Oil cooling motor lubricating system

Abstract

The utility model discloses an oil cooling motor lubrication system, which comprises a main motor, a stator and a bearing, and further comprises an oil pump, a radiator, a radiator temperature control three-way valve, a stator temperature control three-way valve and a filter, the radiator is connected with a radiator bypass oil path in parallel, and the oil outlet end of the oil pump is communicated with the radiator and the oil inlet end of the radiator bypass oil path; the radiator and the radiator bypass oil way are respectively communicated with an inlet of the radiator temperature control three-way valve, and the radiator temperature control three-way valve is communicated with the stator temperature control three-way valve through the stator bypass oil way; two ends of the stator bypass oil path are communicated with the stator; the filter is communicated with an outlet of the stator temperature control three-way valve, and the filter is communicated with the bearing; the stator oil cooler is connected with the bearing lubrication in series; the system can obviously reduce the flow resistance of the system, reduce the power of the oil pump, and achieve the effect of saving oil at the same time.

Description

Technical Field

[0001] The utility model relates to the technical fields of motors and new energy vehicles, and particularly to an oil-cooled motor lubrication system. Background Technique

[0002] Oil cooling is one of the main cooling forms of current medium and low voltage motors and new energy vehicles. Since the cooling oil of the oil-cooled motor is in direct contact with the winding of the motor heating component, the temperature rise of the winding can be significantly reduced. However, the lubricating oil temperature and viscosity are in an exponential relationship. At low temperatures, the oil viscosity is extremely high (the viscosity at 5°C is dozens of times that at 40°C), and a pump needs to have a very large torque. The pump drive motor may burn out or the oil system may leak due to excessive pressure. After calculating the lubrication system, it is found that the flow resistance and pressure resistance weak points of the lubrication system mainly exist in the heat exchange components, that is, the heat exchanger and the stator of the oil-cooled motor, while the flow resistance of the pipeline itself is very small and the leakage risk is also low. In the existing solutions, the pump speed is mainly controlled to match the motor operation mode, there is no pressure reduction method, and a small part monitors the oil pressure and reduces the pump speed when overpressure occurs, but this may cause insufficient lubricating oil supply and there is a risk of excessive temperature of the bearing or the motor winding. The existing oil cooling systems generally use an "oil-water-air" cooling scheme, and after two-layer heat exchange, the system response speed is slow and the efficiency is low.

[0003] When the oil-cooled motor operates under different working conditions, the corresponding losses are different and the generated heat is also different, resulting in a large range of temperature changes inside the motor. At this time, the magnetic field level of the permanent magnet of the motor rotor will change with the temperature, thereby causing a decrease in the control accuracy of the output torque. In various existing lubrication systems and oil-cooled motor solutions, when starting at low temperature, the system pressure is too high, and there are risks of excessive pump power and leakage; when the bearing lubricating oil temperature fluctuates too much, it may cause the bearing oil film to be unstable, resulting in abnormal vibration or abnormal noise of the unit.

[0004] The patent with the application number CN201910636889.5 discloses an oil-cooled motor control device and method. The described oil-cooled motor temperature control method includes: controlling the pump speed according to the predicted working condition of the oil-cooled motor, the temperature control target of the oil-cooled motor, and the temperature control target of the lubricating oil; controlling the water pump speed according to the temperature of the coolant flowing into the heat exchanger, the temperature of the lubricating oil in the oil sump, the flow rate of the lubricating oil, and the temperature control target of the lubricating oil. Due to too many input variables, this control method makes the system too complex, and there is a coupling relationship between the input variables, and the determination basis of the control target is not explained either. Content of the Utility Model

[0005] The main object of the present utility model is directed to various lubrication systems and oil-cooled motor solutions in the prior art, which do not involve content on how to reduce resistance and target temperature control. When the motor starts at low temperature, the system pressure is too high, and there are risks of excessive oil pump power and leakage. When the temperature of the bearing lubricating oil fluctuates too much, it may cause instability of the bearing oil film, resulting in abnormal vibration or abnormal noise of the unit. An oil-cooled motor lubrication system is proposed.

[0006] In view of the above technical problems, the technical solution of the present utility model is as follows:

[0007] An oil-cooled motor lubrication system, comprising a main motor, a stator and bearings, and further comprising an oil pump, a radiator, a radiator temperature control three-way valve, a stator temperature control three-way valve and a filter. The radiator is connected in parallel with a radiator bypass oil circuit. The oil outlet end of the oil pump communicates with the oil inlet ends of the radiator and the radiator bypass oil circuit. The radiator and the radiator bypass oil circuit are respectively connected to the inlets of the radiator temperature control three-way valve. The radiator temperature control three-way valve is connected to the stator temperature control three-way valve through a stator bypass oil circuit. Both ends of the stator bypass oil circuit are connected to the stator. The filter is connected to the outlet of the stator temperature control three-way valve and is connected to the bearings. The stator oil cooling and the bearing lubrication are connected in series.

[0008] Further, it further comprises a bearing inlet oil temperature sensor, a stator winding temperature sensor and a temperature sensor. The bearing inlet oil temperature sensor is arranged on the oil path between the filter and the bearings for obtaining the temperature of the lubricating oil entering the bearings. The stator winding temperature sensor is connected to the stator for obtaining the temperature of the stator winding, and the stator winding temperature sensor is connected to the stator temperature control three-way valve. The temperature sensor is connected to the radiator temperature control three-way valve.

[0009] Further, the radiator is a radiator cooled by an electric fan.

[0010] Further, the speeds of the fan of the radiator and the oil pump are variable.

[0011] Further, the speed of the oil pump is matched with the target speed or the stator loss, and the speed of the oil pump is adjusted in real time according to the total loss.

[0012] Further, the control target temperature of the radiator temperature control three-way valve is the temperature of the lubricating oil after confluence at the radiator temperature control three-way valve, and the control target temperature of the stator temperature control three-way valve is the temperature of the stator winding.

[0013] Further, the preset target oil temperature of the lubricating oil after confluence at the radiator temperature control three-way valve is 45 - 55 °C.

[0014] Further, at the rated power and speed, if the stator power loss is significantly higher than the bearing loss, the positions of the radiator temperature control three-way valve and the stator temperature control three-way valve are interchanged.

[0015] Further, a shielding sleeve is provided on one side of the stator, and the shielding sleeve is fixed on the motor frame.

[0016] Further, the shielding sleeves are symmetrically arranged on the side close to the rotor, so that the lubricating oil is isolated within the range of the stator core.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] 1. The oil-cooling lubrication system of the present application includes a main motor, a stator and bearings, and also includes an oil pump, a radiator, a radiator temperature control three-way valve, a stator temperature control three-way valve and a filter. The radiator is connected in parallel with the radiator bypass oil circuit, and the oil outlet end of the oil pump is connected to the oil inlet ends of the radiator and the radiator bypass oil circuit; the radiator and the radiator bypass oil circuit are respectively connected to the inlets of the radiator temperature control three-way valve, and the radiator temperature control three-way valve is connected to the stator temperature control three-way valve through the stator bypass oil circuit; both ends of the stator bypass oil circuit are connected to the stator; the filter is connected to the outlet of the stator temperature control three-way valve, and the filter is connected to the bearings; through the cooperation of the radiator temperature control three-way valve and the stator temperature control three-way valve, when the oil temperature of the lubrication system is relatively low, the lubricating oil passes through the bypass pipeline, which can significantly reduce the system flow resistance and the power of the oil pump.

[0019] 2. This system uses air-oil direct heat exchange cooling, reduces the intermediate link of cooling water, increases the temperature difference between the heat exchange media, significantly improves the efficiency of the heat exchanger, reduces the volume of the heat exchanger, and improves the reliability of the system; because the system does not require cooling water, it can be used in water-deficient environments.

[0020] 3. By connecting the stator oil cooling in series with the bearing lubrication, the demand for lubricating oil can be significantly reduced, achieving a saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the system schematic diagram of an oil-cooled motor lubrication system;

[0022] Figure 2 is the temperature and pressure control flow chart of an oil-cooled motor lubrication system;

[0023] Figure 3 is the radiator fan operation control logic diagram of an oil-cooled motor lubrication system;

[0024] Figure 4 is the system schematic diagram of another scheme of an oil-cooled motor lubrication system;

[0025] Figure 5Schematic diagram of the spiral flow channel of the motor stator of an oil-cooled motor lubrication system;

[0026] Figure 6 Schematic diagram of the installation of the shielding sleeve of the motor stator of an oil-cooled motor lubrication system.

[0027] In the figure, 1. Oil tank; 2. Oil pump; 3. Radiator; 4. Radiator temperature control three-way valve; 5. Stator temperature control three-way valve; 6. Filter; 7. Motor stator; 8. Stator winding temperature sensor; 9. Bearing inlet oil temperature sensor; 10. Bearing; 11. Main motor; 12. Radiator bypass oil circuit; 13. Stator bypass oil circuit; 14. Temperature sensor; 31. Inlet; 32. Outlet; 33. Spiral flow channel; 34. Outer flow channel cylinder; 35. Inner flow channel cylinder; 36. Stator core; 37. Core flow channel; 38. Shielding sleeve. Detailed implementation manners

[0028] To clearly illustrate the technical features of the application solution of the present utility model, the present utility model will be elaborated in detail below through specific implementation manners and in combination with its accompanying drawings.

[0029] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application may be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0030] In addition, in the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0031] In this application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] Embodiment 1

[0033] As Figure 1 shown, an oil-cooled motor lubrication system includes a main motor 11, a stator 7 and bearings 10, and also includes an oil pump 2, a radiator 3, a radiator temperature control three-way valve 4, a stator temperature control three-way valve 5 and a filter 6. The radiator 3 is in parallel with a radiator bypass oil circuit 12. The oil outlet end of the oil pump 2 communicates with the oil inlet ends of the radiator 3 and the radiator bypass oil circuit 12. The radiator 3 and the radiator bypass oil circuit 12 are respectively communicated with the inlets of the radiator temperature control three-way valve 4. The radiator temperature control three-way valve 4 is communicated with the stator temperature control three-way valve 5 through a stator bypass oil circuit 13. Both ends of the stator bypass oil circuit 13 are communicated with the stator 7. The filter 6 is communicated with the outlet of the stator temperature control three-way valve 5, and the filter 6 is connected to the bearings 10. The oil cooling of the stator 7 and the lubrication of the bearings 10 are in series.

[0034] In this embodiment, both the oil pump 1 and the bearings 10 are communicated with an oil tank 1. In this embodiment, it can be directly communicated with the oil tank 1 through an oil circuit, so that the lubricating oil returns to the oil tank 1 after cooling the bearings 10. If the power of the motor 11 is relatively large, the lubricating oil temperature is relatively high after cooling the bearings 10. A return oil pump can be installed in the oil circuit between the bearings 10 and the oil tank 1. The return oil pump is used to mix the relatively high-temperature lubricating oil with the cold oil in the oil tank 1, so as to achieve heat dissipation and cooling, ensure that the oil temperature is within a suitable range, extend the service life of the oil and system components, and generally the return oil pump is equipped with a filtering device, which can filter the lubricating oil, remove impurities and pollutants therein, ensure the cleanliness of the oil, reduce the wear and damage of system components, and improve the stability of the system.

[0035] This lubrication system also includes a bearing inlet oil temperature sensor 9, a stator winding temperature sensor 8 and a temperature sensor 14. The bearing inlet oil temperature sensor 9 is arranged on the oil circuit between the filter 6 and the bearings 10, and is used to obtain the temperature of the lubricating oil entering the interior of the bearings 10. The stator winding temperature sensor 8 is connected to the stator 7 and is used to obtain the temperature of the stator winding, and the stator winding temperature sensor 8 is communicated with the stator temperature control three-way valve 5. The temperature sensor 14 is connected to the radiator temperature control three-way valve 4.

[0036] As Figure 1 And Figure 2As shown in the figure, in this embodiment, taking the motor supported by the sliding bearing 10 as an example, the oil pump 2 extracts lubricating oil from the oil tank 1, passes through the radiator bypass pipeline 12 or the radiator 3 cooled by the electric fan, and then converges at the radiator temperature control three-way valve 4, and then passes through the generator stator 7 or the stator bypass pipeline 13. The lubricating oil converges at the stator temperature control three-way valve 5. After the converged lubricating oil removes impurities in the lubricating oil through the filter 5, it supplies oil to the motor bearing 10. The lubricating oil after cooling the bearing returns to the oil tank 1 by gravity or the oil return pump. The speeds of the fan of the radiator 3 and the oil pump 2 are adjustable. The radiator temperature control three-way valve 4 controls the target temperature to be the temperature of the lubricating oil after convergence, and the stator temperature control three-way valve 5 controls the target temperature to be the temperature of the stator 7 winding.

[0037] The speeds of the fan of the radiator 3 and the oil pump 2 of the present application are both variable. When the motor is working, the speed of the oil pump 2 can be adjusted in real time according to the loss, so as to match the speed of the oil pump 2 with the target speed or the stator loss, reduce the power consumption of the oil pump 2 during the entire working cycle, and keep the inlet oil temperature stable through the two-stage cooperation of the two-way temperature control three-way valve and the radiator fan speed.

[0038] Embodiment 2

[0039] As Figure 1 shown, an oil-cooled motor lubrication system includes a main motor 11, a stator 7 and a bearing 10, and also includes an oil pump 2, a radiator 3, a radiator temperature control three-way valve 4, a stator temperature control three-way valve 5 and a filter 6. The radiator 3 is connected in parallel with the radiator bypass oil circuit 12, and the oil outlet end of the oil pump 2 communicates with the oil inlet ends of the radiator 3 and the radiator bypass oil circuit 12; the radiator 3 and the radiator bypass oil circuit 12 are respectively connected to the inlets of the radiator temperature control three-way valve 4, and the radiator temperature control three-way valve 4 is connected to the stator temperature control three-way valve 5 through the stator bypass oil circuit 13; both ends of the stator bypass oil circuit 13 are connected to the stator 7; the filter 6 is connected to the outlet of the stator temperature control three-way valve 5, and the filter 6 is connected to the bearing 10; the oil cooling of the stator 7 and the lubrication of the bearing 10 are in series.

[0040] As Figure 3 shown, the system controls the speed of the oil pump 2 through the cooperation of the radiator temperature control three-way valve 4 and the stator temperature control three-way valve 5 to realize the pipeline pressure reduction during the low-temperature operation of the system, and the air-cooled radiator 3 takes away the heat generated by the stator 7 and the bearing 10. The action logic of the fan of the air-cooled radiator 3 is as follows: that is, by monitoring the oil temperature T s after mixing through the radiator temperature control three-way valve 4, this temperature has met the requirement for the fan to act, the preset target oil temperature T 1 , generally 45-55 °C, the lowest speed N 1 that the fan can stably control, the highest speed N e of the fan, and the allowable fluctuation temperature T b, the target rotational speed N is calculated s , since the heat dissipation power designed for the radiator 3 is greater than the heat generation power of the system, generally, the oil inlet temperature of the radiator 3 is higher than T 1 (45 - 55 °C), and it is also significantly higher than the ambient temperature. The radiator 3 has a high efficiency and can achieve the balance of heat generation and heat dissipation power at a relatively low fan rotational speed.

[0041] According to the known parameters, the rotational speed of the fan is calculated, and its expression is:

[0042]

[0043] Embodiment 3

[0044] As Figure 4 shown, for an oil-cooled motor lubrication system, different from Embodiment 1, in this embodiment, the positions of the radiator temperature control three-way valve 4 and the stator temperature control three-way valve 5 can be interchanged. The prerequisite for the replacement is: if the bearing power loss of the stator is significantly higher than the stator power loss under the rated power and rotational speed, and the temperature rise of the lubricating oil after passing through the bearing 10 is relatively significant, then the lubricating oil first passes through the radiator 3, and this scheme is the same as that of Embodiment 1. If under the rated condition, the stator power loss is significantly higher than the bearing loss, and the heating effect of the bearing 10 on the lubricating oil is not obvious, the oil coming out of the fuel tank 1 can directly cool the stator 7, then the positions of the two temperature control three-way valves can be replaced to better control the temperature of the system and ensure the stability of the system lubricating oil.

[0045] Embodiment 4

[0046] As Figure 1 shown, an oil-cooled motor lubrication system includes a main motor 11, a stator 7 and a bearing 10, and also includes an oil pump 2, a radiator 3, a radiator temperature control three-way valve 4, a stator temperature control three-way valve 5 and a filter 6. The radiator 3 is connected in parallel with the radiator bypass oil circuit 12, and the oil outlet end of the oil pump 2 is connected to the oil inlet ends of the radiator 3 and the radiator bypass oil circuit 12; the radiator 3 and the radiator bypass oil circuit 12 are respectively connected to the inlet of the radiator temperature control three-way valve 4, and the radiator temperature control three-way valve 4 is connected to the stator temperature control three-way valve 5 through the stator bypass oil circuit 13; both ends of the stator bypass oil circuit 13 are connected to the stator 7; the filter 6 is connected to the outlet of the stator temperature control three-way valve 5, and the filter 6 is connected to the bearing 10; the oil cooling of the stator 7 and the lubrication of the bearing 10 are in series.

[0047] As Figure 5As shown, the oil-cooled stator 7 is connected in series with the oil supply for the bearing 10 to achieve the effect of fuel saving. The specific solution is as follows: The motor stator 7 using the shielding sleeve 38 is symmetrically arranged with the shielding sleeve 38 in the motor 11. The shielding sleeve 38 is fixed on the frame of the motor 11 and is arranged at one end close to the rotor. The lubricating oil enters from the oil inlet 31, flows through the stator core flow channel 37, and then flows out through the oil outlet 32. The internal shielding sleeve 38 isolates the lubricating oil within the range of the stator core 36, preventing the lubricating oil from entering the air gap between the stator and the rotor, reducing the oil supply amount, and at the same time preventing the rotor from agitating the oil and increasing the lubricating oil loss.

[0048] As Figure 6 shown, in this embodiment, to achieve the series connection of the oil supply for the oil-cooled stator 7 and the bearing 10, the lubricating oil directly passes through the water jacket of a common water-cooled motor, including a return water channel and a spiral water channel. The lubricating oil enters the spiral flow channel 33 through the oil inlet 31 and then returns to the pipeline through the oil outlet 32, which can also achieve the purpose of fuel saving.

[0049] Obviously, the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An oil-cooled motor lubrication system, comprising a main motor, a stator and a bearing, characterized in that: It also includes an oil pump, a radiator, a radiator temperature control three-way valve, a stator temperature control three-way valve and a filter. The radiator is connected in parallel with the radiator bypass oil circuit, and the oil outlet of the oil pump is connected to the radiator and the oil inlet of the radiator bypass oil circuit; the radiator and the radiator bypass oil circuit are respectively connected to the inlet of the radiator temperature control three-way valve, and the radiator temperature control three-way valve is connected to the stator temperature control three-way valve through the stator bypass oil circuit; both ends of the stator bypass oil circuit are connected to the stator; the filter is connected to the outlet of the stator temperature control three-way valve, and the filter is connected to the bearing; the stator oil cooling and the bearing lubrication are connected in series.

2. The oil-cooled motor lubrication system according to claim 1, characterized in that: It also includes a bearing oil inlet temperature sensor, a stator winding temperature sensor and a temperature sensor. The bearing oil inlet temperature sensor is arranged in the oil circuit between the filter and the bearing, and is used to obtain the temperature of the lubricating oil entering the bearing; the stator winding temperature sensor is connected to the stator, and is used to obtain the temperature of the stator winding, and the stator winding temperature sensor is connected to the stator temperature control three-way valve; the temperature sensor is connected to the radiator temperature control three-way valve.

3. The oil-cooled motor lubrication system according to claim 1, characterized in that: The radiator is a radiator cooled by an electric fan.

4. The oil-cooled motor lubrication system according to claim 3, characterized in that: The rotation speeds of the fan and the oil pump of the radiator are both variable.

5. The oil-cooled motor lubrication system according to claim 4, characterized in that: The speed of the oil pump matches the target speed or the stator loss, and the speed of the oil pump is adjusted in real time according to the total loss.

6. The oil-cooled motor lubrication system according to claim 1, characterized in that: The control target temperature of the radiator temperature control three-way valve is the temperature of the lubricating oil after converging at the radiator temperature control three-way valve, and the control target temperature of the stator temperature control three-way valve is the temperature of the stator winding.

7. The oil-cooled motor lubrication system according to claim 6, characterized in that: The preset target oil temperature of the lubricating oil after the radiator temperature control three-way valve converges is 45-55°C.

8. The oil-cooled motor lubrication system according to claim 1, characterized in that: At rated power and speed, if the stator power loss is significantly higher than the bearing loss, the positions of the radiator temperature control three-way valve and the stator temperature control three-way valve are interchanged.

9. The oil-cooled motor lubrication system according to claim 1, characterized in that: A shielding sleeve is provided on one side of the stator, and the shielding sleeve is fixed on the motor frame.

10. The oil-cooled motor lubrication system according to claim 9, characterized in that: The shielding sleeve is symmetrically arranged on a side close to the rotor, so that the lubricating oil is isolated within the range of the stator core.

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