JPH04127469U - Rotating bellows type mechanical seal - Google Patents

Abstract

(57) [Summary] [Purpose] Metal bellows 90 using sliding torque of sliding ring
The structure has excellent sealing performance and durability by preventing damage and deterioration of axial operability. [Structure] A retainer 94 at the free end of an axially expandable metal bellows 90 airtightly interposed between the rotating side sliding ring 50 and the sleeve 80 and the rotating side sliding ring 50 are closely abutted, A plurality of notches 51 are formed on the inner diameter of the rotating side sliding ring 50 at appropriate intervals in the circumferential direction, and a plurality of protrusions 82 extending in the axial direction are formed in the sleeve 80 in the same phase as the notches 51. A plurality of coil springs 130 are engaged with each other in the direction of the protrusion 8 and are located on the inner periphery of the metal bellows 90 and press the rotating side sliding ring 50 toward the stationary side sliding ring 40 side.
It is guided by pins 140 arranged in each recess 83 between the two and fixed in the axial direction.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is used in shaft seals of equipment that handles high temperatures or special fluids, and is A metal bellow is used as an operating packing to support the side sliding ring airtightly and in an axially movable manner. This article relates to a rotary mechanical seal using a mechanical seal.

0002

[Conventional technology]

Conventionally, shaft sealing devices for rotating equipment such as pumps that handle high-temperature fluids such as heated melts have been used. In this case, mechanical seals are installed in two stages in the axial direction, and there is a middle part between both mechanical seals. A double mechanical seal is often used, which circulates the interstitial liquid from the outside. However, in this case, a pressurized circulation supply device is required to supply the intermediate liquid at an appropriate pressure. Not only does the entire device become large-scale, but there is also the problem of high running costs. Ru.

0003 Therefore, when sealing the shaft with a single mechanical seal, it is necessary to Therefore, one sliding ring is replaced with an actuating packing that supports the sliding ring airtightly and movably in the axial direction. A bellows-type mechanical seal with a metal bellows that can be expanded and contracted in the axial direction is used. However, the metal bellows is damaged due to twisting caused by the sliding torque of the sliding ring. There is a fear. In addition, in order to avoid the influence of rotation on the spring load, this metal bellows It is common to use a stationary bellows type mechanical seal structure using a bellows on the stationary side. However, in this case, the metal bellows may be exposed to the adhesion and solidification of the fluid or foreign matter in the fluid. The build-up of these materials will adversely affect its elasticity, and the axial operability of the stationary side sliding ring will deteriorate. It may drop and cause leakage.

0004

[Problem that the idea aims to solve]

The present invention was developed in view of the above problems, and it is a bellows used alone. In type mechanical seals, the metal bellows may be damaged due to sliding torque from the sliding ring. To provide a structure with excellent sealing performance and durability by preventing damage and deterioration of axial operability. This was done as a challenge.

[0005]

[Means to solve the problem]

In order to solve the above problems, the rotary bellows type mechanical seal of the present invention is designed to Airtight between the rotating side sliding ring that axially opposes the side sliding ring and the sleeve on the outer circumference of the shaft. a metal bellows that is axially expandable and retractable; The retainer at the end and the rotating side sliding ring are closely abutted, and the inner diameter of the rotating side sliding ring is circumferentially A plurality of notches are formed at appropriate intervals, and the sleeve is in the same phase as the notches. The inner periphery of the metal bellows is engaged by circumferentially engaging the formed plurality of protrusions extending in the axial direction. multiple coil springs that press and bias the rotating side sliding ring toward the stationary side sliding ring. pins arranged in each recess between the protrusions of the sleeve and fixed in the axial direction, respectively. It is structured so that it is guided by

[0006]

[Effect]

According to the above configuration, the metal bellows moves the rotating side sliding ring axially toward the shaft side. Because it is supported freely and rotates together with each element on the rotating side, it prevents fluid from adhering to it. -No solidification or accumulation of foreign matter in the fluid.

[0007] The rotation side sliding ring engages the shaft with the notch on its inner diameter and the protrusion on the sleeve. The rotating torque of the metal bellows is transmitted and rotates, while the sliding ring on the rotating side and the free end of the metal bellows Because the retainers are closely abutted and can slide against each other, the metal bellows Twisting due to the sliding torque does not occur.

[0008] The axial biasing force against the rotating sliding ring is disposed within each recess between the protrusions of the sleeve. Each coil spring is provided with a plurality of coil springs. The shaft is guided by pins to prevent deformation during rotation. Unlike the case of a single coil spring surrounding the outer circumference of the Uniform biasing force can be obtained in the circumferential direction without being affected by

[0009]

【Example】

In one embodiment shown in FIG. 1, 10 is a high temperature or special fluid such as a heated melt. 30 is a housing 10 for a shaft sealing part of a rotating equipment such as a pump that handles A mechanical mechanism that seals the circumferential space of the shaft 30 with the shaft passing through the shaft hole 20. The Lucille is loosely fitted around the outer periphery of the shaft 30, and its opposing end surfaces slide closely against each other. It has a stationary side sliding ring 40 and a rotating side sliding ring 50.

0010 Of these, the stationary side sliding ring 40 is made of carbon material, and its outer peripheral surface 41 is connected to the shaft hole 20. is airtightly fitted to the inner peripheral surface 21 of the step part through an O-ring 60, and 42 is supported in contact with the step end surface 22 of the shaft hole 20, and is connected to the step end surface 22. It is held in a non-rotating state by engagement with a drive pin 70 inserted therein. child On the other hand, the rotating side sliding ring 50 is made of SiC and rotates together with the shaft 30. There is a weld between the shaft 30 and the sleeve 80 which is hermetically fixed to the exterior. A contact metal bellows 90 is airtightly interposed.

[0011] Welded metal bellows 90 includes a bellows-shaped main body plate 91 that is axially expandable and An adapter 92 welded to the fixed end and a collar welded to the back of this adapter 92. -93 and a retainer 94 welded to the free end of the bellows-shaped main body plate 91. The collar 93 is attached to the flange portion 81 of the sleeve 80 via the gasket 100. It is fixed with a bolt (not shown), and the tip end surface of the retainer 94 is attached to an O-ring. It is in close contact with the back surface of the rotating side sliding ring 50 via 110. 120 is a retainer 94 and the rotating side sliding ring 50 are held in a concentric relationship with each other.

0012 A plurality of notches 51 extending in the axial direction are formed at equal intervals in the circumferential direction on the inner diameter of the rotating side sliding ring 50. A similar notch 94a is formed on the inner diameter of the retainer 94. Ru. On the other hand, a plurality of protrusions 82 extending in the axial direction are provided on the inner diameter portion of the sleeve 80. It is formed in the same phase as the notches 51, 94a, and is circumferentially engaged with the notches 51, 94a. It matches.

[0013] As shown in FIG. 2, the inner periphery of the welded metal bellows 90 and the sleeve 80 are Each recess 83 extending in the axial direction between the plurality of projections 82 has a recess end wall 83a. A coil spring 130 is guided from the inside by a pin 140 that stands upright in the axial direction. is installed. The rotating side sliding ring 50 is rotated by this coil spring 130. Forced in the axial direction via the retainer 94 and pressed against the opposing end surface of the stationary side sliding ring 40 and forms a sealing sliding surface S.

[0014] The rotating bellows type mechanical seal with the above configuration has a sealing sliding surface S and a welded The shaft sealing function is performed by sealing the fluid 150 flowing into the outer circumferential side of the metal bellows 90. This method eliminates the need for a double seal structure using two sets of mechanical seals. When the shaft 30 and the sleeve 80 integrated therewith rotate, the coil The rotation side sliding ring 50, which is biased by the spring 130, engages with the recess 83 on its inner diameter. The engagement of the rib 80 with the protrusion 82 causes it to rotate synchronously with the shaft 30 and seal the sliding surface. At S, it slides closely against the stationary side sliding ring 40. Also, collar 93 is sleeve 80 The welded metal bellows 90 fixed to the flange portion 81 also rotates synchronously with the shaft 30. Turn around.

[0015] At this time, the retainer 94 at the free end of the welded metal bellows 90 is simply an O-ring. It is only in close contact with the back surface of the rotating side sliding ring 50 via the ring 110. The rotation side sliding ring 50 is not responsible for transmitting shaft rotational force to the rotating side sliding ring 50. Since it only has the function of maintaining airtightness between the moving ring 50 and the sleeve 80, this The welded metal bellows 90 connects the flange portion 81 of the sleeve 80 and the rotating side sliding ring 50. There is no risk of damage due to torsional action between the

[0016] Since the weld metal bellows 90 is on the rotating side, the fluid to be sealed 150 is attached to the weld metal bellows 90. Its elasticity is inhibited by adhesion, solidification, or accumulation of foreign matter in the fluid 150. In addition, the coil spring 130 is connected to the welded metal bellows 90. Since it is located in the unsealed space on the inner periphery of the does not occur.

[0017] Here, means for applying sliding surface pressure to the rotating side sliding ring 50 with the stationary side sliding ring 40; For example, a single coil spring surrounding the outer periphery of the sleeve 82 is attached. In this case, the coil coil As the pulling undergoes diameter expansion deformation, the axial biasing force decreases, making it suitable for high-speed rotation conditions. cannot be used. In contrast, in the present invention, a plurality of coil springs 130 are arranged circumferentially. It is a multi-spring type arranged in the direction, and each coil spring 130 is connected to a pin. 140 to prevent deformation due to centrifugal force, so it rotates even in high speed rotation range. The biasing force applied to the side sliding ring 50 does not decrease, and a uniform biasing force in the circumferential direction can be obtained.

[0018]

[Effect of the idea]

As described above, according to the rotary bellows type mechanical seal of the present invention, it is possible to move freely in the axial direction. A rotating seal structure with a sliding ring on the rotating side, and a metal bellows on the rotating side. Therefore, the axial movement of the rotating sliding ring due to fluid adhesion to or clogging of the metal bellows is There is no reduction in dynamics, and the metal bellows does not transmit torque to the rotating sliding ring. Therefore, there is no risk of damage due to twisting, and sliding surface pressure is applied to the rotating side sliding ring. Multiple coil springs are arranged circumferentially, and each coil spring is guided by a pin. Because deformation due to centrifugal force is prevented by It has excellent effects such as being able to

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the main parts.

[Explanation of symbols]

10 Housing 30 shaft 40 Stationary side sliding ring 50 Rotating side sliding ring 51 Notch 80 sleeve 82 Protrusion 83 Recess 90 Welded metal bellows 94 Retainer 130 coil spring 140 pin

Claims (1)

[Scope of utility model registration request] 1. An axially expandable metal bellows is airtightly interposed between a rotating side sliding ring that axially opposes the stationary side sliding ring and a sleeve on the outer periphery of the shaft. The retainer at the free end and the rotating sliding ring are closely abutted, and a plurality of notches are formed on the inner diameter of the rotating sliding ring at appropriate intervals in the circumferential direction, and the sleeve is in the same phase as the notches. A plurality of coil springs are engaged in the circumferential direction with the formed plurality of projections extending in the axial direction, and are located on the inner periphery of the metal bellows and press and bias the rotating sliding ring toward the stationary sliding ring. A rotating bellows type mechanical seal characterized by being guided by pins arranged in each recess between the protrusions of a sleeve and fixed in the axial direction.