A device for automatically controlling the flow rate of rotor cooling oil

Abstract

The device for automatically controlling rotor cooling oil flow of the present invention includes a housing having cooling oil channels; an input shaft, which is a hollow shaft rotatably disposed inside the housing; a rotor shaft connected to the input shaft, the rotor shaft having a first oil chamber arranged axially; and an oil guide pipe, the oil guide pipe being arranged axially inside the input shaft, the oil guide pipe having an oil guide hole arranged axially, the first oil chamber communicating with the cooling oil channels through the oil guide hole, the oil guide hole being a tapered hole with its diameter increasing in the direction away from the rotor shaft. When the motor is running at high speed, the device of this application can reduce the amount of cooling oil in the rotor, so as to reduce the rotor oil slinging and churning losses when the motor is running at high speed. Furthermore, the reduction in the amount of cooling oil in the rotor can increase the temperature of the rotor magnets, reduce the performance of the magnets, reduce the high-speed weak magnetic current, reduce copper loss, thereby improving the motor efficiency.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and more specifically to a device for automatically controlling the flow rate of rotor cooling oil. Background Technology

[0002] The electric drive assembly of new energy vehicles generally consists of a motor, a reducer, and a controller, all integrated into one unit. With the development of new energy vehicles, the demand for efficient and reliable motors is increasing. Especially under high-speed operating conditions, motor efficiency and stability have become one of the key technical challenges of electric drive assemblies. Traditional electric drive assemblies typically use cooling systems to dissipate the heat generated by the motor, ensuring that the temperature rise of the motor does not exceed the allowable range during high-speed operation. Currently, most high-performance motors use oil cooling systems to cool the rotor. This involves injecting cooling oil directly into the rotor shaft through cooling oil circuits. Excessive cooling oil flowing inside the rotor shaft can cause frictional losses, especially under high-speed operating conditions, leading to additional energy losses and affecting motor efficiency. Furthermore, excessive rotor cooling oil can lower the temperature of the rotor magnets, increase magnet performance, increase high-speed weak magnetic current, and increase copper losses, thereby reducing motor efficiency. For high-speed operating motors, excessive cooling oil accumulation inside the motor can accelerate oil deterioration due to high temperatures, reducing its cooling and lubrication effects and further affecting motor performance. Therefore, controlling the rotor cooling oil flow rate is crucial. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, one object of the present invention is to provide a device for automatically controlling the flow rate of rotor cooling oil, which can reduce the flow rate of rotor cooling oil under high-speed operation of motor, thereby improving motor efficiency.

[0005] An apparatus for automatically controlling the flow rate of rotor cooling oil according to an embodiment of the present invention includes a housing having a cooling oil passage; an input shaft, which is a hollow shaft and is rotatably disposed inside the housing; a rotor shaft connected to the input shaft, the rotor shaft having a first oil chamber arranged axially; and an oil guide pipe, which is arranged axially inside the input shaft and rotates with the input shaft, the oil guide pipe having an oil guide hole arranged axially, the first oil chamber communicating with the cooling oil passage through the oil guide hole, the oil guide hole being a tapered hole with its diameter increasing in a direction away from the rotor shaft.

[0006] In the device for automatically controlling the flow rate of rotor cooling oil according to an embodiment of the present invention, a tapered oil guide hole is provided in the oil guide pipe. When the rotor shaft of the motor is running at high speed, the amount of rotor cooling oil can be reduced. As the rotor speed increases, the amount of cooling oil decreases accordingly. This setting can reduce the amount of rotor cooling oil so that the rotor oil throwing and churning losses are reduced when the motor is running at high speed. Furthermore, the reduction of rotor cooling oil can increase the temperature of the rotor magnets, reduce the performance of the magnets, reduce the high-speed weak magnetic current, reduce copper loss, and thereby improve the efficiency of the motor.

[0007] In addition, the device for automatically controlling the flow rate of rotor cooling oil according to the present invention may also have the following additional technical features.

[0008] Optionally, a spiral groove is provided axially on the inner wall surface of the oil guide hole; the spiral groove extends axially to both ends of the oil guide pipe. By providing the spiral groove, the amount of cooling oil entering the rotor can be further reduced as the rotational speed increases, thereby improving motor efficiency.

[0009] Optionally, viewed along the direction from the input shaft to the rotor shaft, when the rotor shaft rotates clockwise, the helical groove is a right-hand thread; viewed along the direction from the input shaft to the rotor shaft, when the rotor shaft rotates counterclockwise, the helical groove is a left-hand thread. When the rotor shaft rotates clockwise, the direction of the helical groove is set to right-hand; when the rotor shaft rotates counterclockwise, the direction of the helical groove is set to left-hand. By setting the helical groove, the amount of cooling oil entering the rotor can be further reduced as the rotational speed increases, thereby improving motor efficiency.

[0010] Optionally, the cross-section of the spiral groove is arc-shaped. As the rotational speed increases, the amount of cooling oil entering the rotor can be effectively reduced, improving motor efficiency; and the arc-shaped spiral groove has a smooth surface, which can reduce the impact of cooling oil on the pipe wall and extend the service life of the oil guide pipe.

[0011] Optionally, the radial height of the spiral groove is 1 mm. Therefore, the radius of the spiral groove is 0.5 mm. This arrangement provides a smooth transition, reduces the amount of cooling oil entering the rotor, and improves motor efficiency. Furthermore, the oil guide tube of this structure can be cast, saving manufacturing costs.

[0012] Optionally, a spiral rib is provided axially on the inner wall surface of the oil guide hole; the spiral rib extends axially to both ends of the oil guide pipe. By providing the spiral rib, the amount of cooling oil entering the rotor can be further reduced as the rotational speed increases, thereby improving motor efficiency; in addition, the spiral rib can also increase the strength of the oil guide pipe.

[0013] Optionally, viewed along the direction from the input shaft to the rotor shaft, when the rotor shaft rotates clockwise, the helical rib is a right-hand thread; viewed along the direction from the input shaft to the rotor shaft, when the rotor shaft rotates counterclockwise, the helical rib is a left-hand thread. When the rotor shaft rotates clockwise, the direction of rotation of the helical rib is set to right-hand; when the rotor shaft rotates counterclockwise, the direction of rotation of the helical rib is set to left-hand. By setting the helical rib, the amount of cooling oil entering the rotor can be further reduced as the rotational speed increases, thereby improving motor efficiency.

[0014] Optionally, the cross-section of the spiral rib is arc-shaped. As the rotational speed increases, the amount of cooling oil entering the rotor can be effectively reduced, improving motor efficiency; and the arc-shaped spiral rib has a smooth surface, further reducing the resistance to backflow and making the cooling oil return smoother.

[0015] Optionally, the radial height of the spiral rib is 1 mm. Therefore, the radius of the spiral rib is 0.5 mm to provide a smooth transition, reduce the amount of cooling oil entering the rotor, and improve motor efficiency; the oil guide tube of this structure can also be cast.

[0016] Optionally, the rotor shaft speed is greater than 10,000 rpm. When the rotor shaft speed is greater than 10,000 rpm, the rotor oil volume will decrease as the motor speed increases, thereby improving motor efficiency.

[0017] The beneficial effects of this invention are as follows: the housing of the device for automatically controlling the flow rate of rotor cooling oil has a cooling oil channel, which is connected to the first oil chamber of the rotor shaft through an oil guide pipe, so that the cooling oil can enter the motor rotor; the oil guide pipe has a tapered oil guide hole and its diameter increases in the direction away from the rotor shaft, so that the amount of cooling oil in the rotor can be controlled when the motor is running at high speed; a spiral groove or spiral rib is provided in the oil guide hole along the axial direction, and under the action of the spiral groove or spiral rib, the amount of cooling oil entering the rotor can be better controlled; the device of this application can reduce the amount of cooling oil in the rotor, so that the rotor oil throwing and churning losses are reduced when the motor is running at high speed, and the reduction of the amount of cooling oil in the rotor can increase the temperature of the rotor magnet, reduce the performance of the magnet, reduce the high-speed weak magnetic current, reduce copper loss, and thus improve the efficiency of the motor. Attached Figure Description

[0018] Other features and advantages of the present invention are described below, which explains the invention in more detail with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a cross-sectional view of the device for automatically controlling the flow rate of rotor cooling oil according to the present invention.

[0020] Figure 2This is a schematic diagram of the cooling oil flow direction of the present invention, with arrows indicating the flow direction of the cooling oil.

[0021] Figure 3 This is a schematic diagram of the three-dimensional structure of the oil guide tube of the present invention.

[0022] Figure 4 This is a cross-sectional view of an existing oil guide tube.

[0023] Figure 5 This is a schematic diagram illustrating the theoretical basis of the effect of the tapered oil guide hole on the flow rate.

[0024] Figure 6 This is a cross-sectional view of the oil guide pipe according to Embodiment 1 of the present invention.

[0025] Figure 7 yes Figure 5 Enlarged view of part A in the image.

[0026] Figure 8 This is a cross-sectional view of the oil guide pipe according to Embodiment 3 of the present invention.

[0027] Figure 9 yes Figure 8 Enlarged view of part B in the image.

[0028] Explanation of reference numerals in the attached figures:

[0029] 100 - Devices for electric drive assemblies;

[0030] 1-Housing casing, 11-Cooling oil passage, 111-Oil outlet;

[0031] 2-Input axis, 21-Internal spline;

[0032] 3-Rotor shaft, 31-External spline, 32-First oil chamber;

[0033] 4-First oil guide tube, 41-First oil guide hole, 411-Left hole, 412-Right hole, 42-Spiral groove.

[0034] 5-Second oil guide tube, 51-Second oil guide hole, 511-First hole, 512-Second hole, 52-Helical rib. Detailed Implementation

[0035] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that the terms "upper," "lower," "left," "right," "front," "rear," and similar expressions used herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] Example 1

[0037] A device for automatically controlling the flow rate of rotor cooling oil includes a housing 1 having a cooling oil passage 11; an input shaft 2, which is a hollow shaft and is rotatably disposed inside the housing 1 via a first bearing; a rotor shaft 3 connected to the input shaft 2 via a spline, the rotor shaft 3 having a first oil chamber 31 arranged axially; and a first oil guide pipe 4, which is arranged axially inside the input shaft 2 and rotates with the input shaft 2, the first oil guide pipe 4 having a first oil guide hole 41 arranged axially, the first oil chamber 31 communicating with the cooling oil passage 11 through the first oil guide hole 41, the first oil guide hole 41 being a tapered hole with its diameter increasing in the direction away from the rotor shaft 3.

[0038] like Figure 1As shown, the device for automatically controlling the flow rate of rotor cooling oil according to this application includes a housing 1, an input shaft 2, a rotor shaft 3, and a first oil guide pipe 4. The input shaft 2, rotor shaft 3, and first oil guide pipe 4 are arranged along the same axis, i.e., the central axis of the input shaft 2, the central axis of the rotor shaft 3, and the central axis of the first oil guide pipe 4 are collinear. A cooling oil passage 11 is provided on the housing 1. The cooling oil passage 11 is used to carry away some of the heat within the electric drive assembly along the housing 1, and also to supply oil to other components inside the housing 1. The cooling oil passage 11 includes an oil inlet and an oil outlet 111. The oil inlet is connected to an oil cooler outside the housing 1, and the oil outlet 111 is used to supply oil to other components inside the housing 1. An input shaft 2 is provided inside the housing 1. The input shaft 2 is the input shaft of a reducer. The input shaft 2 is a hollow shaft with an internal spline 21 at one end. The input shaft 2 is rotatably mounted inside the housing 1 via bearings. The rotor shaft 3 is the rotating shaft of a motor. The rotor shaft 3 has a hollow first oil chamber 32 and an external... Spline 31; Input shaft 2 is sleeved on rotor shaft 3 and fixedly connected to rotor shaft 3 by spline; The device of this application also includes a first oil guide pipe 4, which is axially arranged inside the input shaft 2. The first oil guide pipe 4 has a first oil guide hole 41 that passes through both ends of the first oil guide pipe 4 axially. The left end of the first oil guide pipe 4 is connected to the input shaft 2, and the right end of the first oil guide pipe 4 is connected to the first oil chamber 32. The cooling oil passage 11 of housing 1 and the first oil chamber 32 of rotor shaft 3 are connected through the first oil guide pipe 4 so that cooling oil can enter the rotor; In this application, the first oil guide hole 41 of the first oil guide pipe 4 is a tapered hole, and the diameter of the tapered hole gradually increases in the direction opposite to rotor shaft 3.

[0039] In some embodiments, a spiral groove 42 is provided axially on the inner wall surface of the first oil guide hole 41; the spiral groove 42 extends axially to both ends of the first oil guide tube 4.

[0040] In some embodiments, when viewed along the direction from the input shaft 2 to the rotor shaft 3, the rotor shaft 3 rotates clockwise, and the helical groove 42 is a right-hand thread; when viewed along the direction from the input shaft 2 to the rotor shaft 3, the rotor shaft 3 rotates counterclockwise, and the helical groove 42 is a left-hand thread.

[0041] In some embodiments, the cross-section of the spiral groove 42 is arc-shaped.

[0042] In some embodiments, the radial height of the spiral groove 42 is 1 mm.

[0043] In some embodiments, the rotational speed of the rotor shaft 3 is greater than 10,000 rpm; the cone angle of the first oil guide hole 41 is greater than 1 degree and less than 6 degrees.

[0044] like Figure 6 and Figure 7The diagram shows a cross-sectional view of the first oil guide pipe 41 in Embodiment 1. The first oil guide hole 41 includes a left hole 411 and a right hole 412. The left hole 411 and the right hole 412 are along the same axial direction and are connected. The left hole 411 is a cylindrical hole, and the left end of the left hole 411 is connected to the oil outlet hole 111 of the cooling oil passage 11 so as to introduce cooling oil into the first oil guide pipe 4. The left end of the right hole 412 is connected to the right end of the left hole 411, and the right end of the right hole 412 is connected to the first oil outlet hole 111 of the rotor shaft 3. The cavity 32 is connected so that the cooling oil can enter the rotor 3 through the first oil guide pipe 4; the right hole 412 is a tapered hole, and the diameter of the right hole 412 increases from right to left; the first oil guide pipe 4 has an inner wall surface that defines the right hole 412, and the inner wall surface of the first oil guide pipe 4 is provided with a spiral groove 42 along the axial direction. The spiral groove 42 extends from the left end of the first oil guide hole 41 to its right end. Therefore, the first oil guide pipe 4 can realize the delivery of cooling oil under the action of the spiral groove cross-section circulation and pump effect.

[0045] To facilitate understanding, the spiral groove cross-sectional circulation and pump effect mentioned above will be explained below.

[0046] Spiral channel cross-sectional circulation refers to the centrifugal force generated when liquid flows along the surface of a spiral channel due to continuous changes in its direction of motion. This centrifugal force creates a transverse liquid surface slope from the outer edge to the inner edge of the spiral channel cross-section. Liquid particles in the upper layer of flow are drawn towards the outer edge of the channel by the resultant transverse force, while liquid particles in the lower layer flow towards the inner edge due to the transverse liquid surface slope. This continuity of flow motion creates spiral channel cross-sectional circulation, resulting in a thinner water layer and lower velocity at the inner edge, and a thicker water layer and higher velocity at the outer edge. The transverse inclination angle of the channel surface also enhances the cross-sectional circulation.

[0047] The pumping effect refers to the phenomenon where, when a helical groove is located on a shaft and the corresponding bushing cavity has a smooth surface, the shaft rotating at a certain speed will pump liquid to one side of the bushing. This effect occurs regardless of whether the helical groove is located on the shaft or in the bushing cavity. The pumping direction is related to the direction of the thread and the rotation of the shaft.

[0048] Motor efficiency refers to the energy utilization efficiency of a motor when converting electrical energy into mechanical energy.

[0049] Oil churning loss refers to the energy loss caused by the churning effect of lubricating oil around high-speed rotating parts. This loss usually manifests as the conversion of mechanical energy into heat energy, leading to a decrease in efficiency.

[0050] In Embodiment 1 of this application, the cone angle of the first oil guide hole 41 can be set between 1 degree and 6 degrees according to the actual product size. In this embodiment, the cone angle g is 4°, the pitch d of the spiral groove 42 is 5mm, and the radial height c of the spiral groove 42 is 1mm. In practice, it is not limited to the parameters in this application. The pitch d of the spiral groove 42 can be set between 5mm and 30mm according to the actual product size. As the pitch decreases, the flow rate to the motor rotor at high speed can be controlled to be less. The cross-section of the spiral groove 42 in Embodiment 1 of this application can be arc-shaped, trapezoidal, or triangular. In this application, it is set to arc-shaped. The arc-shaped spiral groove 42 has a smooth surface. The smooth surface can reduce the impact of cooling oil on the inner wall of the oil guide tube, reduce wear, and extend the service life of the oil guide tube. The radius of the spiral groove is 0.5mm, which can provide a smooth transition and reduce the resistance when the cooling oil passes through. As the speed increases, the amount of cooling oil entering the rotor can be further reduced to improve motor efficiency. The oil guide tube with this structure can also be cast, saving manufacturing costs.

[0051] Furthermore, in Example 1, as Figure 6 As shown, viewed from the L direction (from the input shaft 2 to the rotor shaft 3), when the rotor shaft 3 rotates clockwise, the helical groove 42 has a right-hand thread; when the rotor shaft 3 rotates counterclockwise, the helical groove 42 has a left-hand thread. In this embodiment, the rotor shaft rotates clockwise, and the helical groove 42 has a right-hand thread. (Reference) Figure 5 This diagram illustrates the theoretical basis of the effect of the conical oil guide hole on flow rate. When cooling oil enters the oil guide pipe axially, the inner wall of the oil guide pipe exerts a supporting force F on the cooling oil. Component F1 of this supporting force counteracts the centrifugal force generated when the cooling oil rotates, while component F2 points in the opposite direction of the cooling oil flow, causing the cooling oil to tend to flow back. Therefore, the amount of cooling oil flowing to the rotor decreases; and as the rotor speed increases, the amount of rotor cooling oil decreases accordingly. In this application, "high speed" refers to a motor speed greater than 10,000 rpm. Under the action of the spiral groove 42, when the motor is running at high speed, the amount of rotor cooling oil can be better controlled, and as the motor speed increases, the amount of rotor cooling oil decreases accordingly.

[0052] like Figure 4As shown, the existing motor uses an oil guide pipe with cylindrical oil guide holes. Referring to Table 1, the rotor cooling oil flow rate and motor power increase value are shown at different speeds. When the speed is 9000 rpm, the rotor cooling oil flow rate is 1.54 L / min, and the power increase value is 0; when the speed is 12000 rpm, the rotor cooling oil flow rate is 1.75 L / min, and the power increase value is 0; when the speed is 16000 rpm, the rotor cooling oil flow rate is 2.1 L / min, and the power increase value is 0; when the speed is 20000 rpm, the rotor cooling oil flow rate is 2.4 L / min, and the power increase value is 0. The simulation results show that when the rotor operates at high speed, the existing oil guide pipe only serves to guide the oil. The amount of cooling oil in the rotor increases with high-speed operation, but the motor efficiency does not improve. As the motor speed increases, the amount of cooling oil in the rotor increases, and excessive cooling oil flowing inside the rotor shaft will generate frictional losses, especially under high-speed operating conditions, leading to additional energy losses and affecting motor efficiency. At the same time, as the speed increases, the rotor cooling flow increases, reducing the magnet temperature and improving magnet performance. The high-speed weakening current increases, increasing stator copper losses and leading to additional energy losses. Therefore, the technical solution of this application is used to solve this problem.

[0053] In actual cooling, cooling oil is input through the oil inlet 111 of the cooling oil passage 11 of the housing 1. The cooling oil enters the first oil chamber 31 of the rotor 3 along the first oil guide pipe 4 to cool the motor rotor. Referring to Table 1, in Embodiment 1 of this application, when the speed is 9000 rpm, the rotor cooling oil flow rate is 1.42 L / min, and the motor power increases by 5.8 W; when the speed is 12000 rpm, the rotor cooling oil flow rate is 0.62 L / min, and the motor power increases by 77 W; when the speed is 16000 rpm, the rotor cooling oil flow rate is 0.35 L / min, and the motor power increases by 161 W; when the speed is 20000 rpm, the rotor cooling oil flow rate is 0.15 L / min, and the motor power increases by 267 W. According to the above simulation results, when the motor speed is greater than 10000 rpm, as the motor speed increases, the amount of cooling oil in the rotor decreases, which can improve the efficiency of the motor.

[0054] The device for automatically controlling the rotor cooling oil flow rate in this embodiment comprises a housing 1, an input shaft 2, a rotor shaft 3, and a first oil guide pipe 4, forming a cooling and lubrication oil circuit. A tapered first oil guide hole 41 is provided in the first oil guide pipe 4, and a spiral groove 42 is provided in the first oil guide hole 41. Therefore, the structure of this application can reduce the amount of cooling oil in the motor rotor when the rotor is running at high speed. The reduction in rotor oil volume can reduce rotor oil slinging and churning losses. Furthermore, the reduction in rotor cooling oil volume can increase the temperature of the rotor magnets, reduce the performance of the magnets, reduce high-speed weak magnetic current, reduce copper loss, and thus improve motor efficiency. In addition, the oil volume control structure of this application is integrated on the oil guide pipe, eliminating the need for additional parts. The oil guide pipe can be directly cast, saving manufacturing costs.

[0055] Example 2

[0056] The structure and connection method of the housing 1, input shaft 2 and rotor shaft 3 in Embodiment 2 are the same as those in Embodiment 1. The difference is that in Embodiment 2, the cone angle of the oil guide pipe cone hole is 2°.

[0057] Referring to Table 1, in Embodiment 2 of this application, when the rotational speed is 9000 rpm, the rotor cooling oil flow rate is 1.51 L / min, and the motor power increases by 1.5 W; when the rotational speed is 12000 rpm, the rotor cooling oil flow rate is 0.92 L / min, and the motor power increases by 56 W; when the rotational speed is 16000 rpm, the rotor cooling oil flow rate is 0.55 L / min, and the motor power increases by 142 W; when the rotational speed is 20000 rpm, the rotor cooling oil flow rate is 0.22 L / min, and the motor power increases by 142 W. The power is increased by 259W. According to the simulation results above, when the motor speed is greater than 10,000 rpm, the amount of cooling oil in the rotor decreases as the motor speed increases. The reduction in rotor oil volume can reduce rotor oil slinging and churning losses. Furthermore, the reduction in rotor cooling oil volume can increase the temperature of the rotor magnets, reduce the performance of the magnets, reduce high-speed weak magnetic current, and reduce copper loss, thereby improving motor efficiency. In addition, the oil volume control structure of this application is integrated on the oil guide pipe, eliminating the need for additional parts. The oil guide pipe can be directly cast, saving manufacturing costs.

[0058] Example 3

[0059] The structure and connection method of the housing 1, input shaft 2, and rotor shaft 3 in Embodiment 3 are the same as those in Embodiment 1. The difference is that in Embodiment 3, the input shaft 2 has a hollow structure along the axial direction, and a second oil guide pipe 5 is provided inside the input shaft 2. The central axis of the second oil guide pipe 5 is collinear with the central axis of the input shaft 2. The second oil guide pipe 5 has a second oil guide hole 51 along the axial direction. The second oil guide hole 51 is a tapered hole, and its diameter increases in the direction away from the rotor shaft 3. A spiral rib 52 is provided along the axial direction on the inner wall surface of the second oil guide hole 52. The spiral rib 52 extends axially to both ends of the second oil guide pipe 5. By providing the spiral rib 52, as the rotational speed increases, the amount of cooling oil entering the rotor can be effectively reduced, thereby improving the motor efficiency. In addition, the spiral rib can also increase the strength of the oil guide pipe.

[0060] In some embodiments, when viewed along the direction from the input shaft 2 to the rotor shaft 3, the rotor shaft 3 rotates clockwise, and the helical rib 52 is a right-hand thread; when viewed along the direction from the input shaft 2 to the rotor shaft 3, the rotor shaft 3 rotates counterclockwise, and the helical rib 52 is a left-hand thread.

[0061] In some embodiments, the cross-section of the spiral rib 52 is arc-shaped.

[0062] In some embodiments, the radial height of the spiral rib 52 is 1 mm.

[0063] In some embodiments, the rotational speed of the rotor shaft 3 is greater than 10,000 rpm; the cone angle of the second oil guide hole 51 is greater than 1 degree and less than 4 degrees.

[0064] like Figure 8 and Figure 9 As shown, in Embodiment 3 of this application, the second oil guide hole 51 includes a first hole 511 and a second hole 512. The first hole 511 and the second hole 512 are along the same axial direction and are connected. The first hole 511 is a cylindrical hole. The left end of the first hole 511 is connected to the oil outlet 111 of the cooling oil passage 11 so as to introduce cooling oil into the second oil guide pipe 5. The left end of the second hole 512 is connected to the right end of the first hole 511, and the right end of the second hole 512 is connected to the first oil chamber 32 of the rotor shaft 3 so as to allow cooling oil to enter the rotor through the second oil guide pipe 5. The second hole 512 is a tapered hole, and the diameter of the second hole 512 increases sequentially from right to left. The second oil guide pipe 5 has an inner wall surface that defines the second hole 512. The inner wall surface of the second oil guide pipe 5 is provided with a spiral rib 52 along the axial direction. The spiral rib 52 extends from the left end of the second oil guide hole 51 to its right end.

[0065] Furthermore, in Example 3, as Figure 8As shown, viewed from the L direction, that is, from the input shaft 2 to the rotor shaft 3, when the rotor shaft 3 rotates clockwise, the helical rib 52 is a right-hand thread, and when the rotor shaft 3 rotates counterclockwise, the helical rib 52 is a left-hand thread. In this embodiment, the rotor shaft 3 rotates clockwise, and the helical rib 52 is a right-hand thread. Therefore, as the rotor speed increases, the amount of rotor cooling oil decreases accordingly.

[0066] In Embodiment 3 of this application, the cone angle of the second oil guide hole 51 can be set between 1 degree and 6 degrees according to the actual product size. In this embodiment, the cone angle h is 4°, the pitch d of the spiral rib 52 is 5mm, and the radial height e of the spiral rib 52 is 1mm. In practice, it is not limited to the parameters in this application. The pitch f of the spiral rib 52 can be set between 5mm and 30mm according to the actual product size. As the pitch decreases, the flow rate to the motor rotor at high speed can be controlled to be less. The cross section of the spiral rib 52 in Embodiment 3 of this application can be arc-shaped, trapezoidal, or triangular. In this application, it is set to arc-shaped. The arc-shaped spiral rib 52 has a smooth surface, which can reduce the resistance when the cooling oil returns, so as to reduce the amount of cooling oil entering the rotor and improve the motor efficiency. The oil guide tube of this structure can also be cast, saving manufacturing costs.

[0067] Referring to Table 1, in Embodiment 3 of this application, when the rotational speed is 9000 rpm, the rotor cooling oil flow rate is 1.3 L / min, and the motor power is increased by 11.7 W; when the rotational speed is 12000 rpm, the rotor cooling oil flow rate is 0.68 L / min, and the motor power is increased by 73 W; when the rotational speed is 16000 rpm, the rotor cooling oil flow rate is 0.39 L / min, and the motor power is increased by 157 W; when the rotational speed is 20000 rpm, the rotor cooling oil flow rate is 0.13 L / min, and the motor power is increased by 270 W. In addition, high speed in this application refers to the motor speed being greater than 10000 rpm. Under the action of the spiral rib 52, when the motor is running at high speed, the amount of rotor cooling oil can be better controlled, and as the motor speed increases, the amount of rotor cooling oil decreases accordingly, thereby improving the efficiency of the motor.

[0068] The device for automatically controlling the flow rate of rotor cooling oil in this embodiment includes a housing 1, an input shaft 2, a rotor shaft 3, and a second oil guide pipe 5. By opening a tapered second oil guide hole 51 inside the second oil guide pipe 5 and providing spiral ribs 52 axially along the inner wall surface of the second oil guide hole 51, the cooling effect of the motor is ensured. At the same time, the amount of cooling oil in the motor rotor can be reduced when the rotor is running at high speed. The reduction in rotor oil volume can reduce rotor oil sling and churning losses. Furthermore, the reduction in rotor cooling oil volume can increase the temperature of the rotor magnets, reduce the performance of the magnets, reduce high-speed weak magnetic current, and reduce copper loss, thereby improving motor efficiency. In addition, the oil volume control structure of this application is integrated on the oil guide pipe, eliminating the need for additional parts. The oil guide pipe can be directly cast, saving manufacturing costs.

[0069] Table 1

[0070]

[0071] Note 1: The simulation conditions for the data in Table 1 are: total cooling oil flow rate of 16 L / min and oil temperature of 80°C; the unit of rotation speed is rpm, i.e., the number of rotations per minute; the unit of rotor flow rate is L / min, i.e., liters per minute; and the unit of power increase value is W, i.e., watts.

[0072] Note 2: The oil guide hole of the prior art oil guide tube is a round hole; the oil guide hole of the oil guide tube in Embodiment 1 is a conical hole with a cone angle of 4°, and a spiral groove is provided inside the oil guide hole; the oil guide hole of the oil guide tube in Embodiment 2 is a conical hole with a cone angle of 2°, and a spiral groove is provided inside the oil guide hole; the oil guide hole of the oil guide tube in Embodiment 3 is a conical hole with a cone angle of 4°, and a spiral rib is provided inside the oil guide hole.

[0073] In this invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components.

[0074] For those skilled in the art, the specific meanings of the above terms in this invention can be understood according to the specific circumstances. They are included in at least one embodiment or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0075] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0076] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure made using the contents of the present invention specification and drawings, or directly or indirectly applied to other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for automatically controlling the flow rate of rotor cooling oil, characterized in that, include: A housing (1) having a cooling oil passage (11); Input shaft (2), the input shaft (2) is a hollow shaft, and the input shaft (2) is rotatably disposed inside the housing (1); A rotor shaft (3), the rotor shaft (3) being connected to the input shaft (2), the rotor shaft (3) being provided with a first oil chamber (32) along the axial direction; and An oil guide pipe is axially disposed inside the input shaft (2). An oil guide hole is provided in the oil guide pipe along the axial direction. The first oil chamber (32) is connected to the cooling oil passage (11) through the oil guide hole. The oil guide hole is a tapered hole and its diameter increases in the direction away from the rotor shaft (3).

2. The device for automatically controlling rotor cooling oil flow rate according to claim 1, characterized in that, A spiral groove (42) is provided axially on the inner wall surface of the oil guide hole; the spiral groove (42) extends axially to both ends of the oil guide tube.

3. The device for automatically controlling rotor cooling oil flow rate according to claim 2, characterized in that, Looking along the direction from the input shaft (2) to the rotor shaft (3), when the rotor shaft (3) rotates clockwise, the spiral groove (42) is a right-hand thread; looking along the direction from the input shaft (2) to the rotor shaft (3), when the rotor shaft (3) rotates counterclockwise, the spiral groove (42) is a left-hand thread.

4. The device for automatically controlling rotor cooling oil flow rate according to claim 3, characterized in that, The cross-section of the spiral groove (42) is arc-shaped.

5. The device for automatically controlling rotor cooling oil flow rate according to claim 4, characterized in that, The radial height of the spiral groove (42) is 1 mm.

6. The device for automatically controlling rotor cooling oil flow rate according to claim 1, characterized in that, The inner wall surface of the oil guide hole is provided with a spiral rib (52) along the axial direction; the spiral rib (52) extends along the axial direction to both ends of the oil guide pipe.

7. The device for automatically controlling rotor cooling oil flow rate according to claim 6, characterized in that, Looking along the direction from the input shaft (2) to the rotor shaft (3), when the rotor shaft (3) rotates clockwise, the helical rib (52) is a right-hand thread; looking along the direction from the input shaft (2) to the rotor shaft (3), when the rotor shaft (3) rotates counterclockwise, the helical rib (52) is a left-hand thread.

8. The device for automatically controlling rotor cooling oil flow rate according to claim 7, characterized in that, The cross-section of the spiral rib (52) is arc-shaped.

9. The device for automatically controlling rotor cooling oil flow rate according to claim 8, characterized in that, The radial height of the spiral rib (52) is 1 mm.

10. The apparatus for automatically controlling rotor cooling oil flow rate according to claim 5 or 9, characterized in that, The rotor shaft (3) rotates at a speed greater than 10,000 rpm.

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