JPH11248007A - High speed rotating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perfectly prevent backflow of oil by using a magnetic material on a shaft side part of a sealing mechanism, burying magnetic on housing side parts facing against each other and injecting magnetic fluid in a clearance part of the sealing mechanism. SOLUTION: When an electric motor 4 is driven and a shaft 2 and a rotary vane 1 rotate at high speed, oil permeates up through an oil passageway 23 by a centrifugal pump 25. The permeated up oil runs in the centrifugal direction from oil passageways 24a, 24b and flows out of the shaft 2. The flown out oil is supplied to roller bearings 3a, 3b, lubricates them, drops downward and is recovered in an oil reservoir 22. A part of the oil exists in an atomized state in a clearance between the shaft 2 and a housing 5, but, as a gas compression chamber 51 and a bearing holding chamber 52 are blocked from each other by magnetic fluid 63, it is possible to perfectly prevent leakage of atomized lubricating oil to a gas compression part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed rotary drive device, and more particularly to a gas circulation blower such as a turbo blower, an axial fan, and a roots blower, or a vacuum exhaust device such as a dry pump and a turbo molecular pump.

[0002]

2. Description of the Related Art In general, rolling bearings are used for shafts of equipment which is driven to rotate at high speed. However, when a contact type bearing such as a rolling bearing is used, oil lubrication is required. Particularly, in a device that rotates continuously, a mechanism is provided such that oil is forcibly supplied to the bearing portion.

[0003] Japanese Patent Application No. 9-30908 filed by the same applicant as one having such a forced oil supply mechanism is provided.
There is a turbo blower described in No. 4. This is provided with an oil supply passage extending from the lower end of the shaft through the inside of the shaft to the vicinity of the bearing, and the lower end of the shaft is immersed in an oil reservoir, and the oil is sucked up by a centrifugal pump and the vicinity of the bearing is passed through the oil supply passage. The lubrication is performed by spraying the oil from the oil outlet hole provided on the bearing.

In such a high-speed rotating device, a non-contact seal mechanism such as a labyrinth seal is provided around the upper end of the shaft so that the sprayed oil vapor does not flow back to the rotor blade connected to the upper end of the shaft. Have been.

[0005]

However, a non-contact seal mechanism such as a labyrinth seal can reduce the backflow of the oil even though it can reduce the backflow of the oil. There was a problem of backflow on the rotor side.

Accordingly, an object of the present invention is to provide a high-speed rotating device which completely prevents the backflow of oil.

[0007]

According to the present invention, there is provided a high-speed rotating apparatus according to the present invention, wherein an oil reservoir and a rotary wing are attached to an upper end and a lower end is immersed in the reservoir. Further, a shaft rotatably held by a bearing at an intermediate portion between an upper end and a lower end, and an oil formed so that oil can be supplied to the bearing through a shaft from a centrifugal pump mechanism provided at a lower end of the shaft. Path, and a rotation driving means for the shaft, so that the bearing can be lubricated by raising the oil in the oil path by centrifugal force due to the rotation of the shaft,
A high-speed rotating device provided with a seal mechanism between an upper end of a shaft and a bearing, wherein a magnetic material is used on a shaft side of the seal mechanism, and a magnet is embedded in an opposing housing side and a magnet is formed in a gap portion of the seal mechanism. The fluid is inserted.

With this configuration, the bearing side and the rotor blade side can be completely shielded without impeding rotation due to the presence of the magnetic fluid, and oil backflow can be prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a configuration diagram of a turbo blower as a high-speed rotating device showing one embodiment of the present invention, and FIG. 2 is an enlarged view of a main part thereof.

The turbo blower 100 has a housing 5
A rotating blade 1, a shaft 2 on which the rotating blade 1 is mounted, and rolling bearings 3 a and 3 b for rotatably supporting the shaft 2;
And an electric motor 4 for rotating a shaft.

The housing 5 has a gas compression chamber 51 containing the rotary blade 1 and a bearing holding chamber 52 provided continuously from the lower end of the gas compression chamber 51 and into which the shaft 2 is loosely fitted. The gas compression chamber 51 includes a gas introduction port 53 that opens toward the top of each rotor 1 and a gas outlet port 54 that opens to the side of the rotor 1.

The bearing holding chamber 52 supports a motor mounting portion 55 provided near the center thereof for supporting the electric motor 4 and the rolling bearings 3a and 3b mounted above and below the motor mounting portion 55, respectively. Bearing support 56,
An oil reservoir 22 provided on the lower end side.

A gas compression chamber 51 and a bearing holding chamber 52
Are separated by a seal mechanism 6 described later.

The rotary wing 1 is generally used in which a plurality of wing bodies 12 are spirally attached to a slope of a frustoconical base.

The upper end of the shaft 2 is connected to the rotor 1,
The lower end is immersed in the oil in the oil reservoir 22. Oil passages 23, 24a and 24b are provided in the shaft, and the lower end of the oil passage 23 is tapered to constitute a centrifugal pump 25 for sucking up oil.

The rolling bearings 3a and 3b are supported by a bearing support portion 56. The rolling bearing 3a is lubricated by oil sprayed from the oil passage 24a, and the rolling bearing 3b is rotated by oil sprayed from the oil passage 24b.
Is lubricated.

The electric motor 4 has a rotor 41 fixed to the shaft 2 by being externally fitted to the shaft 2 and a stator 42 provided around the rotor 41 by the housing 5.
It is a C type, which is provided integrally with the shaft 2 and directly drives the shaft 2. In the present embodiment, the electric motor 4 is controlled by the inverter 43,
High-speed rotation drive at pm.

As shown in the enlarged view of FIG. 2, a seal mechanism 6 for separating between the gas compression chamber 51 and the bearing holding chamber 52 has several levels of irregularities made of a magnetic material on the outer surface of the shaft 2. The fins 61 are attached, and the magnets 62 are embedded in the housing 5 facing the fins 61. Then, the gap between the fin 61 and the housing 5 is made several tens of microns, and the magnetic fluid 63 is attached to this gap. The magnetic fluid 63 is held by the fins 61 and the magnets 62 embedded in the housing 5.

Therefore, the rolling bearing side and the rotor blade side are completely shut off by the magnetic fluid 63.

When the electric motor 4 is driven to rotate the shaft 2 and the rotary blade 1 at a high speed, the oil is pumped upward along the oil passage 23 by the centrifugal pump 25. The pumped oil flows from the oil passages 24a and 24b in the centrifugal direction and flows out of the shaft 2. The oil that has flowed out is supplied to the rolling bearings 3a and 3b to lubricate the oil, and then falls downward and is collected in the oil reservoir 22. Although a part of the oil exists in a spray state in the gap between the shaft 2 and the housing 5, since the magnetic fluid 63 blocks the space between the gas compression chamber 51 and the bearing holding chamber 52, the spray-like lubricating oil Can be completely prevented from leaking into the gas compression section.

Although the present embodiment is a turbo blower, the present invention is not limited to this, and can be applied to any machine such as a turbo molecular pump as long as it is a turbo machine using a rolling bearing for lubricating oil.

In the case of a high vacuum or a high pressure, a mechanism for controlling the pressure in the motor drive unit is provided if necessary. However, the present invention is effective even in such a case.

[0023]

As described above, according to the present invention,
Since the seal mechanism using the magnetic fluid is provided between the upper end of the shaft and the bearing, the gap can be completely blocked by the magnetic fluid, and the backflow of the oil can be completely prevented.

Further, since pressure sealing can be performed by the magnetic fluid, it is not necessary to control the pressure inside the rotary drive unit under the atmospheric pressure environment even when the gas compression unit is under a low pressure environment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a turbo blower according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a seal mechanism of the turbo blower of FIG.

[Explanation of symbols]

 1: Rotary blade 2: Shaft 3a, 3b: Rolling bearing 4: Electric motor 5: Housing 6: Seal mechanism 61: Fin 62: Magnet 63: Magnetic fluid

Claims (1)

[Claims] An oil storage section, a shaft having a rotating blade attached to an upper end thereof, a lower end immersed in the storage section, and further rotatably held by a bearing at an intermediate portion between the upper end and the lower end; An oil passage formed so that oil can be supplied to the bearing through a shaft from a centrifugal pump mechanism provided at the lower end of the shaft, and a shaft rotation driving means, and the oil is centrifugally generated by the rotation of the shaft. A high-speed rotating device provided with a seal mechanism between the upper end of the shaft and the bearing while allowing the bearing to be lubricated by raising the oil in the path, using a magnetic material for the shaft side portion of the seal mechanism, A high-speed rotating device characterized in that a magnet is embedded in the opposing housing-side portion and a magnetic fluid is inserted in a gap portion of the seal mechanism.