Electric oil pump including pump housing and eccentric assembly non-concentrically arranged with pump housing

Abstract

The present application discloses a high-precision electric oil pump, which relates to the technical field of new energy vehicles. The electric oil pump includes a pump housing connected with an outer gear and an inner gear engaged with each other, the pump housing is internally connected to a fixed shaft concentrically arranged with the pump housing, the outer gear is connected to the fixed shaft and concentrically arranged with the pump housing, the fixed shaft includes a connecting section, an eccentric calibrator is provided on an outer circumferential wall of the connecting section, the eccentric calibrator and the connecting section form an eccentric assembly, the inner gear is rotated around a geometric central axis of the eccentric assembly, and the eccentric assembly is non-concentrically arranged with the pump housing.

Claims

1. An electric oil pump, comprising a pump housing, wherein the pump housing is connected with an outer gear and an inner gear engaged each other, the pump housing is internally connected to a fixed shaft concentrically arranged with the pump housing, the outer gear is connected to the fixed shaft and concentrically arranged with the pump housing, the fixed shaft comprises a connecting section, an eccentric calibrator is provided on an outer circumferential wall of the connecting section, the eccentric calibrator and the connecting section form an eccentric assembly, the inner gear is rotated around a geometric central axis of the eccentric assembly, and the eccentric assembly is non-concentrically arranged with the pump housing; wherein one end of the fixed shaft is press-fitted with a bearing, the inner gear comprises an inner circumference coaxially fit around with the fixed shaft against the eccentric assembly, an inner circumference of a motor rotor is axially arranged to fit around an outer circumference of the outer gear, an upper part of an outer circumference of the motor rotor is provided with an inner circumference to press-fit with an outer ring of the bearing, the eccentric assembly is fit with the fixed shaft via a bushing, and the inner gear is sleeved on the bushing.

2. The electric oil pump according to claim 1, wherein the eccentric calibrator is a crescent calibrator provided on the outer circumferential wall of the fixed shaft, and the crescent calibrator is defined with a curved notch for insertion fitting with the fixed shaft.

3. The electric oil pump according to claim 1, wherein an inner circumference of the outer gear, the outer circumference of the motor rotor, and the inner gear are combined to form multiple intake-expulsion chambers, a volume of the multiple intake-expulsion chambers first increases gradually and then decreases gradually along a rotation direction of the outer gear, and the pump housing is defined with an inlet and an outlet, when the multiple intake-expulsion chambers increase gradually, an open end of the multiple intake-expulsion chambers is aligned with the inlet, and when the multiple intake-expulsion chambers decrease gradually, the open end of the multiple intake-expulsion chambers is aligned with the outlet.

4. The electric oil pump according to claim 3, wherein the pump housing is provided with a housing bottom covering the inlet and the outlet, the housing bottom is defined with a pressing hole fixedly connected to the one end of the fixed shaft, the housing bottom is defined with an intake mouth in communication with the inlet and an expulsion mouth in communication with the outlet, the housing bottom is provided with a partition portion for separating the intake mouth and the expulsion mouth, and one side of the partition portion is attached to one side of the inner gear.

5. The electric oil pump according to claim 4, wherein the eccentric calibrator is a crescent calibrator, one side of the crescent calibrator is defined with a location-guiding hole, and the housing bottom is defined with an assemble guiding hole corresponding to the location-guiding hole.

6. The electric oil pump according to claim 3, wherein the pump housing is provided with a filter screen located at the inlet and covering the inlet.

7. The electric oil pump according to claim 1, further comprising a circuit control module, wherein the circuit control module comprises a controller arranged in the pump housing, a busbar hub, and a motor stator arranged on the busbar hub, the motor stator is provided with multiple stator coils arranged along a circumference of the motor stator, the motor rotor is sleeved on the outer circumference of the outer gear, and an outer circumferential wall of the motor rotor corresponds to an inner circumferential wall of the motor stator.

8. The electric oil pump according to claim 7, wherein an air gap is provided between the outer circumferential wall of the motor rotor and the inner circumferential wall of the motor stator.

9. The electric oil pump according to claim 7, wherein the pump housing is provided with an inner housing for separating the controller and the busbar hub.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of an overall structure of an embodiment of the present application;

(2) FIG. 2 is a schematic diagram of a circuit control module, an outer gear, and an inner gear of an embodiment of the present application;

(3) FIG. 3 is an overall schematic sectional diagram of an embodiment of the present application;

(4) FIG. 4 is a partial sectional schematic diagram of an embodiment of the present application;

(5) FIG. 5 is a schematic structural diagram of a motor stator of an embodiment of the present application;

(6) FIG. 6 is a schematic structural diagram of a bottom of a pump housing of an embodiment of the present application;

(7) FIG. 7 is a schematic structural diagram of an outer gear and an inner gear of an embodiment of the present application; and

(8) FIG. 8 is a schematic structural diagram of an eccentric calibrator of an embodiment of the present application.

DETAILED DESCRIPTION

(9) The present application will be further explained in detail in conjunction with FIGS. 1 to 8. A high-precision electric oil pump is provided in some embodiments of the present application.

(10) Referring to FIGS. 1 and 2, a high-precision electric oil pump is shown, including a pump housing 1, a motor, a circuit control module 9, and a gear set. The motor includes a motor rotor 8, a motor stator 93, and stator coils 94. The motor stator 93 is fixed inside the pump housing 1, the motor rotor 8 is located inside the motor stator 93, and there are multiple groups of stator coils 94 arranged in a circular array around the motor stator 93, located between the motor rotor 8 and the motor stator 93.

(11) In particular, the gear set includes an outer gear 2 integrated and fixed with the motor rotor 8, and an inner gear 3 located inside the outer gear 2 and engaged with inner teeth of the outer gear 2.

(12) For operation, the circuit control module 9 controls multiple stator coils 94 to be energized, so as to generate a magnetic field which interacts with the permanent magnetic field of the motor rotor 8 magnet to drive the motor rotor 8 to rotate. The motor rotor 8 is fixed to the outer gear 2, therefore, the interaction between the motor stator 93 and the magnet of the motor rotor 8 drives the outer gear 2 to rotate. The outer gear 2 drives the inner gear 3 to rotate, achieving relative rotation between the inner gear 3 and the outer gear 2.

(13) Referring to FIGS. 3 and 4, the circuit control module 9 includes a busbar hub 92 located inside the pump housing 1 and above the motor, and a controller 91 located above the busbar hub 92. The busbar hub 92 is configured to collect the incoming and outgoing wires of the stator coils 94, making the distribution of wires neat and clear, while allowing the wires to be welded on the busbar hub 92, providing a simple and clean process. Another role of busbar hub 92 is to separate the controller 91 from a motor section, so that oil only flows through the motor section, forming a cooling and lubrication circuit, without any oil entering the controller 91.

(14) The outer gear 2 includes an inner circumference 23 of the outer gear 2 engaged with the inner gear 3, and a motor rotor inner circumference is fixedly sleeved around an outer gear outer circumference. The permanent magnet of motor rotor 8 is fixed on the outside of the outer circumference 24 of the motor rotor, and there is an air gap 16 provided between the permanent magnet of motor rotor 8 and stator coils 94. For the purpose of research and development, it is necessary to minimize the impact of various factors on the distance stability of the air gap 16. A top of the outer circumference 24 of the motor rotor is integrally formed with a rotor neck 22, and a bearing 6 is installed inside the rotor neck 22.

(15) Referring to FIGS. 5 and 6, there is a pressing hole 131 defined in the housing bottom 13, which is concentric with pump housing 1. The pressing hole 131 is penetrated with a fixed shaft 4, which is tightly matched with the bearing 6. One side of the outer gear 2 is integrally formed with a rotor neck 22 matched with the bearing 6. The inner gear includes inner circumference to coaxially fit around with the fixed shaft against the eccentric assembly, and the motor rotor inner circumference is axially arranged to fit around the outer circumference of the outer gear. One side of the outer circumference 24 of the motor rotor is integrally formed with a rotor neck 22 matched with the bearing 6. The rotor neck 22 form an insertion groove with one side of the outer circumference 24 of the motor rotor for bearing 6 to be inserted. An outer circumferential wall of the bearing 6 is tightly matched with a circumferential groove wall of the insertion groove.

(16) Referring to FIG. 6-8, an inner circumferential wall of the inner circumference 23 of the outer gear and an outer circumferential wall of the inner gear 3 are both attached to an inner end face of the outer circumference 24 of the motor rotor. A zone between the outer gear 2 and the inner gear 3 is divided by tooth-to-tooth contact to form multiple closed intake-expulsion chambers 21, the volume of which gradually increases and then decreases along a rotation direction of the outer gear 2. A bottom of pump housing 1 is integrally formed with an inlet 11, and an outer circumferential wall of the pump housing 1 is integrally formed with an outlet 12. When the intake-expulsion chamber 21 gradually increases, it is aligned with the inlet 11. When the intake-expulsion chamber 21 gradually decreases, it is aligned with the outlet 12. The bottom of pump housing 1 has a filter screen 14 located at the inlet 11 and covering the inlet 11.

(17) The bottom of pump housing 1 is integrally formed with a housing bottom 13 covering the inlet 11 and the outlet 12. An end face of housing bottom 13 is axially defined with a pressing hole 131 fixedly connected to one end of the fixed shaft 4. The fixed shaft 4 is inserted into the pressing hole 131, and an outer circumferential wall of fixed shaft 4 is tightly fit with the hole wall of the pressing hole 131. An end face of the housing bottom 13 is defined with an intake mouth 132 communicating with the inlet 11 and an expulsion mouth 133 communicating with the outlet 12. At the housing bottom 13, a partition portion 134 is formed to separate the intake mouth 132 and the expulsion mouth 133 after the intake mouth 132 and the expulsion mouth 133 are defined. One side of the partition portion 134 is attached to one side of the inner gear 3, improving the sealing between the intake mouth 132 and the expulsion mouth 133.

(18) A location-guiding through hole 52 is defined in one side of a crescent calibrator, and an assemble guiding hole 135 corresponding to the location-guiding through hole 52 at the housing bottom 13. The assemble guiding hole 135 is eccentrically arranged with the pressing hole 131.

(19) An implementation principle of a high-precision electric oil pump in an embodiment of the present application is as follows.

(20) The fixed shaft 4 is arranged in the pump housing 1, and then the eccentric calibrator 5 is provided on a circumferential side wall of the fixed shaft 4 to form an eccentric assembly 41. This allows the outer gear 2 to be rotatably connect with the fixed shaft 4, while ensuring that the eccentric assembly 41 is also rotatably connected with the inner gear 3, achieving the effect of coaxial and eccentric operation of the inner gear 3 and the outer gear 2.

(21) A hole is defined in the pump housing 1 that fits with the fixed shaft 4, effectively reducing the processing complexity of the pump housing 1, improving the processing efficiency of the pump housing 1, and improving the accuracy of the fit between the outer gear 2 and the inner gear 3.

(22) The controller 91 controls the busbar hub 92 to energize multiple stator coils 94 on the motor stator 93. After the multiple stator coils 94 are energized, a magnetic field is generated to drive motor rotor 8 to rotate. The motor stator 93 drives the outer gear 2 to rotate, achieving a relative rotation between the outer gear 2 and the inner gear 3.

(23) When the inner gear 3 and the outer gear 2 are rotated relative to each other, the intake-expulsion chamber 21 gradually increases in size and sucks in oil through the inlet 11, so that the amount of oil in the intake-expulsion chamber 21 increases with the volume of the intake-expulsion chamber 21. Due to a contact between the oil having a lower temperature and the teeth of the inner gear 3 and the outer gear 2 during the suck-in process, the oil absorbs the heat from the teeth. When the intake-expulsion chamber 21 gradually decreases in size, the oil in the intake-expulsion chamber 21 is discharged through the outlet 12, so that the amount of oil in the intake-expulsion chamber 21 decreases as the volume of the intake-expulsion chamber 21 decreases. The oil with higher temperature after absorbing heat during the suck-in process is discharged from the outlet 12, achieving cooling and lubrication of the inner gear 3 and the outer gear 2, and, in turn, cooling of the pump body.

(24) The above are all preferred embodiments of the present application, not intended to limit the scope of protection of this application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be covered within the scope of protection of the present application.

LISTING OF REFERENCE SIGNS

(25) 1 Pump Housing 11 Inlet 12 Outlet 13 Housing Bottom 131 Pressing Hole 132 Intake Mouth 133 Expulsion Mouth 134 Partition Portion 135 Assemble Guiding Hole 14 Filter Screen 15 Inner housing 16 Air Gap 2 Outer gear 21 Intake-expulsion Chamber 22 Rotor Neck 23 Inner Circumference of Outer Gear 24 Outer Circumference of Rotor 3 Inner Gear 4 Fixed Shaft 41 Eccentric Assembly Eccentric Calibrator 51 Curved Notch 52 Location-guiding Through Hole 6 Bearing 7 Bushing 8 Motor Rotor 9 Electrical Control Module 91 Controller 92 Busbar Hub 93 Motor Stator 94 Stator Coils