Automotive Electronic Fluid Pump

Abstract

The present invention relates to an automotive electronic fluid pump (10) having an electric pump motor (14). The electric pump motor (14) includes an electromagnetic motor stator (50) having a plurality of stator coils (52), a motor rotor (54) electromagnetically driven by the motor stator (50), a pump rotor (34), and a rotor shaft (30), a motor electronic circuit (42) disposed in an electronic circuit chamber (40) and including a rectifying electronic circuit and a power semiconductor (44) for energizing the stator coil (52), and a separation tube (70) fluidly separating a wet motor rotor chamber (62) and a dry motor stator chamber (61). A pot-shaped motor housing frame (80) having a frame bottom wall (82) and a substantially cylindrical frame side wall (84) is provided. The frame bottom wall (82) defines a substantially transverse separation wall (64) that fluidly separates the wet motor rotor chamber (62) and the dry electronic circuit chamber (40). The frame side wall (84) supports the radially outer side of the motor stator (50). The motor housing frame (80) is made from a deep-drawn metal sheet body (80'). The motor housing frame (80) also defines a cylindrical axial support collar (66) made by reverse drawing of the metal sheet body (80'). The support collar (66) directly supports the support section (702) of the separation tube (70).

Description

Technical Field

[0001] The present invention relates to an automotive electronic fluid pump, which has an electronic rectifier pump motor for driving a pump rotor provided in a wet motor rotor chamber separated from a dry motor stator chamber by a substantially cylindrical separation tube. The concept of this pump is that no dynamic sealing is performed between the wet part and the dry part of the fluid pump.

Background Art

[0002] An important issue with the concept of this pump is the exact coaxiality of the motor stator, the separation tube, and the motor rotor. If the reproducibility quality of the coaxiality is high, it is possible to define a small gap between the motor stator and the motor rotor, and if the gap is small, the electromagnetic efficiency of the motor will be high. Another important issue for any automotive electrical device is the electromagnetic compatibility (EMC) of the device.

[0003] Generally, a metal motor frame has high reproducibility quality. International Publication No. 2017140334A1 discloses a typical motor concept in which a deep-drawn metal sheet body defines a separation tube, a rotor sliding bearing ring, and a transverse separation wall to fluidly separate a wet motor rotor chamber and a dry electronic circuit chamber. Since the pump housing is completely made of plastic, the motor stator is not electromagnetically shielded. If the pump housing is made of metal, electromagnetic shielding can be performed, but as a result, the fluid pump is considered to be relatively heavy and expensive, and both being heavy and expensive are generally unacceptable for automotive devices and applications.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a competitive automotive electronic fluid pump with good electromagnetic efficiency and electromagnetic compatibility.

Means for Solving the Problems

[0005] This object is solved by an automotive electronic fluid pump having the features according to claim 1.

[0006] The automotive electronic fluid pump according to the invention comprises an electric pump motor including an electronic motor stator having several stator coils. The rotor includes a motor rotor, a pump rotor, and a rotor shaft that mechanically and co-rotatably connects the motor rotor and the pump rotor. The motor rotor is preferably permanently magnetized and is electromagnetically driven by a motor stator surrounding the central motor rotor. The pump rotor may be a positive displacement pump rotor or preferably a flow pump rotor.

[0007] The motor electronic circuit includes a rectifying electronic circuit for energizing the stator coils and several power semiconductors. The motor electronic circuit is arranged in a dry electronic circuit chamber axially adjacent to the wet motor rotor chamber. A non-ferromagnetic separation tube fluidically separates the wet motor rotor chamber and the dry motor stator chamber, and this separation tube is provided in the cylindrical gap between the motor rotor and the motor stator. A substantially transverse separation wall fluidically separates the wet motor rotor chamber and the dry electronic circuit chamber.

[0008] According to the invention, a pot-shaped motor housing frame is provided. The motor housing frame defines a bottom wall that lies substantially in a cross-section, and the cylindrical side wall is substantially cylindrical in shape. The housing frame bottom wall defines the separation wall between the wet motor rotor chamber and the dry electronic circuit chamber. The side wall portion of the motor housing frame supports the radially outer side of the motor stator.

[0009] The motor housing frame is made from a deep-drawn metal sheet body, and the motor housing frame also defines a cylindrical support collar that projects proximally in the axial direction from the frame bottom wall into the motor rotor chamber and is made by reverse drawing. A sufficiently accurate cylindrical support collar can be obtained without further machining. The cylindrical support collar directly supports the cylindrical support section of the separation tube. The separation tube may be made from any suitable non-ferromagnetic material, preferably plastic.

[0010] Preferably, the moment housing frame is made of a ferromagnetic metal material in order to well electromagnetically shield the motor stator and achieve good electromagnetic compatibility (EMC) of the fluid pump. Preferably, the motor housing frame is electrically grounded. The metal motor housing frame also defines a transverse separation wall between the wet motor rotor chamber and the dry electronic circuit chamber, so that the heat generated from the motor electronic circuit can efficiently transfer to the pumping fluid through the transverse separation wall, and this transverse separation wall has a relatively high thermal conductivity. Preferably, the power semiconductor of the motor electronic circuit is thermally coupled to the motor housing frame so that there is no gap therebetween.

[0011] The pumping fluid may generally be a gas or a liquid, but is preferably a liquid. Accordingly, preferably, the fluid pump is a liquid pump, and more preferably, a coolant pump for an automotive coolant and / or heating circuit.

[0012] The motor housing frame of the metal sheet is sufficiently rigid to accurately support and coaxially position the motor stator and the separation tube. Further, the motor housing frame electromagnetically shields the motor stator so that good electromagnetic compatibility (EMC) is achieved. The separation tube is preferably made of a lightweight and non-ferromagnetic material, for example, a plastic material with very good cost efficiency.

[0013] Preferably, the support collar of the motor housing frame supports the radially outer surface of the support section of the separation tube. Preferably, the support collar lies substantially within the cylindrical surface defined by the cylindrical void between the motor rotor and the motor stator. As a result, a relatively large motor stator chamber is obtained that is not constricted radially inward within the section defined by the support collar. Preferably, the separation tube support section has a smaller radius than the void section of the separation tube.

[0014] Preferably, the plastic separation tube body also defines a rotor shaft bearing support section that rotatably supports the rotor shaft. Preferably, the rotor shaft bearing is of the sliding bearing type, and the plastic separation tube body directly supports and even directly defines the outer bearing ring of the sliding bearing.

[0015] Preferably, the entire proximal transverse wall of the electronic circuit chamber is defined by the transverse bottom wall of the pot-shaped motor housing frame. The proximal transverse wall of the electronic circuit chamber is a wall that separates the electronic circuit chamber from the motor rotor chamber and also from the motor stator chamber. Since the entire proximal transverse wall of the electronic circuit chamber is defined by the transverse bottom wall of the motor housing frame, no additional wall is required to separate the electronic circuit chamber from the motor stator chamber.

[0016] Preferably, another further plastic motor housing houses and surrounds the motor housing frame. The plastic motor housing completely surrounds the motor housing frame radially to mechanically protect the motor housing frame. Thus, the motor stator is surrounded radially by the inner wall defined by the motor housing frame and the adjacent outer wall defined by the plastic motor housing. Preferably, the plastic motor housing defines the circumferential side wall of the electronic circuit chamber.

[0017] An embodiment of the present invention will be described with reference to the accompanying drawings. The drawings are as follows.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0019] FIG. 1 shows an automotive electronic fluid pump 10, which is, in this embodiment, a liquid pump for pumping coolant within an automotive coolant circuit. The automotive electronic fluid pump 10 includes a brushless electric pump motor 14, and the pump motor 14 is rectified and energized by a motor electronic circuit 42. The electronic circuit 42 includes a rectifying electronic circuit for energizing some stator coils 52 of an outer motor stator 50 and some power semiconductors 44.

[0020] The pump 10 is designed to be dynamically seal - free, includes a wet - motor rotor chamber 62 containing a wet - motor rotor 54, includes an annular dry - motor stator chamber 61 having a dry - motor stator 50, and the chambers 61, 62 are fluidly separated from each other by a substantially cylindrical plastic separation tube 70.

[0021] The motor rotor 54 is permanently magnetized and includes a plurality of identical transverse ferromagnetic rotor sheets 55 and several permanently magnetized rotor pole magnets 56 that define several magnetic rotor poles. The motor rotor 54 rotates about the longitudinal pump shaft A. The rotor of the fluid pump 10 includes the motor rotor 54, the rotor shaft 30, and the pump rotor 34. The pump rotor 34 is, in this embodiment, an impeller wheel having an axial pump rotor inlet opening 35 and a peripheral radial pump rotor outlet opening 36, whereby the fluid pump 10 is a flow pump. The rotor shaft 30 includes an axial coolant channel bore 31 and mechanically co-rotatably connects the motor rotor 54 to the pump rotor 34.

[0022] The pump rotor 34 is surrounded by a pump outlet volute 26 defined by a fluid housing portion 20 defined by a plastic fluid housing portion body 20', and the fluid housing portion body 20' also defines an axial pump inlet duct 28 and a tangential pump outlet duct (not shown).

[0023] The motor stator 50 includes a plurality of identical ferromagnetic transverse stator metal sheets 51 and a stator coil 52 that defines several electromagnetic stator poles.

[0024] The pump motor 14 includes a pot-shaped motor housing frame 80 made from a deep-drawn metal sheet of ferromagnetic metal. The motor housing frame 80 defines a generally cylindrical frame side wall 84 and a transverse frame bottom wall 82. The frame bottom wall 82 has two parts, which are a central bottom wall part defining a transverse separation wall 64 that fluidly separates the wet motor rotor chamber 62 and the dry electronic circuit chamber 40, and a ring-shaped ring bottom wall part 63 that radially surrounds the transverse separation wall 64. The motor housing frame 80 also defines a cylindrical axial support collar 66 that projects proximally in the axial direction from the cross-section XZ of the frame bottom wall 82. The inner surface of the cylindrical support collar 66 directly supports the radially outer surface 702' of the support section 702 of the separation tube 70. The motor housing frame bottom wall 82 defines the entire proximal transverse wall 90 of the electronic circuit chamber 40 that separates the electronic circuit chamber 40 from the motor rotor chamber 62 and the motor stator chamber 61.

[0025] The plastic separation tube 70 is made from a plastic separation tube body 70', and has a generally cylindrical void section 701 and a generally cylindrical support section 702 having a forced support ring 72. The support section 702, which is substantially defined by the support ring 72, has a smaller radius compared to the void section 701, as shown in FIG. 2. The separation tube 70 also defines a ring-shaped rotor shaft bearing support portion 76 that rotatably supports the rotor shaft 30. The rotor shaft bearing support portion 76 is held by several radial support arms 74. The separation tube 70 is a single integral part.

[0026] The pump housing is defined by the fluid housing part 20, and a separate motor housing 22 completely houses the motor housing frame 80 and the electronic circuit chamber lid 24. The motor housing 22 is defined by a plastic motor housing body 22', and the electronic circuit chamber lid 24 is defined by a plastic lid body 24'.

Claims

1. An automotive electronic fluid pump (10) having an electric pump motor (14), wherein the electric pump motor (14) comprises: an electromagnetic motor stator (50) having a plurality of stator coils (52); a motor rotor (54) electromagnetically driven by the motor stator (50), a pump rotor (34), and a rotor shaft (30), the rotor comprising; a motor electronic circuit (42) disposed within an electronic circuit chamber (40) and including a rectifying electronic circuit and a power semiconductor (44) for energizing the stator coils (52); a separation tube (70) fluidly separating a wet motor rotor chamber (62) and a dry motor stator chamber (61); and comprising; a pot-shaped motor housing frame (80) having a frame bottom wall (82) and a substantially cylindrical frame side wall (84); the frame bottom wall (82) defining a substantially transverse separation wall (64) that fluidly separates the wet motor rotor chamber (62) and the dry electronic circuit chamber (40); the frame side wall (84) supporting the radially outer side of the motor stator (50); the motor housing frame (80) being made from a deep-drawn metal sheet body (80'); the motor housing frame (80) defining a cylindrical axial support collar (66) formed by reverse drawing of the metal sheet body (80'); the support collar (66) directly supporting a support section (702) of the separation tube (70); An automotive electronic fluid pump (10).

2. The automotive electronic fluid pump (10) according to claim 1, wherein the indicated collar (66) of the motor housing frame (80) supports the radially outer surface (702') of the support section (702) of the separation tube (70).

3. The automotive electronic fluid pump (10) according to any one of claims 1 to 2, wherein the separation tube (70) is made from a plastic separation tube body (70').

4. The automotive electronic fluid pump (10) according to any one of claims 1 to 3, wherein the support section (702) has a smaller radius than the void section (701) of the plastic separation tube (70).

5. The plastic separation tube (70) also defines a rotor shaft bearing support portion (76) that rotatably supports the rotor shaft (30). The automotive electronic fluid pump (10) according to any one of claims 1 to 4.

6. The entire proximal transverse wall (90) of the electronic circuit chamber (40) is defined by the motor housing frame bottom wall (82). The automotive electronic fluid pump (10) according to any one of claims 1 to 5.

7. Another plastic motor housing (22) houses the motor housing frame (80). The automotive electronic fluid pump (10) according to any one of claims 1 to 6.

8. The fluid pump (10) is a liquid pump, preferably a coolant pump. The automotive electronic fluid pump (10) according to any one of claims 1 to 7.

Images