JPH0422779A - Pump device - Google Patents

Abstract

PURPOSE:To improve seal performance with a low slide resistance constitution by providing a thin membranous seal member of synthetic resin between a ball bearing jouraling the rotating shaft of a pump device and a positioning member to position the bearing against a housing in the axial direction. CONSTITUTION:When a rotating shaft 14 is driven to rotate through a pulley fitting part 40, fluid is sucked from a reservoir to a pump chamber through a fluid supply passage 30, a bypass passage 29, and suction ports 24, 25. The fluid pressurized by pump action is let flow from discharge ports 26, 27 to a pressure chamber 32 through a through hole 31, and while pressing a pressing plate 19, discharged from the discharge port to a power steering device and the like. At large discharge flow, the flow flowing into a valve chamber 37 through a communicating passage 39 is increased, and hence a valve member 34 is moved against the pushing force of a spring 35, and excess flow is bypassed to the bypass passage 29. In the above-stated constitution, a thin membranous seal member 45 is provided between a ball bearing 15 and a snap ring 43.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pump device that supplies pressurized fluid to a power steering device or the like.

<Prior Art> In a conventional pump device, a configuration in which a rotating shaft is pivotally supported in a pump housing is known as shown in FIG. 3. In FIG. 3, a rotating shaft 51 to which a rotor 52 is connected at one end is rotatably supported on a housing 53 by a ball bearing 54 and a guide bush 55.

The arrangement of the shaft bearing part is such that a ball bearing 54 is provided at a position close to the pulley mounting part 56 at the other end, and this ball bearing 54 is axially positioned with respect to the housing 53 by a snap ring 57, and the rotating shaft 5I is positioned in the axial direction by the large diameter portion 59 and the retaining ring 60. An oil seal 58 is arranged at the back thereof, and is pivotally supported by a guide bush 55 at a position closer to the rotor 52.

With this arrangement, the radial force applied to the pulley mounting portion 56 can be effectively received by the ball bearing 54, and the installation of the oil seal 58 prevents muddy water and dust from entering the housing 53 from the outside. This is to prevent the intrusion of foreign substances such as

<Problems to be Solved by the Invention> With the above configuration, since the ball bearing 54 is disposed outside the oil seal 58 which acts to prevent foreign matter such as muddy water from entering from the outside, the ball bearing 54 The area will be directly exposed to muddy water, etc. from the outside. Therefore, the ball bearing 54 is of the so-called ZZ type, in which shield plates are attached to both sides of the ball sliding portion. However, even if this ZZ type ball bearing is used, it is not possible to completely prevent foreign matter from entering, and muddy water, dust, etc. will enter the ball sliding part of the ball bearing 54, and the life of the ball bearing 54 will be shortened. A problem arises that lowers the

Furthermore, in order to prevent foreign matter from entering the ball bearing 54, an oil seal 58 may be placed on the open end side of the ball bearing 54. The distance between the branches becomes longer, and the moment due to the radial force applied to the pulley mounting portion 56 becomes larger (as a result, the ball bearing 54
The problem arises that the lifespan of the product is reduced.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and includes a housing in which a cylindrical hole is formed, a rotating shaft inserted into the cylindrical hole of this housing, and this rotating shaft. a rotor connected to one end and rotating within the housing; a cam ring disposed to surround the rotor; and a cam ring disposed within the cylindrical hole to rotatably support the rotating shaft with respect to the housing. A pump device including a ball bearing and a positioning member fixed to the housing on the opening side of the cylindrical hole of the ball bearing to position the ball bearing in the axial direction with respect to the housing, the ball bearing and the positioning member being fixed to the housing on the opening side of the cylindrical hole. It is characterized in that a thin film-like sealing member made of synthetic resin is installed between the members.

<Function> An F-shaped synthetic resin sealing member is installed between the ball bearing and the positioning member, so even if muddy water, dust, etc. are applied from the outside, muddy water, dust, etc. will not reach the ball sliding part of the ball bearing. prevent intrusion.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. Reference numeral 10 denotes a rear housing of the pump, and a hollow chamber 11 with a bottom is formed in this rear housing 10, and this hollow chamber 11 opens at one end surface of the rear housing 1°. A circumferential hole 13 is bored in the front housing 12 that closes the opening of the hollow chamber 11, and the rotating shaft 1 is inserted into the circumferential hole 13.
4 is inserted. The rotating shaft 14 is rotatably supported on the front housing 12 by a ball bearing 15 and a guide bush 16, as will be described later.

One end surface of the hollow chamber 11 has a front housing 12.
A cam ring 17 facing each other, a side plate 18 facing the other side of the cam ring 17, and a pressing plate 19 facing the other side of the side plate 18 are housed, and between the pressing plate 9 and the rear housing 10, The spring 20 is compressed and inserted. A cam surface 21 is formed on the inner circumference of the cam ring 17, and this cam surface 2
A rotor 23 that slidably holds a plurality of vanes 22 whose outer ends are in sliding contact with the vanes 1 in the radial direction is housed in the cam ring F. The rotor 23 is splined to one end of the rotating shaft 14 .

Furthermore, one side surface of the vane 22 and the rotor 23 is in sliding contact with the side surface of the front housing 12, and the other side surface is in sliding contact with the side surface of the side plate 18, so that a sealing effect is achieved at each sliding surface. As a result, a plurality of pump chambers are formed by the vanes 22 between the cam surface 21 of the cam ring 17 and the rotor 23, and the volume of each pump chamber changes as the rotor 23 rotates. As shown in FIG. 2, the front housing 12 and the side plate 18 are provided with a suction ball 1-24 corresponding to the pump chamber that performs the expansion stroke.
, 25 are formed, and discharge boats 26 and 27 are formed in the front housing 12 and the side plate 18 in correspondence with the pump chambers without a compression stroke. These suction boats 24, 25 have an annular passage 28 and a pressure brake 1.
It communicates with a bypass passage 29 via a passage groove of the circuit cut in 19. A fluid supply passage 30 is opened in the bypass passage 29 orthogonally thereto, and one end of the fluid supply passage 30 is connected to a reservoir of the circuit, and fluid is supplied from the reservoir. Further, the discharge boat 2627 communicates with the pressure chamber 32 through the through hole 31 of the press plate 19, and communicates with the discharge port of the circuit through the passage of the circuit.

Further, a valve housing hole 33 is formed in the rear housing 10 in a direction perpendicular to the axis of the rotating shaft 14.
A valve member 34 of a flow rate control valve 38 is slidably inserted therein, and valve chambers 36, 37 are formed at both ends of the valve member 34. Further, the valve chamber 36 is provided with a spring 35 that presses the valve member 34, and the valve chamber 37 is communicated with the pressure chamber 32 via a conduction path 39.

Further, the rotating shaft 14 has a boot mounting portion 40 on one end of which a circuit pulley is fixed, and the front housing 12
2 of ball bearing 15 and guide bush 16
It is rotatably mounted on a shaft at one point. The arrangement of the shaft bearing part is such that a ball bearing 15 is provided at a position close to the pulley mounting part 40, an oil seal 44 is arranged at the back of the ball bearing 15, and a guide bush 16 is located at a position close to the rotor 23.
is located. With this arrangement, the ball bearing 15 can effectively receive the radial force applied to the pulley mounting portion 40.

The ball bearing 15 is fitted and fixed into a large diameter hole 41 formed in the front housing 12, and the other end, which is the open end of the through hole 13, is fixed by a snap ring 43. In addition, the ball bearing 15 is connected to the rotating shaft 14,
One end contacts the retaining ring 42 and the other end contacts the large diameter portion 14a provided on the rotating shaft 14, thereby positioning the rotating shaft 14 in the axial direction. This ball bearing 15 is a so-called ZZ type in which shield plates are attached on both sides of the ball sliding part.
type, and care has been taken to prevent foreign matter such as muddy water and dust from entering the ball sliding part.

Furthermore, a thin film seal member 45 is installed between the ball bearing 15 and the snap ring 43. This sealing member 45 is made of tetrafluoroethylene resin (Teflon).
Made of synthetic resin such as
A circular hole is formed through the hole. The outer periphery of the seal member 45 is liquid-tightly fitted between the outer ring of the ball bearing 15 and the snap ring 43, and the inner circular hole is connected to the rotating shaft 1.
The diameter is determined so as to be in liquid-tight sliding contact with the large diameter portion 14a of No. 4. Furthermore, the end of the circular hole is assembled so as to deform toward the snap ring 43 side so as not to come into sliding contact with the inner ring side of the ball bearing 15, thereby reducing the friction caused by sliding contact with the inner ring side.

To explain the operation of the above-mentioned pump device, when rotational force is applied to the pulley of the circuit, the rotating shaft 14 is rotationally driven via the boob mounting portion 40. Thereby, fluid is transferred from the reservoir of the circuit to the fluid supply passage 30, the bypass passage 29,
Through the passage groove, annular passage 28, the suction boat 24.25
is sucked into the pump chamber. The fluid given pressure by the pumping action flows from the discharge bow 1-26.27 to the through hole 3.
1 into the pressure chamber 32, presses the pressure plate 19, and is sent to the power steering device etc. from the discharge port via the passage. Also, when the discharge flow rate increases, the conduction path 39
Since the flow rate flowing into the valve chamber 37 through increases, the valve member 34 moves against the pressing force of the spring 35 and bypasses the excess flow to the bypass passage 29.

The present invention provides a rotating shaft 14 of a pump device that operates as described above.
In the ball bearing ring 15 that supports the ball, a so-called ZZ type is used in which shield plates are attached on both sides of the ball sliding part, and a thin film-like seal member 45 made of synthetic resin is further installed. , it is possible to improve the sealing performance with a configuration that has less sliding resistance without the need for any additional work on the housing of the current pump device.

In the above embodiment, the sealing member 45 is fixed by the snap ring 43, but the present invention is not limited to this structure. For example, a structure in which the sealing member 45 is fixed by a nut or the like can also be applied.

<Effects of the Invention> As described above, the present invention provides a thin film made of synthetic resin between the ball bearing that supports the rotating shaft of the pump device and the positioning member that positions the ball bearing in the axial direction with respect to the housing. By installing this sealing member, it is possible to improve sealing performance with a configuration with less sliding resistance without the need for any additional work on the current pump equipment housing.

[Brief explanation of drawings]

In the drawings, FIG. 1 is a longitudinal sectional view of the pump device of the present invention, and FIG.
The figure is a cross-sectional view taken along the line ■--■ in FIG. 1, and FIG. 3 is a cross-sectional view of the main part of a conventional pump device. 11... Rear housing, 12... Front housing, 13... Cylindrical hole, 14... Rotating shaft, 15...
・Ball bearing, 17 cam ring, 23... Rotor, 43... Positioning member (snap ring), 45
... Seal member.

Claims (1)

[Claims] (1) A housing in which a cylindrical hole is formed, a rotating shaft inserted into the cylindrical hole of the housing, a rotor connected to one end of the rotating shaft and rotating within the housing, and a rotor arranged to surround the rotor. a cam ring provided in the cylindrical hole; a ball bearing disposed within the cylindrical hole to rotatably support the rotating shaft with respect to the housing; and a cam ring fixed to the housing on the opening side of the cylindrical hole of the ball bearing. A pump device having a positioning member for axially positioning a ball bearing with respect to the housing, characterized in that a thin film-like sealing member made of synthetic resin is installed between the ball bearing and the positioning member. Device.