JPS6229725Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a mechanical seal, and its purpose is that when subjected to repeated heat cycles and pressure cycles, the shaft packing of the moving ring will stick tightly to the shaft at high temperatures, and move in the axial direction at low temperatures. There are drawbacks such as the smooth movement of the ring and the contact surface between the moving ring and the fixed ring opening, which reduces the sealing effect and creates a risk of liquid leakage. The purpose is to provide a mechanical seal with good sealing effect by preventing slurry from clogging between the shaft packing and the shaft and causing liquid leakage.

Hereinafter, as an example, the configuration will be described in the case where the present invention is applied to a pump. 1 is a pump casing, 2 is a shaft, 3 is an impeller attached to the shaft end, and 4 is a fixed ring fixed to the inner circumference of the casing, which is attached to the lid of the casing 1 via a buffer ring 5.
Reference numeral 6 denotes a rotating ring that rotates together with the shaft 2, and is fixed on the shaft 2 by a key 7. A movable ring 8 is rotatably fitted onto the shaft 2 via a shaft packing 9 between the fixed ring 4 and the rotating ring 6, and has an engaging piece 10 that engages with the rotating ring 6. A spring 11 provided between the fixed ring and the fixed ring is applied to keep the fixed ring in constant contact with the fixed ring. In addition, as the shaft packing 9,
Usually, O-rings, U-rings, V-rings, etc. are used. 12 is a sliding contact surface between the moving ring 8 and the shaft 2; 13
indicates the contact surface between the movable ring 8 and the fixed ring 4, the movable ring 8 is fitted onto the shaft via the shaft packing 9, rotates together with the rotating ring 6 via the engagement piece 10, and is fixed by the spring 11. It is constantly pressed in the direction of the ring 4 to make close contact, and while sliding on the contact surface 13, it comes in close contact and is completely sealed. The feature of the present invention is that in the movable ring 8, a shaft packing 9 is provided on the sliding contact surface 12 between the movable ring 8 and the shaft 2.
Two grooves 14 and 15 are provided to accommodate the lubricant 9, and the width of the groove 15 on the liquid side is made larger than the other groove, so that a large amount of the lubricant 16 can be enclosed. Note that 17 indicates a through hole provided in the engaging piece 10 of the movable ring.

Since the present invention has the above configuration, it has the following effects. Of the grooves 14 and 15 that accommodate the shaft packings 9 and 9, the groove 15 on the liquid side is filled with a large amount of lubricant, such as grease and oil, which reduces static pressure within the casing and the staff during pump operation. The pump discharge pressure applied to the inking box exerts a pressing force on the movable ring and the fixed ring. Similarly, of the two gaskets housed in the moving ring, a force acts to press the liquid side gasket toward the lubricant side, compressing the lubricant sealed between the two gaskets, and creating pressure on the lubricant. occurs.

This forces the lubricant to act on the sliding parts of the liquid-side gasket and the atmosphere-side gasket, preventing the gasket from coming into close contact with the shaft due to heat and pressure cycles, making it easier to slide on the shaft. It became.

This made it possible to completely eliminate mechanical seal leakage caused by the shaft packing.

In addition, the lubricant makes it easier for the movable ring to slide on the shaft, making it possible to reduce the pressing force exerted by the spring, reducing the contact pressure between the movable ring and the fixed ring, and reducing mechanical It has become possible to extend the life of the seal.

Grooves 14 and 15 for housing the shaft packing provided in two locations
Of these, the larger the groove width, the larger the lubricant storage capacity, the longer it will take to replenish the lubricant, so it is desirable to make the groove as wide as possible structurally.

In addition, when a relatively large through hole 17 is formed in the engagement piece of the movable ring that engages with the rotating ring as shown in FIG. This effect prevents the shaft packing from clogging with slurry, reduces the weight of the engagement piece, and moves the center of gravity of the movable ring 8 closer to the fixed ring 4, improving rotational stability and sealing. Improved effectiveness can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts showing an example of applying the present invention to a pump, Fig. 2 is a plan view of the main parts showing the engagement part between the rotating ring and the movable ring, and Fig. 3 is an exploded perspective view of the vicinity of the shaft. . 1... Casing, 2... Shaft, 4... Fixed ring,
6... Rotating ring, 8... Moving ring, 9... Shaft packing, 10... Engaging piece, 11... Spring, 12
...Sliding contact surface, 14, 15...Groove for housing the shaft packing, 16...Lubricant, 17...Through hole.

Claims (1)

[Claims for Utility Model Registration] (1) A fixed ring fixed to the casing, a rotating ring rotating together with the shaft, and a shaft packing inserted between the fixed ring and the rotating ring, which is rotatably fitted onto the shaft and engaged with the rotating ring. A mechanical seal consisting of a movable ring which has an engaging piece and a movable ring which is always urged by a spring provided between the rotary ring and the fixed ring so as to be in contact with the fixed ring, the movable ring having a sliding contact surface with the shaft. A mechanical seal characterized in that two grooves are provided for housing the shaft packing, and the width of the liquid side of these grooves is larger than that of the other groove so that more lubricant can be sealed. (2) The mechanical seal according to claim 1 of the utility model registration, wherein a through hole is formed in the engaging piece of the movable ring that engages with the rotating ring.