficient lubricating oil and refrigerant are fully mixed and discharged out of the compressor body, so that the lubricating oil is lost, the compressor is abnormally abraded, oil in the system can influence the heat exchange of a condenser and an evaporator, and the whole capacity of the system is reduced.

Disclosure of Invention

Therefore, the invention provides a pump body assembly and a scroll compressor, which can overcome the defect that the performance, noise and reliability of the whole compressor cannot meet the requirements due to insufficient lubrication of a movable scroll and a fixed scroll in the related technology.

In order to solve the above problems, the present invention provides a pump body assembly, which includes an upper bracket, a crankshaft, a movable scroll, a stationary scroll, and a pumping assembly, wherein the upper bracket is sleeved on an outer periphery of the crankshaft, the crankshaft is configured with a central oil passage, the upper bracket is configured with an oil storage cavity, the central oil passage is capable of transporting lubricating oil in an oil pool at a bottom of a compressor housing to the oil storage cavity, the pumping assembly is further configured with a first oil transportation channel, and the pumping assembly is capable of transporting the lubricating oil in the oil storage cavity to a friction position between the movable scroll and the stationary scroll through the first oil transportation channel.

In some embodiments, the oil pumping assembly includes a rotary driving member and a piston rod, the rotary driving member is sleeved on the crankshaft to rotate along with the rotation of the crankshaft, the first oil delivery channel includes a first oil passage, one end of the piston rod is inserted into the first oil passage, the other end of the piston rod is connected to the rotary driving member, and the piston rod can be driven by the rotary driving member to reciprocate linearly along the extending direction of the first oil passage when the rotary driving member rotates, so as to suck the lubricating oil in the oil storage cavity into the first oil delivery channel and press the lubricating oil entering the first oil delivery channel into the friction position.

In some embodiments, the rotary driving member includes a connecting disc and a flange at a side of the connecting disc facing the upper bracket, a height of the flange smoothly changes between a preset maximum height and a preset minimum height in a circumferential direction of the connecting disc, the rotary driving member is sleeved with the crankshaft through the connecting disc, and the other end of the piston rod is connected with a first end face of the flange facing the upper bracket.

In some embodiments, the other end of the piston rod is configured with a sliding groove, the first end face being within the sliding groove.

In some embodiments, a sliding member is disposed between the runner and the flange.

In some embodiments, an oil drain hole is configured on the connection disc; and/or a balance block is arranged on the connecting disc.

In some embodiments, the pump body assembly further comprises a piston rod fixing frame fixedly connected with the upper bracket, a through hole is formed in the piston rod fixing frame, and the piston rod penetrates through the through hole and can move along the axial direction of the through hole; and/or the one end of the piston rod is sleeved with a sealing ring.

In some embodiments, the first oil delivery channel further includes a second oil passage, one end of the second oil passage is communicated with the first oil passage, the other end of the second oil passage is communicated with the oil storage cavity, and a first check valve is arranged in the second oil passage to ensure that the lubricating oil in the oil storage cavity enters the first oil delivery channel in a one-way manner.

In some embodiments, the first oil delivery passage further includes a third oil passage, one end of which communicates with the first oil passage, and the other end of which communicates with a second oil delivery passage provided on the fixed scroll.

In some embodiments, a second check valve is arranged in the third oil passage to ensure that the lubricating oil in the first oil delivery passage enters the second oil delivery passage in a one-way mode; and/or the second oil delivery channel is communicated with a buffer space, and the buffer space is a space between the top of the compressor shell and the fixed scroll.

In some embodiments, the upper bracket is further configured with a first air flow passage, a gas-liquid separation part is arranged in the first air flow passage, the mixed air flow in the buffer space can enter the first air flow passage, the separation of the lubricating oil and the refrigerant air flow is realized under the action of the gas-liquid separation part, and the separated air flow is discharged through an exhaust port of the compressor shell.

In some embodiments, a third oil delivery channel is further configured on the upper bracket, and the lubricating oil separated from the first air flow channel can enter the oil storage chamber through the third oil delivery channel.

In some embodiments, the gas-liquid separation component includes a filter screen assembly and a gas pipe, the filter screen assembly and the gas pipe are respectively located at the upstream and the downstream of the flow direction of the refrigerant gas flow, and the height of the gas inlet of the gas pipe is higher than the height of the outlet of the first gas flow passage.

The invention also provides a scroll compressor which comprises the pump body assembly.

According to the pump body assembly and the scroll compressor, the lubricating oil in the oil storage cavity is pumped to the friction position through the oil pumping assembly, so that the friction pair in the pump body assembly can be fully lubricated, the overall performance and the system reliability of the compressor are improved, and the running noise of the compressor can be reduced.

Drawings

FIG. 1 is a schematic perspective view of a pump body assembly according to an embodiment of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic perspective view of the rotary drive member of FIG. 1;

FIG. 4 is a schematic diagram of a first check valve and a second check valve in an embodiment of the present invention;

fig. 5 is a schematic perspective view of a piston rod according to an embodiment of the present invention;

FIG. 6 is a schematic perspective view of a screen assembly according to an embodiment of the present invention;

FIG. 7 is a schematic view of the internal structure of a scroll compressor according to another embodiment of the present invention, in which arrows show the flow direction of the lubricant and the mixed flow of the refrigerant and the lubricant;

fig. 8 is a partial enlarged view of fig. 7 at B.

The reference numerals are represented as:

1. an upper bracket; 11. an oil storage chamber; 2. a crankshaft; 21. a central oil passage; 3. a movable scroll; 4. a fixed scroll; 51. a rotary drive member; 511. a connecting disc; 512. a flange; 513. a sliding member; 514. an oil drain hole; 515. a counterbalance; 52. a piston rod; 521. a chute; 522. a seal ring clamping groove; 53. a piston rod fixing frame; 54. a seal ring; 61. a first oil passage; 62. a second oil passage; 63. a third oil passage; 64. a second oil delivery passage; 65. a third oil delivery passage; 71. a first check valve; 711. a valve core; 712. a guide bar; 713. an oil outlet hole; 72. a second one-way valve; 81. a screen assembly; 811. a screen support; 812. filtering with a screen; 82. an air tube; 100. a compressor housing; 200. a buffer space; 301. a motor rotor; 302. a motor stator; 303. and a lower bracket.

Detailed Description

Referring to fig. 1 to 8 in combination, according to an embodiment of the present invention, there is provided a pump body assembly, including an upper bracket 1, a crankshaft 2, a movable scroll 3, and a fixed scroll 4, where the upper bracket 1 is sleeved on an outer periphery of the crankshaft 2, the crankshaft 2 is configured with a central oil passage 21, the lubricating oil in an oil pool at a bottom of a compressor casing 100 can be pumped toward one side of the movable scroll 3 and the fixed scroll 4 along an axial direction of the crankshaft 2, the upper bracket 1 is configured with an oil storage chamber 11, specifically, the oil storage chamber 11 may be an annular region surrounding the crankshaft 2, the central oil passage 21 can also transport the lubricating oil in the oil pool at the bottom of the compressor casing 100 into the oil storage chamber 11, the pump body assembly further includes a pump oil assembly, the upper bracket 1 is further configured with a first oil transport passage, and the pump oil assembly can transport the lubricating oil in the oil storage chamber 11 to the movable scroll 3 and the fixed scroll 3 through the first oil transport passage The friction position of the fixed scroll 4 may be, for example, specifically a mating surface (including a wrap provided on each of the mating surfaces and a base provided on each of the mating surfaces) where the movable scroll 3 and the fixed scroll 4 are in contact with each other, a contact surface between the movable scroll 3 and the upper bracket 1, or an abrasion-resistant layer between the upper bracket 1 and the movable scroll 3. In the technical scheme, the oil pumping assembly is independently arranged to pump the lubricating oil in the oil storage cavity 11 to the friction position, so that the friction pair in the pump body assembly can be fully lubricated, the overall performance and the system reliability of the compressor are improved, and the running noise of the compressor can be reduced.

In some embodiments, the oil pumping assembly includes a rotary driving member 51 and a piston rod 52, the rotary driving member 51 is sleeved on the crankshaft 2 to rotate along with the rotation of the crankshaft 2, the first oil delivery channel includes a first oil passage 61, one end of the piston rod 52 is inserted into the first oil passage 61, the other end of the piston rod 52 is connected to the rotary driving member 51, and the piston rod 52 can be driven by the rotary driving member 51 to reciprocate linearly along the extending direction of the first oil passage 61 when the rotary driving member 51 rotates, so as to suck the lubricating oil in the oil storage chamber 11 into the first oil delivery channel and press the lubricating oil entering the first oil delivery channel into the friction position. In this technical solution, the rotational utilization of the crankshaft 2 is realized by the sleeve connection (specifically, for example, interference fit) of the rotary driving member 51 and the crankshaft 2, and then the reciprocating motion of the piston rod 52 is driven, so that the oil pumping assembly is structurally more simplified.

As a specific implementation manner of the rotary driving element 51, the rotary driving element 51 includes a connection pad 511 and a flange 512 located on a side of the connection pad 511 facing the upper bracket 1, a height of the flange 512 smoothly changes between a preset maximum height and a preset minimum height in a circumferential direction of the connection pad 511, the rotary driving element 51 is sleeved with the crankshaft 2 through the connection pad 511, and the other end of the piston rod 52 is connected to a first end surface of the flange 512 facing the upper bracket 1. As shown in fig. 3, the flange 512 protrudes toward one side of the upper bracket 1 along the outer peripheral edge of the connecting plate 511, and the protruding height may be selected according to the sliding fit length between the piston rod 52 and the first oil passage 61. The other end of the piston rod 52 is configured with a sliding groove 521, and the first end surface is located in the sliding groove 521, so that the positions of the piston rod 52 and the flange 512 in the oil pumping process can be relatively stable and reliable. A sliding member 513 is disposed between the sliding groove 521 and the flange 512, and the sliding member 513 may be, for example, a roller (e.g., a ball) clamped between the sliding groove 521 and the flange 512, or may be a roller integrated with one of the sliding members, for example, the roller integrated with an inner wall of the sliding groove 521, so as to ensure smooth sliding of the piston rod 52 on the flange 512. The one end of the piston rod 52 is constructed with a seal ring clamping groove 522, and a seal ring 54 is sleeved in the seal ring clamping groove to ensure the matching sealing performance of the piston rod 52 and the first oil channel 61, and improve the oil pumping efficiency of the oil pumping assembly.

In some embodiments, an oil drain hole 514 is formed in the connecting disc 511, so that lubricating oil on the connecting disc 511 can fall back to a bottom oil pool more timely; the connecting plate 511 is provided with a balance block 515 to ensure the rotation balance of the rotation driving member 51. The pump body assembly further includes a piston rod fixing frame 53 fixedly connected to the upper bracket 1, a through hole is formed thereon, the piston rod 52 passes through the through hole and can move along the axial direction of the through hole, and when the pump body assembly is assembled in the compressor casing 100, the piston rod fixing frame 53 can also be fixedly connected to the compressor casing 100 at the same time, so as to further ensure the position stability and reliability of the piston rod 52.

In some embodiments, the first oil delivery channel further includes a second oil passage 62, one end of the second oil passage 62 is communicated with the first oil passage 61, the other end of the second oil passage 62 is communicated with the oil storage chamber 11, and a first check valve 71 is disposed in the second oil passage 62 to ensure that the lubricating oil in the oil storage chamber 11 enters the first oil delivery channel in a single direction. In this technical solution, the design of the first check valve 71 can ensure that the lubricating oil entering the first oil passage 61 cannot flow back to the oil storage chamber 11, so that the compressor is turned on again after a period of shutdown, and the piston rod 52 lubricates a part of the lubricating oil stored in the first oil passage 61 at the friction position, thereby compensating the hysteresis of the compressor supplying oil from the bottom oil sump.

In some embodiments, the first oil delivery passage further includes a third oil passage 63, one end of the third oil passage 63 communicates with the first oil passage 61, and the other end of the third oil passage 63 communicates with a second oil delivery passage 64 provided on the fixed scroll 4. A second check valve 72 is arranged in the third oil passage 63 to ensure that the lubricating oil in the first oil delivery passage enters the second oil delivery passage 64 in a one-way mode; the second oil delivery passage 64 communicates with a buffer space 200, and the buffer space 200 is a space between the top of the compressor housing 100 and the fixed scroll 4. The second check valve 72 can prevent the occurrence of insufficient lubrication due to the backflow of the lubricating oil at the friction position under the action of gravity. The first check valve 71 and the second check valve 72 may be commercially available components, and in a specific structure, for example, as shown in fig. 4, the first check valve 71 and the second check valve 72 include a guide rod 712 capable of being in clearance fit with the corresponding oil passages (specifically, the second oil passage 62 and the third oil passage 63), a valve core 711 sleeved on the guide rod 712, and a plurality of oil outlet holes 713 located on the valve core 711.

The upper bracket 1 is further provided with a first air flow passage, a gas-liquid separation part is arranged in the first air flow passage, the mixed air flow in the buffer space 200 can enter the first air flow passage, the separation of the lubricating oil and the refrigerant air flow is realized under the action of the gas-liquid separation part, and the separated air flow is discharged through an exhaust port of the compressor casing 100. In the technical scheme, the gas-liquid separation part is arranged in the compressor shell 100 and can separate lubricating oil in mixed gas flow once, the lubricating oil is reserved in the compressor, the quantity of the lubricating oil in the compressor is ensured to be sufficient, the quantity of the lubricating oil entering an external system is reduced, and the performance of the external system (such as an air conditioning system) is improved. The upper bracket 1 is also provided with a third oil delivery channel 65, and the lubricating oil separated in the first air flow channel can enter the oil storage chamber 11 through the third oil delivery channel 65.

In some embodiments, the gas-liquid separation component includes a strainer assembly 81 and a gas pipe 82, the strainer assembly 81 and the gas pipe 82 are respectively located upstream and downstream of the flow direction of the refrigerant gas flow, and the height of the gas inlet of the gas pipe 82 is higher than the height of the outlet of the first gas flow passage. The screen assembly 81 specifically includes a screen support 811 and a screen 812 tensioned on the screen support 811.

As is known, the rotation of the crankshaft 2 is controlled by a motor rotor 301 fitted thereto.

The invention further provides a scroll compressor, which comprises the above pump body assembly, specifically, two ends of a crankshaft 2 in the pump body assembly are respectively supported inside the compressor casing 100 through an upper bracket 1 and a lower bracket 303, and a motor stator 302 is arranged between the outer periphery of the motor rotor 301 and the compressor casing 100, so as to drive the motor rotor 301 to rotate when being electrified.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.