CN112196993A

CN112196993A - Electronic oil pump for steel belt pre-tightening of CVT (continuously variable transmission)

Info

Publication number: CN112196993A
Application number: CN202011276905.3A
Authority: CN
Inventors: 唐业和; 许仲秋; 刘光明; 佘笑梅
Original assignee: Hunan Oil Pump Co Ltd
Current assignee: Hunan Oil Pump Co Ltd
Priority date: 2020-11-16
Filing date: 2020-11-16
Publication date: 2021-01-08

Abstract

The utility model provides an electron oil pump for CVT derailleur steel band pretension, includes motor, the pump body, pump cover, external rotor, inner rotor and location axle, the external rotor is installed in pump body rotor intracavity, inner rotor and external rotor internal gearing, the inner rotor shaft hole comprises location shaft hole and transmission shaft hole two parts, the output shaft transmission of motor is connected in the transmission shaft hole, interference installs a bush in the location shaft hole, location axle one end clearance is installed in the bush, other end interference is installed at pump body shaft downthehole. According to the technical scheme, the internal clearance of the oil pump can be reduced, the bearing capacity of the oil pump is improved, the radial force of the inner rotor required to be born by the output shaft of the motor is reduced, the electronic oil pump can be used for pre-tightening the steel belt of the CVT, the electronic oil pump directly participates in the work of a hydraulic system of the transmission, the response time of the transmission is shortened, the transmission efficiency of the transmission is improved, and the power loss of an engine.

Description

Electronic oil pump for steel belt pre-tightening of CVT (continuously variable transmission)

Technical Field

The invention relates to the technical field of electronic oil pumps of transmissions, in particular to an electronic oil pump for steel belt pre-tightening of a CVT (continuously variable transmission).

Background

From the global energy development trend and international internal combustion engine technology, controlling the fuel consumption and carbon dioxide and other pollutant emissions of internal combustion engines is becoming the most effective way to deal with the problems of environmental protection and energy shortage globally. At present, energy-saving automobiles and new energy automobiles are listed in the key development field of Chinese manufacturing, and national energy-saving and emission-reduction policies also gradually require the fuel consumption index of passenger cars.

In order to meet increasingly demanding emission standards, the field of transmissions has changed from the traditional large-displacement mechanical oil pump to a combined mode of a small-displacement mechanical oil pump and an electronic oil pump. When the engine works (the automatic start-stop function does not work), the mechanical oil pump provides system hydraulic oil and cooling lubricating oil, and during the period, when the oil supply capacity of the mechanical oil pump is insufficient, part of oil can be supplemented properly by the electronic oil pump; and when the engine does not work (the automatic start-stop function works), the electronic oil pump provides cooling lubricating oil. The combined mode can reduce the power consumption of a traditional large-displacement mechanical oil pump on an engine, and can also keep system lubrication by the electronic oil pump when the automatic start-stop function of the engine works, so that the power consumption of the transmission on the engine is reduced, the transmission can be in a standby state all the time, and once the engine is started, the transmission can respond to a gear shifting command and the lubricating and cooling requirements more quickly.

And present electronic oil pump internal gearing rotor is the mainstream, and traditional electronic oil pump inner rotor is usually by the output shaft disect insertion inner rotor shaft hole of motor, through the mode drive of spline or flat tail, and spline or flat tail structure not only need play the effect of drive oil pump this moment, also need play location and radial load supporting effect for the inner rotor simultaneously. This structure requires the cooperation precision of oil pump and motor to be high, otherwise causes the oil pump jamming easily, rotates dumb, if the oil pump wants to obtain higher pressure, then the internal clearance all needs to reduce, then has proposed higher requirement to the precision of the output shaft of motor and oil pump cooperation precision like this, and in fact the cooperation of motor and oil pump all has certain geometric tolerances, just so leads to present electronic oil pump fuel feeding pressure not high.

On the other hand, because the electronic oil pump of the transmission is very compact in structure, the electronic oil pump needs to strictly control the size, the output shaft of the motor is usually small, the output shaft of the motor is usually supported by a bearing to keep the rotor and the shaft rotating, the radial bearing capacity of the small bearing is small, the development of the oil pump towards a high pressure direction can be further limited, and otherwise, the bearing fails due to large radial bearing of the high pressure.

For the reasons, the conventional electronic oil pump of the transmission is usually used as a lubricating oil pump, and the electronic oil pump cannot participate in the work of a hydraulic system of the transmission, so that the application of the electronic oil pump in the aspect of hydraulic pressure of the transmission is blocked.

Disclosure of Invention

The invention aims to provide an electronic oil pump for steel belt pre-tightening of a CVT transmission.

In order to solve the technical problems, the invention adopts the following technical scheme: the utility model provides an electron oil pump for CVT derailleur steel band pretension, includes motor, the pump body, pump cover, external rotor, inner rotor and location axle, the external rotor is installed in pump body rotor intracavity, inner rotor and external rotor internal gearing, the inner rotor shaft hole comprises location shaft hole and transmission shaft hole two parts, the output shaft transmission of motor is connected in the transmission shaft hole, interference installs a bush in the location shaft hole, location axle one end clearance is installed in the bush, other end interference is installed at pump body shaft downthehole.

Preferably, the inner rotor is provided with a protruding part on the end face close to the pump cover, the protruding part is installed in the pump cover shaft hole in a clearance mode, and the transmission shaft hole penetrates through the protruding part.

Preferably, the motor and the pump cover are respectively provided with a positioning boss and a positioning counter bore on the end faces close to each other, and the positioning boss is installed in the positioning counter bore in a matched mode.

More preferably, the height of the positioning boss is lower than the depth of the positioning counter bore.

More preferably, the positioning counter bore side wall is provided with a first oil through groove, the pump cover is provided with a second oil through groove on the end surface close to the motor, and the first oil through groove is communicated with the second oil through groove.

Preferably, the inner hole of the bushing is formed by finish machining, and the surface of the inner hole is provided with a sintered alloy layer.

Preferably, the pump body shaft hole and the rotor cavity are formed by machining and one-step forming.

Preferably, the positioning shaft is provided with a middle through hole.

Preferably, the electronic oil pump further comprises a positioning pin, and the pump body and the pump cover are respectively provided with a positioning hole for installing the positioning pin on the end faces close to each other.

The inner rotor shaft hole is arranged into the positioning shaft hole and the transmission shaft hole, the positioning shaft is arranged, one end of the positioning shaft is fixed on the pump body, and the other end of the positioning shaft is inserted into the positioning shaft hole, so that the inner rotor can be well positioned, the radial runout of the inner rotor is ensured, the radial clearance of the oil pump is favorably reduced, the pressure bearing capacity of the oil pump is improved, meanwhile, the positioning shaft can bear the radial force of the inner rotor, the output shaft of the motor only needs to bear little or even no radial force of the inner rotor, and the oil pump is favorably developed towards a high pressure direction. Therefore, the electronic oil pump can reduce the internal clearance of the oil pump as much as possible, greatly reduce the radial force of an inner rotor required to be born by an output shaft of a motor, and be matched with the excellent positioning performance of a positioning shaft, so that the electronic oil pump can provide the maximum hydraulic pressure far higher than that of a conventional lubricating electronic oil pump, and can provide high-pressure oil through an electric drive oil pump when an engine is automatically started and stopped, and the high-pressure oil is used for pre-tightening a steel belt of a CVT (continuously variable transmission) and directly participates in the work of a hydraulic system of. Meanwhile, in the standby state of the engine, the electronic oil pump can enable the steel belt of the CVT transmission to be in a pre-tightening state, and once the engine works, the transmission can immediately enter a working state, so that the response time of the transmission is shortened, the transmission efficiency of the transmission is improved, and the power loss of the engine can be effectively reduced.

Drawings

FIG. 1 is a cross-sectional view of an electronic oil pump in an embodiment of the present invention;

FIG. 2 is an exploded schematic view of an electronic oil pump;

FIG. 3 is a top view of a pump cap;

fig. 4 is a cross-sectional view of the inner rotor.

In the figure:

1-motor 1 a-positioning boss 2-pump cover

2 a-a first oil through groove 2 b-a second oil through groove 2 c-a positioning counter bore

3-external rotor 4-internal rotor 4 a-convex part

4 b-positioning shaft hole 4 c-transmission shaft hole 5-lining

6-positioning pin 7-positioning shaft 7 a-middle through hole

8-pump body 9-output shaft 10-positioning hole.

Detailed Description

In order to facilitate understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

It should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used broadly in the present invention, and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Further, in the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not in direct contact, but via another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature. The terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the invention.

As shown in fig. 1 to 4, an electronic oil pump for steel belt pre-tightening of a CVT transmission comprises a motor 1, a pump body 8, a pump cover 2, an outer rotor 3, an inner rotor 4 and a positioning shaft 7, wherein the outer rotor 3 is installed in a rotor cavity of the pump body 8, the inner rotor 4 is internally engaged with the outer rotor 3, a shaft hole of the inner rotor 4 is composed of two parts, namely a positioning shaft hole 4b and a transmission shaft hole 4c, an output shaft 9 of the motor 1 is in transmission connection with the transmission shaft hole 4c, a bushing 5 is installed in the positioning shaft hole 4b in an interference manner, a gap is installed in the bushing 5 at one end of the positioning.

Above-mentioned embodiment provides an electronic oil pump for CVT derailleur steel band pretension, establish location shaft hole 4b and transmission shaft hole 4c two parts through 4 shaft holes with inner rotor, and set up location axle 7, fix location axle 7 one end on the pump body 8, the other end inserts in location shaft hole 4b, can play fine positioning action to inner rotor 4, guarantee inner rotor 4's runout, be favorable to reducing the radial clearance of oil pump, improve the oil pump bearing capacity, and simultaneously, location axle 7 can also undertake 4 radial force of inner rotor, make motor 1's output shaft 9 only need undertake few or even need not undertake 4 radial force of inner rotor, be favorable to the oil pump toward high pressure direction development. Therefore, the electronic oil pump can reduce the internal clearance of the oil pump as much as possible, greatly reduce the radial force of the inner rotor 4 required to be born by the output shaft 9 of the motor 1, and be matched with the excellent positioning performance of the positioning shaft 7, so that the electronic oil pump can provide the maximum hydraulic pressure far higher than that of the conventional lubricating electronic oil pump, and can provide high-pressure oil through the electric drive oil pump when the automatic start-stop function of an engine works, and the high-pressure oil is used for pre-tightening a steel belt of a CVT (continuously variable transmission) and directly participates in the work of a. Meanwhile, in the standby state of the engine, the electronic oil pump can enable the steel belt of the CVT transmission to be in a pre-tightening state, and once the engine works, the transmission can immediately enter a working state, so that the response time of the transmission is shortened, the transmission efficiency of the transmission is improved, and the power loss of the engine can be effectively reduced.

It should be noted that, the transmission connection mode between the output shaft 9 of the motor 1 and the inner rotor 4 may be that the end of the output shaft 9 is a flat tail structure, the transmission shaft hole 4c of the inner rotor 4 is a flat tail hole, and the flat tail end of the output shaft 9 is installed in the flat tail hole of the inner rotor 4 in a gap manner. Of course, other transmission connection modes, such as spline connection, can be adopted between the output shaft 9 of the motor 1 and the inner rotor 4. In the above technical solution, the diameters of the positioning shaft hole 4b and the transmission shaft hole 4c may be the same or different, and in this embodiment, the diameter of the positioning shaft hole 4b is preferably larger than the diameter of the transmission shaft hole 4 c.

In this embodiment, as a preferred mode, the end face of the inner rotor 4 close to the pump cover 2 is provided with the protruding portion 4a, the protruding portion 4a is installed in the shaft hole of the pump cover 2 in a clearance manner, the transmission shaft hole 4c penetrates through the protruding portion 4a, and the radial limiting on the inner rotor 4 can further reduce the radial force of the inner rotor 4 which needs to be borne by the output shaft 9 of the motor 1, which is beneficial to the development of the oil pump in the higher pressure direction.

Preferably, the height of the positioning boss 1a may be lower than the depth of the positioning counterbore 2c, so that the high-pressure oil accumulated in the casing of the motor 1 can partially flow into the space between the positioning boss 1a and the positioning counterbore 2c, and a certain pressure reduction effect is achieved.

More preferably, the side wall of the positioning counter bore 2c is provided with a first oil through groove 2a, the pump cover 2 is provided with a second oil through groove 2b on the end surface close to the motor 1, and the first oil through groove 2a is communicated with the second oil through groove 2 b. The heat dissipation of the rotor of the motor 1 is of an immersion type, oil is required to enter the shell of the motor 1 to dissipate heat of the rotor and a coil of the motor 1, oil leaked by an oil pump enters the shell of the motor 1 through the shaft hole of the pump cover 2, the oil pressure in the shell of the motor 1 cannot be too large, otherwise, the running resistance of the motor 1 is increased, the normal running of the motor 1 is affected, meanwhile, if the pressure is too large, the generated high-pressure oil can possibly damage the sealing performance between the controller and the motor 1, the oil enters the controller, and the controller is disabled. And the first oil groove 2a and the second oil groove 2b that lead to of intercommunication that set up on pump cover 2 form an oil drainage passageway, then can release the high-pressure oil of hoarding at motor 1 casing, guarantee to be full of fluid in motor 1 casing, nevertheless can not form too high pressure.

Preferably, the inner hole of the bushing 5 is formed by finish machining, the surface of the inner hole is provided with a sintered alloy layer, and the inner hole of the bushing 5 is formed by finish machining, so that the radial runout of the inner rotor 4 can be further ensured, the radial clearance of the oil pump can be reduced, and the pressure-bearing capacity of the oil pump can be improved; and the surface of the inner hole of the lining 5 is a sintered alloy layer, so that the PV value of the lining 5 can be effectively improved, the radial bearing capacity of the lining 5 is improved, and the lining 5 is prevented from losing efficacy due to larger radial force when the oil pump works under high pressure.

Preferably, the shaft hole of the pump body 8 and the rotor cavity are formed by one-step machining, so that the shaft hole of the pump body 8 and the rotor cavity have very good position, the positioning shaft 7 can keep good position after being pressed into the shaft hole of the pump body 8, the position of the inner rotor 4 and the outer rotor 3 after being installed is high, the radial gap between the inner rotor 4 and the outer rotor 3 can be reduced as much as possible, the oil leakage amount is reduced, and the pressure bearing capacity of the oil pump is improved.

Preferably, the positioning shaft 7 is provided with a middle through hole 7a, and the middle through hole 7a can be used as an exhaust hole when the positioning shaft 7 is pressed and mounted, so that large resistance is prevented from being generated between the positioning shaft 7 and the shaft hole of the pump body 8 in the pressing and mounting process, and the positioning shaft 7 is convenient to press and mount.

Preferably, the electronic oil pump further comprises a positioning pin 6, and the pump body 8 and the pump cover 2 are respectively provided with positioning holes 10 for installing the positioning pin 6 on the end surfaces close to each other, so that the structure can ensure that the installation positions of the pump body 8 and the components thereof and the pump cover 2 are accurate.

Although the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention.

Claims

1. The utility model provides an electron oil pump for CVT derailleur steel band pretension, includes motor (1), the pump body (8), pump cover (2), outer rotor (3), inner rotor (4), install in pump body (8) rotor cavity outer rotor (3), inner rotor (4) and outer rotor (3) inner gearing, its characterized in that: the electronic oil pump still includes location axle (7), inner rotor (4) shaft hole comprises location shaft hole (4 b) and transmission shaft hole (4 c) two parts, output shaft (9) transmission of motor (1) is connected in transmission shaft hole (4 c), bushing (5) are installed to the interference in location shaft hole (4 b), location axle (7) one end clearance is installed in bushing (5), the other end interference is installed in pump body (8) shaft hole.

2. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: inner rotor (4) are equipped with bellying (4 a) on being close to the terminal surface of pump cover (2), bellying (4 a) clearance is installed in pump cover (2) shaft hole, bellying (4 a) are passed in transmission shaft hole (4 c).

3. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: the motor (1) and the pump cover (2) are respectively provided with a positioning boss (1 a) and a positioning counter bore (2 c) on the end faces close to each other, and the positioning boss (1 a) is installed in the positioning counter bore (2 c) in a matched mode.

4. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 3 characterized by: the height of the positioning boss (1 a) is lower than the depth of the positioning counter bore (2 c).

5. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 4 characterized by: the pump cover is characterized in that a first oil through groove (2 a) is formed in the side wall of the positioning counter bore (2 c), a second oil through groove (2 b) is formed in the end face, close to the motor (1), of the pump cover (2), and the first oil through groove (2 a) is communicated with the second oil through groove (2 b).

6. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: the inner hole of the bushing (5) is formed by fine machining, and a sintered alloy layer is arranged on the surface of the inner hole.

7. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: the pump body (8) shaft hole and the rotor cavity are formed by machining and one-step forming.

8. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: the positioning shaft (7) is provided with a middle through hole (7 a).

9. The electronic oil pump for steel belt pretensioning of CVT transmission of claim 1 characterized in that: the electronic oil pump further comprises a positioning pin (6), and positioning holes (10) used for installing the positioning pins (6) are respectively formed in the end faces, close to each other, of the pump body (8) and the pump cover (2).