A sealing structure of a control chamber of a micro electronic oil pump and the electronic oil pump

Abstract

A sealing structure of a control cavity of a micro electronic oil pump, the pump body upper section is built-in pump function part, the lower section extends as the bottom end opening cylinder, the opening is inserted and closed by the convex stop of the flange part of the bottom cover in the form of ring convex platform, presents as ring convex platform, and is closed to contain the control cavity of PCB control panel, the end surface of the cylinder opening is provided with annular groove, the bottom cover is provided with annular convex rib, the ring convex platform is inserted into the inner circumferential wall of the cylinder and is matched and welded to form the circumferential surface welding area, the annular convex rib is matched and welded with the annular groove to form the ring end surface welding area.By the annular convex rib and the annular groove, the ring end surface welding area is formed on the end surface of the bottom cover and the pump cylinder, and the ring circumferential surface welding area is formed by the ring convex platform of the bottom cover inserted into the inner circumferential wall of the pump cylinder, the sealing performance is improved and the material is saved by fully utilizing the welding of the end surface and the side circumferential surface of the thin-walled pump cylinder.

Description

Technical Field

[0001] This utility model relates to a miniature electronic oil pump, and more particularly to the sealing structure of the control chamber of the electronic oil pump, which can be classified as F04C14 / 00 by IPC. Background Technology

[0002] The existing internal meshing cycloidal gear pump (referred to as rotor pump) is a typical internal combustion engine oil pump (referred to as oil pump) in JB / T 8413. Its gears usually use powder metallurgy inner and outer rotors (referred to as inner and outer rotors). On this basis, its drive mechanism is changed to micro motor drive and an electronic control unit is introduced to adjust the oil volume and pressure of the pump, evolving into a new type of controllable oil pump (referred to as electronic oil pump). It can not only adjust the oil volume and pressure of the pump in real time according to the engine operating conditions (such as speed, temperature, load), but also be widely used in electric vehicle electric drive and battery thermal management cooling systems, braking and steering lubrication systems and other situations with high control and adjustment requirements. This electronic oil pump incorporates a micro-motor and an electronic control unit. A motor is located in the middle section of the pump housing, directly driving the inner and outer rotors of the pump mechanism located at one end of the pump housing. An electronic control unit is located at the other end of the pump housing. For example, the electronic oil pump described in Chinese patent CN222415219U forms a cavity (i.e., a control cavity) at the bottom of the pump housing to house the PCB control board. This cavity is covered with a bottom cover and secured with screws, while a sealing ring is used to seal the cover. However, sealing rings are mostly used to seal dry control cavities, and installing the sealing ring requires high-precision machining of the sealing groove, increasing processing difficulty and cost. Secondly, the cavity housing the PCB control board is a wet control cavity immersed in working oil. Even during normal operation, it must meet the harsh conditions of high temperature (150℃) and low temperature (-40℃) and be oil-resistant. Ordinary sealing rings are prone to aging. If oil-resistant materials with good high and low temperature performance are used, the cost increases significantly, and the production process is demanding, which is not conducive to mass production. On the other hand, existing technologies, such as the electronic oil pump described in Chinese patent CN222457752U, are limited by the small space for accommodating the PCB control board. The diameter of the PCB board cannot exceed 10cm. In order to retain more board area, the PCB board, the bottom cover, and the pump body are only indirectly positioned without direct limiting. In addition, the female connector is directly soldered to the PCB board without the use of plastic insulating base for installation constraint. This makes it easy for the corresponding pin blind insertion female connector on the bottom cover to have poor contact failure, resulting in burning.

[0003] Common knowledge and related terms can be found in Chinese patents CN222415219U and CN222457752U, as well as JB / T8413 "Internal Combustion Engine Oil Pump", JB / T 14395 "Technical Specification for Powder Metallurgy Inner and Outer Rotors for Automobile Oil Pumps", QC / T 289 "Automobile Engine Oil Pump", GB / T 33925.1 "General Terms, Definitions, Quantities, Characters and Units for Liquid Pumps and Their Devices - Part 1: Liquid Pumps", GB / T 7021 "Centrifugal Pump Terminology", JB / T5415 "Miniature Centrifugal Electric Pump", "IEC Electrical and Electronic Standards Terminology Dictionary" (China Standards Press, 1st edition, 1992), "Electrical Manufacturing Technology" (Mechanical Industry Press, 1st edition, 1982), "Mechanical Engineering Handbook", and "Electrical Engineering Handbook" (Mechanical Industry Press, 1st edition, 1978 and 2nd edition, 1997). Utility Model Content

[0004] This invention aims to solve at least one of the aforementioned technical problems existing in the prior art. To this end, this invention proposes a miniature electronic oil pump with an improved sealing structure for the control chamber.

[0005] The technical solution of this utility model is:

[0006] A sealing structure for the control chamber of a miniature electronic oil pump is disclosed. The pump body has a pump function unit built into the upper section along the pump axis, and the lower section extends along the pump axis as a cylindrical body with an open bottom end. The opening is closed by a bottom cover through a convex stop on its flange, forming a control chamber for accommodating a PCB control board. The convex stop is an annular boss. The end face of the cylindrical body opening is provided with an annular groove. The flange of the bottom cover facing the end face is also provided with an annular rib facing the annular groove. The annular boss is inserted into the inner peripheral wall of the cylindrical body and welded together to form a circumferential welding area. The annular rib is welded together with the annular groove to form an annular end face welding area.

[0007] Compared to existing micro electronic oil pumps that use sealing rings, this invention achieves sealing of the control chamber by welding the bottom cover to the pump body. This method is easy to manufacture, low in cost, and can reliably seal for a long time even when immersed in high-temperature or low-temperature oil. The annular ribs and annular grooves form an annular end face welding area between the end face of the pump body opening and the flange of the bottom cover. The annular boss of the bottom cover is inserted into the inner circumferential wall of the pump body to form an annular circumferential surface welding area. This fully utilizes the welding on both the end face and the side circumferential surface of the thin-walled cylinder to further improve sealing performance and save materials.

[0008] Furthermore, the welding is ultrasonic welding, the axial length L0 of the annular boss is not less than 1.5mm, and the axial length L1 of the circumferential welding area is not less than 1.5mm. Increasing the welding contact area when the cylinder wall is thin results in a better sealing effect. The axial length L1 of the circumferential welding area is preferably 1.7-4.0mm, which has good manufacturability and excellent sealing effect.

[0009] Furthermore, the annular boss extends axially with an inwardly inclined guide platform. The guide platform guides the annular boss to be inserted into the inner peripheral wall of the cylinder and welded together to form the circumferential welding area. With the guidance of the inwardly inclined guide platform, even if the opening of the cylinder is deformed, the annular boss can still be smoothly inserted into the inner peripheral wall of the cylinder, improving production efficiency and reducing the defect rate. At the same time, it can also increase the axial length L1 of the circumferential welding area, further improving the sealing effect.

[0010] The typical design of this technical solution is:

[0011] A second pin is embedded through the bottom cover. The second pin has an inner pin end, an outer pin end, and a connecting section. The inner pin end and the outer pin end are connected by the connecting section and offset. The inner pin end is partially exposed on the inner side of the bottom cover along the axial direction, and the outer pin end is partially exposed on the outer side of the bottom cover along the axial direction. The connecting section is embedded in the bottom cover material. The offset L2 between the inner pin end and the outer pin end is (5 to 10) times the pin thickness t. This increases the plastic sealing contact length and extends the liquid leakage path from the inside to the outside along the second pin. The bottom cover is formed by injection molding with the second pin as an insert, and a receiving groove around the inner pin end is formed at the same time. The groove is filled with sealant, which can further enhance the sealing performance of the second pin. Thus, together with the welding of the pump body and the bottom cover, it can strengthen the sealing of the internal control cavity and the outside of the bottom side of the pump body.

[0012] The more specific design and technical effects of this utility model are further explained in conjunction with the accompanying drawings in the specific embodiments. Attached Figure Description

[0013] Figure 1 This is an axial sectional view of the electronic oil pump of this utility model;

[0014] Figure 2 yes Figure 1 A magnified view of a portion of region A in the middle;

[0015] Figure 3 yes Figure 1 A magnified view of a portion of region B in the middle;

[0016] Figure 4 This is a schematic axial cross-sectional view of the electronic oil pump of this utility model along another cutting plane;

[0017] Figure 5 This is an exploded view of the pump body, PCB control board assembly, and bottom cover;

[0018] Figure 6 This is an exploded view of the pump body, PCB control board assembly, and bottom cover from another angle;

[0019] Figure 7 This is a three-dimensional partial cross-sectional view of the pump body, PCB control board assembly, and bottom cover assembly.

[0020] Figure 8 This is a bottom view of the PCB control board assembly;

[0021] Figure 9 yes Figure 8 CC section view in the image.

[0022] Figure label:

[0023] Pump body 100, cylinder 110, control chamber 111, first positioning post 112, annular groove 113;

[0024] PCB control board assembly 200, PCB board 210, first through hole 211, small positioning hole 212, first connecting terminal 220, first pin part 221, socket contact part 222, terminal block 230, small positioning pin 231;

[0025] Bottom cover 300, annular rib 301, annular boss 302, guide platform 303, guide post 304, guide blind hole 305, receiving groove 306, flange part 307, second pin 310, inner pin end 311, outer pin end 312, connecting section 313;

[0026] Circumferential welding area 10, circumferential end welding area 20;

[0027] Stator 400, motor rotor 500, pump internal rotor 600, pump external rotor 700. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] The terms "center," "top or above," and "bottom or below" used in the text are based on Figure 1 The indicated orientation or positional relationship Figure 1 The centerline is the central axis of the pump body (i.e., the pump and motor axis), and the orientation of "top or above" and "bottom or below" can be interchanged.

[0030] like Figure 1-4 As shown, the electronic oil pump of this utility model adopts a typical internal meshing cycloidal gear pump assembly. The electronic oil pump includes a pump body 100, a PCB control board assembly 200, and a bottom cover 300. A motor section consisting of a stator 400 and a motor rotor 500 is installed in the middle section of the pump body 100. Along the motor axis, a gear pump functional section consisting of an internal pump rotor 600 and an external pump rotor 700 is built into the upper section of the pump body 100. The lower section of the pump body 100 extends into a cylindrical body 110 with an open bottom end. This cylindrical body 110 can be cylindrical, elliptical, square, or other shapes suitable for industrial production. The cylindrical body 110 forms an opening towards the bottom. The cavity has a first circular positioning post 112 and several connecting terminals extending from the stator portion deep within the cavity toward the opening along the motor axis. The end face of the opening of the cylinder 110 is provided with an annular groove 113. The PCB control board assembly 200 is installed and fixed in the cavity and electrically connected to the stator through several connecting terminals to control the pump motor. The end face of the opening of the cylinder 110 is covered by the flange portion 307 on the bottom cover 300, which is opposite to it, to form a control cavity 111 that accommodates the PCB control board assembly 200, which includes the aforementioned cavity. The flange portion 307 of the bottom cover 300 is also provided with a protruding stop that inserts into the opening of the cylinder 110.

[0031] like Figure 3 , Figure 5-9 As shown, the PCB control board assembly 200 includes a PCB board 210, a first connecting terminal 220, and a terminal block 230. The first connecting terminal 220 has a first pin portion 221 and a socket contact portion 222. The connecting terminal is inserted into the terminal block 230 to limit the socket contact portion 222 and expose the first pin portion 221. The terminal block 230 has two small positioning pins 231 protruding from the exposed end of the first pin portion 221. The PCB board 210 has a first through hole 211 and two small positioning holes 212. The two small positioning pins 231 of the terminal block 230 are inserted into the two small positioning holes 212 of the PCB board 210. The first pin portion 221 is soldered to the PCB board 210 and assembled into the PCB control board assembly 200.

[0032] like Figure 2-4As shown, the flange portion 307 of the bottom cover 300 is provided with an annular rib 301 that is inserted into the annular groove 113. The flange portion 307 is designed as an annular boss 302. The annular boss 302 extends along the pump axis and has an inwardly inclined guide platform 303. The guide platform 303 can also be divided into several small segments along the circumferential direction on the continuous annular surface of the annular boss 302. The bottom cover 300 is provided with a guide post 304. The guide post 304 is hollow inward to form an axial guide blind hole 305. A second pin 310 is embedded through the bottom cover 300. The second pin 310 has an inner pin end 311, an outer pin end 312 and a connecting section 313. The inner pin end 311 and the outer pin end 312 are connected by the connecting section 313 and offset. The offset amount L2 is the second pin. The thickness 310 is (5 to 10) times that of the bottom cover 300. The inner needle end 311 is partially exposed along the pump axis inside the bottom cover 300, and the outer needle end 312 is partially exposed along the pump axis outside the bottom cover 300. The connecting section 313 is embedded in the bottom cover 300 material. The bottom cover 300, annular rib 301, annular boss 302, guide platform 303, guide post 304 and guide blind hole 305 are integrally formed by injection molding with the second needle 310 as the insert. A receiving groove 306 is formed around the inner needle end 311. The receiving groove 306 is filled with sealant (not shown). The insert injection molding here can also first use the second needle 310 as the insert to injection mold a plastic seat with the second needle 310, and then use the plastic seat as the insert to injection mold the bottom cover 300 and the above-mentioned auxiliary structures.

[0033] like Figure 1-9 As shown, during the specific installation of the pump body 100, PCB control board assembly 200, and bottom cover 300, the first positioning post 112 on the pump body 100 is first inserted into the first through hole 211 of the PCB control board assembly 200. Then, the PCB board 210 is welded and fixed perpendicular to the pump axis to several connecting terminals on the pump body 100. Then, the first positioning post 112 is inserted into the guide blind hole 305 of the bottom cover 300, and the guide platform 303 guides the annular boss 302 to be inserted into the inner circumferential wall of the cylinder 110, thereby guiding the inner needle end 311 of the bottom cover 300 to be inserted into the insertion hole contact part 222. The annular boss 302 and the inner circumferential wall of the cylinder 110 are paired and welded to form the circumferential surface welding area 10. The annular rib 301 of the bottom cover and the annular groove 113 of the cylinder are paired and welded to form the annular end face welding area 20. Ultrasonic welding is preferred.

[0034] The annular rib 301 and the annular groove 113 form an annular end face welding area 20 at the end face of the opening of the cylinder 110 and the flange portion 307 of the bottom cover 300. The convex stop of the bottom cover 300 is inserted into the inner peripheral wall of the cylinder 110 in the form of an annular boss 302 to form an annular circumferential surface welding area 10. This fully utilizes the welding in both directions of the thin wall end face and the inner peripheral surface of the cylinder 110 to improve sealing performance and save materials. The guide platform 303, which extends axially inward from the annular boss 302, can smoothly guide the cylinder 110 inner peripheral wall that is deformed at the opening, thereby improving production efficiency and reducing defect rate. The axial length L0 of the annular boss 302 is not less than 1.5mm, and the axial length L1 of the annular surface welding area 10 is not less than 1.5mm. When the pump cylinder 110 has a thin wall, it can increase the welding contact area and improve the sealing effect. The axial length L1 of the annular surface welding area 10 is preferably 1.7-4.0mm, which has good manufacturability and excellent sealing effect. The annular groove and annular rib that are paired and welded here can also be set on the flange of the bottom cover and the end face of the cylinder opening, respectively.

[0035] The offset L2 between the inner and outer ends of the second pin 310 embedded in the bottom cover 300 is (5 to 10) times the thickness t of the pin. This increases the plastic seal contact length and extends the liquid leakage path from the inside to the outside along the pin. The bottom cover 300 forms a receiving groove 306 around the exposed part of the inner pin end 311 and fills it with sealant, which can further enhance the sealing performance of the pin.

[0036] The first positioning post 112 on the pump body 100 passes through the first through hole 211 on the PCB board 210 and is accurately aligned with the guide blind hole 305 on the bottom cover 300. Compared with the prior art, where the PCB board is fixed to the pump body first and therefore lacks direct alignment with the bottom cover, this reduces the cumulative error of the three components during manufacturing. The two small positioning pins 231 on the terminal block 230 are inserted into the small positioning holes 212 on the PCB board 210 for accurate alignment. Compared with snap-fit ​​or direct welding, the positioning accuracy is high. At the same time, the terminal block 230 blocks and limits the insertion hole contact part 222, ensuring that the inner pin end 311 on the bottom cover 300 is accurately inserted into the insertion hole contact part 222 in the terminal block 230. This prevents poor contact due to misalignment or deformation and displacement of the insertion hole contact part, thus avoiding burning of the insertion hole contact part.

[0037] For a small-area PCB board 210 with an external dimension D not exceeding 10cm, the distance S between the first through hole 211 on the PCB board and the terminal block 230 is set to not exceed 4cm, and preferably to be close to each other by no more than 1cm. With the PCB board 210 fixed to the pump body 100, only one first positioning pin 112 is used to achieve accurate alignment of the pump body 100, PCB board 210, and bottom cover 300, thus saving space on the small-area PCB board. To further save space, the first through hole 211 on the PCB board 210 is set as a circular hole with an inner diameter not exceeding 3mm, and the small positioning hole 212 is set as a circular hole with an inner diameter not exceeding 1.5mm. The first positioning pin 112 and the small positioning pin 231 are both cylindrical, providing high positioning accuracy and ease of manufacturing.

[0038] The pump functional unit, consisting of an internal rotor and an external rotor, is an internal meshing cycloidal gear pump. The pump functional unit can also be replaced by another typical external meshing involute gear pump, such as an oil pump. Alternatively, the pump functional unit can be replaced by a centrifugal pump with an impeller rotating inside the pump casing, used as an electronic water pump in the power thermal management system of electric vehicles.

[0039] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A sealing structure for the control chamber of a miniature electronic oil pump, wherein the pump body (100) has a pump function unit built into the upper section along the pump axis, and the lower section extends along the pump axis as a cylindrical body (110) with an open bottom end, the opening being closed by a bottom cover (300) inserted through the convex stop of its flange (307) to form a control chamber (111) for accommodating a PCB control board, characterized in that: The convex stop is presented as an annular boss (302), and the end face of the opening of the cylinder (110) is provided with an annular groove (113). The flange part (307) of the bottom cover (300) facing the end face is also provided with an annular rib (301) facing the annular groove (113). The annular boss (302) is inserted into the inner peripheral wall of the cylinder (110) and paired for welding to form an annular surface welding area (10). The annular rib (301) and the annular groove (113) are paired for welding to form an annular end face welding area (20).

2. The sealing structure according to claim 1, characterized in that: The welding is ultrasonic welding, and the axial length L1 of the circumferential welding area (10) is not less than 1.5 mm.

3. The sealing structure according to claim 2, characterized in that: The axial length L1 of the circumferential welding area (10) is 1.7-4.0 mm.

4. The sealing structure according to claim 1, characterized in that: The annular boss (302) extends along the pump axis and has an inwardly inclined guide platform (303). The guide platform (303) guides the annular boss (302) to be inserted into the inner circumferential wall of the cylinder (110) and welded together to form the circumferential surface welding area (10).

5. The sealing structure according to claim 4, characterized in that: The guide platform (303) consists of several discontinuous segments along the circumferential direction on the continuous ring of the annular boss (302).

6. The sealing structure according to claim 1, characterized in that: A second pin (310) is embedded through the bottom cover (300). The second pin (310) has an inner pin end (311), an outer pin end (312), and a connecting section (313). The inner pin end (311) and the outer pin end (312) are connected by the connecting section (313) and offset. The inner pin end (311) is partially exposed on the inner side of the bottom cover (300) along the axial direction, and the outer pin end (312) is partially exposed on the outer side of the bottom cover (300) along the axial direction. The offset L2 between the inner pin end (311) and the outer pin end (312) is (5 to 10) times the thickness t of the second pin (310).

7. The sealing structure according to claim 1, characterized in that: A second pin (310) is embedded through the bottom cover (300). The second pin (310) has an inner pin end (311) and an outer pin end (312). The inner pin end (311) is partially exposed on the inner side of the bottom cover (300) along the axial direction, and the outer pin end (312) is partially exposed on the outer side of the bottom cover (300) along the axial direction. The bottom cover (300) and the receiving groove (306) surrounding the inner pin end (311) are formed by injection molding with the second pin (310) as an insert, and the groove is filled with sealant.

8. A miniature electronic oil pump, comprising the sealing structure described in any one of claims 1-7.

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