JPH064069Y2 - Mechanical booster pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a mechanical booster pump, and particularly to a mechanical booster pump designed to stabilize the sealing performance of a mechanical seal for shaft sealing.

(Prior Art) An input shaft of a vacuum pump such as a mechanical booster pump has one end protruding outside from an end plate of a casing and connected to a rotary shaft of a drive motor, and is driven and rotated by the motor. A mechanical seal is usually used as a bearing for sealing the input shaft. In addition, vacuum pump oil is usually used as the lubricating oil for bearings and timing gears, and the vacuum pump oil stored in the bottom of the casing is used to prevent oil leakage from the shaft seal to the outside. The oil level of the pump oil is set below the sliding portion of the mechanical seal. Then, attach bounce plates to both ends of the driven shaft respectively, and hook the oil surface of the vacuum pump oil by the rotation of the bounce plate to bounce up the vacuum pump oil to form bearings, timing gears, mechanical seals of the input shaft, etc. It is supplied to lubricate each sliding part.

Further, when the vacuum pump is used, the mineral lubricating oil may be deteriorated depending on the kind of the sucked gas. In such a case, a fluorine-based synthetic oil is usually used as the lubricating oil.

(Problems to be solved by the invention) However, in the mechanical booster pump having the above-mentioned conventional structure, since the splash plate is attached to the driven shaft of the pump, the vacuum pump oil is applied to the bearing of the input shaft, that is, the mechanical seal portion. It is hard to be supplied, and the shortage will occur. Furthermore, when the above-mentioned fluorine-based synthetic oil is used as the vacuum pump oil, the fluorine-based synthetic oil has poor lubricity, the oil film of the mechanical seal is broken, and the liquid tightness is reduced, and the outside air flows into the vacuum pump. There is also a problem that the sliding portion of the mechanical seal is extremely worn.

The present invention has been made in view of the above points, and reliably supplies the lubricating oil to the sliding portion of the mechanical seal to stabilize the sealing performance to ensure the sealing of the shaft sealing portion. An object of the present invention is to provide a mechanical booster pump designed to improve the durability of the mechanical seal.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, in a mechanical booster pump in which a rotary shaft is axially supported by a mechanical seal, the mating ring that constitutes the mechanical seal is An annular groove concentric with the rotating shaft is formed in the center of the end face of the mating ring facing the sealing member, and the base end communicates with the annular groove. Is provided on the outer peripheral surface and has a spiral oil passage for scooping the oil and guiding the oil to the annular groove as the mating ring rotates.

(Function) The mating ring rotates with the rotation of the rotating shaft to scoop up the oil stored in the bottom of the casing from the tip of the oil passage and guide it to the central annular groove. The oil introduced into the annular groove is Scattered by rotation of the mating ring,
Alternatively, it is supplied to each sliding portion of the mechanical seal along the wall surface. As a result, the mechanical seal is constantly supplied with sufficient lubricating oil, the sealing performance is stabilized, the seal is well secured, and the durability of the sliding portion is improved.

Embodiment An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a cross section of a main part of a mechanical booster pump to which the present invention is applied, in which an input shaft (main shaft) 2 and a driven shaft 3 of a mechanical booster pump 1 rotate on an end plate 5 of a casing 4 via bearings 6 and 7. The input shaft 2 is rotatably and liquid-tightly rotatably supported by the end plate 8 of the casing 4 via a mechanical seal 9 so as to be rotatably supported.
Projecting outward. The tip of the input shaft 2 is connected to the rotary shaft of a drive motor (not shown) via an electric motor connecting coupling 20.

The mechanical seal 9 is interposed between the holder 10 mounted and fixed in the shaft hole of the end plate 8 of the casing 4 and the shaft hole of the holder 10 and the input shaft 2 so as to rotatably support the input shaft 2. The seal member 1 is defined between the collar 11, the seal member 12 and the O-ring 13 mounted and supported on the holder 10, and the holder 10 and one end surface of the seal member 12.
2, a spring chamber 14 for pressing 2, a mating ring 15 fitted to the input shaft 2 and having a peripheral edge of a shaft hole at one end face contacting the other end face of the seal member 12 in a liquid-tight manner, and one end face at the mating ring. Collar 17 that abuts on the peripheral edge of the shaft hole on the other end surface of 15 through O-ring 16, and the other end surface abuts on the end surface of the bearing 7.
Etc.

The mating ring 1 that constitutes this mechanical seal 9.
The diameter of 5 is larger than that of the conventional mating ring, and its size is set to be approximately the same as that of the above-mentioned bounce plate. As shown in FIG. 2, the mating ring 15 has an annular groove 15c formed concentrically on the peripheral edge of the opening end that opens to the end surface 15b of the shaft hole 15a. Furthermore,
On the end surface 15b of the mating ring 15, the central annular groove 1
A spiral groove 15d extending from 5c to the outer peripheral surface is formed, the base end 15e of the groove 15d communicates with the annular groove 15c, and the tip 15f is open to the outer peripheral surface. The direction of the spiral from the base end 15e of the groove 15d toward the tip 15f is the mating ring 1 when viewed from the coupling 29 side.
When 5 rotates clockwise (clockwise) indicated by arrow C, it is set in the same direction as the rotation direction.

An annular groove 15c at the center of the mating ring 15 serves as an oil reservoir, and a spiral groove 15d takes in vacuum pump oil (hereinafter referred to as oil) stored in the casing, that is, between the end plates 5 and 8. Further, it serves as an oil passage for supplying to the annular groove 15c.

As shown in FIGS. 1 and 3, the mating ring 15 is fitted to the input shaft 2 with its end face 15b facing the seal member 12, and is rotatably mounted integrally with the input shaft 2. Then, the opening end peripheral edge 1 on the end face 15b side of the shaft hole 15a
The end surface 12a of the seal member 12 is brought into contact with a position near the inside of the 5 g annular groove 15c, and the opening end peripheral edge 15i of the shaft hole 15a on the end surface 15h side contacts the end surface of the bearing 7 via the O-ring 16 and the collar 17. Contacted. The end face 12a of the seal member 12 is a end face 12a of the mating ring 15 by a spring (not shown) defined in the spring chamber 13 defined between the holder 11 and the other end face of the seal member 12.
And the input shaft 2 is supported by the end plate 8 in a liquid-tight manner.

In the state where the mating ring 15 is attached to the input shaft 2 as described above, as shown in FIG. 2, the lower part of the mating ring 15 is a liquid surface s (indicated by a chain double-dashed line) of oil stored in the bottom of the casing. ) Is located slightly below.

The operation will be described below.

When the mechanical booster pump 1 is driven by the motor and the input shaft 2 rotates at high speed in the clockwise direction as viewed from the coupling 20 side, the mating ring 15 mounted on the input shaft 2 is indicated by an arrow C in FIG. Rotate clockwise at high speed as shown. As the mating ring 15 rotates in the clockwise direction, it scoops up the oil until the tip 15f of the spiral groove 15d is soaked in the oil until it is separated, and the inside of the groove 15d is indicated by an arrow CC. The leading end 15f to the central annular groove 15c,
Store in c.

The vacuum pump oil stored in the annular groove 15c scatters as the mating ring 15 rotates, or travels along the wall surface and is supplied to the seal member 12 of the mechanical seal 9 and each sliding portion. As a result, the mechanical seal 9 is always sufficiently supplied with oil, and as a result, good lubricating performance can be maintained.

In the above embodiment, the spiral oil passage formed in the mating ring 15 is described as a simple groove, but the groove is not limited to this, and the groove may be covered or replaced with a groove. A pipe may be used, and with such a structure, oil can be more reliably supplied to the central annular groove 15c (oil sump).

(Effects of the Invention) As described above, according to the present invention, it is possible to always supply a sufficient amount of oil to the sliding portion of the mechanical seal, which can greatly improve the sealing performance of the mechanical seal. In addition to being possible, the durability of the sliding portion can be improved. In addition, the mating ring, which is a component of the mechanical seal, can be achieved by slight processing, and has an excellent effect that the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing an embodiment of a mechanical booster pump according to the present invention, FIG. 2 is an end view of the mating ring of FIG. 1, and FIG. 3 is a mechanical seal of FIG. FIG. 1 ... Mechanical booster pump, 2 ... Input shaft, 3 ... Driven shaft, 4 ... Casing, 5, 8 ... End plate, 6, 7 ... Bearing, 9
... Mechanical seal, 12 ... Seal member, 15 ... Mating ring, 17 ... Color.

Claims (1)

[Scope of utility model registration request] 1. A mechanical booster pump in which a rotary shaft is supported by a mechanical seal, wherein a lower part of a mating ring forming the mechanical seal is formed so as to be immersed in oil stored in a casing, and the mating ring is formed. An annular groove concentric with the rotating shaft at the center of the end surface facing the seal member of the ring, the base end communicates with the annular groove, the tip opens to the outer peripheral surface, and the oil is transferred along with the rotation of the mating ring. A mechanical booster pump, comprising: a spiral oil passage that is picked up and guided to the annular groove.