A motor heat dissipation assembly and motor

Abstract

The application provides a motor heat dissipation assembly and a motor. The motor heat dissipation assembly comprises a rotating shaft, a shell, a first end cover and a second end cover. The rotating shaft is internally provided with a hollow flow channel. The rotating shaft is further provided with a gas inlet and a gas outlet. The gas inlet is communicated with one end of the hollow flow channel to enable the hollow flow channel to intake gas. The gas outlet is communicated with the other end of the hollow flow channel to enable the hollow flow channel to discharge gas. The gas inlet is arranged on the side of the first end cover away from the second end cover to intake gas from the outside of the first end cover. The gas outlet is arranged on the side of the second end cover away from the first end cover to discharge gas towards the outside of the second end cover. According to the application, the heat dissipation and cooling effect of the motor interior can be improved, and the sealing performance of the motor interior can be ensured, so that the high protection level of the motor is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to an electric machine heat dissipation assembly and electric machine. BACKGROUND

[0002] Servo motors are widely used in the field of robots and are the power source of robots. With the continuous development of the robot market, servo motors not only need to have the characteristics of high protection level and high reliability, but also need to continuously improve the power. However, improving the power means that the temperature rise will increase. According to the structural characteristics of the inner rotor servo motor, the heat dissipation of the stator winding mainly relies on the heat exchange between the motor shell and the external air. However, due to the high protection level requirement of the servo motor, the conventional inner rotor structure is basically isolated from the external air, and the heat of the rotor components can only be transferred through the bearings and the internal air of the motor. It is difficult for the heat to dissipate, and the permanent magnet in the rotor is prone to demagnetization in a high-temperature environment, which affects the reliability of the servo motor. Therefore, the present application aims to solve the problem of difficult heat dissipation of the rotor and invents a forced air-cooled high-protection servo motor.

[0003] Due to the high protection level requirement of the servo motor in the prior art, the inner rotor structure is basically isolated from the external air, and the heat of the rotor components can only be transferred through the bearings and the internal air of the motor. It is difficult for the heat to dissipate, and the permanent magnet in the rotor is prone to demagnetization in a high-temperature environment, which affects the reliability of the servo motor. Therefore, the present application researches and designs an electric machine heat dissipation assembly and electric machine. SUMMARY

[0004] Therefore, the present application aims to solve the problem of difficult heat dissipation of the rotor and invents a forced air-cooled high-protection servo motor.

[0005] In order to solve the above problems, the present application provides an electric machine heat dissipation assembly, which comprises:

[0006] The rotating shaft, the motor shell, the first end cover and the second end cover, the rotating shaft is internally provided with a hollow flow channel, the rotating shaft is further provided with a gas inlet and a gas outlet, the gas inlet is in communication with one end of the hollow flow channel to enable the hollow flow channel to intake gas, the gas outlet is in communication with the other end of the hollow flow channel to enable the hollow flow channel to discharge gas, and the gas inlet is arranged on the side of the first end cover away from the second end cover to intake gas from the outside of the first end cover, and the gas outlet is arranged on the side of the second end cover away from the first end cover to discharge gas towards the outside of the second end cover.

[0007] In some embodiments, a rotating impeller is further included, the rotating impeller is sleeved on the rotating shaft and can rotate integrally with the rotating shaft, and the rotating impeller is arranged on the side of the second end cover away from the first end cover. An exhaust end cover is arranged on the outer periphery of the rotating shaft and is connected with the second end cover. An exhaust chamber is formed in the exhaust end cover, and the rotating impeller is arranged in the exhaust chamber. The gas outlet is in communication with the exhaust chamber.

[0008] In some embodiments, the rotating impeller is a centrifugal impeller, and exhaust holes are formed in a penetrating manner on the peripheral wall of the exhaust end cover opposite to the radial outer side of the centrifugal impeller, and the exhaust holes are in communication with the exhaust chamber.

[0009] In some embodiments, one axial end of the rotating shaft penetrates through the first end cover, and the gas inlet is arranged on the axial end of the rotating shaft. The hollow flow channel extends to the axial end of the rotating shaft and is in communication with the gas inlet. The other axial end of the rotating shaft penetrates through the exhaust end cover. One end of the gas outlet is in communication with the hollow flow channel, and the other end is in communication with the exhaust chamber. The gas outlet is a straight passage, and the included angle between the central axis of the gas outlet and the central axis of the rotating shaft is greater than 0.

[0010] In some embodiments, the gas outlet is a plurality of gas outlets, and the plurality of gas outlets are arranged in sequence and at intervals along the circumferential direction of the rotating shaft.

[0011] In some embodiments, a heat-conducting inner tube is further included, the heat-conducting inner tube is arranged in the hollow flow channel and at least opposite to the motor rotor. The inner part of the heat-conducting inner tube has a hollow flow channel two, which penetrates from one axial end to the other axial end of the heat-conducting inner tube, and the hollow flow channel two is in communication with the hollow flow channel. The heat-conducting inner tube can realize contact heat conduction to the motor rotor.

[0012] In some embodiments, the heat-conducting inner tube includes an inner tube body and a heat-conducting rib. The inner tube body is a cylindrical structure. One end of the heat-conducting rib is arranged on the outer wall of the inner tube body, and the other end of the heat-conducting rib protrudes outward. The position opposite to the heat-conducting inner tube of the rotating shaft is provided with a through groove, and the through groove penetrates the inner wall to the outer wall of the rotating shaft. The heat-conducting rib is arranged in the through groove and can contact the motor rotor.

[0013] In some embodiments, the heat-conducting rib is a plurality of heat-conducting ribs, and the plurality of heat-conducting ribs are arranged in sequence and at intervals along the circumferential direction of the outer wall of the inner tube body. The through groove is also a plurality of through grooves, and the plurality of through grooves are arranged in sequence and at intervals along the circumferential direction of the rotating shaft. The heat-conducting rib and the through groove are arranged in one-to-one correspondence.

[0014] In some embodiments, the inner wall of the heat-conducting inner tube is provided with grooves to form heat dissipation grooves; and / or the heat-conducting inner tube is made of copper alloy.

[0015] The application also provides an electric machine comprising the aforementioned electric machine heat dissipation assembly, and further comprising an electric machine rotor and an electric machine stator, the electric machine rotor being sleeved on the outer periphery of the rotating shaft, the electric machine stator being located on the outer periphery of the electric machine rotor, and the electric machine rotor and the electric machine stator being arranged in the space formed by the machine shell, the first end cover and the second end cover.

[0016] In some embodiments, further comprising a brake rotor and a brake stator, the brake rotor and the brake stator being arranged between the first end cover and the electric machine stator, the electric machine further comprising an encoder and an encoder cover, the encoder cover being connected to the side of the first end cover away from the second end cover, and the encoder cover being arranged on the outer periphery of the rotating shaft, the inside of the encoder cover forming an encoder space, and the encoder being arranged on the outer periphery of the rotating shaft and located in the encoder space.

[0017] The electric machine heat dissipation assembly and the electric machine provided by the application have the following beneficial effects:

[0018] 1. The hollow flow channel is arranged in the electric machine rotating shaft, the gas inlet at one end of the hollow flow channel is located on the side of the first end cover away from the second end cover, the gas outlet at the other end of the hollow flow channel is located on the side of the second end cover away from the first end cover, the electric machine rotor and the electric machine stator are arranged in the space formed by the first end cover, the second end cover and the machine shell, and therefore the hollow flow channel of the application can introduce gas from the outside of the electric machine rotor and the stator, the gas is discharged through the gas outlet after heat dissipation in the hollow flow channel together with the structures such as the electric machine rotor, the gas does not enter the inside of the electric machine shell, the heat dissipation and cooling effect of the inside of the electric machine can be improved, the sealing performance of the inside of the electric machine is ensured, the high protection level of the electric machine is ensured, the poor heat dissipation performance of the rotor structure is solved, the demagnetization of the permanent magnet is avoided, and the reliability of the servo motor is affected.

[0019] 2. The heat-conducting inner tube is arranged in the hollow flow channel of the rotating shaft and opposite to the electric machine rotor, the heat-conducting inner tube can realize the conduction of the gas and the heat conduction to the electric machine rotor, and the heat dissipation and cooling effect of the electric machine rotor is further improved; the contact area between the heat-conducting inner tube and the electric machine rotor is increased through the cooperation of the plurality of heat-conducting ribs and the through grooves, and the heat dissipation effect is further improved; the sealing structure formed by the end cover and the oil seal isolates the air cooling flow channel from the inside of the electric machine and the external reducer, foreign matters are prevented from entering the inside of the electric machine or the external reducer, and the high protection level is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a longitudinal sectional view of a conventional servo motor;

[0021] Figure 2 is a longitudinal sectional view of a servo motor of the present application;

[0022] Figure 3 is an A-A sectional view of Figure 2

[0023] Figure 4 is a sectional view of a rotation shaft, a heat-conducting inner tube and a motor rotor of the present application;

[0024] Figure 5 is a B-B sectional view of Figure 4

[0025] Figure 6a is a perspective view of a heat-conducting inner tube of the present application;

[0026] Figure 6b is a front view of a heat-conducting inner tube of Figure 6a

[0027] is a C-C sectional view of Figure 6c Figure 6b

[0028] Figure 7a is a perspective view of a rotation shaft of the present application;

[0029] Figure 7b is an axial side view of Figure 7a

[0030] Figure 7c is a D-D sectional view of Figure 7b

[0031] Figure 8 is a perspective view of an exhaust end cover in a motor heat-dissipation assembly of the present application;

[0032] Figure 9 is a perspective view of a centrifugal impeller in a motor heat-dissipation assembly of the present application;

[0033] Figure 10 is a flow structure diagram of a cooling and heat-dissipation air flow of a motor of the present application.

[0034] Reference signs are indicated as:

[0035] ​​​​​​1, rotating shaft; 100, hollow flow channel; 101, gas inlet; 102, gas outlet; 2, casing; 3, first end cover; 4, second end cover; 5, rotating impeller; 6, exhaust end cover; 7, exhaust chamber; 8, exhaust hole; 9, heat-conducting inner tube; 91, inner tube body; 92, heat-conducting rib; 93, heat dissipation groove; 10, motor rotor; 104, permanent magnet; 11, hollow flow channel two; 12, through groove; 13, motor stator; 14, brake rotor; 15, brake stator; 16, encoder; 17, encoder cover; 18, encoder space; 19, first sealing structure; 20, second sealing structure; 21, third sealing structure; 22, first bearing; 23, second bearing. DETAILED DESCRIPTION

[0036] The conventional servo motor structure is shown in Figure 1 When the motor is working, heat is generated, and the heat dissipation of the motor stator, the brake stator, and the front and rear bearings is mainly through the conduction of the casing and the end cover, so as to exchange heat with the external air to dissipate heat. In order to achieve high protection level, the motor rotor (permanent magnet), the encoder, the brake rotor, and the rotating shaft are isolated in the motor, and they can only conduct heat through the bearings and the air in the motor, so the heat cannot be effectively dissipated, and finally the motor temperature rise can only be reduced by reducing the power of the motor, so as to obtain reliable operation. The oil seal-1 of the front end cover of the motor mainly functions to isolate the motor inside and the external reducer, and prevent foreign matters from entering the motor or the reducer.

[0037] As shown in Figures 2-10 The motor heat dissipation assembly provided by the application comprises:

[0038] The rotating shaft 1, the casing 2, the first end cover 3, and the second end cover 4, the inside of the rotating shaft 1 is provided with a hollow flow channel 100, the rotating shaft 1 is further provided with a gas inlet 101 and a gas outlet 102, the gas inlet 101 communicates with one end of the hollow flow channel 100 to enable the hollow flow channel 100 to intake air, the gas outlet 102 communicates with the other end of the hollow flow channel 100 to enable the hollow flow channel 100 to exhaust air, and the gas inlet 101 is arranged on the side of the first end cover 3 away from the second end cover 4 to intake air from the outside of the first end cover 3, and the gas outlet 102 is arranged on the side of the second end cover 4 away from the first end cover 3 to exhaust air towards the outside of the second end cover 4.

[0039] The hollow flow channel is arranged in the inside of the motor rotating shaft, the gas inlet at one end of the hollow flow channel is located at the side of the first end cover away from the second end cover, and the gas outlet at the other end of the hollow flow channel is located at the side of the second end cover away from the first end cover, the motor rotor and the motor stator are arranged in the space surrounded by the first end cover, the second end cover and the shell, therefore, the hollow flow channel can introduce the gas from the outside of the motor rotor and the stator, the gas is discharged through the gas outlet after heat dissipation in the hollow flow channel, the gas does not enter the inside of the motor shell, the heat dissipation and cooling effect of the motor inside can be improved, the sealing performance of the motor inside is ensured, the high protection level of the motor is ensured, the poor heat dissipation performance of the rotor structure is solved, the demagnetization of the permanent magnet is avoided, and the reliability of the servo motor is affected.

[0040] The application point of the application is that: a special inner hole flow channel and a heat conduction inner tube structure are designed in the motor rotating shaft, a centrifugal impeller is installed on the rotating shaft, the impeller rotates under the driving of the rotating shaft during the operation of the motor, the external cold air is sucked into the flow channel of the rotating shaft, the encoder, the rear bearing, the brake, the rotor and the front bearing are cooled, and the hot air is discharged from the exhaust end cover, so that the heat dissipation of the motor rotor components is realized.

[0041] The following technical problems are solved:

[0042] 1. The temperature rise of the servo motor is effectively reduced, and the power of the servo motor is improved.

[0043] 2. The high protection level requirement is met, the efficient heat dissipation of the motor rotor is realized, the demagnetization of the permanent magnet due to high temperature is prevented, and the reliable operation of the servo motor is beneficial.

[0044] 3. The problem of poor heat dissipation effect caused by poor heat conduction performance of the rotating shaft material and small heat dissipation area of the inner hole flow channel is solved, and the heat dissipation effect is improved.

[0045] The beneficial effects are as follows:

[0046] Due to the adoption of the rotating shaft inner hole flow channel and the centrifugal impeller forced exhaust structure of the application, the temperature rise of the motor is effectively reduced, the air cooling flow channel is isolated from the inside of the motor and the external reducer by the sealing structure such as the oil seal, foreign matters are prevented from entering the inside of the motor or the external reducer, the high protection level is ensured, and the special rotating shaft inner hole flow channel and heat conduction inner tube structure are adopted to effectively improve the heat dissipation effect.

[0047] Compared with the conventional servo motor structure, the motor components of the application obtain good cooling effect, wherein the motor rotor, encoder and bearing obtain direct heat dissipation effect, and the actual measured cooling is 30%; and the motor stator and brake also obtain cooling effect due to the cooling of the rotor components, and the actual measured cooling is 10%.

[0048] The structure of the motor of the application is shown in Figure 2 Compared with the conventional servo motor, the application has the following significant differences:

[0049] 1. The rotating shaft is designed with an inner hole flow channel (hollow flow channel 100) and a gas outlet hole (gas outlet 102);

[0050] 2. The rotating shaft is designed with a heat conduction inner tube 9 structure in the inner hole flow channel;

[0051] 3. A new centrifugal impeller is installed on the rotating shaft, which rotates under the driving of the rotating shaft;

[0052] 4. The rotating shaft passes out of the motor from the encoder rear cover, and a third sealing structure 21 (preferably an oil seal) is installed between the encoder cover and the rotating shaft as a seal;

[0053] 5. A new exhaust end cover 6 is formed with the front end cover (second end cover 4) to form an exhaust chamber 7, the centrifugal impeller rotates and works in the exhaust chamber 7, and a first sealing structure 19 (preferably an oil seal) and a second sealing structure 20 (preferably an oil seal) are installed on the exhaust end cover and the front end cover as seals.

[0054] The process of air exchange in the wind chamber is analyzed as follows: Figure 3 As shown in the figure, a plurality of exhaust holes are arranged on the outer circumference of the exhaust end cover, when the centrifugal impeller rotates, the blades will drive the air in the wind chamber to the exhaust holes, so that the air pressure in the wind chamber is reduced to form a negative pressure, and due to the sealing effect of the first sealing structure 19 and the second sealing structure 20, the air in the inner hole flow channel of the rotating shaft will flow to the wind chamber through the gas outlet hole, so as to realize the air exchange of the wind chamber.

[0055] In some embodiments, it further comprises a rotating impeller 5 and an exhaust end cover 6, the rotating impeller 5 is sleeved on the rotating shaft 1 and can rotate integrally with the rotating shaft 1, and the rotating impeller 5 is arranged on the side of the second end cover 4 away from the first end cover 3, and the exhaust end cover 6 is arranged on the outer circumference of the rotating shaft 1 and is connected with the second end cover 4, an exhaust chamber 7 is formed in the exhaust end cover 6, the rotating impeller 5 is arranged in the exhaust chamber 7, and the gas outlet 102 is communicated with the exhaust chamber 7. This is the preferred structure form of the application, the rotating impeller is sleeved on the rotating shaft, which can be driven to rotate by the rotation of the rotating shaft, and then drives the airflow to enter the exhaust chamber through the hollow flow channel and the gas outlet, so that the airflow can cool and heat the motor rotor, motor stator and other components when passing through the hollow flow channel.

[0056] In some embodiments, the rotating impeller 5 is a centrifugal impeller, the circumferential wall of the exhaust end cover 6 opposite to the radial outer side of the rotating impeller 5 is formed with exhaust holes 8 in a penetrating manner, the exhaust holes 8 are in communication with the exhaust chamber 7; a first sealing structure 19 is arranged between the second end cover 4 and the rotating shaft 1, and a second sealing structure 20 is arranged between the exhaust end cover 6 and the rotating shaft 1. The rotating impeller of the present application is preferably a centrifugal impeller, which can suck gas from the axial direction and discharge it to the exhaust holes of the exhaust end cover from the radial outer side, and then to the outside, thereby completing the effect of making the gas flow into the hollow flow channel from one end of the rotating shaft, cooling the motor rotor and the like, and discharging it from the other end, ensuring that the gas flow does not enter the motor internal space, improving the sealing performance, and ensuring the high protection level of the motor.

[0057] The exhaust end cover of the present application is assembled with the front end cover to form an air chamber, and a plurality of exhaust holes are arranged on the outer circumference of this side; the other side is a stop end face for installing the motor and the speed reducer, and a structure for installing the second sealing structure 20 is designed to provide sealing for forming the air chamber and prevent foreign matters from entering the speed reducer. As shown in Figure 5 .

[0058] The centrifugal impeller structure of the present application is shown in Fig. 6. When the impeller rotates, it works on the air between the blades, and the air is thrown to the periphery from the center of the impeller under the centrifugal action.

[0059] In some embodiments, the axial one end of the rotating shaft 1 penetrates out of the first end cover 3, the gas inlet 101 is arranged at the axial one end of the rotating shaft 1, the hollow flow channel 100 extends to the axial one end of the rotating shaft 1 and is in communication with the gas inlet 101, the axial other end of the rotating shaft 1 penetrates out of the exhaust end cover 6, one end of the gas outlet 102 is in communication with the hollow flow channel 100 and the other end is in communication with the exhaust chamber 7, and the gas outlet 102 is a straight passage with a central axis and the central axis of the rotating shaft 1 forming an included angle greater than 0. This is a further preferred structure of the rotating shaft, the first end cover, the second end cover and the exhaust end cover of the present application, i.e. the rotating shaft penetrates out of the first end cover at one end and out of the second end cover and the exhaust end cover at the other end, and the gas outlet is inclined to discharge the gas in the hollow flow channel to the exhaust chamber, thereby completing the effective sealing effect between the gas and the internal chamber of the casing and improving the protection level.

[0060] In some embodiments, the gas outlet 102 is a plurality of gas outlets, which are arranged in sequence and spaced apart along the circumferential direction of the rotating shaft 1. The gas outlet of the present application is preferably a plurality of gas outlets, which are arranged in sequence and spaced apart along the circumferential direction of the rotating shaft, thereby improving the air outlet area in the circumferential direction and improving the air outlet effect.

[0061] In some embodiments, a heat-conducting inner tube 9 is further included, which is arranged in the hollow flow channel 100 and at least opposite to the motor rotor 10, the inside of the heat-conducting inner tube 9 has a hollow flow channel two 11 penetrating from one axial end to the other axial end of the heat-conducting inner tube 9, and the hollow flow channel two 11 is in communication with the hollow flow channel 100, and the heat-conducting inner tube 9 can realize contact heat conduction to the motor rotor 10.

[0062] The heat-conducting inner tube arranged in the hollow flow channel of the rotating shaft and opposite to the motor rotor can realize the heat conduction to the motor rotor through the hollow flow channel two inside the heat-conducting inner tube while realizing the gas conduction, and further improves the heat dissipation and cooling effect of the motor rotor; and through the cooperation structure of the plurality of heat-conducting ribs and the through grooves, the contact area between the heat-conducting ribs and the motor rotor can be enhanced, and the heat dissipation effect is further improved.

[0063] The heat-conducting inner tube structure is designed in the inner hole of the rotating shaft, which can improve the heat dissipation performance of the heat generating component (mainly the motor rotor) and the convection of the cold air flowing in the inner hole.

[0064] In some embodiments, the heat-conducting inner tube 9 includes an inner tube body 91 and a heat-conducting rib 92, the inner tube body 91 is a cylindrical structure, one end of the heat-conducting rib 92 is arranged on the outer wall of the inner tube body 91 and the other end protrudes outward, the rotating shaft 1 opposite to the inner tube body 91 is provided with a through groove 12 penetrating the inner wall to the outer wall of the rotating shaft 1, and the heat-conducting rib 92 is arranged in the through groove 12 and can contact the motor rotor 10. This is the preferred structure of the heat-conducting inner tube of the present application, which includes an inner tube body and a heat-conducting rib, so that the inner tube body is arranged in the hollow flow channel and flush with the inner peripheral wall of the hollow flow channel, the heat-conducting rib protrudes outward from the outer wall of the inner tube body and cooperates with the through groove arranged on the rotating shaft, so that the heat-conducting rib protrudes to contact the motor rotor, effectively realizing the heat conduction and heat exchange effect between the heat-conducting rib and the motor rotor, and enhancing the heat exchange efficiency of the motor rotor.

[0065] In some embodiments, the heat-conducting rib 92 is a plurality of heat-conducting ribs 92, which are arranged in the circumferential direction of the outer wall of the inner tube body 91 in sequence, the through groove 12 is also a plurality of through grooves 12 arranged in the circumferential direction of the rotating shaft 1 in sequence, and the heat-conducting rib 92 is arranged in one-to-one cooperation with the through groove 12. The heat-conducting rib of the present application is a plurality of heat-conducting ribs, and the through groove is also a plurality of through grooves, which can improve the contact area between the heat-conducting rib and the motor rotor in the circumferential direction, thereby improving the heat dissipation and heat exchange effect of the motor rotor.

[0066] In some embodiments, the inner wall of the heat-conducting inner tube 9 is provided with grooves to form heat dissipation grooves 93; and / or the heat-conducting inner tube 9 is made of copper alloy. The present application can also increase the heat exchange area by providing heat dissipation grooves on the inner wall of the heat-conducting inner tube when the gas passes through, further improving the heat exchange between the gas in the hollow flow channel and the heat-conducting inner tube, and then the heat exchange and heat dissipation effect of the motor rotor. The heat-conducting inner tube of the present application is preferably made of copper alloy, which can further improve the heat exchange efficiency.

[0067] The conventional rotating shaft is usually made of carbon steel or stainless steel, and the thermal conductivity coefficient thereof is only 40-60 W / (m·K). In the present application, carbon steel is used as the body structure of the rotating shaft, and a heat-conducting inner tube is embedded in the rotating shaft under the condition of meeting the structural strength. As shown in Figure 4 and Figure 5 , the outer circle of the heat-conducting inner tube has a tooth-shaped heat-conducting rib structure, and the tooth top directly contacts the inner surface of the motor rotor core, so that the heat of the motor rotor core can be directly conducted through the heat-conducting inner tube. The material of the heat-conducting inner tube is copper alloy or other material with high thermal conductivity coefficient. The thermal conductivity coefficient of copper alloy is 390 W / (m·K), and the heat conduction capacity is improved.

[0068] In addition, the conventional inner hole flow channel is a circular hole, and the area of convective heat exchange is small due to the small inner diameter. In the present application, a radial heat dissipation groove structure is added to the heat-conducting inner tube, as shown in Figures 6a-6c , the actual convective heat exchange area of the structure of the present application is increased by 30% compared with the conventional circular hole, and the convective heat exchange amount is also improved due to the increase of the contact area. In addition, the conventional servo motor heat dissipation groove is arranged in the axial direction, but it will generate resistance due to the rotation of the rotor. The present application has a radial distribution of the groove structure, which can increase the heat dissipation area and will not adversely affect the efficiency of the motor.

[0069] The rotating shaft of the present application is composed of a steel pipe part and a heat-conducting inner tube embedded therein. The steel pipe part is designed with an inner hole flow channel, a groove matched with the heat-conducting inner tube, and air holes uniformly distributed in the radial direction of the rotating shaft, as shown in Figure 4 . In order to ensure smooth air flow, the included angle between the air hole and the axis of the rotating shaft is obtuse. Considering the machinability, the included angle is 135°±35°.

[0070] The present application also provides a motor, which comprises the motor heat dissipation assembly of any one of the preceding items, and further comprises a motor rotor 10 and a motor stator 13. The motor rotor 10 is sleeved on the outer periphery of the rotating shaft 1, the motor stator 13 is located on the outer periphery of the motor rotor 10, and the motor rotor 10 and the motor stator 13 are arranged in the space surrounded by the machine shell 2, the first end cover 3 and the second end cover 4.

[0071] The hollow flow channel formed in the rotating shaft can introduce gas from the outside of the motor rotor and stator, and the gas is discharged through the gas outlet after heat dissipation with the motor rotor and other structures, so that the gas does not enter the inside of the motor housing, so that the heat dissipation and cooling effect of the motor inside can be improved, and the sealing performance of the motor inside is ensured, the high protection level of the motor is ensured, and the problems of poor heat dissipation performance of the rotor structure, easy demagnetization of the permanent magnet, and influence on the reliability of the servo motor are solved.

[0072] In some embodiments, further comprising a brake rotor 14 and a brake stator 15, the brake rotor 14 and the brake stator 15 are arranged between the first end cover 3 and the motor stator 13, the motor further comprises an encoder 16 and an encoder cover 17, the encoder cover 17 is connected to the side of the first end cover 3 away from the second end cover 4, and the encoder cover 17 is arranged on the outer periphery of the rotating shaft 1, the inside of the encoder cover 17 forms an encoder space 18, and the encoder 16 is arranged on the outer periphery of the rotating shaft and located in the encoder space 18. The hollow flow channel inside the rotating shaft of the present application can further cool the encoder and the brake, and further improve the heat dissipation effect of the internal structure of the motor.

[0073] In summary, when the motor of the present application works, the rotor rotates, the rotating shaft drives the centrifugal impeller to rotate, according to the above analysis of the air exchange process in the air chamber, the air in the inner hole flow channel of the rotating shaft flows to the air chamber through the air hole, which causes the air pressure in the inner hole flow channel to decrease, and the external air pressure is higher than that in the inner hole flow channel. Therefore, the external air will enter the inner hole flow channel from the tail inlet (behind the encoder cover) of the rotating shaft, and finally form an air exchange and heat dissipation process in which air enters from the tail inlet of the rotating shaft and is discharged from the exhaust port of the exhaust end cover, as shown in Figure 10 In this air exchange and heat dissipation process, cold air flows in the inner hole flow channel of the rotating shaft, passes through the encoder, the rear bearing inner ring, the brake rotor, the motor rotor and the front bearing inner ring in turn, and finally is discharged out of the motor through the air chamber. In order to improve the heat conduction capacity of the rotating shaft and the convective heat transfer capacity of the inner hole of the rotating shaft, a special heat conduction inner tube structure is designed in the inner hole of the rotating shaft, so that the heat of the motor rotor core is better dissipated.

[0074] Due to the size limitation of the servo motor, the heat conduction inner tube structure is mainly used for optimizing the heat dissipation of the motor rotor, and in the case that the size of the rotating shaft of some large motors allows, the heat conduction inner tube can be arranged in the whole inner hole flow channel of the rotating shaft, and the heat dissipation effect is better. It should also be within the scope of the present application.

[0075] The form of the impeller blade of the present application is not limited to straight blades, but can be other involute blades. The pressure air efficiency can be increased in the working direction, but the efficiency is low in the reverse direction, so it is only suitable for single-direction running motors.

[0076] The above description is only the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application. The above description is only the preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can be made, and these improvements and variations should be considered as the protection scope of the present application.

Claims

1. A motor heat dissipation assembly, characterized in that: The motor heat dissipation assembly comprises a rotating shaft (1), a shell (2), a first end cover (3) and a second end cover (4), the rotating shaft (1) is internally provided with a hollow flow channel (100), the rotating shaft (1) is further provided with a gas inlet (101) and a gas outlet (102), the gas inlet (101) is communicated with one end of the hollow flow channel (100) to enable the hollow flow channel (100) to intake gas, the gas outlet (102) is communicated with the other end of the hollow flow channel (100) to enable the hollow flow channel (100) to discharge gas, and the gas inlet (101) is arranged on the side of the first end cover (3) away from the second end cover (4) to intake gas from the outside of the first end cover (3), and the gas outlet (102) is arranged on the side of the second end cover (4) away from the first end cover (3) to discharge gas towards the outside of the second end cover (4). The motor heat dissipation assembly further comprises a heat-conducting inner tube (9), the heat-conducting inner tube (9) is arranged in the hollow flow channel (100) and at least opposite to a motor rotor (10), the heat-conducting inner tube (9) has a hollow flow channel II (11) in the inside, the hollow flow channel II (11) penetrates from one axial end of the heat-conducting inner tube (9) to the other axial end, and the hollow flow channel II (11) is communicated with the hollow flow channel (100), and the heat-conducting inner tube (9) can realize contact heat conduction to the motor rotor (10). The heat-conducting inner tube (9) comprises an inner tube body (91) and a heat-conducting rib (92), the inner tube body (91) is a cylindrical structure, one end of the heat-conducting rib (92) is arranged on the outer wall of the inner tube body (91) and the other end protrudes outward, the rotating shaft (1) is provided with a through groove (12) at the position opposite to the inner tube body (91), the through groove (12) penetrates the inner wall to the outer wall of the rotating shaft (1), and the heat-conducting rib (92) is arranged in the through groove (12) and can contact the motor rotor (10).

2. The motor heat dissipation assembly according to claim 1, further comprising a rotating impeller (5) and an exhaust end cover (6), the rotating impeller (5) is sleeved on the rotating shaft (1) and can rotate integrally with the rotating shaft (1), the rotating impeller (5) is arranged on the side of the second end cover (4) away from the first end cover (3), the exhaust end cover (6) is arranged on the outer periphery of the rotating shaft (1) and is connected with the second end cover (4), an exhaust chamber (7) is formed in the inside of the exhaust end cover (6), the rotating impeller (5) is arranged in the exhaust chamber (7), and the gas outlet (102) is communicated with the exhaust chamber (7).

3. The motor heat dissipation assembly according to claim 2, further comprising a rotating impeller (5) and an exhaust end cover (6), the rotating impeller (5) is sleeved on the rotating shaft (1) and can rotate integrally with the rotating shaft (1), the rotating impeller (5) is arranged on the side of the second end cover (4) away from the first end cover (3), the exhaust end cover (6) is arranged on the outer periphery of the rotating shaft (1) and is connected with the second end cover (4), an exhaust chamber (7) is formed in the inside of the exhaust end cover (6), the rotating impeller (5) is arranged in the exhaust chamber (7), and the gas outlet (102) is communicated with the exhaust chamber (7). ​ ​ The rotating impeller (5) is a centrifugal impeller, a gas exhaust hole (8) is formed in a penetrating manner on a peripheral wall of the exhaust end cover (6) opposite to a radially outer side of the rotating impeller (5), and the gas exhaust hole (8) is in communication with the exhaust chamber (7); a first sealing structure (19) is arranged between the second end cover (4) and the rotating shaft (1), and a second sealing structure (20) is arranged between the exhaust end cover (6) and the rotating shaft (1).

4. The motor heat dissipation assembly according to claim 2, wherein: An axial one end of the rotating shaft (1) penetrates through the first end cover (3), the gas inlet (101) is arranged at the axial one end of the rotating shaft (1), the hollow flow channel (100) extends to the axial one end of the rotating shaft (1) and is in communication with the gas inlet (101), an axial other end of the rotating shaft (1) penetrates through the exhaust end cover (6), one end of the gas outlet (102) is in communication with the hollow flow channel (100) and the other end is in communication with the exhaust chamber (7), and the gas outlet (102) is a straight passage, a central axis of which and a central axis of the rotating shaft (1) form an included angle greater than 0.

5. The motor heat dissipation assembly according to claim 4, wherein: The gas outlet (102) is a plurality of gas outlets, and the plurality of gas outlets are arranged in sequence and at intervals along a circumferential direction of the rotating shaft (1).

6. The motor heat dissipation assembly according to claim 1, wherein: The plurality of heat conduction ribs (92) are arranged in sequence and at intervals along a circumferential direction of an outer wall of the inner tube body (91), the plurality of through grooves (12) are arranged in sequence and at intervals along a circumferential direction of the rotating shaft (1), and the heat conduction rib (92) and the through groove (12) are arranged in one-to-one correspondence.

7. The motor heat dissipation assembly according to any one of claims 1-6, wherein: An inner wall of the heat conduction inner tube (9) is provided with a groove, forming a heat dissipation groove (93); and / or the heat conduction inner tube (9) is made of copper alloy.

8. An electric machine characterized by: The motor heat dissipation assembly according to any one of claims 1-7, further comprising a motor rotor (10) and a motor stator (13), the motor rotor (10) is sleeved on an outer periphery of the rotating shaft (1), the motor stator (13) is located on an outer periphery of the motor rotor (10), and the motor rotor (10) and the motor stator (13) are arranged in a space enclosed by the machine shell (2), the first end cover (3) and the second end cover (4).

9. The motor according to claim 8, wherein: Further comprising a brake rotor (14) and a brake stator (15), the brake rotor (14) is arranged between the first end cover (3) and the motor stator (13) with the brake stator (15), the motor further comprises an encoder (16) and an encoder cover (17), the encoder cover (17) is connected to the side of the first end cover (3) away from the second end cover (4), and the encoder cover (17) is arranged on the outer periphery of the rotating shaft (1), the inside of the encoder cover (17) forms an encoder space (18), and the encoder (16) is arranged on the outer periphery of the rotating shaft and located in the encoder space (18).

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