Electric pump

• US 10,451,074 B2
• Filed: 09/22/2016
• Issued: 10/22/2019
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: Zhejiang Sanhua Automotive Components Company Limited (Sanhua Holding Group Company Limited)
• Original Assignee: Zhejiang Sanhua Automotive Components Company Limited (Sanhua Holding Group Company Limited)
• Inventors: Shi, Yongxiang, Bao, Junfeng, Song, Hongmin
• Primary Examiner(s): Lee, Jr., Woody A
• Application Number:
  US15/272,992
• Publication Number:
  US 20170089354A1
• Time in Patent Office: 1,125 Days
• CPC Class Codes: F04D 13/0606 Canned motor pumps
• CPC Class Codes: F04D 29/041 Axial thrust balancing
• CPC Class Codes: F04D 29/628 especially adapted for liquid pumps
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 2205/03 Machines characterised by thrust bearings
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 5/128 using air-gap sleeves or air-gap discs
• CPC Class Codes: H02K 5/1677 radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
• CPC Class Codes: H02K 7/086 radially supporting the rotor around a fixed spindle; radially supporting the rotor directly H02K7/09 takes precedence

Abstract

An electric pump is provided, which includes a housing, a shaft, a rotor assembly and a stop assembly. The shaft is fixed to the housing, the rotor assembly is rotatable about the shaft, and the rotor assembly is sleeved on the shaft. The stop assembly is configured to limit the position of the rotor assembly in the chamber. The stop assembly includes a first stop and a second stop, the first stop is fixed with respect to a second portion of the shaft, and the second stop is fixed with respect to a first portion of the shaft. No relative movement occurs between the stop assembly and the shaft, which reduces the abrasion between the stop assembly and the shaft resulted from friction, and facilitates improving a service life of the stop assembly.

Claims

1. An electric pump, comprising a housing, a shaft and a rotor assembly, a chamber being formed in the housing, and the rotor assembly being arranged in the chamber, wherein:

the shaft comprises a first portion and a second portion, the first portion is fixed to the housing, and the second portion is in non-direct contact with the housing;

the rotor assembly is rotatable about the shaft, and the rotor assembly is sleeved on the shaft;

the electric pump comprises a stop assembly, the stop assembly is configured to limit a position of the rotor assembly in the chamber and comprises a first stop and a second stop; and

the first stop is configured to limit a position of the rotor assembly moving along the shaft in a direction away from the first portion, and the second stop is configured to limit a position of the rotor assembly moving along the shaft in a direction towards the first portion, the first stop is fixed to the second portion, and the second stop is fixed to the first portion;

wherein the first stop comprises a connecting element and a stop element, the connecting element is fixed to the second portion, and the stop element is arranged between the connecting element and the second portion and is pressed onto the second portion;

wherein the shaft comprises a connecting portion, and the connecting element is connected to the shaft via the connecting portion;

the connecting portion comprises a threaded hole, and the threaded hole extends into the second portion; and

the connecting element comprises a screw, the screw is in a threaded connection with the shaft, and the stop element is pressed onto the second portion of the shaft by the screw; and

wherein a hole is provided in the stop element, the hole is smaller than an outer edge of the second portion, and a size of an outer edge of the stop element is larger than a size of an outer periphery of the second portion.

2. The electric pump according to claim 1, wherein the stop element comprises an upper end surface and a lower end surface, the upper end surface is in contact with the screw, the lower end surface is in contact with the second portion.

3. The electric pump according to claim 2, wherein the stop element comprises a coating, at least a lower end surface of the stop element is coated with the coating, and the coating is made of a diamond-like carbon.

4. The electric pump according to claim 1, wherein adhesive is coated on a threaded section of the threaded hole and/or an outer surface of a threaded section of the screw, and an outer peripheral surface of the screw is non-detachably fixed to the shaft provided with the threaded hole by the adhesive.

5. The electric pump according to claim 1, wherein the rotor assembly comprises an impeller, the impeller comprises an upper plate, blades and a lower plate;

the blades are arranged between the upper plate and the lower plate; and

seeing from the upper plate towards the lower plate, each of the blades comprises a convex side and a concave side, and a screw-in direction of the screw is consistent with a protruding direction of the convex sides of the blades.

6. The electric pump according to claim 2, wherein the rotor assembly comprises a bearing, the bearing is fixed to the rotor assembly by injection molding;

in an axial direction of the shaft, a surface, close to the second portion of the shaft, of the bearing is an upper end surface, the upper end surface of the bearing is spaced apart from the lower end surface of the stop element by a certain distance, and the upper end surface of the bearing is higher than an upper end of the lower plate.

7. The electric pump according to claim 1, wherein the rotor assembly comprises a rotor and an impeller, the rotor is fixed to the impeller, the rotor comprises a permanent magnet, and the impeller comprises an upper plate, a lower plate and blades;

the blades are formed between the upper plate and the lower plate, the blades comprise first blades and second blades, each of the first blades has a length larger than a length of each of the second blades, and the first blades and the second blades are alternately distributed;

an outer edge of the upper plate is defined as a first circumference, the second blades start from a second circumference, a diameter of the first circumference is a first diameter, a diameter of the second circumference is a second diameter, and the second diameter ranges from 0.6 times to 0.7 times of the first diameter; and

a third circumference is defined as a circumference where the first blades starts from, a diameter of the third circumference is a third diameter, the lower plate of the impeller is provided with balance holes, centers of the balance holes are located on a fourth circumference, a diameter of the fourth circumference is a fourth diameter, the fourth diameter is larger than the third diameter, and the fourth diameter is less than the second diameter.

8. The electric pump according to claim 7, wherein the number of the balance holes is greater than or equal to two, a total flowing area of the balance holes is equal to the sum of flowing areas of the balance holes;

and

an annular clearance is formed between an outer edge of the impeller and the housing, the annular clearance has an annular cross-sectional flowing area for a working medium passing through the annular clearance, and the total flowing area of the balance holes is larger than or equal to the annular cross-sectional flowing area.

9. The electric pump according to claim 7, wherein the number of the balance holes is greater than or equal to two, a total flowing area of the balance holes is equal to the sum of flowing areas of the balance holes, and the total flowing area of the balance holes is greater than or equal to 3 mm² and less than or equal to 18 mm².

10. The electric pump according to claim 9, wherein the number of the balance holes is less than or equal to the number of the first blades, each of the balance holes is arranged between the first blades that are adjacent, each of the balance holes has a circulation section which is generally circular-shaped, and a flowing area of each of the balance holes is greater than or equal to 1.7 mm² and less than or equal to 3.2 mm².

11. The electric pump according to claim 10, wherein the first blades and the upper plate are fixed integrally, the lower plate is provided with mounting grooves, the mounting grooves are arranged to correspond to the first blades, each of the balance holes is arranged between the mounting grooves that are adjacent, a distance between a concave side of a mounting groove closer to the balance hole and an outer edge of the balance hole is greater than or equal to 1 mm.

12. The electric pump according to claim 10, wherein:

in the case that the balance holes are projected onto the upper plate in a direction from the lower end surface to the upper end surface of the upper plate and along the axial direction of the impeller,

a connecting line between a starting end of each of the second blades and the center of the impeller is defined as a first line;

a connecting line between a starting end of each of the first blades which are adjacent to the concave sides of the second blades and the center of the impeller is defined as a second line;

a connecting line between the center of each of balance holes and the center of the impeller is defined as a third line; and

a connecting line between, an intersection point of the second circumference with the first side of the first blade close to the balance hole, and the center of the impeller is defined as a fourth line; and

an included angle between the first line and the fourth line is defined as a first included angle, an included angle between the third line and the second line is defined as a second included angle, and the second included angle is less than the first included angle.