JP3907415B2 - Electric pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric pump as a drive source that is integrally attached to one side of a pump body via a positioning bracket, and more particularly to an electric pump that is miniaturized for use in a vehicle. .
[0002]
[Prior art]
Recent automobiles are equipped with a number of auxiliary machines that operate by hydraulic pressure and assist driving operations, such as power steering devices and automatic transmissions. A pump is installed. As this hydraulic pump, a rotary displacement pump such as a vane pump or a gear pump is used as a hydraulic pump that can generate high hydraulic pressure while being small.
[0003]
This type of hydraulic pump is generally driven using an engine as a drive source. However, an engine that changes the rotational speed over a wide range during travel is not preferable as a drive source, and instead of the engine, an on-vehicle battery is used. An electric pump using an electric motor driven by power supply as a drive source is used.
[0004]
Such an electric pump can be driven at an appropriate speed by controlling the speed of the electric motor, and is also useful for suppressing unnecessary power consumption of the engine and improving fuel consumption. In recent years, electric vehicles (EV) using an electric motor as a driving source for traveling have been put into practical use in order to prevent environmental degradation due to exhaust gas. In this electric vehicle, an auxiliary machine that operates by hydraulic pressure may be provided, and an electric pump that uses an electric motor as a drive source is inevitably used as a generation source of the hydraulic pressure of such an auxiliary machine. .
[0005]
Now, in the electric pump used by being mounted on a vehicle as described above, since the installation space is limited, as disclosed in JP-A-10-82377 by the applicant of the present application, An electric pump as a drive source is attached to the side via a positioning bracket to make it compact, and an electric pump with improved mountability on a vehicle is used.
[0006]
FIG. 3 is a side sectional view of a conventional electric pump disclosed in Japanese Patent Laid-Open No. 10-82377. In the figure, 1 is a pump body configured as a gear pump, and a motor 3 as a drive source is attached to one side of the pump body 1 via a cylindrical bracket 2. The pump shaft 10 of the pump body 1 and the motor shaft 30 of the motor 3 are abutted with each other inside the bracket 2 and are coaxially connected via a fitting-type coupling 4. The main body 1 is rotationally driven to perform a predetermined pump operation.
[0007]
Further, a bottomed cylindrical tank cylinder 5 is attached to the mounting surface of the bracket 2 on the pump body 1 so as to surround the outside of the pump body 1, and an oil tank for storing hydraulic oil inside the tank cylinder 5. T is formed. Inside the oil tank T, working oil is recirculated through a return oil pipe 5a connected to the circumferential surface of the tank cylinder 5 in a substantially tangential direction. The pressure is increased by the operation of the pump body 1 that is introduced through the suction port that opens to the outer surface, and is driven by the motor 3, and the discharge passage 5 b that extends to the bracket 2 side, and the peripheral surface of the bracket 2 opens. It is sent through the discharge port 5c.
[0008]
[Problems to be solved by the invention]
As described above, the electric pump disclosed in Japanese Patent Laid-Open No. 10-82377 has a configuration in which the pump body 1 and the driving motor 3 are integrated with an oil tank T that stores hydraulic oil. Although it is excellent in convenience as a vehicle-mounted pump, the oil tank T, the pump main body 1 and the motor 3 have a structure aligned in the axial direction through the bracket 2, and the axial length is shortened. For example, there is a problem that it is difficult to meet the demand for further downsizing for mounting in a small car.
[0009]
Here, the bracket 2 interposed between the pump main body 1 and the motor 3 secures a space for connection between the pump shaft 10 and the motor shaft 30 by the coupling 4, and the pump main body at the time of this connection. It is a part necessary for performing alignment such as adjustment of the concentricity between 1 and the motor 3, and it is not desirable to shorten the axial length of the bracket 2. In addition, the tank cylinder 5 forming the oil tank T prevents the temperature of the internal hydraulic oil from rising due to heat exchange with the outside air via the peripheral wall, and allows the hydraulic oil to be stably sucked into the pump body 1. Therefore, it is difficult to shorten the axial length of the tank cylinder 5 without increasing the diameter.
[0010]
Further, the tank cylinder 5 is integrally formed of a resin material together with the return oil pipe 5a connected to the peripheral surface thereof, and a large stroke molding machine is required for molding the tank cylinder 5 which is long as described above. There was also a problem that this resulted in an increase in product cost.
[0011]
The present invention has been made in view of such circumstances, and by utilizing the inner space of the bracket interposed between the pump body and the motor for accommodating hydraulic oil (hydraulic liquid), An object of the present invention is to provide a compact electric pump that can reduce the internal volume of an oil tank provided on the side and meet the demand for shortening the axial length.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an electric pump that connects a motor shaft of an electric motor attached to one side of a pump main body via a cylindrical bracket to a pump shaft protruding from the pump main body into the bracket. In the electric pump, a housing chamber is provided in the bracket so as to surround the motor shaft and the coupling portion of the pump shaft, and contains a low-pressure working liquid sucked into the pump body, and is attached to the bracket And a storage tank for the working liquid formed so as to surround the outside of the pump body, and the storage tank and the storage chamber are formed by a communication hole formed through the bracket. wherein the are communicated.
[0013]
In the present invention, an annular space formed so as to surround the connecting portion of the motor shaft and the pump shaft is formed inside the cylindrical bracket interposed between the pump body and the motor. And the axial length of the tank cylinder that is mounted on the other side of the bracket so as to surround the pump body and forms an oil tank is shortened.
[0014]
The electric pump according to a second aspect of the present invention is characterized in that the storage chamber according to the first aspect is communicated with a return port of the working liquid formed through the peripheral wall of the bracket.
[0015]
In this invention, the return oil port of the oil (liquid) returning from the oil supply (liquid supply) destination is formed so as to communicate with the housing chamber inside the bracket, and the shape of the tank cylinder forming the oil tank is simplified. To facilitate molding and reduce product costs.
[0016]
Furthermore, in the electric pump according to the third invention of the present invention, the return port in the second invention is reverse in the radial direction with the suction port communicating with the suction side of the pump body and the connecting portion of the motor shaft and the pump shaft. It is provided in the position.
[0017]
In this invention, the return port formed through the peripheral wall of the bracket is formed at a position as far as possible from the suction port for suction into the pump body, and the return oil (liquid) flowing from the return port is formed. Prevents inhalation that is unstable due to speed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a side sectional view of an electric pump according to the present invention configured as a hydraulic pump, and FIG. 2 is a transverse sectional view taken along line II-II in FIG.
[0019]
As with the conventional electric pump shown in FIG. 3, the electric pump according to the present invention has a drive motor 3 attached to one side of the pump body 1 via a cylindrical bracket 2 and serves as an input shaft to the pump body 1. The pump shaft 10 and the motor shaft 30 as the output shaft of the motor 3 are coaxially abutted inside the bracket 2, and these are connected by a fitting type coupling 4 to be output to the motor shaft 30. The rotational force of the motor 3 is transmitted to the pump shaft 10 via the coupling 4 to drive the pump body 1.
[0020]
The illustrated pump body 1 has a driving gear and a driven gear meshed with each other in a hollow portion inside the housing 11, and hydraulic oil in a suction chamber provided on one side of the meshing portion is rotated by rotation of both gears. The gear pump is configured to be confined between each tooth and the inner peripheral surface of the hollow portion, and discharged into a discharge chamber provided on the other side of the meshing portion. In FIG. 1, only the drive gear 12 is shown, and the driven gear is disposed so as to overlap the back side of the drive gear 12.
[0021]
The drive gear 12 and the driven gear are both supported by a pair of side plates 14 and 14 that are fitted and inserted into the cavity of the housing 11 from both sides thereof. The thus configured pump body 1 has one end surface of the housing 11 placed on the center of a thick disc-shaped pump seat plate 20 provided on one side of the bracket 2, and the housing 11 Along with an end plate 15 that closes the other end surface of the pump plate, a plurality of fixing bolts 16, 16,... The pump shaft 10 of the pump main body 1 is coaxially fitted to the drive gear 12, and the bracket 2 passes through a support hole of the side plate 14 on the same side and a through hole formed in the axial center portion of the pump seat plate 20. It protrudes coaxially inside.
[0022]
As shown in FIG. 2, the pump seat plate 20 has an area sufficiently larger than the mounting portion of the pump main body 1 and is used as a mounting seat for the tank cylinder 5 constituting the oil tank T. The tank cylinder 5 is a bottomed cylinder made of a thin plate material. The opening edge of the tank cylinder 5 is fitted in an inlay groove 17 provided in the vicinity of the outer periphery of the pump seat plate 20 and is prevented from being removed by a circlip 18. In addition, the oil tank T is attached so as to surround the outside of the pump body 1, and an oil tank T for accommodating low-pressure hydraulic oil is formed inside the pump body 1. The tank cylinder 5 is continuously provided with an oil supply cylinder 50 extending upward from a peripheral wall in the vicinity of the bottom, and the hydraulic oil in the oil tank T is supplied through the oil supply cylinder 50.
[0023]
In the opening on the other side of the bracket 2, the motor 3 is attached by tightening and fixing a mounting flange 21 provided on one side thereof with a plurality of fixing bolts 31 in the circumferential direction. The motor shaft 30 of the motor 3 is coaxially projected inside the bracket 2, butts against the pump shaft 10, and is connected by the coupling 4.
[0024]
The bracket 2 interposed between the pump body 1 and the motor 3 in this way is a cylindrical body that is closed over the entire circumference, and in the inside thereof, is a contact portion between the mounting flange 21 and the bracket 2. Is sealed in a liquid-tight manner by an O-ring 32, and the outer periphery of the motor shaft 30 is sealed in a fluid-tight manner by an oil seal 33 fitted to the inner peripheral portion of the mounting flange 21. An annular oil storage chamber 6 is formed surrounding the outside of the connecting portion with the motor shaft 30.
[0025]
The oil storage chamber 6 is communicated with the oil tank T on the other side of the pump seat plate 20 through a plurality of communication holes 60, 60... (See FIG. 2) formed through the pump seat plate 20. Together with the oil tank T, it is used to contain the hydraulic oil. The oil storage chamber 6 communicates with a return oil port 61 that penetrates the peripheral wall of the bracket 2 at an upper position, and low-pressure hydraulic oil (return oil) that recirculates from an oil supply destination (not shown) It is adapted to be received in the oil storage chamber 6 through the mouth 61.
[0026]
The pump seat plate 20 is formed with a suction port 62 penetrating the lower position of the mounting portion of the pump body 1, and the opening on the oil tank T side of the suction port 62 is a suction pipe 63 bent in an L shape. Is connected to a suction chamber provided at a lower position inside the pump body 1. Further, the discharge chamber of the pump body 1 provided at the upper position so as to correspond to the suction chamber is extended from one side of the housing 11 to the inside of the pump seat plate 20 as shown by a broken line in FIG. The discharge passage 64 communicates with an oil feed port 65 that opens on the peripheral surface of the pump seat plate 20.
[0027]
In the electric pump according to the present invention configured as described above, the return oil port 61 and the oil supply port 65 that open to the outside of the bracket 2 are used as the oil supply destination of pressure oil such as a power steering device and an automatic transmission. As well as being connected, hydraulic oil is supplied into the oil tank T through the oil supply cylinder 50, and an appropriate amount of hydraulic oil is filled in the oil tank T and the oil storage chamber 6 communicated by the communication holes 60, 60. Used.
[0028]
When the motor 3 as a drive source is driven in this state, the rotational force output to the motor shaft 30 of the motor 3 is transmitted to the pump shaft 10 via the coupling 4 and is fitted to the pump shaft 10. The drive gear 12 rotates in the inner cavity of the housing 11 together with the driven gear engaged therewith. By such rotation of the drive gear 12 and the driven gear, the hydraulic oil stored in the oil storage chamber 6 is sucked into the pump body 1 through the suction port 62 and the suction pipe 63, and the drive gear 12 and the driven gear are The pressure is increased by the rotation of, and the oil is delivered to the oil supply destination through the discharge path 64 and the oil supply port 65. The reflux oil from the oil feed destination is returned to the oil storage chamber 6 through the return oil port 61 and stays in the oil storage chamber 6 and the oil tank T, and is then sucked into the pump body 1 and circulated. Is done.
[0029]
Such circulating use involves raising the temperature of the hydraulic oil, but in the electric pump according to the present invention, the oil tank T formed inside the tank cylinder 5 and the oil storage chamber 6 formed inside the bracket 2 Therefore, the temperature rise of the hydraulic oil is slightly suppressed by heat exchange with the outside air during the stay in the oil storage chamber 6 and the oil tank T, and the pump The suction and discharge operations described above in the main body 1 can be stably performed.
[0030]
Further, the formation of the oil storage chamber 6 makes it possible to reduce the internal volume of the oil tank T, and to reduce the size of the tank cylinder 5 forming the oil tank T, in particular, to shorten the axial length. The oil storage chamber 6 is formed by utilizing the inner space of the bracket 2 that is originally necessary for connecting the pump shaft 10 of the pump body 1 and the motor shaft 30 of the motor 3. The dimensions do not increase. As a result, the electric pump according to the present invention can be made compact by shortening the axial length as compared with the conventional electric pump, and can be easily used as an on-vehicle pump.
[0031]
Further, since the return oil port 61 for receiving the return oil from the oil supply destination is provided not to connect to the oil tank T but to the oil containing chamber 6 inside the bracket, the tank cylinder 5 forming the oil tank T is provided. Further, it can be configured as a simple cylinder without the return oil pipe 5a (see FIG. 3) for receiving the return oil, and the product cost can be reduced by facilitating the molding of the tank cylinder 5.
[0032]
Further, the return oil port 61 communicating with the upper position of the oil storage chamber 6 is connected to the pump shaft 10 and the motor shaft 30 with respect to the suction port 62 for sucking into the pump body 1 also communicating with the lower position. The return oil flowing into the return oil port 61 at an appropriate speed is in the oil storage chamber because the two are formed in positions opposite to each other in the radial direction with respect to each other. 6 and the oil tank T lose the speed, reach the suction port 62 and are sucked into the pump body 1, and a stable suction state is obtained without being influenced by the speed of the return oil.
[0033]
In the above embodiment, the use as an in-vehicle pump mounted in an automobile has been described in order to obtain an operating hydraulic pressure of an auxiliary machine such as a power steering apparatus and an automatic transmission, but the present invention is an in-vehicle pump. Needless to say, the present invention can be applied to a hydraulic pump that is used for purposes other than the above, and can also be applied to a pump that handles liquids other than oil. Further, the pump body 1 is not limited to the gear pump described in the above embodiment, and it is needless to say that other types of pumps such as a vane pump may be used.
[0034]
【The invention's effect】
As described above in detail, in the electric pump according to the first aspect of the present invention, the inner space of the cylindrical bracket provided for realizing the connection between the pump shaft and the motor shaft is operated between the pump body and the motor. used as storage chamber for the liquid, from communicating via the communication hole in the holding tank of the hydraulic liquid which is formed by the tank tube to the mounting side of the pump body of the bracket, to reduce the internal volume of the storage tank, said tank By shortening the axial length including the cylinder, it becomes possible to meet the demand for further compactness.
[0035]
In the electric pump according to the second aspect of the invention, since the return port for the liquid returning from the liquid supply destination is formed on the peripheral wall of the bracket so as to communicate with the storage chamber inside the bracket, the tank forming the liquid storage tank The shape of the cylinder is simplified, the molding is facilitated, and the product cost can be reduced.
[0036]
Furthermore, in the electric pump according to the third aspect of the invention, the return port for the reflux liquid is provided at a position opposite to the suction port to the pump body in the radial direction, and both are located as far as possible from the return port. The present invention has excellent effects such as reducing the influence of the speed of the returning liquid flowing into the suction port on the suction port and allowing stable suction.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an electric pump according to the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a side sectional view of a conventional electric pump.
[Explanation of symbols]
1 Pump body 2 Bracket 3 Motor 4 Coupling 5 Tank cylinder 6 Oil storage chamber
10 Pump shaft
30 Motor shaft
61 Return outlet
62 Suction port T Oil tank

Claims (3)

In the electric pump in which the motor shaft of the electric motor attached to one side of the pump main body via a cylindrical bracket is connected to the pump shaft protruding from the pump main body into the bracket,
A storage chamber that is provided inside the bracket so as to surround the coupling portion of the motor shaft and the pump shaft, and stores a low-pressure working liquid that is sucked into the pump body ;
An inside of a tank cylinder attached to the bracket, and a storage tank for the working liquid formed so as to surround the outside of the pump body,
The electric pump characterized in that the storage tank and the storage chamber communicate with each other through a communication hole penetratingly formed in the bracket . The electric pump according to claim 1, wherein the storage chamber is communicated with a return port of the working liquid that is formed through the peripheral wall of the bracket. 3. The electric pump according to claim 2, wherein the return port is provided at a position opposite to a radial direction with a suction port communicating with a suction side of the pump body and a connecting portion between the motor shaft and the pump shaft interposed therebetween.

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