JPS6118068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of mechanical seals, and more specifically, by providing a required narrow groove on the sliding surface of the seat ring or driven ring, which is a component of the mechanical seal, it has excellent lubricity and no leakage. The purpose is to provide mechanical seals.

Conventionally, the configuration of a widely known mechanical seal is to prevent fluid leakage by applying pressure between the sliding surfaces of the seat ring and the driven ring. A cut having a certain directionality is formed, and leakage of fluid is prevented by the pumping action of the cut as the sliding surface rotates in sliding contact. However, in this prior art, no consideration is given to the lubrication effect of the fluid between the sliding surfaces, which leaves problems with the shaft sealing performance of the mechanical seal during long-term use. Ta.

In view of the above points, the present invention focuses on the viscous effect of fluid, and also provides a required number of narrow grooves on the sliding surface of a seat ring or driven ring, which are components of a mechanical seal, and slides both ends of the narrow grooves into sliding contact. An internally pressurized mechanical seal for reaching the outer peripheral end and the inner peripheral end of the surface, tilting the direction of the narrow groove forward and backward in the direction of relative rotation, and performing a pumping action in the narrow groove. Due to the structure in which narrow grooves are predominantly provided at the front in the direction of relative rotation, and in the case of externally pressurized mechanical seals at the rear, fluid is once sucked between the sliding surfaces during sliding rotation. By discharging the fluid to the suction side again through the thin grooves that handle the pumping action instead of using the same flow path without causing any leakage to the side opposite to the suction side, excellent lubricity between the sliding surfaces and zero leakage are achieved. It is intended to provide a mechanical seal against leakage. Another object of the present invention is to provide a mechanical seal having the above-mentioned structure excellent in shaft sealing performance in large quantities at a low price since it can be produced extremely easily.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes an externally pressurized mechanical seal whose main parts are shown enlarged, and a seat ring fixed to a housing 2. 3 and the driven ring 5, which is fixed to the rotating shaft 4 inserted through the seat ring 3 and rotates together with the rotating shaft 4, leakage of the fluid A sealed in the outer periphery of the mechanical seal 1. The sliding surface 6 of the driven ring 5 is provided with a narrow groove 7 that is inclined rearward in the diametrical direction of the sliding surface 6 with respect to the rotational direction (arrow B) of the driven ring 5. Also, thin grooves 7', which also slope forward, are provided so that their ends reach the outer circumferential end 6' and the inner circumferential end 6'' of the sliding surface 6, and intersect with each other. The narrow grooves 7...7'... are provided so that the narrow grooves 7... which are inclined rearward are predominant.

In the present invention having the above configuration, the fluid A
As shown in FIG. 3, due to the rotating direction of the sliding surface 6 and its viscous action, it is sucked into the forward-sloping narrow grooves 7', and moves while being retained in the narrow grooves 7'. (in the direction of arrow C), the sliding surface 6 of the driven ring 5 and the sliding surface 8 of the seat ring 3 are lubricated. As a result, the fluid A moved along the narrow grooves 7'...
At the point where the forward-sloping narrow groove 7'... and the backward-sloping narrow groove 7 intersect, it transitions to the backward-sloping narrow groove 7..., and the inner circumferential end 6 of the sliding surface 6 Therefore, in the present invention, the forward-sloping narrow grooves 7' and the backward-sloping narrow grooves 7 are used as sliding surfaces. 6,
8, that is, so that the discharge capacity of the rearwardly inclined narrow grooves 7 exceeds the suction capacity of the forwardly inclined narrow grooves 7'... It is sufficient that the number, shape, direction, etc. of the narrow grooves 7 are provided as dominantly as possible. In this case, in order to completely stop leakage when the mechanical seal 1 is stopped, the narrow groove 7...
It is necessary to prevent the narrow grooves 7...7'... from being affected by 0.2 to 7'...
The goal is achieved by finishing within 0.7μ.
In addition, if a certain amount of leakage is allowed, the narrow groove 7...
...7'... is allowed to be about 1.0 to 3μ, and a normal sealing effect can be obtained within this range. Therefore, the diameter of the narrow grooves 7...7' is controlled within the range of 0.2 to 3μ depending on the purpose.
Further, the thin grooves 7...7' having the above-mentioned directionality
. . . is provided by a photoedge method, a laser processing method, an electrolytic processing method, or a special lap method.
Furthermore, the narrow grooves 7...7' do not necessarily have to be curved as shown in FIG. 2, but may be straight as shown in FIG. In the above embodiment, the sliding surface 6 of the driven ring 5 is provided with the narrow grooves 7...7'... having the above configuration, but the narrow grooves 7...7'... are provided in the seat ring. 3 sliding contact surface 8
In this case, the seat ring 3
The narrow grooves 7 inclined rearward in the diametrical direction of the sliding surface are predominant with respect to the relative rotational direction.

FIG. 5 shows another embodiment of the present invention. In contrast to the first embodiment, which is an externally pressurized mechanical seal, an internally pressurized mechanical seal has thin grooves 7a...7'a. This shows the configuration of the seat ring or driven ring 5.
The narrow grooves 7'a, which are inclined forward in the diametrical direction of the sliding surface, are predominant with respect to the relative rotational direction of a.

The present invention has the above-mentioned configuration, and by providing the necessary sliding surfaces of the seat ring or driven ring of a mechanical seal, fluid is once sucked between the sliding surfaces to perform a lubricating action and achieve the above-mentioned effects. The fluid can be discharged to the suction side again without leaking to the side opposite to the suction side, smoothing the movement of fluid between the sliding surfaces and preventing air entrainment, which was a problem with conventional technology. A mechanical seal with excellent lubricity between sliding surfaces can be provided. In addition, the present invention can increase the amount of heat transferred from the sliding surfaces by suction and discharge of the fluid between the sliding surfaces, and can have a higher PV value with the same material as the conventional technology. This mechanical seal with excellent lubricity and shaft sealing properties can be provided in large quantities at low cost, and its practical effects are extremely significant.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is an enlarged front sectional view of the main part showing the installed state of the mechanical seal of the present invention, and FIGS. 2 and 4 show the driven ring sliding in the mechanical seal of the present invention. FIG. 3 is a front view of the contact surface, FIG. 3 is an enlarged view of the same essential part showing the state of fluid movement, and FIG. 5 is a front view of the sliding contact surface of the driven ring showing another embodiment of the present invention. 1... Mechanical seal, 2... Housing,
3... Seat ring, 4... Rotating shaft, 5, 5a...
...Followed ring, 6, 8...Sliding surface, 7, 7', 7
a, 7'a...Small groove.

Claims (1)

[Claims] 1. In a mechanical seal that prevents fluid leakage by sliding contact between a seat ring fixed to a housing and a driven ring fixed to a rotating shaft inserted through the seat ring and rotating together with the rotating shaft, the above-mentioned seat ring A required number of thin grooves are provided on the sliding surface of the ring or the driven ring so that both ends thereof reach the outer and inner peripheral ends of the sliding surface and whose directions are inclined forward and backward in the direction of relative rotation. A mechanical seal characterized in that, among the narrow grooves, narrow grooves in the direction of relative rotation for performing a pumping action are predominant.