JP2001271992A - Bearing lubricating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a sufficient quantity of a lubricating oil to a bearing by a small-sized substituting means when a motor-driven pump is stopped due to abnormality. SOLUTION: When a machine tool is operated normally, the motor-driven pump 7 supplies the lubricating oil from a tank 1 through an oil feeding pipe 3 to a main spindle unit 2. When the motor-driven pump 7 is stopped due to abnormal condition such as power failure or the like, an electromagnetic switch device 23 is opened to demagnetize a solenoid valve 8, so that an air driving pump 11 is connected to an air source 9. Thus, the air driving pump 11 is immediately started instead of the motor-driven pump 7 to supply the lubricating oil from the tank 1 through a substituting pipe 13 and the oil feeding pipe 3 to the main spindle unit 2, thereby lubricating a main spindle bearing until the main spindle is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for lubricating a bearing.

[0002]

2. Description of the Related Art For example, in a main spindle unit of a machine tool, lubricating oil is normally supplied to a main spindle bearing by using an electric pump. When the rotation is stopped, the supply of the lubricating oil is stopped during the inertial rotation of the main shaft, so that the lubricating oil temperature rises rapidly, which may cause damage to the bearing. Therefore, conventionally, as shown in FIG. 2, the accumulator 5 is connected to the oil supply pipe 3 between the tank 1 and the main shaft unit 2, and when the electric pump 7 stops abnormally, the accumulator 5 substitutes the electric pump 7 for lubrication. There has been proposed a bearing lubrication device configured to supply oil to a main shaft bearing (not shown).

[0003]

However, according to the conventional bearing lubrication system, it is necessary to store a large amount of lubricating oil in the accumulator 5 in case of a power failure or the like when the main shaft is rotating at high speed. For this reason, the volume of the accumulator 5 increases, and especially in the case of a hydrostatic bearing, the accumulator 5 having a large volume is used.
Therefore, there is a problem that the size of the lubricating device is increased.

It is an object of the present invention to provide a bearing lubricating device that can supply a sufficient amount of lubricating oil to a bearing by a small substitute means when the electric pump stops abnormally.

[0005]

In order to solve the above problems, a bearing lubricating apparatus according to the present invention provides an electric pump for supplying lubricating oil to a bearing, and supplies lubricating oil to the bearing in place of the electric pump. It comprises an air-driven pump and control means for activating the air-driven pump when the electric pump stops abnormally.

In the bearing lubrication device of the present invention,
The control means includes a detector for detecting abnormal stop of the electric pump and an air-driven pump connected to the air source in response to the operation of the detector so that the air-driven pump can be started immediately when the electric pump abnormally stops. And a solenoid valve for communication.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a spindle unit 2 of a machine tool.
FIG. 1 shows a device for lubricating a main shaft bearing (not shown) provided in the present invention. The bearing lubrication device of this embodiment is configured such that the lubricating oil is supplied to the tank 1 by the electric pump 7 during normal operation of the machine tool.
The oil is supplied to the spindle unit 2 through a refueling pipe 3 and passed through a bearing gap of the spindle bearing, and then returned to the tank 1 through a drain pipe 4.

The bearing lubricating apparatus of this embodiment is provided with an air drive pump 11 which supplies lubricating oil to the main shaft bearings in place of the electric pump 7 when the electric pump 7 stops abnormally due to a power failure or the like. I have. The air drive pump 11 is connected via an air pipe 12 to an air source 9 in the factory which operates even in the event of a power outage, and is connected via a substitute pipe 13 to the tank 1 and the refueling pipe 3. An electromagnetic valve 8 and an on-off valve 15 are provided on the air pipe 12, and the electromagnetic valve 8 communicates or shuts off the air drive pump 11 with the air source 9 when the on-off valve 15 is open. In addition, lubrication piping 3
A check valve 14 for preventing a reverse flow of the lubricating oil at the time of abnormality is provided above.

On the other hand, an electric circuit of the bearing lubrication device includes a main switch 22 for selecting operation or stop of the electric pump 7.
And an electromagnetic switch 23 as a detector for detecting an abnormal stop of the electric pump 7. The electromagnetic switch 23 and the electromagnetic valve 8 constitute control means of the air-driven pump 11. When the electric pump 7 stops abnormally due to a power failure or the like, the electromagnetic switch 23 opens and disconnects the electromagnetic valve 8 from the power supply 21. The electromagnetic valve 8 is demagnetized to connect the air drive pump 11 to the air source 9, and the air drive pump 11 is started immediately.

When operating the bearing lubrication device having the above-described configuration, the main switch 22 is turned on and the on-off valve 15 is opened.
Then, the electromagnetic valve 8 is excited, and the air drive pump 11 is shut off from the air source 9. Then, while the air drive pump 11 is stopped, the electric pump 7 is started, and lubricating oil is supplied from the tank 1 to the main spindle unit 2 through the oil supply pipe 3,
The main shaft bearing is lubricated by the lubricating oil. To stop the operation of the lubrication device, the on-off valve 15 is closed and the main switch 22 is turned off.

When the electric pump 7 stops abnormally due to a power failure during lubrication, the electromagnetic switch 23 is opened, the electromagnetic valve 8 is demagnetized, and the air drive pump 11 is connected to the air source 9. As a result, the air-driven pump 11 is immediately started in place of the electric pump 7, and the lubricating oil is supplied from the tank 1 to the spindle unit 2 through the substitute pipe 13 and the oil supply pipe 3, and the lubricating oil is supplied until the spindle stops. The main shaft bearing is lubricated by the oil.

Therefore, according to the bearing lubrication apparatus of this embodiment, even if the electric pump 7 stops abnormally while the main shaft is rotating at a high speed, a sufficient amount of lubricating oil is supplied to the main shaft unit 2 by the air drive pump 11. By supplying, it is possible to reliably prevent the spindle bearing from being damaged. The electric pump 7
The air-driven pump 11 which is a substitute means of the above is smaller in size and less limited in supply time as compared with the accumulator,
The lubricating device can be made compact and can be adapted to the high-speed spindle unit 2 of the machine tool. In particular, when a hydrodynamic bearing is used for the main shaft bearing, the supply pressure of the lubricating oil is lower than that of the hydrostatic bearing, so that there is an advantage that a smaller air-driven pump 11 can be used.

The present invention is not limited to the above embodiment. For example, an abnormal stop of the electric pump can be detected by a detector attached to the pump, or the lubricating device can be mounted on bearings of various machines other than the spindle unit. It is also possible to change the shape and configuration of each part as appropriate without departing from the spirit of the present invention, for example, by applying the present invention.

[0014]

As described above in detail, according to the bearing lubricating apparatus of the present invention, when the electric pump is abnormally stopped, a small amount of substitute means can supply a sufficient amount of lubricating oil to the bearing. To play.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a bearing lubrication device showing one embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional bearing lubrication device.

[Explanation of symbols]

1. Lubricating oil tank, 2. Spindle unit, 3. Oil supply piping, 4. Drain piping, 7. Electric pump, 8. Solenoid valve, 9. Air source, 11. Air driven pump, 12 ・
・ Air piping, 13 ・ ・ Substitute piping, 21 ・ ・ Power supply, 22 ・
・ Main switch, 23 ・ ・ Electromagnetic switch.

Claims (2)

[Claims] An electric pump for supplying lubricating oil to a bearing;
A bearing lubrication device comprising: an air-driven pump that supplies lubricating oil to a bearing in place of an electric pump; and control means for activating the air-driven pump when the electric pump abnormally stops. 2. The bearing according to claim 1, wherein the control means includes a detector for detecting an abnormal stop of the electric pump, and a solenoid valve for communicating the air drive pump to an air source in response to the operation of the detector. Lubrication device.