CN114320881A

CN114320881A - Motor oil pump

Info

Publication number: CN114320881A
Application number: CN202011062877.5A
Authority: CN
Inventors: 杨鲁川
Original assignee: Changzhou Rich Engine Technology Co ltd
Current assignee: Changzhou Rich Engine Technology Co ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2022-04-12

Abstract

The invention provides an electric motor oil pump which comprises a base (1), a pump body (2), an electric motor (3) and an electric motor cover plate (4) which are sequentially assembled along the axial direction, wherein when the electric motor oil pump works, a positive pressure area for pumping out engine oil and a negative pressure area for sucking in the engine oil are formed in the electric motor oil pump. The motor stator (34) is provided with a distal end bearing portion (346) at one end remote from the pump body, and one end of the motor rotating shaft (33) is supported by the distal end bearing portion. A through hole (342) extending along the axial direction is arranged in the cylinder wall of the motor stator, one end of the through hole is communicated with the positive pressure area, and the other end of the through hole is communicated with the far-end bearing part. This allows pressurized oil from the positive pressure region to be directed through the through-hole in the stator to the distal bearing portion to lubricate it. In addition, the motor oil pump of the present invention is further provided with an oil return passage for returning the oil accumulated in the motor stator cavity to the negative pressure region. The invention can realize the quick cooling of the motor oil pump and improve the performance of the motor.

Description

Motor oil pump

Technical Field

The invention relates to an oil pump of a motor, in particular to a lubricating mechanism of the oil pump of the motor.

Background

With the increasing motorization of automobiles, the oil pump, one of the key parts of the automobiles, is upgraded to the motor oil pump more and more. In general, a motor oil pump is a unit in which a conventional mechanical oil pump is integrated with a drive motor and a controller thereof, and then is mounted on a service object.

The conventional motor oil pump is generally classified into a cantilever-type motor oil pump having a single bearing and a double-bearing motor oil pump having two ends supported by a single bearing, in terms of the type of supporting the rotating shaft.

As is well known, automobiles, particularly passenger cars, have extremely stringent requirements for installation space of parts, and electric motor oil pumps are no exception. In particular, the space available for mounting an oil pump that provides pressure or lubrication services to an engine or transmission is more limited. Therefore, in order to obtain sufficient power in a limited space, the axial dimension of the electric motor oil pump must be increased, and in this case, both ends must be supported by double bearings. Typically, ball bearings or needle bearings are used. However, due to the space structure, the price of parts, and the like, a sliding bearing is sometimes required, and one problem to be solved at this time is the lubrication of the bearing at the end far from the oil pump part.

In the prior art, lubricating grease is generally sealed at a bearing part by an oil seal for lubrication. The conventional lubrication method has problems that the rotating shaft rotating at high speed causes high temperature of a bearing part, grease can be deteriorated after being in a high-temperature environment for a long time, and the high-speed rotation of the shaft can generate tensile acting force on grease molecules to damage the grease, so that the lubrication effect of the grease is failed, the shaft is damaged, and the whole motor oil pump is damaged as a result. Therefore, the grease lubrication is difficult to meet the requirements of automobile parts on long service life and even lifetime. In addition, the oil seal can create resistance to the movement of the shaft, causing a loss of system energy.

In the other technical scheme in the prior art, a lubricating oil way is arranged outside a product, and the technical scheme has the advantages of complex structure, huge system, excessive occupied space, more parts and higher cost, and is not suitable for increasingly severe requirements of modern passenger cars on motor oil pumps.

In addition, the motor and the electric control components thereof integrated in the motor oil pump can generate a large amount of heat during working, if the heat can not be dissipated in time, the motor is overheated, the efficiency of the motor is reduced, the energy consumption is increased, and the motor and the electric control components thereof can be damaged even in severe cases. In order to improve the efficiency of the motor and the whole motor oil pump and the reliability of the motor and the electric control components thereof, the high-power motor oil pump must take active measures to actively dissipate heat.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a motor oil pump capable of solving the problem of lubrication of a distal end bearing of the motor oil pump and the problem of heat dissipation of a motor and its electrically controlled components in the prior art with a simple structure.

In order to achieve the above and other related objects, the present invention provides an electric motor oil pump in which a positive pressure region for pumping out oil and a negative pressure region for sucking in oil are formed when the electric motor oil pump is operated, the electric motor oil pump including a motor stator having a substantially cylindrical shape, wherein the motor stator is provided with a distal end bearing portion at a cylinder bottom portion on one side, and at least one first through hole extending substantially in an axial direction is provided in an interior of a cylinder wall, a first end of the first through hole communicating with the positive pressure region, and a second end of the first through hole communicating with the distal end bearing portion.

In one embodiment of the present invention, the motor oil pump further includes a hollow motor shaft having one end supported by the distal end bearing portion, a first end of the internal passage of the hollow motor shaft is communicated with the negative pressure region, and a second end of the internal passage of the hollow motor shaft is communicated with the distal end bearing portion.

In an embodiment of the present invention, the inside of the cylinder wall of the motor stator is further provided with at least one second through hole extending substantially in the axial direction, a first end of the second through hole is communicated with the negative pressure region, and a second end of the second through hole is communicated with the distal end bearing portion.

In one embodiment of the present invention, the motor oil pump includes a pump body axially fitted with the motor stator, a pump body positive pressure chamber and a pump body negative pressure chamber are formed in the pump body when the motor oil pump is operated, a first communication passage communicating with the pump body positive pressure chamber is provided on the pump body, and a second communication passage communicating the first through hole and the first communication passage is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other.

In one embodiment of the present invention, the motor oil pump includes a pump body axially fitted with the motor stator, a pump body positive pressure chamber and a pump body negative pressure chamber are formed in the pump body when the motor oil pump is operated, a third communication passage communicating with the pump body negative pressure chamber is provided on the pump body, and a fourth communication passage communicating the second through hole with the third communication passage is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other.

In one embodiment of the present invention, a plurality of first through holes are provided, a first communication oil passage is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other, and first ends of the plurality of first through holes are respectively communicated with the first communication oil passage.

In one embodiment of the present invention, a plurality of second through holes are provided, a second communication oil passage is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other, and first ends of the plurality of second through holes are respectively communicated with the second communication oil passage.

In an embodiment of the present invention, the present invention further provides an electric motor oil pump, when the electric motor oil pump is operated, a positive pressure region for pumping out oil and a negative pressure region for sucking in oil are formed in the electric motor oil pump, the electric motor oil pump includes a substantially cylindrical motor stator, wherein the motor stator is provided with a distal end bearing portion at a cylinder bottom portion on one side, at least one second through hole extending substantially in an axial direction is provided in an interior of the cylinder wall, a first end of the second through hole is communicated with the negative pressure region, a second end of the second through hole is communicated with the distal end bearing portion, the electric motor oil pump further includes a hollow motor shaft having one end supported by the distal end bearing portion, a first end of an internal channel of the hollow motor shaft is communicated with the positive pressure region, and a second end of the internal channel of the hollow motor shaft is communicated with the distal end bearing portion.

In one embodiment of the present invention, the motor oil pump includes a pump body axially fitted with the motor stator, a pump body negative pressure chamber is formed in the pump body when the motor oil pump is operated, a third communicating channel communicating with the pump body negative pressure chamber is provided on the pump body, and a fourth communicating channel communicating the second through hole and the third communicating channel is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other.

In one embodiment of the present invention, a plurality of second through holes are provided, and a sixth communication oil passage that communicates second ends of the second through holes with each other is provided on at least one of axial end surfaces where the motor stator and the pump body are fitted to each other.

In an embodiment of the present invention, a stator cavity is formed in the motor stator, the motor oil pump further includes an oil return path, one end of the oil return path is communicated with the stator cavity, and the other end of the oil return path is communicated with the negative pressure region.

In an embodiment of the invention, the electric motor oil pump further includes a motor cover plate, the motor cover plate is disposed axially outside the distal end bearing portion of the motor stator and is configured to cover the motor stator, a drainage channel is formed between the motor stator and the motor cover plate, and the second end of the first through hole is communicated with the distal end bearing portion via the drainage channel.

In the motor oil pump of the present invention, the through hole is provided in the motor stator, one end of the through hole is communicated with the oil outlet, and the other first end is communicated with the distal end bearing portion, so that a part of oil is pressed into the through hole of the motor stator from the positive pressure region, for example, the oil outlet of the oil pressure chamber, and reaches the distal end bearing portion far away from one end of the oil pump through the through hole in the stator, thereby lubricating the distal end bearing.

In above-mentioned technical scheme, make above-mentioned motor shaft with the hollow shaft, the inside passage one end and the machine oil entry intercommunication of hollow shaft, the other end and distal end bearing portion intercommunication, get into distal end bearing portion through the through-hole at the machine oil and realize lubricated back to distal end bearing, get back to the negative pressure zone through the inside passage of hollow shaft, and simultaneously, in the circulation process through motor stator, utilize fluid directly to contact with motor stator and carry out the heat transfer, carry out the initiative cooling to motor stator, can realize the rapid cooling of motor, improve motor efficiency, reduce the energy consumption, promote motor performance and reliability. The motor rotating shaft is made of a hollow shaft, so that engine oil passes through the hollow shaft, the flow can be increased, and the heat dissipation effect is enhanced. Besides, the motor rotor arranged on the hollow shaft can be actively radiated by using the engine oil flowing through the hollow shaft, so that the overall radiating effect of the motor is further enhanced.

In addition, the motor controller is arranged close to the oil way, so that partial heat of the controller can be taken away when oil flows through the controller, active heat dissipation of the motor controller is facilitated, and as a result, the power density of the motor controller can be improved, the overload resistance of the controller is improved, the reliability of a product is improved, and the requirement on the heat resistance grade of an electronic component can be reduced when the electronic component is selected, so that the component with low price can be used, and the raw material cost is reduced.

Further, by guiding the oil to the distal end bearing portion, it is possible to wash away debris generated and accumulated by the wear of the bearing portion, and as a result, it is possible to reduce the secondary wear of the bearing by the debris and to extend the service life of the product.

Drawings

Fig. 1 is an exploded view of an electric oil pump according to an embodiment of the present invention.

Fig. 2 is a plan view of a pump body of the motor oil pump in an embodiment of the present invention.

Fig. 3 is a sectional view of the electric motor oil pump according to an embodiment of the present invention taken along line a-a of fig. 2.

Fig. 4 is a bottom view of the motor stator of fig. 3.

Fig. 5 is a plan view of a base of the motor oil pump in an embodiment of the present invention.

Fig. 6 is a bottom view of a stator of an electric machine according to another embodiment of the present invention.

Fig. 7 is a sectional view of an electric motor oil pump according to another embodiment of the present invention, taken along line B-B of fig. 6.

Fig. 8 is a bottom view of a stator of an electric machine in accordance with yet another embodiment of the present invention.

Fig. 9 is a sectional view of an electric motor oil pump according to still another embodiment of the present invention, taken along the line C-C of fig. 8.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

The embodiment of the present invention is described by taking an electric motor oil pump 100 as an example, and fig. 1 is an exploded perspective view of the electric motor oil pump 100 of an embodiment, where the electric motor oil pump 100 is an internal-meshing cycloid rotor electric motor oil pump, and as shown in fig. 1, the electric motor oil pump 100 includes an oil pump portion 10, a motor 3, and a cover plate 4 which are assembled in an axial direction.

Fig. 1 is an exploded view of a motor oil pump according to an embodiment of the present invention, fig. 2 is a plan view of a pump body of the motor oil pump according to an embodiment of the present invention, fig. 3 is a sectional view of the motor oil pump according to an embodiment of the present invention taken along line a-a in fig. 2, fig. 4 is a bottom view of a motor stator in fig. 3, and fig. 5 is a top view of a base of the motor oil pump according to an embodiment of the present invention. Referring to fig. 1 to 5, the oil pump portion 10 includes a base 1 and a pump body 2. In the present embodiment, an oil inlet 11 and an oil outlet 12 of the electric motor oil pump 100 are provided at the bottom of the base 1, the oil inlet 11 is used for connecting with an external oil tank, and the oil outlet 12 is used for pumping out the oil pressurized by the electric motor oil pump 100. The top axial end surface 101 of the base 1 is provided with a base negative pressure chamber 14 and a base positive pressure chamber 15, the base negative pressure chamber 14 is communicated with the engine oil inlet 11, and the base positive pressure chamber 15 is communicated with the engine oil outlet 12. The pump body 2 includes a pump body 24 as a pump housing and a pair of rotors as pump cores, i.e., a driving rotor 22 and a driven rotor 21 that meshes with the driving rotor 22, and a cavity 23 as a pump chamber is formed inside the pump body 24, and the cavity 23 has a substantially cylindrical shape. The cavity 23 may be formed in the pump body 24, the base 1, or a part of the pump body 24 and a part of the base 1, and the driving rotor 22 and the driven rotor 21 are accommodated in the cavity 23 in an internally engaged state. A pump body negative pressure chamber 27 and a pump body positive pressure chamber 28 are formed in the pump body 24 at positions inside the top of the cavity 23, and the positions of the pump body negative pressure chamber 27 and the pump body positive pressure chamber 28 correspond to the positions of the base negative pressure chamber 14 and the base positive pressure chamber 15 in the base 1, respectively. Further, a proximal bearing portion 25 is formed on the pump body 24 upward from the cavity 23, and the proximal bearing portion 25 has a pump body axial hole 26 axially penetrating therethrough, one side of which communicates with the cavity 23.

The motor 3 includes a motor rotor 32, a motor shaft 33 and a motor stator 34, the motor stator 34 is formed into a substantially hollow cylindrical shape, the hollow portion is the stator cavity 5, and the motor rotor 32 is sleeved on the motor shaft 33 and is disposed in the stator cavity 5. In the present embodiment, as shown in fig. 1 and 2, the motor shaft 33 is also a shaft of the driving rotor 22 of the pump body 2, and the motor shaft 33 is inserted into the pump body shaft hole 26, and is connected to the driving rotor 22 at a lower portion of the pump body bearing portion 25, and is connected to the motor rotor 32 at an upper portion of the pump body bearing portion 25. In the present embodiment, a distal end bearing portion 346 is provided at an end of the motor stator 34 remote from the oil pump portion 10, the distal end bearing portion 346 having a motor shaft hole 347 axially penetrating therethrough, one side of the motor shaft hole 347 communicating with the stator cavity 5. Both ends of the motor shaft 33 are supported at the proximal bearing portion 25 and the distal bearing portion 346, respectively. In the present embodiment, the sliding bearing at the proximal bearing portion 25 is substantially constituted by the pump body shaft hole 26, and the sliding bearing at the distal bearing portion 346 is substantially constituted by the motor shaft hole 347.

When the motor oil pump 100 is operated, the motor shaft 33 rotates the driving rotor 22, the driven rotor 21 is driven by the driving rotor 22 to rotate, an oil suction chamber 271 and an oil extrusion chamber 281 are periodically formed between the driving rotor 22 and the driven rotor 21 according to the change of the volume of the liquid between the gears, the lower end of the oil suction chamber 271 is communicated with the base negative pressure chamber 14, the upper end is communicated with the pump body negative pressure chamber 27, the lower end of the oil extrusion chamber 281 is communicated with the base positive pressure chamber 15, and the upper end is communicated with the pump body positive pressure chamber 28, thus, external oil is sucked into the base negative pressure chamber 14 through the oil inlet 11, then into the oil suction chamber 271 and the pump body negative pressure chamber 27, and then, the oil is pumped to the pump body plenum 28 and the oil pressure chamber 281, and the finally pressurized oil is pumped out to the outside of the motor oil pump 100 through the base plenum 15 and the oil outlet 12.

When the electric motor oil pump 100 is operated, the oil pressures at the base negative pressure chamber 14, the pump body negative pressure chamber 27, and the oil inlet 11 are substantially the same, the oil pressures at the base positive pressure chamber 15, the pump body positive pressure chamber 28, and the oil outlet 12 are substantially the same, and the oil pressures at the base negative pressure chamber 14, the pump body negative pressure chamber 27, and the oil inlet 11 are lower than the oil pressures at the base positive pressure chamber 15, the pump body positive pressure chamber 28, and the oil outlet 12, where the base negative pressure chamber 14, the pump body negative pressure chamber 27, and the oil inlet 11 are collectively referred to as a negative pressure region, and the base positive pressure chamber 15, the pump body positive pressure chamber 28, and the oil outlet 12 are collectively referred to as a positive pressure region.

In the present embodiment, as shown in fig. 3, since the axial dimension of the electric motor oil pump 100 is relatively large, it is necessary to perform shaft support at both the proximal bearing portion 25 and the distal bearing portion 346. In order to reduce the cost of the parts, the sliding bearing is used for the support in the present embodiment, as described above, the sliding bearing in the present embodiment is composed of the motor shaft hole 347 embedded in the distal end bearing portion 346, and the motor shaft hole 347 is shown as a bush made of a wear-resistant material, but of course, the bush may be omitted in the case where the bush is not required. In order to solve the problem of lubrication of the distal end bearing at the end remote from the oil pump portion 10, in the present embodiment, as shown in fig. 1 to 5, a lubrication oil passage is provided, which is designed to lead pressure oil to the distal end bearing from a positive pressure region such as the base positive pressure chamber 15 or the pump body positive pressure chamber 28 or the oil outlet 12. For convenience of explanation, the sectional view of fig. 3 is bounded by the shaft axis of the motor shaft 33, and the left side of the shaft axis schematically shows the structure of a lubrication oil passage, and the right side of the shaft axis schematically shows the structure of an oil return passage to be described below. As an example, the lubricating oil path includes a plurality of substantially axially extending first through holes 342 provided in the cylinder wall of the motor stator 34 at a distance from each other, the lower ends (first ends) of the first through holes 342 communicating with the pump body plenum 28, and the upper ends (second ends) communicating with the distal end bearing portions 346. In the present embodiment, as shown in fig. 3, a first communication channel 282 communicating with the pump body positive pressure chamber 28 is provided on the pump body 24, and a second communication channel 341 communicating with 342 is provided at the bottom of the motor stator 34 (see fig. 4), and when the motor stator 34 and the pump body 24 are assembled in the axial direction, the first communication channel 282 and the second communication channel 341 are communicated to form communication between the pump body positive pressure chamber 28 and the first through hole 342. A flow guide passage 343 is provided at the top of the motor stator 34, and one end of the flow guide passage 343 communicates with the first through hole 342 and the other end communicates with the distal bearing portion 346. Of course, the method of communicating both ends of the first through hole 342 with the pump body positive pressure chamber 28 and the distal end bearing portion 346, respectively, is not limited to the example given in this embodiment, and various appropriate design changes may be made as necessary.

In addition, when the motor stator 34 is provided with the plurality of first through holes 342, in order to simplify the structure, as shown in fig. 4, a first communication oil passage 3411 for communicating bottom ends (first ends) of the respective first through holes 342 with each other and a second communication passage 341 are provided on a bottom surface of the motor stator 34, that is, a surface to be assembled with the pump body 24, so that the second communication passage 341 provided in the motor stator 34 and the first communication passage 282 provided in the pump body 24 can be communicated with each other only by providing the first communication passage 282 in the pump body 24 after the motor 3 and the pump body 2 are assembled. Of course, if it is possible to directly communicate the at least one first through hole 342 with the first communication passage 282, the second communication passage 341 need not be provided. Thus, a part of the pressure oil from the pump body plenum 28 is sent to the distal bearing portion 346 through the first communication passage 282, the second communication passage 341, the first communication oil passage 3411, and the first through hole 342, and lubricates and dissipates the oil, and washes away friction debris accumulated in the bearing.

Although the first communicating oil passage 3411 is C-shaped and the second communicating passage 341 is straight on the bottom surface of the motor stator 34 in the present embodiment, the shape, size, and arrangement position of these communicating oil passages and communicating passages may be freely designed and changed as necessary as long as the communicating function of the oil passages is achieved. For example, the first communication oil passage 3411 and the second communication passage 341 may be provided on the top surface of the pump body 24, that is, the fitting surface with the bottom surface of the motor stator 34, or may be provided on the bottom surface of the motor stator 34 and the top surface of the pump body 24, respectively.

Although 6 first through holes 342 are provided as shown in fig. 4 in the present embodiment, the number of first through holes 342 is not limited to 6, and may be any number of 1 or more as long as pressure oil can be guided to the distal bearing portion. Further, the first communication passage 282 is merely an example, and the elements such as the position, the number, the arrangement form, and the shape of the first communication passage 282 may be arbitrary as long as pressure oil can be guided from the base positive pressure chamber 15, the pump body positive pressure chamber 28, or the oil outlet 12 to the first through hole 342. In addition, the drainage channel 343 is not limited to the number, position, etc. corresponding to the first through hole 342, and as long as the pressure oil can be guided from the first through hole 342 to the distal bearing portion 346, the arrangement position, number, arrangement form, shape, etc. may be any elements, for example, the drainage channel 343 may be arranged on the bottom surface of the motor cover 4 connected to the motor stator 34, and the drainage channel 343 may be a flat oil pool, etc. defined by the motor cover 4 and the motor stator 34, which communicates the first through hole 342 with the distal bearing portion 346.

Through set up the through-hole on the section of thick bamboo wall of motor stator, utilize this through-hole to form lubricated oil circuit, direct pressure oil to distal end bearing department from positive pressure district such as base plenum 15 or pump body plenum 28 or even engine oil export 12, not only can lubricate and wash the bearing of distal end, can also carry out initiative heat dissipation to the motor simultaneously.

Although the present embodiment exemplifies the case of a sliding bearing, the present invention has advantageous effects even in the case of using a rolling bearing, since the size of the bearing can be reduced and thus the volume of the motor oil pump product as a whole can be reduced, bearing loss can be reduced, and oil pump efficiency can be improved, as compared with a rolling bearing structure without lubrication.

In addition, the fully lubricated bearing can reduce noise, avoid excessive temperature rise of the bearing, reduce bearing loss and improve the efficiency of the oil pump, so that the motor and the oil pump with the same specification can bear higher rotating speed and higher current than the original motor and oil pump, and the reliability is also improved.

In addition, as a first modified example of the embodiment of the present invention, although not shown, it is conceivable that a single hollow shaft (see hollow motor shaft 33' in fig. 9) may be used instead of motor shaft 33, and in this case, the lower end (first end) of the hollow motor shaft is made to communicate with the negative pressure region such as oil inlet 11, base negative pressure chamber 14, or pump body negative pressure chamber 27, and the upper end (second end) is made to communicate with distal end bearing portion 346, and after the oil enters the distal end bearing portion through first through hole 342 to lubricate the distal end bearing portion, the oil returns to the negative pressure region through the internal passage of the hollow motor shaft. Therefore, the flow of the engine oil flowing through the first through hole 342 can be increased, the effect of active heat dissipation of the motor stator 34 is enhanced, and meanwhile, when the lubricating oil flows through the axis through hole serving as the hollow motor rotating shaft, the heat of the motor rotor 32 sleeved on the hollow shaft can be taken away, so that the motor rotor 32 can be actively dissipated.

A second modified example of the embodiment of the present invention is explained with reference to fig. 6 and 7. Fig. 6 is a bottom view of a stator of a motor according to another embodiment of the present invention, and fig. 7 is a sectional view of an oil pump of the motor according to another embodiment of the present invention taken along line B-B of fig. 6. As shown in fig. 7, in addition to the first through hole 342, the first communication passage 282 and the second communication passage 341 which communicate the first through hole 342 with the pump body positive pressure chamber 28, a second through hole 344 which extends substantially in the axial direction may be further provided in the motor stator 34, the upper end (second end) of the second through hole 344 may be made to communicate with the distal end bearing portion 346, a third communication passage 284 may be provided in the pump body 24, one end of the third communication passage 284 may be made to communicate with the pump body negative pressure chamber 27 (of course, may be made to communicate with other negative pressure regions such as the oil inlet 11, the base negative pressure chamber 14, etc.), and a fourth communication passage 345 which extends substantially in the radial direction may be provided in the lower surface of the motor stator 34, that is, the fitting surface with the pump body 24, one end of the fourth communication passage 345 may be made to communicate with the lower end (first end) of the second through hole 344, and the other end may be made to communicate with the third communication passage 284, that is, the upper ends of the first through hole 342 and the second through hole 344 are both communicated with the distal end bearing portion 346, the lower end of the first through hole 342 is communicated with the pump body positive pressure chamber 28 (certainly, it may be communicated with other positive pressure regions such as the oil outlet 12, the base positive pressure chamber 15, etc.), the lower end of the second through hole 344 is communicated with the pump body negative pressure chamber 27 (certainly, it may be communicated with other negative pressure regions such as the oil inlet 11, the base negative pressure chamber 14, etc.), so that the oil entering the first through hole 342 from the positive pressure region reaches the distal end bearing portion 346 and is divided into two parts, one part lubricates the distal end bearing portion 346, the other part enters the second through hole 344 and goes to the negative pressure region through the fourth communication passage 282, thus forming a circuit of the oil from the positive pressure region to the negative pressure region inside the cylinder wall of the motor stator 34.

Here, the positional relationship between the first through hole 342 and the second through hole 344 is arbitrary, and the shape and the number thereof are not limited at all, and those skilled in the art can design arbitrarily as needed. Further, although the communication structure of the second through hole 344 with the negative pressure region is similar to that between the first through hole 342 and the positive pressure region as shown in fig. 6, the communication structure between the second through hole 344 and other negative pressure regions may be provided with reference to or using an oil return passage in fig. 3, which will be described below.

Further, when the plurality of first through holes 342 and the plurality of second through holes 344 are provided, in order to simplify the structure, a C-shaped second communication oil path 3415 is provided to communicate the lower end of each first through hole 342, a C-shaped third communication oil path 3417 is provided to communicate the lower end of each second through hole 344, a straight fourth communication oil path 3412 communicates the second communication oil path 3415 with the first communication passage 282, a straight fifth communication oil path 3416 communicates the third communication oil path 3417 with the third communication passage 284, pressure oil from the positive pressure region is guided to the second communication oil path 3415 and distributed to the plurality of first through holes 342, and oil from the plurality of second through holes 344 is collected in the third communication oil path 3417 and is collectively guided to the negative pressure region, as shown in fig. 6.

In addition, as a third modified example of the embodiment of the present invention, as shown in the right part of fig. 3, an oil return path is provided in the electric motor oil pump 100, and in this example, the oil return path is constituted by a guide groove 3413 provided on the bottom surface of the motor stator 34 in the substantially radial direction and an oil return path 242 provided on the pump body 24 in the substantially axial direction, one end of the guide groove 3413 communicates with the stator cavity 5, and after the motor stator 34 and the pump body 24 are assembled, the guide groove 3413 communicates with the upper end (first end) of the oil return path 242. The lower end (first end) of the oil return passage 242 communicates with the linear first oil return groove 17 provided on the top surface of the base 1, and further communicates with the base negative pressure chamber 14 via the annular second oil return groove 18 communicating with the first oil return groove 17 and the third oil return groove 19 communicating the second oil return groove 18 with the base negative pressure chamber 14 (see also the top view of the base 1 of fig. 5). In this way, oil accumulated in the stator cavity 5 after lubricating the distal bearing can be led back to the base underpressure chamber 14 by means of underpressure in the system.

Through setting up the oil return oil circuit, when lubricated the bearing of distal end, can also discharge participating in lubricated machine oil from the stator cavity, this has not only strengthened lubricated, washing and radiating effect, can not make fluid pile up in the stator cavity because of introducing machine oil to distal end bearing moreover, consequently has almost no resistance to electric motor rotor's rotation, can not make motor efficiency reduce.

Of course, this is merely a specific design example of the oil return passage, and the present invention is not limited to this, and any design change may be made in the shape, size, and installation position of each oil passage as long as the oil accumulated in the stator cavity 5 due to the lubrication of the distal end bearing can be led back to the negative pressure region such as the pump body negative pressure chamber 27, the base negative pressure chamber 14, or the oil inlet 11, and for example, an oil passage such as a through hole for communicating the stator cavity with the pump body negative pressure chamber may be provided in the proximal end bearing portion 25.

Next, a fourth modification of the present embodiment will be described with reference to fig. 8 and 9. Fig. 8 is a bottom view of a stator of a motor according to still another embodiment of the present invention, and fig. 9 is a sectional view of an oil pump of the motor according to still another embodiment of the present invention taken along the line C-C of fig. 8. As shown in fig. 8 and 9, the motor rotating shaft in the present embodiment is a hollow motor rotating shaft 33', and its upper end (second end) communicates with the distal end bearing portion 346 and its lower end (first end) communicates with the base plenum 15 through the oil supply groove 16 (of course, it may communicate with other plenums such as the engine oil outlet 12 or the pump body plenum 28). The oil return passage 242 is provided in the pump body 24, a fifth communication passage 349 is provided on the bottom surface of the motor stator 34, that is, on the fitting surface with the pump body 24, the upper end (second end) of the second through hole 344 communicates with the distal end bearing portion 346 through the drainage passage 343, and the lower end (first end) of the assembled second through hole 344 communicates with the oil return passage 242 provided in the pump body 24 through the fifth communication passage 349.

As shown in fig. 8, a sixth communicating oil path 3414 for communicating bottom ends (first ends) of the second through holes 344 with each other is provided on a bottom surface of the motor stator 34, and a fifth communicating oil path 349 is provided, so that only one oil return path 242 needs to be provided on the pump body 24, and after the motor 3 and the pump body 2 are assembled, the second through holes 344 provided on the motor stator 34 and the oil return path 242 provided on the pump body 24 can be communicated with each other through the sixth communicating oil path 3414. Of course, if it is possible to make the sixth communication oil passage 3414 directly communicate with the oil return passage 242, it is not necessary to additionally provide the fifth communication passage 349. Thus, the pressure oil can be sent from the lower end of the hollow motor shaft 33' to the distal end bearing 346 through the lower end of the inner through hole thereof, and the pressure oil reaching the distal end bearing is divided into two paths, wherein one path lubricates and dissipates the heat of the distal end bearing and washes away the friction chips accumulated on the bearing to fall into the stator cavity 5, and the other path returns to the negative pressure region through the drainage channel 343, the second through hole 344, the sixth communication oil path 3414, the fifth communication channel 349, the oil return channel 242, the first oil return groove 17, the second oil return groove 18 and the third oil return groove 19 which are communicated with the oil return channel 242.

Although the sixth communicating oil path 3414 is provided in a substantially annular shape on the bottom surface of the motor stator 34 and the fifth communicating passage 349 is provided in a linear shape on the bottom surface of the motor stator 34 in the present embodiment, the shape, size, and arrangement position of these communicating oil paths and communicating passages may be freely designed and changed as necessary as long as the communicating function of the oil paths is achieved. For example, the sixth communication oil passage 3414 and the fifth communication passage 349 may be provided on the top surface of the pump body 24, that is, the fitting surface with the bottom surface of the motor stator 34, and may be provided on the bottom surface of the motor stator 34 and the top surface of the pump body 24, respectively.

Like this, guide pressure oil to the distal end bearing of keeping away from the oil pump part from the inside through-hole of the hollow shaft as the motor shaft, not only can realize the lubrication to distal end bearing, moreover, compare with the flow direction of lubricating oil in the lubricating oil circuit of first modification, the pressure oil in the lubricating oil circuit of this modification is closer to the central point of motor oil pump, is favorable to alleviateing the pressure to the sealing member between each connection terminal surface.

In addition, when the motor controller is integrated in the motor oil pump, as shown in fig. 8, the motor controller 6 is disposed close to the upper surface of the motor cover plate 4 as much as possible, so that the motor controller 6 can be actively cooled by the oil flowing through the vicinity of the lower surface of the motor cover plate 4.

As described above, the through holes are formed in the cylinder wall of the motor stator, a space through which oil can pass is formed between the top of the motor stator and the cover plate, and a circulating oil path is formed by using the through holes and the space, so that pressure oil is guided from the positive pressure region to a region where heat dissipation is required, such as the cylinder wall of the motor stator and the bottom region of the motor cover plate where the motor controller is installed, and the oil takes away heat when flowing around the periphery of the parts, thereby achieving the purpose of dissipating heat of the parts, avoiding the failure of the motor and the motor controller due to temperature rise, and improving the reliability of the motor oil pump product.

Although the above description has been given by way of example of the motor oil pump 100, the pump core of which is in the form of a trochoidal rotor, it will be appreciated by those skilled in the art that the pump core of the motor oil pump of the present invention is not limited thereto, but may be in any other form, such as a gear pump, a vane pump, a plunger pump, and the like. The form of meshing of the two rotors is not limited to inner meshing.

In conclusion, the invention effectively overcomes the problems of the prior art that the far-end bearing of the motor oil pump product is lubricated, the motor and the motor controller are heated and the engine oil between the assembly sections leaks to the outside by using a simple structure, improves the product performance, reduces the manufacturing cost of the product, and improves the reliability of the product, thereby having high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments and combinations of elements thereof without departing from the spirit and scope of the invention, as will be apparent to those skilled in the art. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. An electric motor oil pump in which a positive pressure region (12, 15, 28) for pumping out oil and a negative pressure region (11, 14, 27) for sucking in oil are formed when the electric motor oil pump is operated, the electric motor oil pump including a motor stator (34) having a substantially cylindrical shape, the electric motor oil pump being characterized in that:

the motor stator (34) is provided with a far-end bearing part (346) at the bottom of the cylinder on one side, and at least one first through hole (342) extending along the axial direction is arranged in the cylinder wall, the first end of the first through hole (342) is communicated with the positive pressure area (12, 15, 28), and the second end of the first through hole (342) is communicated with the far-end bearing part (346).

2. The electric motor oil pump of claim 1,

the motor oil pump further includes a hollow motor shaft (33 ') having one end supported by the distal end bearing portion (346), a first end of an internal passage of the hollow motor shaft (33 ') communicating with the negative pressure region (11, 14, 27), and a second end of the internal passage of the hollow motor shaft (33 ') communicating with the distal end bearing portion (346).

3. The electric motor oil pump according to claim 1 or 2,

the inner part of the cylinder wall of the motor stator (34) is also provided with at least one second through hole (344) extending along the axial direction, the first end of the second through hole (344) is communicated with the negative pressure area (11, 14, 27), and the second end of the second through hole (344) is communicated with the far-end bearing part (348).

4. The motor oil pump of claim 3,

the motor oil pump includes a pump body (24) axially fitted with the motor stator (34), a pump body positive pressure chamber (28) and a pump body negative pressure chamber (27) are formed in the pump body (24) when the motor oil pump is operated,

a first communication passage (282) communicating with the pump body positive pressure chamber (28) is provided on the pump body (24), a second communication passage (341) communicating the first through hole (342) and the first communication passage (282) is provided on at least one of axial end surfaces where the motor stator (34) and the pump body (24) are fitted to each other,

and/or the like and/or,

a third communication passage (284) that communicates with the pump body negative pressure chamber (27) is provided on the pump body (24), and a fourth communication passage (345) that communicates the second through hole (344) and the third communication passage (284) is provided on at least one of axial end surfaces at which the motor stator (34) and the pump body (24) are fitted to each other.

5. The motor oil pump of claim 3,

the first through holes (342) are provided in plurality, a first communication oil passage (3411) is provided on at least one of axial end surfaces where the motor stator (34) and the pump body (24) are fitted to each other, the first ends of the plurality of first through holes (342) are respectively communicated with the first communication oil passage (3411),

and/or the like and/or,

the second through holes (344) are provided in plurality, a second communication oil passage (3415) is provided on at least one of axial end surfaces where the motor stator (34) and the pump body (24) are fitted to each other, and the first ends of the second through holes (344) are respectively communicated with the second communication oil passages (3415).

6. An electric motor oil pump in which a positive pressure region (12, 15, 28) for pumping out oil and a negative pressure region (11, 14, 27) for sucking in oil are formed when the electric motor oil pump is operated, the electric motor oil pump including a motor stator (34) having a substantially cylindrical shape, the electric motor oil pump being characterized in that:

the motor stator (34) is provided with a far end bearing part (346) at the bottom of the cylinder on one side, at least one second through hole (344) extending along the axial direction is arranged in the cylinder wall, the first end of the second through hole (344) is communicated with the negative pressure area (11, 14, 27), the second end of the second through hole (344) is communicated with the far end bearing part (346),

the motor oil pump further includes a hollow motor shaft (33 ') having one end supported by the distal end bearing portion (346), a first end of an internal passage of the hollow motor shaft (33 ') communicating with the positive pressure region (12, 15, 28), and a second end of the internal passage of the hollow motor shaft (33 ') communicating with the distal end bearing portion (346).

7. The electric motor oil pump of claim 6,

the motor oil pump comprises a pump body (24) axially assembled with the motor stator (34), when the motor oil pump works, a pump body negative pressure chamber (27) is formed in the pump body (24),

8. The motor oil pump according to claim 6 or 7,

the second through hole (344) is provided in plurality;

a sixth communication oil passage (3414) is provided on at least one of the axial end surfaces where the motor stator (34) and the pump body (24) are fitted to each other, the sixth communication oil passage (3414) communicating the second ends of the second through holes (344) with each other.

9. The motor oil pump according to any one of claims 1 to 8,

a stator cavity (5) is formed in the motor stator (34),

the motor oil pump further comprises an oil return path, one end of the oil return path is communicated with the stator cavity (5), and the other end of the oil return path is communicated with the negative pressure area (11, 14 and 27).

10. The motor oil pump according to any one of claims 1 to 9,

the electric motor oil pump further includes a motor cover plate (4), the motor cover plate (4) being disposed axially outside the distal end bearing portion (346) of the motor stator (34) for covering the motor stator (34), and a drainage passage (343) being formed between the motor stator (34) and the motor cover plate (4), the second end of the first through hole (342) communicating with the distal end bearing portion (346) via the drainage passage (343).