JPS62110079A - Shaft sealing device for supercharger - Google Patents

Abstract

PURPOSE:To reduce the contact resistance between a follower ring and a seat ring by shifting the parting direction at the time of manufacture of an O-ring from the diametral direction so that the flash developed along the parting surface may not interfer with the sliding surface. CONSTITUTION:The parting direction of an O-ring 1 has an angle to the axial direction, and the direction in which flashes 2 are developed is shifted from the inner and outer diametral direction. When a mechanical seal is assembled, the O-ring 1 is flattened in the diametral direction by a case 3 and a follower ring 4 so as not to case leakage. The follower ring 4 is depressed by a spring 5 to a seat ring 6, and even if any wear occurs on the contact surface 7 between the follower ring 4 and the seat ring 6, the securement of the contact surface can be enabled.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an O-ring used in a mechanical seal for a supercharger, and particularly to an O-ring structure that has low sliding resistance ('b) and excellent leakage characteristics. Concerning the direction of mold division during production.

[Conventional technology]

The conventional mechanical seal for turbochargers was developed in 1984.
As described in Publication No. 329 and Japanese Utility Model Application Publication No. 59-114425, only OIJ song sealing performance is emphasized, and sliding resistance is not considered.

[The problem that the invention is trying to solve]

The above conventional technology emphasizes leakage characteristics and ensures sufficient OIJ song crushing allowance, but does not consider the sliding resistance of the O ring sandwiched between the case and the driven ring. The spring force pressing against the seat ring is greatly affected by the sliding resistance of the OIJ song.
If you lower the spring force, there are six dangers that may cause malfunction in the axial direction.

Also, if the crushing allowance of the O-ring is made smaller, the sliding resistance will be lowered, but there is a risk that the sealing performance will deteriorate due to burrs that occur in the direction of mold division, which occur on the inner and outer diameters of the OIJ song.

Therefore, the spring force that presses the driven ring against the seat ring cannot be lowered, and the low-speed boost pressure characteristics of the turbocharger are said to be worse than non-contact type shaft sealing devices due to the sliding resistance between the driven ring and the clutch. There was a problem.

An object of the present invention is to reduce the contact resistance between the driven ring and the seat ring in order to improve the low-speed supercharging characteristics of a supercharger.

[Means for solving problems]

The above purpose is to reduce the crushing allowance of the O-ring that is installed in the mechanical seal and seals between the driven ring and the case, thereby lowering the spring force that presses the driven ring against the seat ring, and reducing the crushing allowance of the OIJ song. This is achieved by eliminating the influence of burrs that occur in the inner and outer radial directions during the production of the O-ring, so that no leakage occurs even if the O-ring is made.

[Effect]

The burrs that are created during the production of the 0-ring occur along the cutting surface of the mold. Furthermore, the sliding resistance of the O-ring is determined by the crushing amount in the radial direction. Therefore, even if the crushing allowance is reduced by making sure that the molding surfaces do not overlap with the inner and outer radial directions when making the O-ring and creating a structure that prevents the generated burrs from hitting the sliding parts, the leakage characteristics will worsen. There isn't.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

Conventionally, the die side direction of the O-ring 1 is the axial direction as shown in FIG. 3, and burrs 2 are generated in the inner and outer radial directions along the die dividing surface. However, according to the present invention, as shown in FIG.
Since the mold dividing direction of the ring is at an angle with the axial direction, the direction in which the burr 2 is generated deviates from the inner and outer radial directions.

When assembled into a mechanical seal, the O-ring 1 is crushed in the radial direction by the case 3 and the driven ring 4 to prevent leakage. The driven ring 4 is pressed against the seat ring 6 by a spring 5, and is structured to ensure a contact surface even if the contact surface 7 between the driven ring 4 and the seat ring 6 is worn out. When a conventional O-ring is used, the direction of the burr 2 and the crushing direction both overlap in the radial direction, so it is necessary to increase the crushing margin to prevent deterioration of sealing performance due to the burr 2. On the other hand, in the case of the OIJ song of the present invention, the crushing direction is the same radial direction as in the conventional case, but since the direction in which burrs are generated is shifted from the radial direction, it is possible to reduce the crushing allowance without degrading the sealing performance. can.

The sliding resistance between the driven ring 4 and the case 3 due to the O-ring 1 increases as the crushing amount increases, and the variation in the sliding resistance also increases as the crushing amount increases.

Therefore, the spring 50 set load is 0 to the surface pressure required on the contact surface 7.
Although it is assumed that the sliding resistance of 1 J ng 1 is added, the conventional OI
When J-song is used, there is a large variation in sliding resistance, so for safety reasons, it is necessary to increase the set load of the spring 5 by the variation in heart motion resistance. It was much larger than that. When using the O-ring of the present invention, since the variation in sliding resistance is small, the variation in sliding resistance taken into account for the 50-set load of springs is small, and on average the contact pressure on the contact surface 7 can be brought close to the designed 1st shift. be able to.

Therefore, according to the present invention, the driven ring 4 and the seat ring 6
By reducing contact resistance with the supercharger and mechanical loss of the supercharger, it was possible to improve supercharging pressure characteristics during low-speed engine operation.

〔Effect of the invention〕

According to the present invention, the mechanical loss of the supercharger can be reduced by reducing the contact resistance of the mechanical seal, so the supercharging pressure characteristics are particularly high when the engine is operating at low speed and the power obtained by the turbine is small. This has the effect of making it comparable to a supercharger using a non-contact shaft sealing device.

[Brief Description of the Drawings] Fig. 1 is a sectional view of an O-ring showing an embodiment of the present invention, Fig. 2 is a sectional view of a mechanical seal showing an embodiment of the present invention, and Fig. 3 is a sectional view of a mechanical seal showing an embodiment of the present invention. FIG. 1... O'Jing, 2... Burr, 3... Case,
4... Driven ring, 5... Spring, 6... Seat ring, 7... Contact surface. ￥1 Figure 'FJ2 Figure 13 Figure

Claims (1)

[Claims] 1. A seat ring that rotates together with the rotating shaft, a driven ring that has one end in contact with the seat ring and is biased by a spring in a direction that generates surface pressure on the contact surface, and is provided between the driven ring and the case; In a mechanical seal constituted by an O-ring that is crushed in the radial direction and has a sliding surface between the case and the driven ring, the sliding surface seals between the case and the driven ring. A shaft sealing device for a supercharger, characterized in that the direction of mold division during ring production is shifted from the radial direction so that burrs generated along the mold division surface do not interfere with the sealing sliding surface.