JPS6159053B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding contact surface of a mechanical seal in an underwater motor, particularly for rotating a pump for pumping muddy water, by increasing the lubricating effect of oil. The purpose is to increase the durability of mechanical seals.

To explain the drawings of the embodiment, 1 is a motor shaft led out from the motor chamber 2 and extends vertically through the oil chamber 3, and 4 is a fixed side that is loose with the motor shaft 1 and fitted into the hole edge of the boundary wall 5. The annular support 6 is a fixed side sliding ring which is supported by the support 4 and whose front end surface is formed into a sliding surface 6a that is in contact with a sliding surface 7a of a rotating side sliding ring 7, which will be described later. The rotating side sliding ring 7 is supported by the rotating side annular support 8 while being loosely engaged with the motor shaft 1, and as the motor shaft 1 rotates, the rotating side sliding ring 7 also rotates. The action of the pressing spring 9 maintains a watertight sliding contact between the sliding surfaces 6a and 7a.

Near the outer periphery of both sliding surfaces 6a and 7a that are in contact with each other, the outer periphery of the rotating side sliding ring 7 is eccentric from the axis of the motor shaft 1, as shown in FIG.
Alternatively, as shown in FIG. 2B, by providing a short diameter portion on a part of the outer circumference of the rotating side sliding ring 7, an intermittent contact surface 10 is formed when the motor shaft 1 rotates. It is desirable that the intermittent contact surface 10 be formed on the sliding surface 6a of the stationary sliding ring 6. When a short diameter portion is provided in a part of the outer circumference of the stationary side sliding ring 6 to form an intermittent contact surface on the sliding surface 7a of the rotating side sliding ring 7, the oil in this portion absorbs centrifugal force. This is not preferable because it tends to dissipate in the tangential direction due to the action. Further, in order to prevent muddy water from entering between the contact surfaces, it is desirable that the inner circumferential surfaces of both sliding rings 6 and 7 that come into contact with the pumped liquid are concentrically aligned.
In short, the inner circumferential circles of both sliding rings are concentric and have the same diameter.
For the fixed side sliding ring 6, the inner circumference and the outer circumference are concentric and have different diameters, and for the rotating side sliding ring 7, the outer circumference is eccentric or a part of the outer circumference is provided with a short diameter part. This mode is the most ideal, and when the motor shaft 1 rotates, the sliding surface 6 of the fixed side sliding ring 6
The intermittent contact surface 10 formed near the outer periphery of a enhances the lubrication effect between the contact surfaces of both sliding rings. That is, the oil adhering to the surface 10a which is in a non-contact state at the position shown in FIG.
The oil adhering to the surface 10a', which is impregnated with the surface 10b and newly brought into a non-contact state, is also impregnated with the surface 10b' which comes into contact at the rotational position shown in FIG. As a result, oil is naturally supplied to the entire sliding surface.

In conventional mechanical seals for underwater motors, the outer circumferential circles of the stationary sliding ring and rotating sliding ring are concentric and have the same diameter, which means that oil is naturally replenished to the sliding surface as the motor shaft rotates. Since the sliding surface is only kept lubricated by the oil that has been impregnated from the beginning, mechanical seals have poor durability, and a special device with a complicated mechanism is required to replenish the oil. I need. However, in the sliding contact surface of the present invention, an intermittent contact surface is formed as the motor shaft rotates, and oil is naturally replenished to the sliding surfaces of the stationary sliding ring and the rotating sliding ring. The lubricating effect can be maintained without the need for special equipment, and the durability of the mechanical seal can be significantly improved. Moreover, since the inner circumferential circles of both sliding rings remain concentric and have the same diameter, a structure is maintained that prevents the intrusion of external liquid, so there is an advantage that the sliding surfaces will not be worn out due to the intrusion of muddy water or the like.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional side view of a main part of a mechanical seal having a sliding contact surface according to the present invention, and A and B in FIG. 3A to 3C are explanatory diagrams showing the state of oil impregnation from the intermittent contact surface as the motor shaft rotates. 1... Motor shaft, 3... Oil chamber, 6... Fixed side sliding ring, 7... Rotating side sliding ring, 10... Intermittent contact surface.

Claims (1)

[Claims] 1 Between the contact surfaces of the rotating side sliding ring attached to the circumferential side of the motor shaft that runs vertically in the oil chamber and the stationary side sliding ring supported by a stationary body and loosely mating with the motor shaft, the rotating side sliding ring By making the outer circumferential circle of the moving ring eccentric from the axis of the motor shaft, or by providing a short diameter part in a part of the outer circumferential circle of the rotating side sliding ring, the pairing of both sliding rings is prevented when the motor shaft rotates. A sliding contact surface of a mechanical seal in an underwater motor, characterized in that an intermittent contact surface is formed near the outer periphery of the contact surface.