JPH0448379Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of a mechanical seal that seals the rotating shaft of a machine body such as a compressor for a car air conditioner.

[Conventional technology] Conventionally, in this type of mechanical seal,
As shown in FIG. 3, when sealing the rotating shaft 2 inserted into the housing 1 of the aircraft body, a mating ring 4, which is a fixed ring, is attached to the inner circumference of the housing 1 through an O-ring 3 to the atmosphere side. and the rotating shaft 2 is provided on the liquid side of the mating ring 4.
A seal ring 6 made of a carbon material, which is a rotary ring with an O-ring 5 interposed between the Coil spring 8 housed in rotating casing 7
The urging force (spring load) causes the mating ring 4 to be elastically pressed through the spring retainer 9, while the groove 61 formed in a part of the outer circumferential surface 6a of the seal ring 6 is pressed from the casing 7 to the mating ring 4 side. Rotation is prevented by engaging the distal end 71a of the arm 71 integrally protruding parallel to the axial direction, thereby sealing the rotational force of the rotating shaft 2 through the casing 7. Some have a seal structure that transmits the signal to the ring 6 side.

However, with the conventional structure described above,
As shown in FIG. 4, a casing 7 for transmitting the rotational force of the rotary shaft 2 to the seal ring 6 is formed of a metal material into a cap shape, and the tip end 71a of the arm 71 is made into a T-shape. At present, the seal ring 6 is locked so as to suppress its movement in the axial direction by engaging with a groove 61 formed on the outer circumferential alligator portion 6a of the seal ring 6.

[Problems to be Solved by the Invention] Therefore, when assembling and storing parts such as the seal ring 6 in the casing 7 via the coil spring 8 and the spring retainer 9, the third
As shown by the two-dot chain line in FIG. 2, the arm 71 integrally protruding from the casing 7 is forcibly bent to open outward in advance, and after the components are assembled and stored, it is opened outward. Since the arm 71 is pushed back toward the inner diameter side toward the inside of the groove 61 of the seal ring 6, a residual strain 71b is generated at the base of the arm 71 toward the inner diameter side, and this residual strain 71
Since the portion b comes into pressure contact with the groove bottom of the groove 61, it has an adverse effect on the followability of the seal ring 6 in the axial direction, causing abnormal leakage due to malfunction of the seal ring and reducing sealing performance. There was a problem.

[Purpose of the invention] The present invention was made under the above circumstances, and its purpose is to improve the structure of the casing that provides the seal ring with a rotation-preventing function to prevent long-term operation. It is an object of the present invention to provide a mechanical seal that can maintain stable sealing performance even in

[Means for solving the problems] In order to solve the above problems, the present invention has the following features:
A non-return claw-like protrusion facing the inner diameter is provided at the tip of the arm that protrudes in the axial direction of the casing made of synthetic resin and engages with the groove in the outer circumference of the seal ring. It is configured such that it is brought into contact with the outer circumferential surface of the stepped portion on the side.

[Function] That is, the present invention has the above-mentioned configuration in which the casing is integrally formed with an elastic strength member made of synthetic resin, and the arm integrally projects from the casing in the axial direction. A non-return claw-like protrusion is provided at the tip, and this protrusion locks the seal ring so as to control its movement in the axial direction, so the seal ring, etc. When assembling and storing parts, the elasticity of the arm allows each part to be inserted and easily assembled, and the arm can always be kept parallel to the axial direction after each part is assembled. As a result, there is no residual strain at the base of the arm that presses against the bottom of the groove of the seal ring, unlike in the past, and the inner diameter end of the protrusion at the tip of the arm is aligned with the step on the front side of the crocodile part. The contact load between the protrusion at the tip and the outer circumferential surface of the stepped portion is extremely small due to the centrifugal force acting on the tip of the arm during rotation. Therefore, the operability of the seal ring is not hindered, and it is therefore possible to maintain stable sealing performance.

[Example] Hereinafter, the present invention will be described in detail with reference to an example shown in FIGS. 1 and 2. In the illustrated embodiment of the present invention, parts having the same structure as the conventional mechanical seal shown in FIGS. 3 and 4 will be described using the same reference numerals.

In other words, the mechanical seal according to the present invention is
As shown in FIGS. 1 and 2, the casing 7 is formed of an elastic strength member made of synthetic resin, and the tip 71a of the arm 71 that integrally projects from the casing 7 in the axial direction extends linearly. A protrusion 10 in the shape of a non-return claw is provided on the inner diameter side of the distal end portion 71a, and this arm 71 is engaged in the circumferential direction with a groove 61 formed in the outer circumferential crocodile portion 6a of the seal ring 6. The inner diameter end of the protrusion 10 comes into contact with the outer peripheral surface of the stepped portion on the front side of the crocodile portion 6a to prevent the seal ring 6 from coming off from the casing 7.

Therefore, when parts such as the seal ring 6 are assembled and stored in the casing 7 via the coil spring 8 and the spring retainer 9, each part is attached to an arm 71 that integrally projects from the casing 7.
The protrusion 10 of the tip 71a of the arm 7 can be assembled and stored by forcibly pushing it up against the elasticity of the arm 7. After each part is assembled and stored, the arm 71
Since the arm 71 naturally elastically returns to its original state, the arm 71 can be maintained parallel to the axial direction at all times. Groove 6
Since the inner diameter end of the protrusion 10 at the tip of the arm 71 is in contact with the outer peripheral surface 6b of the front stepped portion of the seal ring 6, the seal ring 6 can be held concentrically. Also, during rotation, the contact load between the protrusion 10 and the outer circumferential surface 6b of the stepped portion becomes extremely small due to the centrifugal force acting on the tip 71a of the arm 71, so that the axial followability of the seal ring 6 is improved. It becomes possible to keep it in good condition.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effects of the invention] As is clear from the above explanation, according to the invention, residual strain is not generated in the base of the arm toward the inner diameter side and the arm does not come into pressure contact with the groove bottom of the groove of the seal ring.
The inner diameter end of the protrusion at the tip of the arm comes into contact with the outer peripheral surface of the front stepped part of the seal ring to hold the seal ring concentrically, and during rotation, the centrifugal force acting on the tip of the arm causes the tip to The contact load between the protrusion and the outer peripheral surface of the front step of the seal ring is extremely small, which reliably prevents the seal ring from malfunctioning and maintains stable sealing performance over long periods of operation. It has the excellent effect of being able to

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of the main parts of an embodiment of the mechanical seal according to the present invention, Fig. 2 is a perspective view of the main parts of the casing, and Fig. 3 is a schematic cross-sectional view of the main parts of a conventional mechanical seal. , FIG. 4 is a perspective view of the main part of the conventional casing. DESCRIPTION OF SYMBOLS 1... Housing, 2... Rotating shaft, 4... Mating ring (fixed ring), 6... Seal ring (rotating ring), 6a... Outer circumferential alligator part, 61... Concave groove, 7
...Casing, 71...Arm, 71a...Tip, 8...Coil spring, 10...Protrusion.

Claims (1)

[Scope of utility model registration request] A mating ring that is airtightly fixed to the inner circumference of the housing is pressed against a seal ring that is airtightly and movably fixed in the axial direction via a casing on the rotating shaft side by a coil spring housed in the casing. A mechanical seal in which an arm protruding in the axial direction from the casing is engaged with a concave groove formed in an outer circumferential crocodile portion of the seal ring to transmit rotational force to the seal ring, wherein the casing includes the arm. is made of synthetic resin, and a protrusion shaped like a non-return claw is provided at the tip of the arm, and the inner diameter end of the protrusion is brought into contact with the outer peripheral surface of the step on the front side of the alligator part. mechanical seal.