JPH0968173A - Electric motor-driven type pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize, weight-lighten an integral type pump comprising a fluid pressure pump, electric motor and the tank and reduce a cost by decreasing a number of constitutional part items of a tank. SOLUTION: An electric motor-driven type pump 1 is constituted by an integral type structure comprising a fluid pressure pump part 2, its driving electric motor part 3 and a tank part 4 storing a fluid accumulated. The electric motor part is constituted of a DC brushless motor. The fluid pressure pump part is provided around a motor shaft 16 in one end side of this motor part. Further, the tank part is provided in the internal space of casings 11, 12, 13 in the DC brushless motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor drive type pump used as a fluid pressure source in a fluid pressure utilizing device such as a power steering apparatus, and in particular, a fluid pressure pump, an electric motor and a tank are integrally formed. The present invention relates to an electric motor driven pump.

[0002]

2. Description of the Related Art In a hydraulic power steering apparatus, an oil pump serving as a hydraulic pressure source (fluid pressure source) and an electric motor driving the oil pump are integrally connected, and a casing is provided so as to surround the oil pump. 2. Description of the Related Art Electric motor driven pumps having an integrated structure including a pump, an electric motor, and a tank, which are provided with an oil tank, are conventionally known, including, for example, Japanese Utility Model Publication No. 2-132873.

This type of electric motor driven pump is a hydraulic power source for obtaining a steering assist force (hereinafter referred to as steering assist force or assist force) by feeding hydraulic pressure to a power cylinder in response to steering operation of a steering wheel. In a fluid pressure utilizing device such as a steering device, a pump, which is a hydraulic pressure source driven by an electric motor, is driven by using the electric motor, and the working oil in a tank provided around the pump is sucked and discharged by the pump. It is configured.

Here, in the conventional device as described above,
A DC brush motor is generally used as the electric motor. That is, in such a brushed motor,
Electrical connection to the rotor is made using sliding contact of a brush to a commutator on the motor shaft. Then, the direction of the current flowing through the armature winding of the rotor is switched through the connecting portion formed by the sliding contact of the brush to obtain the rotational driving force depending on the required direction and the number of rotations.

[0005]

However, in the above-mentioned conventional electric motor drive type pump, the pump is provided on the motor shaft at one end side of the electric motor, and the tank is surrounded so as to accommodate the pump. A structure is provided in which a casing constituting the above is disposed, and the opening end of the casing is continuously connected to the side portion of the electric motor on the side where the motor shaft projects through a seal member, while the periphery of the pump can be used as a tank. However, not only the entire pump device becomes large, but also parts such as a casing, a connecting member, and a seal member for forming the tank are required, resulting in high cost.

Further, in the motor with a brush used as the above-mentioned electric motor, since the brush slidingly contacting the commutator is abraded, not only the life of the brush and the commutator becomes a problem, but also the sliding contact portion. Noise is also a problem.

Further, in the above brush motor,
As an accidental failure, the contact between the brush and the commutator may be broken, and the motor may stop rotating. In addition, as described above, when the brush is worn, the abrasion powder of the brush enters the slot portion of the commutator and causes a short circuit, resulting in a decrease in motor output.

The present invention has been made in view of the above circumstances, and is an electric motor D for driving a fluid pressure pump.
By using a C brushless motor and utilizing the internal space of this motor as a tank,
The entire pump consisting of the electric motor section and tank section can be made compact and lightweight, and the cost can be reduced by reducing the number of tank components that were required in the past, and also the cooling effect of the motor section can be expected. The purpose is to obtain a pump that can be driven by an electric motor.

Further, according to the present invention, the electric motor for driving the pump, which is the fluid pressure source, is constituted by the DC brushless motor, so that the need for maintenance of the electric motor is eliminated, and the drive control of the motor and the pump is also performed. An object of the present invention is to obtain an electric motor drive type pump that can be appropriately operated by using a detection means attached to a DC brushless motor.

[0010]

In order to meet such a demand, an electric motor drive type pump according to the present invention stores a fluid pressure pump section, an electric motor section for driving the fluid pressure pump section, and a fluid sucked into the pump section. Is an electric motor drive type pump that integrally configures a tank part that
A C brushless motor is provided, and a fluid pressure pump portion is provided around the motor shaft on one end side of the DC brushless motor, and a tank portion is provided in the internal space of the DC brushless motor.

Further, the electric motor driven pump according to the present invention is a fluid pressure pump portion provided around the motor shaft at one end of a DC brushless motor which constitutes an electric motor portion and has a tank portion in the internal space. A pump cartridge having a pump body, a rotor provided at the tip of a motor shaft in the pump body, a pressure plate arranged on the tip side of the motor shaft in the pump cartridge, and a tip side of the motor shaft in the pressure plate. And a pump discharge chamber formed on the motor shaft, a pressure relief plate is provided in a part of the pressure plate to prevent an increase in pressure in the pump discharge chamber above a predetermined pressure, and is provided in a clearance space formed around the motor shaft and the motor shaft. The fluid pressure is recirculated to the pump suction side through the passage hole.

According to the present invention, D as the electric motor unit
Since the fluid pressure pump section is provided around the motor shaft protruding at one end of the C brushless motor, and the inside of the casing of the DC brushless motor is used as the tank section, the overall size and weight can be reduced, and the tank section can be reduced. There is no need for a casing for the construction and a seal member for the casing and the motor unit or pump unit.

Further, according to the present invention, the effect of cooling the inside of the motor can be obtained by the fluid in the tank portion provided in the internal space of the DC brushless motor which is the electric motor portion.
Moreover, it is also possible to remove the metal powder in the fluid by adsorbing it with the magnet used in the main body of the electric motor unit.

Further, according to the present invention, in the pump section, the fluid pressure can be circulated from the pump discharge chamber through the clearance space by the relief valve provided in the pressure plate and further through the passage hole provided in the motor shaft. .

The tank portion in the present invention is formed in an internal space inside a casing which constitutes a DC brushless motor. A vane type oil pump is used for the fluid pressure pump unit. Then, in the pressure plate in this pump portion, a pump discharge chamber is formed on the side opposite to the pump cartridge, and a relief space provided on the pressure plate forms a clearance space on the pump suction side formed around the motor shaft on the pump cartridge side. The fluid pressure can be returned to the suction side of the pump via the pump.

[0016]

1 and 2 show one embodiment of an electric motor driven pump according to the present invention. In these drawings, FIG. 1 is a feature of the present invention as an electric motor driven pump. FIG. 2 is a sectional view in which a DC brushless motor to be attached, an oil pump driven by this motor, and an oil tank are integrated, and FIG. 2 is a sectional view of the brushless motor portion in FIG.

That is, according to this embodiment, the electric motor drive type pump 1 is a pump unit 2 which is a vane type oil pump which is a hydraulic power source of a hydraulic power steering apparatus as a fluid pressure utilizing device, and this pump unit. An electric motor unit 3 that is a DC brushless motor that drives 2 and a tank unit 4 that stores hydraulic oil are integrally formed. The pressure oil discharged from the pump unit 2 described above has hydraulic circuits in the left and right chambers of the power cylinder that generates the power assist force according to the steering operation in the device main body of the power steering device (not shown). It is connected via a flow path switching valve for switching.

In these figures, the specific structure of the electric motor driven pump 1 described above will be described below. The DC brushless motor serving as the electric motor section 3 includes a tubular housing 11 and an end body section 1 that closes both ends thereof.
2 and 13 are provided. A rotor 17 formed of a magnetic material and having a large diameter is provided on the motor shaft 16 rotatably supported by the end body portions 12 and 13 via bearings 14 and 15 at a substantially central portion in the axial direction. Has been.

As shown in FIG. 2, permanent magnets 17a and 17b having different magnetic poles are alternately arranged around the rotor 17, and the inner wall portion of the housing 11 is surrounded by a circumference so as to surround the circumference thereof. A stator 18 in which a coil 18b is wound around six cores 18a protruding at equal intervals in the direction is provided. Where this stator 1
As shown in FIG. 2, a structure in which a portion to be the stator 18 is prepared separately from the housing 11 by a tubular member and is fitted into the housing 11 is used as the member 8.

In FIG. 1, reference numeral 19 is a rotor position detection sensor attached to the brushless motor, and this sensor 19 includes a switch magnet 19a provided at the outer end of the motor shaft 16 penetrating the end body portion 12. The Hall element 19b is provided on a part of the body portion 12 on the fixed side so as to face the periphery of the body element 12 at a predetermined interval. This sensor 19 detects the rotational position of the motor shaft 16, that is, the rotor 17 provided on this shaft, and
The switching signal to the coil on the side is controlled so that the timing is accurately matched according to this position information, and the rotor 17 is driven. In the figure, 12a is an oil seal that seals the motor shaft 16 at the end body portion 12, and 12b is a cover attached to the outer end of the end body portion 12.

The oil pump portion 2 is provided on the outer end side of the end body 13 of the electric motor portion 3 at the tip end portion of the motor shaft 16 coaxially side by side. 21 and 22 are provided, and a space for incorporating pump components is formed inside these bodies 21 and 22. That is, reference numeral 23 denotes a pump cartridge including a rotor 24 having a vane provided on the motor shaft 16 in the space, and a cam ring 25 arranged so as to form a pump chamber around the vane, and 26 denotes a cam ring in the space. 25 is a pressure plate that is laminated so as to be pressed against one side of 25. The pump cartridge 23 and the pressure plate 26 form a pump component.

Reference numeral 27 denotes a pump discharge chamber formed inside the second pump body 22 and between the pressure plate 26 and 28, which is a device for utilizing pressure oil on the pump discharge side from the pump discharge chamber 27 as a fluid pressure utilizing device. A pump discharge side passage for sending to the steering apparatus PS, and 28a is a pump discharge port. Here, the first pump body 21 that comes into contact with the other side of the cam ring 25 described above has a function as a side plate.

In the pump section 2 described above, as is conventionally known, the pump oil is sucked by the pump suction side passage 29 formed in the pump body 21 serving as the side plate and is formed in the pressure plate 26. It is widely known that the pressure oil is discharged from the discharge port 30 to the pump discharge chamber 27.

Reference numeral 31 in the drawing denotes the first pump body 21 facing the tip of the motor shaft 16 and the pump cartridge 2.
3 is a shaft supporting portion of the rotor 24 and a clearance space formed in an inner center portion of the pressure plate 26. In the clearance space 31, the rotor 24 and the bodies 2 on both sides thereof are formed.
1. The hydraulic oil leaking from the gap between the pressure plate 26 and the pressure plate 26 is stored. The hydraulic oil on the return side is supplied to the first pump body 21 by the passage hole 32 bored in the axial direction from the tip of the motor shaft 16 and the passage hole 33 bored continuously in the radial direction. And a return passage communicating with the pump suction side passage 29 through a gap 34 formed between the end body portion 13 on the side of the motor portion 3 and the end body portion 13 on the motor portion 3 side.

According to the present invention, in the electric motor drive type pump 1 having the above-mentioned structure, the electric motor unit 3
When a DC brushless motor is used for the above, paying attention to the fact that there is no mechanical sliding contact portion between the rotating side and the fixed side due to the brush, and the cylindrical housing 11 that constitutes this motor portion 3
It is characterized in that the internal space defined by the end body portions 12 and 13 closing both ends thereof is used as an oil tank portion 4 for storing hydraulic oil.

That is, in this embodiment, as is apparent from FIG. 1, in the electric motor section 3 of the DC brushless motor, both sides of the motor main body section composed of the rotor 17 and the stator 18, especially the rotor position detection sensor 19 are provided.
The side portion is formed as a positive space and is used as the tank portion 4. Here, the structure between the rotor 17 and the stator 18, which are the main parts of the electric motor unit 3 described above, is as shown in FIG.
8 does not hinder the flow of the hydraulic oil due to the space between it and the coil 18b.

In FIG. 1, reference numeral 41 is a lubrication port that opens upward in a portion of the cylindrical housing 11 that corresponds to the internal space that serves as the tank portion 4, and 42 is a cap with an oil gauge that closes the lubrication port 41. 43 is a cylindrical housing 11
Is a return port that is connected to the lower part of the power steering device PS for returning the return oil from the main body of the power steering device PS.

In the above-mentioned structure, since the tank portion 4 is formed up to the inside of the end body portion 13 of the motor portion 3, the passage holes 44, 44 are formed in the body portion 13, and the passage holes 44, 44 are formed on the pump suction side. By communicating with the passage 29, suction into the pump portion 2 can be appropriately performed. Here, in order to remove various dusts, metal powders, and the like contained in the hydraulic oil in the tank portion 4, the filter 45 is provided by being fitted to a part of the passage holes 44, 44, for example, an opening portion. Good.

According to the above-mentioned configuration, in the electric motor drive type pump 1, since the internal space formed in the DC brushless motor portion constituting the electric motor portion 3 is used as the oil tank portion 4, this In constructing the pump 1 in which the pump portion 2, the motor portion 3, and the tank portion 4 are integrally formed, it is possible to reduce the overall size and weight. That is, as in the conventional case, the pump unit 2
A casing for forming a tank portion around the is not required, and when the tank portion 4 having the same volume as that of the conventional case is configured, the miniaturization of the entire pump 1 can be achieved.

Further, according to the above-mentioned structure, the conventional casing surrounding the pump unit 2 and the seal member for connecting the casing to the body on the electric motor unit 3 side while maintaining the sealing property are unnecessary. Therefore, the number of tank components can be reduced, the cost can be reduced, and the entire pump 1 can be easily assembled.

Further, according to the above configuration, the tank portion 4
Is formed inside the DC brushless motor as the electric motor unit 3, it is possible to obtain the effect of cooling the heat generated in the motor unit 3 by the hydraulic oil stored in the tank unit 4. On the contrary, the effect of warming the hydraulic oil stored in the tank portion 4 at a low temperature can be obtained. That is, at low temperature, the hydraulic oil in the tank portion 4 has a large viscosity and a large load. When the electric motor unit 3 is started in this state, a high current flows, energy loss is converted into heat, and the coil 18b generates heat, so that the hydraulic oil in the tank unit 4 is warmed and the conventional motor drive type is used. The viscosity of hydraulic oil can be reduced in a shorter time than with a pump. Such an advantage is obvious as compared with the case where a heating means such as a heater is specially provided around or in the tank in order to warm the hydraulic oil at a low temperature.

Further, according to the tank portion 4 provided in the motor portion 3 as described above, the magnets 17a, 17 in the motor portion 3 are provided.
Since part b also serves as a tank and the operating oil flows, it adsorbs metal powder such as iron powder mixed in this operating oil,
The purified hydraulic oil can be sucked into the oil pump section 2 side. Therefore, the pump cartridge 23 in the pump unit 2, the bodies 21 on both sides, the pressure plate 2
It is possible to prevent the mixing of the metal powder into the gap 6 and 6, and there is no problem that the operation of the pump component is impaired by the mesh of the metal powder, and the reliability of the pump function is improved.

Here, in the above-described embodiment, the relief valve 35 for preventing the pressure increase above the predetermined pressure in the pump discharge chamber 27 is provided in the hole formed in the pressure plate 26. , The gap space 31 can be selectively communicated with. Further, the hydraulic oil flowing into the clearance space 31 is recirculated to the pump suction side through the recirculation side oil passages formed by the passage holes 32 and 33 provided in the motor shaft 16 and the clearance portion 34. According to such a relief valve 35, by providing it on the pressure plate 26, it is possible to have a more compact structure than when it is provided on other members, and it is possible to contribute to the miniaturization of the entire apparatus. In particular, such an advantage is advantageous when the tank portion 4 is provided in the electric motor portion 3 of the DC brushless motor on the motor shaft 16 side of the pump portion 2.

It is needless to say that the present invention is not limited to the structure described in the above-mentioned embodiment, and the shape, structure, etc. of each part can be appropriately modified or changed. For example, in the above-described embodiment, the position of the rotor 17 of the DC brushless motor that is the electric motor 3 is detected by the sensor 19 that uses the magnet 19a and the hall element 19b, but the present invention is not limited to this. A rotational position detection sensor such as an encoder may be used.

Further, in the above-described embodiment, the casing which constitutes the DC brushless motor which is the electric motor portion 3 is formed by the cylindrical housing 11 and the end body portions 12 and 13 which close both ends thereof, The case where the both sides of the motor main body portion including the rotor 17 and the stator 18 and the void portion of the motor main body portion in the casing are used as the tank portion 4 has been shown, but the present invention is not limited to this, and the motor is provided in the casing. A space portion formed on either one of the main body portions may be used as the tank portion 4.

Further, in the above-described embodiment, the case where the oil injection port 41 is closed by the oil gauge cap 42 has been shown, but an appropriate modification can be considered as such a cap.

In the above embodiment, the vane type hydraulic pump is exemplified as the fluid pressure pump unit 2. However, the present invention is not limited to this, and any pump having various structures such as a gear pump and a piston pump can be used. Good. The point is that the pump may be driven by rotation by a motor.

Further, in the above-described embodiment, the case where the electric motor drive type pump 1 according to the present invention is used as a hydraulic pressure source in the power steering apparatus has been described, but the present invention is not limited to this and may be appropriately applied. A pump for obtaining the fluid pressure of
It is needless to say that it can be applied to various fluid pressure utilizing devices.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric motor driven pump is an oil pump that serves as a hydraulic power source for a hydraulic power steering system, and includes a pump section 2 which is a vane type oil pump, an electric motor section 3 which is a DC brushless motor, and an oil tank. The tank portion 4 has an integral structure. Also, the rotor 1 of the motor
Rotor position detection sensor 1 for detecting the rotational position of 7
9 is a switch magnet 19 provided on the motor shaft 16.
a and a Hall element 19b provided in a part of the body portion 12 on the fixed side so as to face each other at a predetermined interval around the a.

[0040]

As described above, according to the electric motor drive type pump of the present invention, the fluid pressure pump portion, the electric motor portion for driving the fluid pressure pump portion, and the tank portion for storing the fluid sucked into the pump portion are integrated. The electric motor drive type pump, which is configured in a similar manner, in which the electric motor unit is a DC brushless motor, the fluid pressure pump unit is provided around the motor shaft on one end side of the DC brushless motor, and the internal space of the DC brushless motor is also provided. Since the tank portion is provided in the pump, the structure of the entire pump can be simplified, and the size and weight of the pump can be reduced.

Further, according to the present invention, the electric motor portion for driving the pump portion, which is the fluid pressure source, is constituted by the DC brushless motor, so that the need for maintenance in the electric motor portion can be eliminated, and further, this motor can be eliminated. The drive control of the pump section and the pump section can be appropriately performed by using the detection means attached to the DC brushless motor.

Further, according to the present invention, the effect of cooling the inside of the motor can be obtained by the fluid in the tank portion provided in the internal space of the DC brushless motor as the electric motor portion, and the main body portion of this electric motor portion can be obtained. It is possible to remove the metal powder in the fluid by adsorbing the metal powder in the fluid easily and surely.

Particularly, according to the present invention, the fluid pressure pump portion is provided around the motor shaft protruding at one end of the DC brushless motor as the electric motor portion, and the inside of the casing of the DC brushless motor is used as the tank portion. Therefore, the overall size and weight can be reduced, and the casing for constituting the tank portion and the sealing member for the casing and the motor portion and the pump portion are not required, and the cost can be reduced.

Further, according to the present invention, the fluid pressure pump portion provided around the motor shaft on one end side of the DC brushless motor constituting the electric motor portion and having the tank portion in the inner space is used as the pump body. , A pump cartridge having a rotor provided at the tip of the motor shaft in the pump body, a pressure plate arranged at the tip side of the motor shaft in the pump cartridge, and a pump formed at the tip side of the motor shaft in the pressure plate A discharge valve is provided in a part of the pressure plate to prevent a pressure higher than a predetermined pressure in the pump discharge chamber, and a clearance space formed around the motor shaft and a passage hole provided in the motor shaft are provided. Since the fluid pressure is returned to the suction side of the pump, the overall size and size of the pump can be reduced. .

Further, according to the present invention, since the brushless motor is used as the electric motor unit for driving the pump, wear and failure caused by this are unlikely to occur, and the reliability in operation is high. Further, unlike the brushed motor, there is no noise in the sliding contact portion of the brush, the rotor can be smoothly rotated in the motor, and the pump can be efficiently driven. Further, according to the present invention, only the motor rotation speed can be controlled regardless of the presence or absence of a load, and the control result can be simplified by diverting the detection result of the rotor position detection means included in the brushless motor. Since the detection means can be omitted, the apparatus can be simplified and the cost can be reduced.

Further, according to the present invention, by using the inside of the electric motor portion as the tank portion, it is possible to obtain the effect of heating the working oil stored in the tank portion at a low temperature.
That is, at low temperature, the hydraulic oil in the tank has a large viscosity and a large load, but when the electric motor is started in this state, the energy loss due to the flow of a high current is converted into heat and the coil heats up. , There is an advantage that the hydraulic oil in the tank portion flowing through the wound portion of the coil can be warmed to lower the viscosity of the hydraulic oil in a shorter time than the conventional pump, and no special heating means is required. .

[Brief description of drawings]

FIG. 1 shows an embodiment of an electric motor driven pump according to the present invention, in which an electric motor unit using a DC brushless motor, a fluid pressure pump unit driven by the electric motor unit, and a tank unit are integrated. It is sectional drawing of the electric motor drive type pump comprised.

FIG. 2 is a cross-sectional view of an essential part of an electric motor unit using the DC brushless motor in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric motor drive type pump, 2 ... Pump part by vane type oil pump, 3 ... Electric motor part by DC brushless motor, 4 ... Tank part as an oil tank, 11
... Cylindrical housing, 12, 13 ... End body part, 12a
… Oil seals, 14,15… Bearings, 16… Motor shafts,
Reference numeral 17 ... Rotor, 17a, 17b ... Permanent magnet, 18 ... Stator, 18a ... Core, 18b ... Coil, 19 ... Motor rotor position detection sensor 21, 22 ... First and second pump bodies, 23 ... Pump cartridge, 24 ... rotor,
25 ... Cam ring, 26 ... Pressure plate, 27 ...
Pump discharge chamber, 28 ... Pump discharge side passage, 28a ... Pump discharge port, 29 ... Pump suction side passage, 30 ... Pump discharge port, 31 ... Pump suction side gap space, 32, 33
... passage hole, 34 ... gap, 35 ... relief valve, 41 ... oil inlet, 42 ... cap with oil gauge, 43 ... return port to tank, 44 ... passage hole, 45 ... filter, PS
… Hydraulic power steering device (power cylinder).

Claims (3)

[Claims] 1. An electric motor drive type pump in which a fluid pressure pump section, an electric motor section for driving the fluid pressure pump section, and a tank section for storing fluid to be sucked into the pump section are integrally formed, wherein the electric motor section is An electric motor driven pump, characterized in that it is composed of a DC brushless motor, and the internal space of this DC brushless motor is used as the tank portion. 2. The electric motor drive type pump according to claim 1, wherein a fluid pressure pump section is provided around the motor shaft on one end side of the DC brushless motor constituting the electric motor section. pump. 3. An electric motor drive pump in which a fluid pressure pump section, an electric motor section for driving the fluid pressure pump section, and a tank section for accumulating fluid sucked into the pump section are integrally formed, and the electric motor section is constituted. And a fluid pressure pump portion provided around the motor shaft on one end side of a DC brushless motor having a tank portion in the internal space, a pump body, and a rotor provided at the tip of the motor shaft in the pump body. A pump cartridge, a pressure plate arranged on the tip side of the motor shaft in the pump cartridge, and a pump discharge chamber formed on the tip side of the motor shaft in the pressure plate, and a part of the pressure plate includes A relief valve is installed to prevent the pressure in the pump discharge chamber from rising above a certain level. Through a passage hole formed in the gap space and the motor shaft is formed around the axis, an electric motor driven pump, characterized by being configured so as to reflux the fluid pressure to the pump suction side.