WO2015027965A1

WO2015027965A1 - Electronic cooling water pump with floating impeller for motor vehicle

Info

Publication number: WO2015027965A1
Application number: PCT/CN2014/088462
Authority: WO
Inventors: Hongming Dai; Jinshun ZHU; Feifei YE; Feng Chen
Original assignee: Borgwarner Thermal Systems Of Michigan, Inc.
Priority date: 2013-08-27
Filing date: 2014-10-13
Publication date: 2015-03-05
Also published as: CN103452858A; CN103452858B

Abstract

Disclosed is a cooling water pump with a floating impeller for a motor vehicle, comprising a support (6), wherein a stator (5), a water pump cover (2), a socket injection molding (2), a controller (8) and a rear cover (9) are mounted on the support separately by bolts. A rotor impeller injection molding (3) is mounted at the center of the stator (5). The rotor impeller injection molding (3) is of a design integrating a water pump impeller with an electric machine rotor. When the electronic cooling water pump is operating, the interaction between the magnetic field generated by the stator (5) and the magnetic field generated by the permanent magnets in the rotor impeller injection molding (3) can not only turn the rotor impeller injection molding (3) at a certain rotation speed, but also make the rotor impeller injection molding float automatically in the center of the stator. As it rotates, the impeller remains at all times in a magnetic floating state, so it will not experience friction with other components, and the mechanical loss in the motor vehicle cooling water pump is reduced and the efficiency of the motor vehicle cooling water pump is increased, thereby reducing the fuel consumption of the motor vehicle.

Description

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DESCRIPTION

Electronic cooling water pump with floating impeller for motor vehicle

Technical field

The present invention relates to a motor vehicle cooling system component, in particular to an electronic cooling water pump for a motor vehicle.

Background art

As society has developed and technology has advanced, motor vehicles have gradually become part of innumerable households, and people are demanding greater comfort when traveling. Therefore, a leader in the field of motor vehicle cooling systems has a duty to make constant innovations in cooling system technology, to meet the ever-increasing demands of consumers.

Abnormal noises in motor vehicles have now become a major factor affecting the comfort of travelers. Abnormal noise from the motor vehicle cooling water pump accounts for a significant proportion of all abnormal noise from the motor vehicle, and is also the principal form of failure of the motor vehicle cooling water pump. Abnormal noise produced by the bearing in the motor vehicle cooling water pump makes the most significant contribution to abnormal noise from the motor vehicle cooling water pump. Thus, solving the problem of abnormal noise from the bearing of the motor vehicle cooling water pump is of vital importance to the improvement of comfort for motor vehicle occupants.

The motive power for all conventional mechanical cooling water pumps for motor vehicles comes from the main shaft of the engine. The motive power provided by the main shaft is transmitted to the motor vehicle’s cooling water pump shaft via a belt or chain, enabling the motor vehicle’s cooling water pump impeller to do work on the coolant so that the latter circulates in the cooling system and thereby cools the relevant components of the motor vehicle. The characteristics of transmission by belt or chain are such that the belt or chain must exert a significant radial force on the water pump shaft during transmission, and for this reason it is necessary to fit a bearing to a mechanical motor vehicle cooling water pump, to bear the radial force exerted on the water pump by the belt or chain. With a bearing, there will be friction, and with friction, there is the possibility of abnormal noise.

The development in recent years of electronic cooling water pumps for motor vehicles has provided a fine platform for solving the problem of abnormal noise from cooling water pump bearings in motor vehicles. The main difference between transmission mechanical cooling water pumps for motor vehicles and electronic cooling water pumps for motor vehicles is that their motive power comes from different sources. The motive power for mechanical cooling water pumps for motor vehicles comes from the main shaft of the engine, whereas the motive power for electronic cooling water pumps for motor vehicles comes from a generator or battery pack. Therefore electronic cooling water pumps for motor vehicles do not need a belt or chain for transmission of motive power. It is only necessary to connect the wiring port of the electronic cooling water pump of the motor vehicle to the wiring port of the motor vehicle’s power supply. Exploiting the characteristics of electronic water pumps, we have invented a cooling water pump with a floating impeller for a motor vehicle. This invention can completely eliminate abnormal motor vehicle noise produced by the bearing of a motor vehicle cooling water pump.

Content of the present invention

The technical problem to be solved by the present invention is to provide a cooling water pump with a floating impeller for a motor vehicle, to completely eliminate abnormal noise produced by a motor vehicle cooling water pump bearing.

The technical solution by which the present invention solves the above technical problem is: a cooling water pump with a floating impeller for a motor vehicle, comprising a support, on which are mounted a stator, a water pump cover, a socket injection molding, a controller and a rear cover. A rotor impeller injection molding is mounted at the center of the rotor. It is characterized in that:

The rotor impeller injection molding is of a design integrating a water pump impeller with an electric machine rotor. The electric machine rotor principally comprises 4 permanent magnets, 1 permanent magnet support and 1 permanent magnet protective cover. The water pump impeller principally comprises blades, a front cover plate and a rear cover plate. An injection molding process is used to form the water pump impeller and electric machine rotor as a single piece. The injection molding process involves putting the electric machine rotor into an injection molding mold first as an insert, then injecting a plastic material into the mold, to form a component (the rotor impeller injection molding) in which the water pump impeller is integrated with the electric machine rotor. A through-hole with precise dimensions is provided at the center of the rotor impeller injection molding, to fit an electric machine shaft.

At the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft and the rotor impeller injection molding ensures that the shaft core of the rotor impeller injection molding coincides with the shaft core of the stator, i.e. at this time, in terms of radial position, the rotor impeller injection molding is located at the center of the stator. The magnetic effect of permanent magnets in the rotor impeller injection molding ensures that the permanent magnets are located in a central position in the longitudinal direction of the stator. That is to say, at this time the longitudinal position of the rotor impeller injection molding is in a floating state.

Once the electronic cooling water pump for the motor vehicle has been energized, the stator will generate a magnetic field. The interaction between the magnetic field generated by the stator and the magnetic field generated by the permanent magnets in the rotor impeller injection molding can not only turn the rotor impeller injection molding at a certain rotation speed, so that the impeller does work on coolant, but also make the rotor impeller injection molding float automatically in the center of the stator. That is to say, as it rotates and does work, the impeller remains at all times in a magnetic floating state, and so will not experience friction with other components.

Compared with the prior art, the present invention has the following advantages: The cooling water pump with a floating impeller for a motor vehicle dispenses with a bearing, putting an end to friction between a rotating part and a fixed part. Thus, it not only resolves the fault of abnormal vehicle noise produced by bearing friction, but also eliminates consumption of mechanical energy by bearing friction, thereby reducing the fuel consumption of the motor vehicle.

Description of the accompanying drawings

Fig. 1 is a sectional structural diagram of the present invention. It comprises components such as bolts 1, a water pump cover 2, a rotor impeller injection molding 3, an electric machine shaft 4, a stator 5, a support 6, a socket injection molding 7, a controller 8 and a rear cover 9.

Fig. 2 is an exploded structural diagram showing the components of the present invention.

Fig. 3 is a sectional structural diagram of the rotor impeller injection molding 3 of the present invention. It comprises components such as an impeller I, a permanent magnet support II, permanent magnets III (4 pieces) and a permanent magnet protective cover IV.

Particular embodiments

The present invention is described in further detail below with reference to the accompanying drawings.

As Fig. 1 shows: a cooling water pump with a floating impeller for a motor vehicle comprises a support 6, a stator 5 mounted on the support 6, a water pump cover 2, a socket injection molding 7, a controller 8 and a rear cover 9. The stator 5, water pump cover 2, socket injection molding 7, controller 8 and rear cover 9 are all fixed to the support by bolts. Sealing rings for sealing are mounted between the stator 5 and water pump cover 2, between the stator 5 and support 6, between the socket injection molding 7 and support 6, and between the rear cover 9 and support 6, to prevent leakage. This ensures that coolant will not leak to the outside, and also that liquid and damp gases from the outside will not enter the interior of the motor vehicle’s electronic cooling water pump and thereby damage the components thereof.

A welding process is employed to ensure electric current and signal communication between the stator 5 and controller 8 and between the controller 8 and socket injection molding 7. When the plug-in injection molding 7 is in communication with a power supply of the motor vehicle and a signal source, and has received a signal, the plug-in injection molding 7 will input the signal and a current to the controller 8. After intelligent processing by the controller 8, the controller 8 will drive the rotor impeller injection molding 3 to rotate at a certain speed； as it rotates, the impeller part of the rotor impeller injection molding 3 does work on the coolant, so that the latter circulates in the cooling system circuit of the motor vehicle, thereby cooling the relevant components of the motor vehicle.

The rotor impeller injection molding 3 comprises an impeller I, a permanent magnet support II, permanent magnets III (4 pieces) and a permanent magnet protective cover IV. At the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft 4 and the rotor impeller injection molding 3 ensures that the shaft core of the rotor impeller injection molding 3 coincides with the shaft core of the stator, i.e. at this time, in terms of radial position, the rotor impeller injection molding 3 is located at the center of the stator 5. The magnetic effect of the permanent magnets III in the rotor impeller injection molding 3 ensures that the permanent magnets are located in a central position in the longitudinal direction of the stator 5. That is to say, at this time the longitudinal position of the rotor impeller injection molding 3 is in a floating state.

Once the electronic cooling water pump for the motor vehicle has been energized, the stator 5 will generate a magnetic field. The interaction between the magnetic field generated by the stator 5 and the magnetic field generated by the permanent magnets III in the rotor impeller injection molding 3 can not only turn the rotor impeller injection molding 3 at a certain rotation speed, so that the impeller does work on the coolant, but also make the rotor impeller injection molding 3 float automatically in the center of the stator 5. That is to say, as it rotates and does work, the impeller part of the rotor impeller injection molding 3 remains at all times in a magnetic floating state, and so will not experience friction with other components.

The objective ultimately achieved by the present invention is to increase the overall efficiency of the motor vehicle cooling water pump while completely eliminating abnormal noise produced by a motor vehicle cooling water pump bearing. The specific objective is elaborated from the following perspectives:

The present invention can completely eliminate abnormal noise produced by a bearing of an electronic cooling water pump for a motor vehicle, greatly reducing the probability of abnormal motor vehicle noise arising, and hence increasing customer satisfaction.

Not only can the present invention completely eliminate abnormal noise produced by a bearing of an electronic cooling water pump for a motor vehicle, but the failure rate after sale of the motor vehicle cooling water pump can be reduced by around 25％.

Bearing lifespan is one of the main factors limiting the overall lifespan of a motor vehicle cooling water pump. For this reason, a structural design with no bearing is employed in the present invention, which can increase lifespan by around 30％compared to product designs in the same class employing a bearing structure.

The use of a structural design with no bearing in the present invention eliminates mechanical loss arising from bearing friction. It can increase motor vehicle cooling water pump efficiency by 1％-2％, thereby reducing the fuel consumption of the motor vehicle.

The use of a structural design with no bearing in the present invention can reduce design costs by about 6％.

Description of specific operating principles:

At the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft 4 and the rotor impeller injection molding 3 ensures that the shaft core of the rotor impeller injection molding 3 coincides with the shaft core of the stator, i.e. at this time, in terms of radial position, the rotor impeller injection molding 3 is located at the center of the stator 5. The magnetic effect of the permanent magnets III in the rotor impeller injection molding 3 ensures that the permanent magnets are located in a central position in the longitudinal direction of the stator 5. That is to say, at this time the longitudinal position of the rotor impeller injection molding 3 is in a floating state.

Claims

A floating impeller structure for a motor vehicle cooling water pump, comprising a stator, an electric machine shaft, and a rotor impeller injection molding, wherein:

at the instant in time when the electronic cooling water pump for the motor vehicle is not energized and is just starting up, the precise fit between the electric machine shaft and the rotor impeller injection molding ensures that the shaft core of the rotor impeller injection molding coincides with the shaft core of the stator, i.e. at this time, in terms of radial position, the rotor impeller injection molding is located at the center of the stator； the magnetic effect of permanent magnets in the rotor impeller injection molding ensures that the permanent magnets are located in a central position in the longitudinal direction of the stator； that is to say, at this time the longitudinal position of the rotor impeller injection molding is in a floating state；

once the electronic cooling water pump for the motor vehicle has been energized, the stator will generate a magnetic field； the interaction between the magnetic field generated by the stator and the magnetic field generated by the permanent magnets in the rotor impeller injection molding can not only turn the rotor impeller injection molding at a certain rotation speed, so that the impeller does work on coolant, but also make the rotor impeller injection molding float automatically in the center of the stator； that is to say, as it rotates and does work, the impeller remains at all times in a magnetic floating state, and so will not experience friction with other components.
The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 1, wherein: the rotor impeller injection molding is of a design integrating a water pump impeller with an electric machine rotor； the electric machine rotor principally comprises 4 permanent magnets, 1 permanent magnet support and 1permanent magnet protective cover； the water pump impeller principally comprises blades, a front cover plate and a rear cover plate； an injection molding process is used to form the water pump impeller and electric machine rotor as a single piece； the injection molding process involves putting the electric machine rotor into an injection molding mold first as an insert, then injecting a plastic material into the mold, to form a component (the rotor impeller injection molding) in which the water pump impeller is integrated with the electric machine rotor.
The floating impeller structure for a motor vehicle cooling water pump as claimed in claim 1, wherein: the electric machine shaft is fixed at the center of the stator, to ensure that the shaft core of the electric machine coincides with the shaft core of the electric machine.
The rotor impeller injection molding structure as claimed in claim 2, wherein: an inner hole with precise dimensions is provided at the center of gravity of the rotor impeller injection molding and fits the outer circle of the electric machine shaft.