An integrated electronic oil pump

Abstract

The invention discloses an integrated electronic oil pump with a pump housing in which a motor and a rotor pump are provided, wherein the rotor pump is installed in the motor, wherein a ball bearing is provided between the motor and the rotor pump, wherein the motor comprises a stator assembly and a motor rotor, wherein the rotor pump comprises an internal gear, an external gear and a pin, wherein the motor rotor is hollow and is installed within the stator assembly, wherein the external gear is arranged in the motor rotor such that the external gear is integrated into the motor rotor, thereby significantly reducing the size and weight of the system.A shaft sleeve is mounted in the center of the motor rotor, the pin being arranged inside the shaft sleeve, the internal gear being arranged outside the shaft sleeve, the internal gear and the pin each being press-fitted to the shaft sleeve, and the internal gear meshing with the external gear. The integrated electronic oil pump of the invention features a reasonable design, a high degree of integration, small size and weight, and good cooling effect on heating elements.

Description

Technical FieldThe invention relates to the technical field of electronic oil pumps for alternative driven vehicles, and more particularly to an integrated electronic oil pump.Prior ArtWith the rapid development of vehicle electrification and alternative driven vehicles, integrated electronic oil pumps are increasingly being used due to their high efficiency, energy saving, and flexible and varied control. The integrated electronic oil pump is mainly composed of three parts: a rotor pump, an engine, and a controller, etc.At present, most electronic oil pumps are large in size, take up many spaces, and their manufacturing cost is high. In most cases, the bearing between the engine and the rotor pump is mounted on a bearing carrier, whereby the electronic oil pump is relatively high there. In most cases there is a cavity between the pump housing and the rotor pump, so that the friction on the end face of the rotor pump is greater, which leads to severe wear of the rotor pump. In order to prevent the stator in the drive motor from being damaged by too high a temperature, it is necessary to cool the stator in the drive motor with the oil in the transmission. At present, the path over which the lubricant flows through the stator is mostly long, which impairs the cooling effect.Content of the InventionThe object of the invention is to propose a highly integrated electronic oil pump with reasonable design, small size, good cooling effect and low manufacturing costs.In view of the problems in the related art, the object of the invention is to provide a highly integrated electronic oil pump that is small in size, in which a short time is required for cooling the stator and there is low friction on the end face of the rotor pump, and in which the efficiency of the electronic oil pump system can be effectively improved.The technical solution of the invention will be described in this respect.An integrated electronic oil pump having a pump housing is provided, wherein a motor and a rotor pump are provided in the pump housing, wherein the rotor pump is installed in the motor, wherein a ball bearing is provided between the motor and the rotor pump, wherein the motor comprises a stator assembly and a motor rotor, wherein the rotor pump comprises an internal gear, an external gear and a pin, wherein the motor rotor is formed hollow, which is installed within the stator assembly, wherein the external gear is arranged in the motor rotor such that the external gear is integrated into the motor rotor, so that the size and weight of the system is significantly reduced. A shaft sleeve is mounted at a center of the motor rotor, the pin is disposed within the shaft sleeve, the internal gear is disposed outside the shaft sleeve, the internal gear and the pin are each assembled with an interference fit with the shaft sleeve, and the internal gear is engaged with the external gear. Moreover, the ball bearing is disposed between the motor rotor and the external gear such that the ball bearing is attached to one end of the rotor pump so as not to have a cavity between the motor and the rotor pump, which reduces the height of the electronic oil pump and significantly reduces the weight and size of the rotor pump.Moreover, the ball bearing and the pump housing are manufactured with a same mechanical device to ensure a uniform gap between the stator and the rotor of the motor.Moreover, a stator of the motor and a pump body of the rotor pump have a same thermal expansion coefficient, thereby significantly reducing the influence of temperature on the gap of the oil pump.Moreover, the pump housing is formed with an oil inlet and an oil outlet. Moreover, the motor rotor and the external gear drive the internal gear to rotate about the shaft sleeve so that a cooling oil flowing in from the oil inlet is pressurized, a first part of the cooling oil flows under pressure via the pin to the stator assembly to cool the stator assembly and flows back into a low pressure region after heat exchange, and a second part of the cooling oil is directly discharged from the oil outlet via a high pressure region.In addition, a flow channel for the flow of cooling oil through is provided in the pin.As compared with the prior art, the advantageous effects of the invention are as follows: 1) In the technical solution of the invention, the external gear is arranged in the motor rotor, so that the external gear is integrated into the motor rotor. On the one hand, this significantly reduces the size, weight and material and production costs of the system. On the other hand, the friction in the cavity of the rotor pump is effectively reduced, which positively affects the improvement of the system efficiency. According to the present invention, 2) the ball bearing is disposed between the motor rotor and the external gear, the ball bearing supporting the motor and the external gear, so that the ball bearing is attached to the end of the rotor pump to have no hollow space between the motor and the rotor pump, which reduces the height of the electronic oil pump and significantly reduces the weight and size of the rotor pump. According to the present invention, the present invention is not provided with a bearing base in comparison with the conventional electronic oil pump in which the motor rotor is press-fitted into the ball bearing base and then the ball bearing and the pump gear. On the one hand, the overall height of the electronic oil pump is reduced so that the flow path of the cooling oil flowing to the stator assembly under pressure is short, so that it takes a few times and thus the cooling effect is improved. On the other hand, cumulative assembly errors are avoided so that no hidden risks of air gap eccentricity arise. In Fig. 4), the external gear of the rotor pump and the motor rotor are directly assembled with the ball bearings so that the clearance at the end face of the rotor pump can be directly controlled. The external gear drives the housing to rotate synchronously, thereby significantly reducing friction on the pump face and effectively improving system efficiency. In the present invention, since the external gear is integrated with the motor rotor, the motor stator and the pump housing have the same thermal expansion coefficient, whereby the influence of the temperature on the gap of the oil pump is significantly reduced to ensure the gap at the end face of the pumps accurately and to effectively reduce or avoid the influence of the temperature on the system flow rate. In addition, the ball bearing and the pump housing of the invention are machined with the same mechanical device, so that both have very precise coaxiality and concentricity, and the air gap eccentricity can be accurately controlled. 7) The air gap between the outer diameter of the ball bearing and the inner diameter of the pump housing in the invention is accurately controlled, whereby via the ball bearing without a bearing carrier the gap at the end face of the pump is directly controlled, which effectively reduces or eliminates the hidden risk of air gap eccentricity in connecting the ball bearing and the pump gear. In the 8) of the invention, the motor rotor and the external gear commonly drive the internal gear to rotate about the shaft sleeve to pressurize the cooling oil flowing in from the oil inlet, and a first portion of the cooling oil flows under pressure to the stator assembly via the pin to cool the stator assembly, which effectively reduces the temperature of the heating elements. In Fig. 9) the pen of the invention is designed to be statically fixed. The shaft sleeve is placed directly on the pin with press fit. The internal gear rotates relative to the shaft sleeve when driven by the external gear. The friction is reduced by the lubrication, so that the system loss of the pump is reduced and the rotation stability of the pump is effectively improved. In the present invention, 10) is short in comparison with the conventional electronic oil pump, and the period of time for which the cooling oil under pressure flows to the stator assembly is short, so that the cooling effect is improved. In addition, the integrated electronic oil pump of the invention has a reasonable configuration, a high degree of integration, a small size and a light weight, and a good cooling effect on heating elements.DESCRIPTION OF THE DRAWINGSFIG. 1 schematically shows a view of the overall structure of the highly integrated electronic oil pump of the invention; and FIG. 2 is a sectional view of the highly integrated electronic oil pump of the invention.Detailed EmbodimentsThe invention will be further described below with reference to the accompanying drawings. However, the scope of the invention is not limited to the described scope.As shown in FIG. 1, an integrated electronic oil pump includes a pump housing 1. an oil inlet 101 is formed on the bottom of the pump housing 1, and an oil outlet 102 is formed on the side of the pump housing 1, and a filter 14 for filtering the lubricating oil is disposed at the oil inlet 101.In this embodiment, the pump housing 1 is made of aluminum.A motor and a rotor pump are provided in the pump housing 1. The rotor pump is installed in the engine. A ball bearing 7 is arranged between the motor and the rotor pump, the ball bearing being attached to one end of the rotor pump. The motor comprises a stator assembly and a motor rotor 2. the rotor pump comprises an internal gear 6, an external gear 3 and a pin 5.As shown in FIG. 2, the motor rotor 2 is mounted within the stator assembly. The external gear 3 is arranged in the motor rotor 2, wherein the external gear 3 is integrated into the motor rotor 2. A shaft sleeve 4 is mounted at the center of the motor rotor 2. The pin 5 is disposed inside the shaft sleeve 4, and the internal gear 6 is disposed outside the shaft sleeve 4. The internal gear 6 and the pin 5 are respectively press-fitted to the shaft sleeve 4 with the internal gear 6 engaged with the external gear 3.The external gear of the invention is integrated into the motor rotor 2. On the one hand, this significantly reduces the size, weight and material and production costs of the system. On the other hand, the friction in the cavity of the rotor pump is effectively reduced, which increases the system efficiency.The ball bearing 7 of the invention is disposed between the motor rotor 2 and the external gear 3. The ball bearings 7 support the motor rotor 2 to secure the rotation of the external gear 3 in the rotor pump. The ball bearing 7 is attached to the end of the rotor pump so that there is no cavity between the motor and the rotor pump, which reduces the height of the electronic oil pump and significantly reduces the weight and size of the rotor pump.According to the present invention, as compared with the conventional electronic oil pump in which the motor rotor is press-fitted into the ball bearing carrier and then into the ball bearing and the pump gear, no ball bearing carrier is provided. On the one hand, the overall height of the electronic oil pump is reduced so that the flow path of the cooling oil flowing to the stator assembly under pressure is short, so that it takes a few times and thus the cooling effect is improved. On the other hand, cumulative assembly errors are avoided so that no hidden risks of air gap eccentricity arise.The ball bearing 7 and the pump housing 1 of the present embodiment are machined with the same mechanical device so that both have very precise coaxiality and concentricity, whereby the air gap eccentricity can be accurately controlled.According to the present invention, since the external gear is integrated into the motor rotor, and the stator 8 of the motor and the pump casing have an equal coefficient of thermal expansion, whereby the influence of the temperature on the oil pump gap is significantly reduced, the gap at the end face of the pumps is accurately secured, and the influence of the temperature on the system flow rate is effectively reduced or avoided.The mechanism by which the cooling oil cools the stator assembly according to the invention is described in this respect.The motor rotor 2 and the external gear 3 commonly drive the internal gear 6, rotates around the shaft sleeve 4 to pressurize the cooling oil flowing in from the oil inlet 101, a first part of the cooling oil flows under pressure to the stator assembly via the pin 5 to cool the stator assembly, and thereafter flows back to a low pressure region after heat exchange.Moreover, a second part of the cooling oil is discharged under pressure directly from the oil outlet 102 via a high-pressure region.In this exemplary embodiment, a flow channel for cooling oil to flow through is provided in the pin 5.Furthermore, the pin 5 is hollow or full.In particular, the pin 5 of the invention is designed to be statically fixed. The shaft sleeve 4 is pressed directly onto the pin 5. The pump internal gear 6 rotates relative to the shaft sleeve 4 when driven by the external gear 3. The friction is reduced by the lubrication with each other, so that the system loss of the rotor pump is reduced and the rotation stability of the rotor pump is effectively improved.In the invention, due to the reduced overall height of the electronic oil pump, the time for which the cooling oil flows under pressure to the stator assembly is shorter compared to the conventional electronic oil pump, so that the cooling effect is also better.In this embodiment, the stator assembly includes a stator 8 and a stator winding 9 on the stator 8, and in this embodiment, the stator 8 is formed of a silicon iron sheet to reduce manufacturing cost and reduce friction of rotating components. The wire diameter of the stator winding 9 is 1.8 mm. As compared with the conventional wire diameter of 1.6 mm, the performance of the rotor pump is significantly improved.In this embodiment, a radial magnet 10 is attached to the soft magnetic alloy rotor 2 to monitor its position.In order to simplify the construction of the electronically controlled arrangement, the conventional winding is simplified. Above the stator assembly, a stroke 11 is provided. The base pins of the stator winding 9 are connected to the hub 11.A controller 12 is arranged above the stroke 11. Fast reagation can be achieved by the controller 12 of the invention. The control according to the invention is polarity proof, by means of which the signal interferences and the overtemperature can be prevented and by means of which the oil temperature can be monitored. Furthermore, the control according to the invention is characterized in that the control has an independent communication channel, that the control can detect the angular position of the motor, that the control can receive and calculate a rotational speed comparison of the motor, and that the control can regulate the rationality of the actual rotational speed of the rotor.In order to disconnect the oil circuit and the electronically controlled arrangement, a heat insulating sealing plate 13 is provided between the controller 12 and the stroke 11 to improve the tightness. The heat insulating seal plate 13 is engaged with and fixed to the stroke 11 to avoid a screwed fixing structure inside the oil pump.A PTC (Positive Temperature Coefficient) temperature sensor (not shown in the figures) for detecting and feedbacking the temperature of the cooling oil is attached to the heat insulating seal plate 13. The PTC temperature sensor (not shown in the figures) is electrically connected to the controller 12. The oil temperature can be detected with an accuracy of 0.1° C. by the PTC temperature sensor according to the invention.The detailed course for cooling the stator assembly in the invention is as follows. 1) The device is first connected to a power source. At this time, the controller 12 is energized. The controller 12 converts the current into a three-phase alternating current to supply current to the stator winding 9 at the hub 11. The electromagnetic force drives the motor rotor 2 and the external gear 3 to rotate. The rotor 2 and the external gear 3 rotate, so that the cooling oil flowing in from the oil inlet 101 flows over the filter 14 and then reaches the low-pressure region. In addition, as shown in FIG. 2), the motor rotor 2 and the external gear 3 commonly drive the internal gear 6 to rotate about the shaft sleeve 4 so that the cooling oil flowing in from the oil inlet 101 is pressurized, a first part of the cooling oil flows under pressure to the stator assembly via the pin 5 to cool the stator assembly, and flows back to the low pressure region after the heat exchange. At this time, the cooling oil is pressurized with the centrifugal force generated due to the difference between the internal gear and the external gear. At this time, the current temperature value of the oil is fed back from the PTC temperature sensor and passed to the controller 12, which passes the current oil temperature value to an external control system. In FIG. 3 ), a second portion of the cooling oil under pressure is directly discharged from the oil outlet 102 via a high pressure region.List of reference characters1 Pump housing 101 Oil inlet 102 Oil outlet 2 Motor rotor 3 External gear 4 Shaft sleeve 5 Pin 6 Internal gear 7 Ball bearing 8 Stator 9 Stator winding 10 Radial magnet 11 Stroke 12 Controller 13 Heat insulating seal plate 14 Filter

Claims

An integrated electronic oil pump comprising a pump housing (1), wherein a motor and a rotor pump are provided in the pump housing (1), wherein the rotor pump is installed in the motor, wherein a ball bearing (7) is provided between the motor and the rotor pump, wherein the motor comprises a stator assembly and a motor rotor (2), wherein the rotor pump comprises an internal gear (6), an external gear (3) and a pin (5), characterized in that the motor rotor (2) is formed hollow, which is installed within the stator assembly, wherein the external gear (3) is arranged in the motor rotor (2) such that the external gear (3) is integrated in the motor rotor (2), wherein a shaft sleeve (4) is mounted in a center of the motor rotor (2), wherein the pin (5) is arranged within the shaft sleeve (4), wherein the internal gear (6) is disposed outside the shaft sleeve (4), wherein the internal gear (6) and the pin (5) are assembled with press fit with the shaft sleeve (4), respectively, and wherein the internal gear (6) is engaged with the external gear (3).The integrated electronic oil pump according to claim 1, characterized in that the ball bearing (7) is disposed between the motor rotor (2) and the external gear (3) such that the ball bearing (7) is attached to one end of the rotor pump.The integrated electronic oil pump according to claim 1, characterized in that the ball bearing (7) and the pump housing (1) are manufactured with a same mechanical device.The integrated electronic oil pump according to claim 2, characterized in that a stator of the motor and a pump body of the rotor pump have a same thermal expansion coefficient.The integrated electronic oil pump according to claim 1, characterized in that the pump housing (1) is formed with an oil inlet (101) and an oil outlet (102).The integrated electronic oil pump according to claim 5, characterized in that the motor rotor (2) and the external gear (3) drive the internal gear (6) to rotate about the shaft sleeve (4) so that a cooling oil flowing in from the oil inlet (101) is pressurized, a first part of the cooling oil flows under pressure to the stator assembly via the pin (5) to cool the stator assembly and flows back to a low pressure region after heat exchange, and a second part of the cooling oil is directly discharged from the oil outlet (102) via a high pressure region.The integrated electronic oil pump according to claim 1 or 6, characterized in that a flow channel for cooling oil to flow through is provided in the pin (5).

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