Motor stator cooling structure, motor, and hybrid system
By employing a motor stator cooling structure consisting of pumps, cooling injectors, and valves in the hybrid transmission, the problem of unstable coolant supply under low pressure was solved, achieving a stable cooling effect for the motor stator.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2025-04-27
- Publication Date
- 2026-06-12
AI Technical Summary
In hybrid transmissions, at low vehicle speeds or low internal combustion engine speeds, the mechanical pump of the hydraulic system supplies insufficient coolant pressure, resulting in unstable cooling flow and affecting the cooling effect of the motor stator.
The motor stator cooling structure consists of a pump, cooling jet, valve, and heat exchanger. The coolant distribution is controlled by valves to ensure that coolant is preferentially supplied to the motor stator at low pressure, thereby improving the cooling effect.
When the coolant pressure is insufficient, ensure that the motor stator receives sufficient coolant first, stabilize the cooling effect, and improve the cooling performance of the motor stator.
Smart Images
Figure CN224355978U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of hybrid vehicle technology, and specifically relates to a motor stator cooling structure, a motor, and a hybrid power system. Background Technology
[0002] In existing hybrid transmissions (DHTs), coolant is injected into the transmission via a hydraulic system. However, at low vehicle speeds or low internal combustion engine speeds, the mechanical pump in the hydraulic system supplies insufficient pressure for the coolant, resulting in unstable cooling flow and affecting the cooling effect. Utility Model Content
[0003] This application aims to propose a motor stator cooling structure, a motor, and a hybrid power system to improve or solve the problem of poor motor stator cooling performance when the coolant pressure is insufficient.
[0004] This application provides a motor stator cooling structure, comprising:
[0005] A pump, with a first branch and a second branch connected downstream of the pump, the pump being used to pump coolant into the first branch and the second branch;
[0006] A cooling sprayer is provided in the first branch and is located next to the motor stator for spraying the coolant onto the motor stator.
[0007] A valve is provided in the second branch, which is used to supply coolant to parts other than the motor stator. The valve can keep the second branch open when the pressure upstream of it is greater than a preset value, and can block the second branch when the pressure upstream of it is less than or equal to the preset value, so that the motor stator cooling structure preferentially supplies coolant to the cooling injector.
[0008] In at least one possible implementation, the valve is an overflow valve or a sequence valve.
[0009] In at least one possible implementation, the pump is a mechanical pump that is driven to a gear transmission mechanism for transmitting power to the wheels, and the pumping capacity of the mechanical pump is positively correlated with the rotational speed of the traction motor or the vehicle speed.
[0010] In at least one possible implementation, the valve is a sequence valve, and the motor stator cooling structure further includes a valve controller, which is capable of adjusting the preset opening and closing pressure of the sequence valve according to the operating power of the motor.
[0011] In at least one possible implementation, when the motor is operating at a first operating power, the sequence valve has a first preset opening and closing pressure value; when the motor is operating at a second operating power greater than the first operating power, the sequence valve has a second preset opening and closing pressure value greater than the first preset opening and closing pressure value.
[0012] In at least one possible implementation, the motor stator cooling structure further includes:
[0013] A heat exchanger is disposed downstream of the pump and upstream of the first branch and the second branch;
[0014] A pressure relief valve, wherein the pressure relief valve is disposed between the pump and the heat exchanger; and
[0015] A filter is disposed upstream of the pump.
[0016] In at least one possible implementation, the preset value is 0.8 bar.
[0017] The cooling sprayer is located at the axial end of the motor stator.
[0018] The embodiments of this application also propose an electric motor, which includes the motor stator cooling structure described in any of the above technical solutions.
[0019] In at least one possible implementation, the motor is a dual-rotor motor, which includes a first stator and a second stator, the second stator being disposed radially outside the first stator. In the radial direction of the dual-rotor motor, the cooling sprayer is disposed between the end windings of the first stator and the end windings of the second stator, for simultaneously spraying coolant into the end windings of the first stator and the end windings of the second stator.
[0020] The embodiments of this application also propose a hybrid power system, which includes the motor stator cooling structure described in any one of the above technical solutions, or includes the motor described in any one of the above technical solutions.
[0021] By adopting the above technical solution, and by using a valve to supply coolant to the first branch or to both the first and second branches under different conditions, the motor stator cooling structure prioritizes supplying the coolant to the cooling jet, thereby improving the motor stator cooling effect. Attached Figure Description
[0022] Figure 1 A schematic diagram of a motor stator cooling structure according to an embodiment of this application is shown.
[0023] Figure 2 A schematic diagram of a portion of the structure of a motor according to an embodiment of this application is shown.
[0024] Explanation of reference numerals in the attached figures
[0025] 1. Filter
[0026] 2 pumps
[0027] 3. Heat exchanger
[0028] 4 valves
[0029] 5 Cooling Injectors
[0030] 6. Pressure relief valve
[0031] 7 Cooling section
[0032] 8 Oil pan
[0033] L1 First Branch Road, L2 Second Branch Road
[0034] 100 First motor unit; 101 First stator; 102 Inner rotor
[0035] 200 Second motor unit 201 Second stator 202 External rotor Detailed Implementation
[0036] To more clearly illustrate the above-mentioned objectives, features, and advantages of this application, specific embodiments of this application are described in detail in conjunction with the accompanying drawings in this section. Besides the embodiments described in this section, this application can also be implemented in other different ways. Those skilled in the art can make corresponding improvements, modifications, and substitutions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed in this section. The scope of protection of this application should be determined by the claims.
[0037] The embodiments of this application propose a hybrid power system that can be used in a hybrid vehicle. The hybrid power system includes a hybrid power transmission (DHT) and an internal combustion engine, wherein the hybrid power transmission (DHT) can be connected to the internal combustion engine.
[0038] The hybrid transmission includes an electric motor, which can be a dual-rotor motor.
[0039] like Figure 2As shown, a dual-rotor motor may include a first motor unit 100, a second motor unit 200, and a motor stator cooling structure. The second motor unit 200 may be disposed radially outside the first motor unit 100, and the first motor unit 100 and the second motor unit 200 are coaxially arranged. The first motor unit 100 includes a first stator 101 and an inner rotor 102, which may be disposed radially inside the first stator 101. The second motor unit 200 includes a second stator 201 and an outer rotor 202, which may be disposed radially outside the second stator 201, and the second stator 201 may be disposed radially outside the first stator 101. The inner rotor 102 and the outer rotor 202 are coaxially arranged.
[0040] The motor stator cooling structure is used to cool the stator of the motor (including the first stator 101 and the second stator 201). The first stator 101 and the second stator 201 may share a stator core. Both the first stator 101 and the second stator 201 may include windings, which can extend from the axial end of the stator core to form end windings.
[0041] like Figure 1 and Figure 2 As shown, the motor stator cooling structure includes a filter 1, a pump 2, a heat exchanger 3, a valve 4, a cooling jet 5, a pressure relief valve 6, and an oil pan 8.
[0042] The cooling sprayer 5 can be disposed next to the motor stator (first stator 101 and second stator 201). For example, the cooling sprayer 5 can be annular. The cooling sprayer 5 can be disposed at the axial ends of the first stator 101 and the second stator 201 to spray coolant onto the motor stator to cool it. In the radial direction of the dual-rotor motor, the cooling sprayer 5 can be disposed between the end windings of the first stator and the end windings of the second stator. The cooling sprayer 5 can spray coolant radially inward to cool the end windings of the first stator and radially outward to cool the end windings of the second stator. Figure 2 The arrows in the diagram schematically indicate the direction of coolant injection. Figure 2 The dashed line in the diagram represents the central axis of the motor.
[0043] The stator core can be provided with a channel running through it along the axial direction. Cooling jets 5 can be provided at both ends of the stator core along the axial direction. Coolant can pass through the channel from the cooling jet 5 at one end of the axial direction to the cooling jet 5 at the other end of the axial direction, thereby spraying coolant to cool the end winding at the axial end.
[0044] It is understood that the cooling jet 5 sprays coolant onto both the end windings of the first stator and the end windings of the second stator. Above the motor axis, spraying coolant onto the radially outward end windings of the second stator requires overcoming gravity; below the motor axis, spraying coolant onto the radially inward end windings of the first stator requires overcoming gravity. Sufficient pressure needs to be provided for the coolant flowing through the cooling jet 5 so that the coolant needs to overcome gravity to be sprayed onto the end windings of both the first and second stators.
[0045] The downstream side of pump 2 can be connected to a first branch L1 and a second branch L2, and pump 2 is used to pump coolant into the first branch L1 and the second branch L2 respectively. Cooling injector 5 can be installed in the first branch L1, and valve 4 can be installed in the second branch L2.
[0046] The second branch L2 may include an injector for spraying oil into the cooling section 7, which may be a hybrid power system or other parts of the motor that require cooling besides the motor stator (e.g., gear meshing). The second branch L2 is used to supply coolant to other parts besides the motor stator (i.e., the cooling section 7).
[0047] Valve 4 can keep the second branch L2 connected when the pressure upstream of it is greater than a preset value, and valve 4 can block the second branch L2 when the pressure upstream of it is less than or equal to the preset value. As a result, the motor stator cooling structure preferentially supplies coolant to the cooling jet 5, thereby increasing the pressure of the coolant so that it can be sprayed onto the first and second stators.
[0048] Valve 4 can be either a relief valve or a sequence valve. The sequence valve can adjust a preset pressure value. The motor stator cooling structure may also include a valve controller, which can adjust the preset opening and closing pressure of the sequence valve according to the motor's operating power. For example, under different operating conditions, valve 4 can be adjusted to have different preset pressure values, thereby adjusting the supply of coolant at a certain pumping pressure according to the actual operating conditions. Optionally, the preset pressure value can be 0.8 bar. When the cooling demand of the motor stator is high, such as when the motor runs for a long time or when the motor's operating power is high, the preset pressure value can be higher; when the cooling demand of the motor stator is low, the preset pressure value can be lower.
[0049] The motor can operate at a first operating power and a second operating power, with the second operating power being greater than the first operating power. The higher the operating power of the motor, the greater the cooling demand on the motor stator. When the motor operates at the first operating power, the sequence valve has a first preset opening and closing pressure value. When the motor operates at the second operating power, the sequence valve has a second preset opening and closing pressure value, which is greater than the first preset opening and closing pressure value. Therefore, when the motor operates at a higher power, the preset opening and closing pressure value of the sequence valve is also higher, making it less likely for coolant to flow to the second branch L2, and prioritizing the supply to the cooling jets 5 of the first branch L1.
[0050] Valve 4 supplies coolant to the first branch L1 or to both the first branch L1 and the second branch L2 under different conditions. In a dual-mode transmission (DHT), the cooling of the motor stator has a high priority. The motor stator cooling structure of this application can stabilize the oil pressure at the stator cooling injector when the pumping pressure is insufficient, prioritize pumping coolant to the motor stator, stop or reduce the supply of coolant to other cooling locations (i.e., cooling section 7), and when the pumping pressure is sufficient, can supply coolant to multiple cooling locations, including the electronic stator and cooling section 7.
[0051] Optionally, the filter 1 can be connected to the upstream side of the pump 2. When the pump 2 is working, coolant can be drawn from the oil pan 8 through the filter 1. The filter 1 can filter out impurities in the coolant, keeping the coolant flow path unobstructed.
[0052] Heat exchanger 3 can be connected downstream of pump 2 and located upstream of the first branch L1 and the second branch L2. Heat exchanger 3 can cool the coolant and supply coolant at a lower temperature to the parts that need cooling.
[0053] The pressure relief valve 6 can be installed between the pump 2 and the heat exchanger 3. When the pressure of the coolant is too high, the pressure can be relieved through the pressure relief valve 6, so that part of the coolant can flow back directly to the oil pan 8.
[0054] It is understood that pump 2 here can be a mechanical pump. This mechanical pump can be driven to the gear transmission mechanism of the hybrid power system, particularly the gear transmission mechanism used to transmit power to the wheels. The pumping capacity of this mechanical pump is affected by the rotational speed of the traction motor or the vehicle speed, especially it is positively correlated with the rotational speed of the traction motor or the vehicle speed; that is, the pumping capacity of the mechanical pump is greater when the rotational speed of the traction motor or the vehicle speed is higher, and the pumping capacity of the mechanical pump is smaller when the rotational speed of the traction motor or the vehicle speed is lower.
[0055] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.
[0056] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.
[0057] In this application, unless otherwise expressly stated or limited, terms such as "installation," "assembly," "connection," "linking," "joining," "linking," "abutment," "communication," "connection," "conduction," "fixing," and "fastening" should be interpreted broadly, for example, they can be direct or indirect. For instance, regarding connection, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly stated or limited. For instance, regarding communication / conduction, it can be direct communication / conduction or indirect communication / conduction through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0058] In this application, unless otherwise expressly stated or limited, a component being disposed / installed / located / enclosed / placed within, inside, or incorporated in another component can be either of the following two situations: a portion or a majority of the one component is located within the other component; or the one component is completely enclosed within the other component.
[0059] Although the present application has been described in detail using the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described herein. The present application can be modified and implemented as alternative embodiments without departing from the spirit and scope of the present application as defined by the claims. Therefore, the description in this specification is for illustrative purposes only and does not have any limiting meaning for the present application.
Claims
1. A motor stator cooling structure, characterized in that, include: A pump, with a first branch and a second branch connected downstream of the pump, the pump being used to pump coolant into the first branch and the second branch; A cooling sprayer is provided in the first branch and is located next to the motor stator for spraying the coolant onto the motor stator. A valve is provided in the second branch, which is used to supply coolant to parts other than the motor stator. The valve can keep the second branch open when the pressure upstream of it is greater than a preset value, and can block the second branch when the pressure upstream of it is less than or equal to the preset value, so that the motor stator cooling structure preferentially supplies coolant to the cooling injector.
2. The motor stator cooling structure according to claim 1, characterized in that, The valve is either an overflow valve or a sequence valve.
3. The motor stator cooling structure according to claim 1, characterized in that, The pump is a mechanical pump, which is driven by a gear transmission mechanism for transmitting power to the wheels. The pumping capacity of the mechanical pump is positively correlated with the rotational speed of the traction motor or the vehicle speed.
4. The motor stator cooling structure according to claim 1, characterized in that, The valve is a sequence valve, and the motor stator cooling structure also includes a valve controller, which can adjust the preset opening and closing pressure of the sequence valve according to the operating power of the motor.
5. The motor stator cooling structure according to claim 4, characterized in that, When the motor is running at a first operating power, the sequence valve has a first preset opening and closing pressure value. When the motor is running at a second operating power greater than the first operating power, the sequence valve has a second preset opening and closing pressure value greater than the first preset opening and closing pressure value.
6. The motor stator cooling structure according to claim 1, characterized in that, The motor stator cooling structure also includes: A heat exchanger is disposed downstream of the pump and upstream of the first branch and the second branch; A pressure relief valve, wherein the pressure relief valve is disposed between the pump and the heat exchanger; and A filter is disposed upstream of the pump.
7. The motor stator cooling structure according to claim 1, characterized in that, The preset value is 0.8 bar. The cooling sprayer is located at the axial end of the motor stator.
8. An electric motor, characterized in that, The motor includes the motor stator cooling structure according to any one of claims 1 to 7.
9. The motor according to claim 8, characterized in that, The motor is a dual-rotor motor, which includes a first stator and a second stator. The second stator is located radially outside the first stator. In the radial direction of the dual-rotor motor, the cooling sprayer is located between the end windings of the first stator and the end windings of the second stator, and is used to simultaneously spray coolant into the end windings of the first stator and the end windings of the second stator.
10. A hybrid power system, characterized in that, The hybrid power system includes the motor stator cooling structure according to any one of claims 1 to 7, or includes the motor according to claim 8 or 9.