JPS6111484A - pump equipment - Google Patents

Abstract

PURPOSE:To prevent the slight movement of a rotor and improve performance by increasing the discharge pressure, by using a pair of brushless motors for driving a vane pump and shifting each center position of the both permanent magnets of the motors to the same side in the direction of axis line from each center position of the both stators. CONSTITUTION:The fluid discharge pressure is increased and the performance can be improved by using a pair of brushless motors 6a and 6b for driving a vane pump. Each center position ma, mb of the permanent magnets 26a and 26b is shifted to the ame side in the direction of axis line from the center position la, lb of stators 25a and 25b. Therefore, the permanent magnets 26a and 26b are excited for magnetism-attraction towards the stator 25a, 25b side, and the rotors 27a and 27b are excited toward the lower part on the figure along the direction of axis line of a rotary shaft 3, and the slight movement of the rotors can be suppressed. Therefore, the slight movement of a rotor 4 can be prevented, and the generation of the bad influence such as pulsation discharge can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a pump device driven by a motor, and particularly to a pump device suitably used as a fuel pump for automobiles, motorcycles, etc.

(2) Prior Art Conventionally, a typical pump device uses a so-called brush motor to drive a rotary pump such as a vane pump.

(3) Problems to be Solved by the Invention In such a conventional device, there are the following problems shown by +al to (dl) due to the use of a brush motor.

That is, the sliding contact of the ial brush motor causes a torque reduction of the output shaft, and therefore the discharge flow rate is small compared to the power consumption. (mountain) Sliding contact of the brushes causes the brushes to wear out, thus reducing their lifespan. (C) Sparks generated near the brushes may have an adverse effect, such as electromagnetic noise, on the control circuits of electrical equipment such as electronic fuel injection devices mounted on automobiles and the like. (d+above (in connection with the negative influence of the spark of C1) the pump equipment; the mounting equipment of i' is limited.

The present invention has been made in view of the circumstances described in Section 51, -1-, and an object of the present invention is to provide a pump device with improved performance by driving a rotary pump with a pair of brushless motors.

B0 Structure of the Invention (Means for Solving Problems 1 and 1) The pump apparatus of the present invention includes a rotary pump having a rotor fixed to a rotary shaft within a pump chamber, and a rotary pump connected to both ends of the rotary shaft of the rotary pump. A pair of brushless motors and a single drive circuit that is commonly provided to both brushless motors to drive the brushless motors in phase and synchronization are housed in a casing.

(2) Operation: Both brushless motors are driven by the drive circuit, which causes the rotary shaft to rotate, thereby causing the rotary pump to suction and discharge fluid.

(3) Embodiment Below, an embodiment of the present invention will be explained with reference to the drawings. First, in FIG. a vane pump 5, a pair of brushless motors a and 6b respectively connected to both ends of the rotating shaft 3 of the vane pump 5, and their brushless motors 5a and 5.
A drive circuit 7 for driving the casing 8 is housed within the casing 8.

The casing 8 includes a basically cylindrical casing body 9 and a pair of end plates 10a, 1 that close both ends of the casing body 9.
0b and a cylindrical cover 1 with a bottom that covers one end plate 10a.
) are integrally combined. An inner flange 12 that extends radially inward over the entire circumference is integrally provided on the inner surface of the casing body 9 at approximately the center along the axial direction. Moreover, the amount of radially inward protrusion of the inner flange 12 changes along the circumferential direction, and the hole defined at the center of the inner flange 12 is eccentric to the casing 8.

Closing plates 13a and 13b are press-fitted into the center of the inner flange 12 to close both ends of the hole, and the inner flange 12 and the occluding plates 13a and 13b define the pump chamber 2 which is eccentric to the casing 8. will be accomplished.

Referring also to FIG. 2, the vane pump 5 is mounted inside the pump chamber 2 on a rotary shaft 3 that has the same axis as the casing 8 and is rotatably supported by both opening plates 13a and 13'b. A ring-shaped rotor 4 is fixed thereto.

Moreover, both axial end surfaces of the rotor 4 are closed plates 13a.

13b, respectively. In addition, the casing body 9
A suction passage 14 and a discharge passage 15, which open to the inner surface of the pump chamber 2 at positions shifted in the circumferential direction, are formed in the inner flange portion 12 of the pump. The suction passage 14 and the discharge passage 15 include a suction pipe section 16 and a discharge pipe section 1 that are integral with the casing body 9.
7 are connected to each other, and the suction pipe section 16 and the discharge pipe section 1
7 is connected in the middle with a connecting pipe 18. This connecting pipe 18 is equipped with a relief valve 19 .

A plurality of guide grooves 20, for example four, are bored in the rotor 4 between both ends thereof in the axial direction. These guide grooves 20 are open on the outer surface of the rotor 4 at equally spaced positions in the circumferential direction of the rotor 4, and are mutually connected to adjacent grooves around the rotation axis 3 in a plane perpendicular to the rotation axis 3. It is arranged so as to extend in a direction perpendicular to the direction.

A vane blade 21 is slid into each guide groove 20, respectively. Each vane blade 21 rotates while slidingly contacting the inner surface of the pump chamber 2 according to the rotational movement of the rotating shaft 3 and the rotor 4, whereby the fluid sucked from the suction path 14 is discharged from the discharge path 15.

Here, when the vane blade 21 passes through the open end of the suction passage 14 according to the rotation of the rotor 4 and enters the suction process,
In order to prevent a gap from being formed between the vane blade 21 and the inner surface of the pump chamber 2 due to insufficient discharge amount from the rotor 4, pressure regulating grooves are formed on the end surface of the rotor 4 of one of the closing plates 13a. 22 is drilled. This pressure regulating groove 22 functions to communicate the bottom of the guide groove 20, in which the vane blade 21 in the suction process is slid, with the bottom of the guide groove 20, in which the vane blade 21 is in the discharge process, in the sliding process. As a result, the fluid pressure generated when the vane blade 21 in the discharge process is pushed into the guide groove 20 acts as back pressure on the vane blade 21 in the suction process, causing sliding contact with the inner surface of the pump chamber 2. connection is ensured. Moreover, since the pressure regulating groove 22 also functions to release the back pressure of the vane blade 21 during the discharge process, it is possible to prevent excessive force from being applied to the vane blade 21 during the discharge process.

Motor chambers 23a, 2 are provided on both sides of the vane pump 5 in the axial direction by the casing body 9 and both end plates 10a, 10b.
3b are respectively defined, and their motor chambers 23a, 2
Brushless motors 5a and 6b are housed in each of the motors 3b. These brushless motor rotors a, 6b
are basically the same in structure, and the structure of only one brushless motor a will be described in detail below with the subscript a, and the other brushless motor b will be illustrated with the subscript a. Only.

Referring also to FIG. 3, the brushless motor 6a has a plurality of phase (two-phase, four-pole in this embodiment) coils fixed to an end plate 10a concentrically with the rotating shaft 3 and spaced apart in the circumferential direction. 24a is wound around the stator 25a, and the stator 2
5a, and a rotor 27a fixed to the end of the rotating shaft 3.

The stator 25a is fixed to a support protrusion 28a that protrudes from the inner end of the end plate 10a and is coaxial with the rotating shaft 3.

The rotor 27a is basically formed into a cylindrical shape with a bottom, and a ring-shaped permanent magnet 26a is fixed to the inner surface of the cylindrical portion so as to surround the stator 25a. Furthermore, the center position Jma of the permanent magnet 26a along the axial direction and the center position 1)a of the stator 25a along the axial direction are shifted from each other. To explain in detail, the center position m of the permanent magnet 26a
The relative positions of the permanent magnet 26a and the stator 25a are set such that a is located closer to the vane pump 5 along the axis of the rotary shaft 3 than the center position ea of the stator 25a.

In the other brushless motor b, the center position mb of the permanent magnet 26b is the center position 7! of the stator 25b!
The permanent magnet 26b and the stator 2 are arranged so that the permanent magnet 26b and the stator 2 are located on the opposite side of the vane pump 5 along the axis of the rotating shaft 3
The relative position of 5b is set.

In this way, the center position of the permanent magnets 26a and 26b is 1 ma,
mb is the center position la of the stators 25a and 25b,
By being shifted to the same side in the axial direction from Ilb, slight movement of the rotors 27a and 27b in the axial direction during operation is prevented. That is, the permanent magnet 26a.

Since the rotors 26b are biased to be magnetically attracted to the stators 25a and 25b, the rotors 27a and 27b are biased downward in FIG. Fine movements of the children 27a and 27b are prevented. As a result, the fine movement of the rotor 4 due to the fine movement of the rotors 27a and 27b is prevented, and the negative effects such as pulsating discharge due to the fine movement of the rotor 4 can be prevented.

Rotor 27a of both brushless motors 5a, 5b.

27b are fixed to both ends of the rotating shaft 30, so that the relative positions of the magnetic poles of the permanent magnets 26a and 26b along the circumferential direction are kept constant.

A circuit chamber 29 is defined by one end plate] Oa and the cover 1), and this circuit chamber 29 includes a drive circuit 7 for driving the brushless motors 26a and 26b, and a drive circuit 7 for driving the brushless motors 26a and 26b. .

Hall element 30a as a magnetic pole detection sensor for detecting the magnetic pole position of permanent magnets 26a and 26b in 6b,
30b and a safety circuit 31 for the drive circuit 7 are housed. Drive circuit 7 and safety circuit 31, end plate 10
It is provided on a circuit board 32 supported by a. Further, one Hall element 30a is connected to the end plate 10 in order to detect the magnetic pole position of the permanent magnet 26a in one brushless motor 6a.
provided in a. Furthermore, the other Hall element 30b is
This is to detect the magnetic pole position of the permanent magnet 26b in the other brushless motor 6b, but since the relative magnetic pole position of the permanent magnets 26a, 26b in both brushless motors 6a, 5b is constant, the By detecting the magnetic pole position, it is possible to detect the magnetic pole position of the other permanent magnet 26b, and for this purpose, the Hall element 3
0b is the end plate 10 at a position different from the Hall element 30a.
provided in a.

In FIG. 4, the drive circuit 7 has first and second drive sections 33 and 34 having the same configuration, and the first drive section 33 drives both brushless motors in response to the input of the magnetic pole detection signal of one Hall element 30a. Coil 24 of one phase in 6a, 6b
a+, 24b+, and the second drive unit 34 excites the coils 24 of the other phase in both brushless motors 6a, 6b in response to the input of the magnetic pole detection signal of the other Hall element 30b.
a.

24b2 is excited.

The first drive section 33 includes a comparator 35, an amplifier 36, and four transistors 37.3B and 39.40. The detection signal of the Hall element 30a is input to the comparator 35. Further, the series circuit consisting of transistors 37 and 38 and the series circuit consisting of transistors 39 and 40 are connected in parallel between power supply terminal 41 and ground. Comparator 35
The output terminal of is connected to the base of transistor 38.39, and is connected to transistor 37.4 via amplifier
Connected to the base of 0. Also transistor 37.38
O-coils 24a+ and 24b+ are connected in parallel between the connection point of the transistors 39 and 40 and the connection point of the transistors 39 and 40.

Similar to the first drive unit 33, the second drive unit 34 includes a comparator 3
5, an amplifier 36, and four transistors 37.3B,
39 and 40, and the detection signal of the Hall element 30b is input to the comparator 35. Also, transistor 37.
Coils 24az, 24t)z are connected in parallel between the connection point of 38 and the connection point of transistors 39 and 40.

In such a drive circuit 7, one Hall element 3
When the magnetic pole is detected at 0a, the transistor 37.40 of the first drive section 33 conducts the conductor 1ffiL, the coils 24a, 2
4t)+ is excited and the other Hall element 30h detects the magnetic pole, the transistor 37.4 of the second drive unit 34
0 becomes conductive, and the coils 24a2 and 24bz are excited.

Therefore, the single drive circuit 7 performs in-phase synchronous driving of the two brushless motors 6a and 6b.

Next, the operation of this embodiment will be explained.
By magnetizing each coil 24a, 24b synchronously with 'Frh', the rotor 27a.

A rotational force is applied to 27b, and these rotors 27a,
By co-rotating the rotating shaft 3 integrally with 27h,
The vane pump 5 performs a pumping operation.

As a result, fluid such as fuel is drawn into the pump chamber 2 through the suction pipe section 16 and continuously discharged from the discharge pipe section 17.

In such a pump device 1, the vane pump 5 is driven by brushless motors 6a and 6b from both sides thereof, so that the operating torque of the vane pump 5 is large and the fluid discharge pressure can be increased. Further, by using the brushless motors 6a and 6b, it is possible to prevent torque reduction, deterioration of durability, and adverse effects on electrical equipment due to sparks, which occur when conventional brush motors are used.

Furthermore, both brushless motor rotors a and 6b have the same structure, reducing manufacturing costs. Moreover, since only one drive circuit 7 needs to be provided in common to both brushless motors a and 6b, the number of parts is reduced.

As another embodiment of the present invention, the rotary pump may be a trochoid pump instead of a vane pump, in which case an inner rotor provided with external teeth is fixed to the rotating shaft 3, and an inner rotor that meshes with the external teeth. An outer rotor having teeth is fitted into the inner flange 12 of the casing body 9.

Furthermore, the pump device of the present invention can be widely implemented not only as a fuel pump but also as a pump for pumping other fluids.

C0 Effects of the Invention As described above, the pump device of the present invention includes a rotary pump having a rotor fixed to a rotary shaft within a pump chamber, a pair of brushless motors respectively connected to both ends of the rotary shaft of the rotary pump, In order to drive these brushless motors in phase and synchronously, a single drive circuit commonly provided to both brushless motors is housed and arranged within the casing, making it possible to increase fluid discharge pressure and improve performance. At the same time, it is possible to avoid adverse effects on electrical equipment. Moreover, since only one drive circuit is required, the number of parts can be reduced, and since brushless motors of the same structure can be used, manufacturing costs can be reduced. Furthermore, the overall size can be reduced by reducing the nl discharge pressure.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical side view, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. 4 are electrical circuit diagrams showing the configuration of the drive circuit. DESCRIPTION OF SYMBOLS 1... Pump device, 2... Pump chamber, 3... Rotating shaft, 4... Rotor, 5... Vane pump as a rotary pump, 6a, 6b... Brushless motor, 7...
・Drive circuit, 8...Casing, 30 a, 30
b... Hall element as a magnetic pole detection sensor

Claims (2)

[Claims] (1) A rotary pump having a rotor fixed to a rotating shaft in a pump chamber, a pair of brushless motors each connected to both ends of the rotating shaft of the rotary pump, and in-phase synchronous driving of these brushless motors. A pump device characterized in that a single drive circuit provided in common to both brushless motors is housed and arranged in a casing. (2) The permanent magnets of both brushless motors are connected via the rotating shaft with their relative magnetic pole positions along the circumferential direction unchanged, and a magnetic pole detection sensor for detecting the magnetic pole positions of both permanent magnets is connected to one of the brushless motors. The pump device according to claim 1, wherein the pump device is disposed only on the motor side.