JP2005207310A - Motor-driven pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven pump less in the number of parts, small in size, and low in manufacturing cost. <P>SOLUTION: The rotating side seal ring 12 of a mechanical seal is fitted, through an O-ring 14, to the outer periphery of a spindle 4 on the pump section 3 side of a ball bearing 5 supporting the rotation of the spindle 4, and an elastic body (spring 13) pressing the rotating side seal ring 12 is interposed between the rotating side seal ring 12 and the inner ring 5a of the ball bearing 5. The spring 13 can develop such actions that pre-loads the ball bearing 5 and presses the rotating side seal ring 12 of the mechanical seal against the step part 1e (equal to the fixed side seal ring of the mechanical seal) of a through hole 1d. By this structure, the number of parts, the size, and the weight of the motor-driven pump can be decreased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a compact electric pump in which a pump chamber for circulating a liquid and an electric motor chamber in an air environment are arranged adjacent to each other, such as an on-vehicle water pump and an oil pump.

  In recent years, electric vehicles with less environmental impact and so-called hybrid cars with less exhaust gas have attracted attention, and those that have entered the practical stage have also appeared. Automobiles that use electric motors for these runs have no engine or perform intermittent operation, so it is necessary to replace the drive source with a motor for auxiliary equipment such as pumps that have been driven by an infinite belt that has been placed around the engine. There is.

  Conventionally, in this type of electric pump, the pump unit and the motor unit are formed separately, and the pump rotating shaft and the motor rotating shaft are connected to each other so as to be able to transmit the drive using a joint such as an Oldham joint. Was. However, in such a configuration, since bearings and oil seals are provided corresponding to the pair of shafts, the number of parts is large, the apparatus is large, and the manufacturing cost is high. In view of this, the present applicants have proposed a small and inexpensive electric pump by combining a motor shaft and a pump shaft with a single shaft (see Patent Document 1).

  Further, a mechanical seal is used as a means (shaft sealing means) for preventing leakage of liquid from a through-hole through which a rotating shaft is inserted into a compartment (pump chamber) through which the working fluid circulates (for example, Patent Document 2). See ~ 3 etc.).

  FIG. 3 is a schematic cross-sectional view showing a configuration of a conventional electric pump, and FIG. 4 is an enlarged view of a portion Q in FIG.

  An electric motor chamber (motor unit 2) and a pump chamber (pump unit 3) are formed adjacent to each other inside the housing 1 of the electric pump. A main shaft 4 that is a drive shaft that is driven to rotate by the motor unit 2 and also a rotation shaft of the pump unit 3 is disposed in the housing 1 and is rotatably supported by ball bearings 5 and 6. Yes. In the drawings, reference numerals 11 and 21 denote preload springs for ball bearings, 31 denotes a rotor portion of the motor, 32 denotes a magnet, 33 denotes a stator portion of the motor, 34 denotes a coil, and 35 denotes an impeller of the pump. Further, in order to prevent the explanation from becoming complicated, detailed explanations regarding the operations and functions of the members constituting the motor unit 2 and the pump unit 3 are omitted.

  The housing 1 is made of, for example, an aluminum alloy, and mainly includes a motor housing 1b in which the motor unit 2 is housed, a pump housing 1c in which the pump unit 3 is mainly housed, and a partition member 1a as an inner wall that separates them. And connected. Further, the partition member 1a is provided with a through hole 1d through which the main shaft 4 is inserted, and a mechanical seal for shaft sealing the through hole 1d is provided on the pump part 3 side.

  As shown in the enlarged view of FIG. 4, the mechanical seal includes a rotation-side seal ring 22 fixed to the outer periphery of the main shaft 4 and a fixed-side seal fitted into the inner periphery of the through hole 1d via an O-ring 25. It is composed of a ring 23 and an elastic body (spring 24) that presses the fixed side seal ring 23 toward the rotation side seal ring, and the liquid (working fluid) on the pump unit 3 side enters the motor unit 2 side. To prevent it.

JP 2002-31065 A Japanese Patent Laid-Open No. 10-89489 JP 2002-333069 A

  By the way, in the electric pump as described above, a bearing for supporting the rotating shaft and a mechanical seal for sealing the periphery of the rotating shaft are separately arranged at different positions in the axial direction. There is a problem in that the axial dimension of the is increased.

  In addition, auxiliary machinery mounted on automobiles is always required to be smaller and lighter for energy saving (improving fuel efficiency) and cost reduction to improve competitiveness. There is a demand for a more compact and low-cost product while having functions and reliability equivalent to those of the prior art.

  The present invention has been made to address the above-described problems, and an object thereof is to provide a small and inexpensive electric pump having a small number of parts.

  In order to achieve the above-mentioned object, the invention according to claim 1 is a pump that sucks and discharges fluid on both sides of a rotary shaft disposed through a through-hole provided in an inner wall dividing the housing. And a motor unit that drives the pump, wherein a ball bearing that supports the rotation of the rotary shaft is disposed on the inner periphery of the through-hole, and the pump unit is configured from the ball bearing. The rotation side seal ring of the mechanical seal is fitted on the outer periphery of the rotation shaft on the side, and an elastic body is disposed between the rotation side seal ring and the inner ring of the ball bearing.

  The present invention relates to an electric pump in which a pump chamber and a motor chamber are formed on both sides of a single rotating shaft, a force for preloading a ball bearing that supports the rotating shaft, and a force for pressing one of the seal rings of a mechanical seal against the other. Is intended to achieve the intended purpose by using it as one elastic body.

  That is, according to the first aspect of the present invention, the elasticity that presses the rotation-side seal ring toward the fixed-side seal ring between the rotation-side seal ring fitted on the outer periphery of the rotation shaft and the inner ring of the ball bearing. By interposing the body, it is possible to omit one of the ball bearing preload elastic body and the mechanical seal elastic body, which were conventionally required individually. Also, with this configuration, it is possible to integrate the rotary shaft bearing and the mechanical seal, which have been conventionally arranged at different positions in the axial direction.

  As described above, according to the present invention, the axial dimension of the electric pump can be shortened, and the miniaturization and weight reduction can be realized. Moreover, since the number of components to be configured is reduced and the work for assembling the components is simplified, the cost of the entire electric pump can be reduced.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a configuration of an electric pump according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a portion P in FIG. In addition, the same code | symbol is attached | subjected to the structural member which has the same function as a prior art example.

  An electric motor chamber (motor unit 2) and a pump chamber (pump unit 3) are also formed adjacent to each other inside the housing 1 of the electric pump. In addition, a main shaft 4 that is a drive shaft that is rotationally driven by the motor unit 2 and at the same time the rotational shaft of the pump unit 3 is disposed in the housing 1 and is rotatably supported by ball bearings 5 and 6. ing.

  The feature of the electric pump in this embodiment is that, as shown in the enlarged view of FIG. 2, a mechanical seal is provided on the outer periphery of the main shaft 4 on the pump portion 3 side from the ball bearing 5 that supports the rotation of the main shaft 4 via an O-ring 14. The rotation-side seal ring 12 is fitted, and an elastic body (spring 13) that presses the rotation-side seal ring 12 is interposed between the rotation-side seal ring 12 and the inner ring 5a of the ball bearing 5. It is a point. The spring 13 preloads the ball bearing 5 and exerts an action of pressing the rotation-side seal ring 12 of the mechanical seal toward the step portion 1e of the through hole 1d (corresponding to the fixed-side seal ring of the mechanical seal).

  With this configuration, it is possible to omit one of the preloading elastic body and the mechanical sealing elastic body of the ball bearing that has been conventionally required. Further, conventionally, the bearing of the main shaft 4 and the mechanical seal that are separately disposed in the axial direction are integrated, and the axial dimension of the entire electric pump can be shortened. Therefore, the electric pump in the present embodiment can realize a reduction in size and weight of the entire pump.

  In this embodiment, the elastic body for preloading the ball bearing and the elastic body used for the mechanical seal are springs. However, the elastic body used in the present invention is not particularly limited. There is an effect.

  Further, the shaft seal mechanism of the mechanical seal has a structure in which the rotation side seal ring 12 is in sliding contact with the step portion 1e of the through hole 1d. You may do it. However, an increase in the number of parts causes an increase in cost and product weight, so the configuration in the present embodiment is more advantageous.

  Further, the structure of the motor and the pump is not limited to the example in the present embodiment, and it goes without saying that the present invention can be applied to an electric pump having another configuration such as a gear pump.

It is typical sectional drawing which shows the structure of the electric pump in embodiment of this invention. It is the P section enlarged view of FIG. It is typical sectional drawing which shows the structure of the conventional electric pump. It is the Q section enlarged view of FIG.

Explanation of symbols

1 Housing 1a Partition member (inner wall)
DESCRIPTION OF SYMBOLS 1b Motor housing 1c Pump housing 1d Through-hole 1e Step part 2 Motor part 3 Pump part 4 Main shaft 5 Ball bearing 5a Inner ring 6 Ball bearing 11 Preload spring 12 Rotation side seal ring 13 Spring 14 O-ring 21 Preload spring 22 Rotation side seal ring 23 Fixed side seal ring 24 Spring 25 O-ring 31 Rotor part 32 Magnet 33 Stator part 34 Coil 35 Impeller

Claims (1)

An electric pump in which a pump part for sucking and discharging fluid and a motor part for driving the pump are formed on both sides of a rotating shaft arranged through a through hole provided in an inner wall defining the housing. A ball bearing for supporting the rotation of the rotating shaft is disposed on the inner periphery of the through hole, and the rotation side seal of the mechanical seal is disposed on the outer periphery of the rotating shaft closer to the pump portion than the ball bearing via an O-ring. An electric pump characterized in that a ring is fitted and an elastic body is interposed between the rotary side seal ring and the inner ring of the ball bearing.

Images