JPH0223836Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mechanical booster pump that is widely used in various industrial equipment fields that require vacuum evacuation.

[Prior Art] Conventionally, mechanical booster pumps of this type as shown in FIGS. 3 and 4 are known. That is, this device has an oval-shaped casing c with oil storage chambers a and b adjacent to each other on both sides and a suction port s and a discharge port t on the peripheral wall, and an eyebrow-shaped rotor e supported on an input shaft d. , an eyebrow-shaped rotor g supported by a driven shaft f is housed with a phase difference of 90°, and one end of the input shaft d and the driven shaft f is provided on one side wall h of the casing c. Storage chamber a
The timing gears i and j extend inward and are connected by timing gears i and j. The other end of the input shaft d is connected to the other side wall k of the casing c and the second oil storage chamber b.
By penetrating the pump and projecting it to the outside, and rotating its discharge end by the motor 1, a well-known pump function can be performed. In such a mechanical booster pump, the input shaft d and the driven shaft f are supported by bearings m and n provided on both side walls h and k of the casing c, and the input shaft d is supported on the side wall k and the driven shaft f. A vacuum seal mechanism p using an oil seal type is provided at a portion that penetrates the oil storage chamber b of No. 2 and projects to the outside to isolate the inside and outside of the casing c. Then, each of the timing gears i and j and the bearing m on this gear side are lubricated with the lubricating oil q in the first oil storage chamber a, and the vacuum seal mechanism p and the bearing n on this seal side are lubricated. Said second oil storage chamber b
The lubricating oil r inside is supplied.

[Problems to be solved by the invention] However, when the oil seal type vacuum seal mechanism p is used in this way, the lubricating oil r in the second oil storage chamber b passes through the input shaft d. It is difficult to reliably prevent oil from leaking to the outside, and most of the maintenance is related to this oil leakage. In addition, the oil-lubricated seal mechanism p has a relatively short life of 2000 to 5000 hours, for example,
There is a problem in that it is difficult to adopt this method in important manufacturing processes because of the risk of product trouble.

The present invention aims to eliminate all such inconveniences.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a mechanical booster pump in which a rotor supported by an input shaft and a rotor supported by a driven shaft are housed in a casing. , one end of the input shaft and the driven shaft extend into an oil storage chamber adjacent to the outside of one side wall of the casing and are connected by a timing gear, and the other end of the input shaft is connected to the other side wall of the casing. The input shaft and the driven shaft are supported by grease-filled or oil-free bearings provided on the side wall of the casing, and the input shaft extends through the side wall of the casing. The casing is characterized in that a magnetic fluid seal mechanism is provided in the casing to separate the inside and outside of the casing.

[Function] With this configuration, there is no need to provide an oil storage chamber on the input shaft leading-out side of the casing, so it is possible to prevent the lubricating oil in the oil storage chamber from leaking to the outside through the input shaft. can be lost. Moreover, since the inside and outside of the casing are isolated by the magnetic fluid sealing mechanism, there is no risk of deterioration in evacuation performance even if the oil storage chamber on one side is omitted.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

As shown in FIG. 3, this mechanical booster pump has a cocoon-shaped rotor 3 supported on an input shaft 2 and a cocoon-shaped rotor 5 supported on a driven shaft 4 in a casing 1 at a 90-degree angle to each other. ° The input shaft 2 and the one end 2 of the driven shaft 4 are housed with different phases.
a, 4a extend into an oil storage chamber 6 adjacent to the outside of one side wall of the casing 1 and are connected by timing gears 7, 8, and the input shaft 2
The other end 2b passes through the other side wall of the casing 1 and projects to the outside.

The casing 1 includes a peripheral wall 11 having an oval cross section;
A side wall 12 that closes the openings at both ends of the peripheral wall 11;
13 are airtightly joined via a seal 14, and the peripheral wall 11 is provided with an inlet and an outlet (not shown). And the side wall 1
2 and 13 are provided with bearing holding holes 15, and the input shaft 2 and the driven shaft 4 are rotatably supported by grease-filled ball bearings 16 provided in the holding holes 15. Note that labyrinth seals 18 are provided between these ball bearings 16 and a pump chamber 17 formed inside the casing 1, respectively.

Further, a cylindrical portion 21 that is continuous with the bearing holding hole 15 is integrally provided on the side wall 13 at a portion where the input shaft 2 protrudes to the outside. A magnetic fluid seal mechanism 22 is provided to isolate the . As shown in FIG. 3, the magnetic fluid sealing mechanism 22 includes a cylindrical permanent magnet 23 hermetically fitted to the inner periphery of the cylindrical portion 21 via a sealing material 20, and a permanent magnet 23 to the outer periphery of the input shaft 2. A plurality of annular protrusions 24 are formed in parallel at a predetermined pitch, and a magnetic fluid 25 is interposed between the outer periphery of each of these annular protrusions 24 and the inner periphery of the permanent magnet 23. be.

In addition, 26 is a frame 2 attached to the casing 1.
The output shaft 29 of this motor 26 is connected to the input shaft 2 of this mechanical booster pump through a shaft coupling 31. Further, reference numeral 32 denotes an oil splashing blade for supplying the lubricating oil 33 in the oil storage chamber 6 to the timing gears 7 and 8.

With such a configuration, the motor 2
6 to rotate the input shaft 2,
Since the rotation of the input shaft 2 is also transmitted to the driven shaft 4 via the timing gears 7 and 8, both rotors 5 rotate at the same speed in opposite directions and perform the well-known pump function. In this pump, only the timing gears 7 and 8 are lubricated by the lubricating oil 33 stored in the oil storage chamber 6.
Oil leakage can be effectively prevented. That is, in this pump, the input shaft 2 and the driven shaft 4 are supported by a grease-filled bearing 16, and the portion of the input shaft 2 that protrudes outside is sealed by a magnetic fluid seal mechanism 22 that does not require lubricating oil. Therefore, there is no need to provide any oil storage chamber on the side of the casing 1 where the magnetic fluid seal mechanism 22 is provided. Therefore, oil leakage, which has been a problem in the past, can be reasonably and reliably prevented, and maintenance can be facilitated. Moreover, since the magnetic fluid sealing mechanism 22 performs shaft sealing by filling the gap with the magnetic fluid 25, it is possible to exhibit high sealing performance, but the sealing performance may deteriorate due to wear or the like. There is no such problem, and the desired evacuation performance can be maintained for a long period of time. Specifically, for example, the durability of the vacuum seal part
It is possible to dramatically improve the speed to 10,000 to 15,000 hours. Further, the magnetic fluid seal mechanism 22
Since this type does not create a seal by sliding solid objects together, it has less frictional resistance than conventional oil seal types. Therefore, it is possible to effectively prevent heat generation, and there is also an effect that less driving force is required and the capacity of the motor 26 can be reduced.

In addition, although the said Example demonstrated the case where the casing supported the motor which drives an input shaft, this invention is not necessarily limited to such a structure.

Further, the bearing is not limited to a grease filled type, but may be a non-lubricated type.

[Effects of the invention] Since the present invention has the above-described structure, it is possible to reasonably and reliably prevent the inconvenience of oil leaking from the shaft sealing part of the input shaft. It is possible to provide a mechanical booster pump that can maintain vacuum sealing performance over a long period of time, and can operate with high efficiency by suppressing heat generation and unnecessary power consumption.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention;
FIG. 2 is an enlarged sectional view showing main parts in the same embodiment. FIG. 3 is a schematic sectional view corresponding to FIG. 1 showing a conventional example, and FIG. 4 is a sectional view taken along the - line in FIG. 1... Casing, 2... Input shaft, 3... Rotor, 4... Driven shaft, 5... Rotor, 6... Oil storage chamber, 7, 8... Timing gear, 12, 13...
Side wall, 16...bearing, 18...labyrinth seal, 22...magnetic fluid seal, 33...lubricating oil.

Claims (1)

[Scope of utility model registration request] A rotor supported by an input shaft and a rotor supported by a driven shaft are housed in a casing, and one ends of the input shaft and the driven shaft are extended into an oil storage chamber adjacent to the outside of one side wall of the casing. A mechanical booster pump, wherein the input shaft and the driven shaft are connected to each other by a timing gear, and the other end of the input shaft extends through the other side wall of the casing and projects to the outside. Supported by grease-filled or oil-free bearings installed on the side wall of the
In the side wall penetrating portion of the input shaft, inside the casing,
A mechanical booster pump characterized by having a magnetic fluid seal mechanism that isolates the outside.