JPH0565728B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-shaft cooling device for cooling bearings such as a plurality of main shafts of a machine tool, for example.

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In each of these figures, 1, 1
Reference numeral 1 designates first and second spindle devices of the machine tool, which are arranged at an interval of an arbitrary span P by a movement adjustment device (not shown). 2, 21 are main shafts, 3, 31
are bearings that support the main shafts 2 and 21, 4 and 41 are bearing stands that support the bearings 3 and 31, and 5 and 51 are pulleys;
6 is bed.

Next, the operation will be explained. The main shafts 2, 21 are rotated by the rotational force transmitted to the pulleys 5, 51 via the V-belt by a driving electric motor (not shown). At this time, the bearings 3, 31 located between the main shafts 2, 21 and the bearing stands 4, 41 have the purpose of helping the main shafts 2, 21 rotate smoothly.
As the bearings 3 and 31 rotate, they generate heat due to friction and their temperature increases. The amount of heat generated in the bearings 3, 31 is transmitted to the bearing stands 4, 41, and is transferred to the bed 6 and the surrounding air to radiate heat. At this time, the temperature of the bearing stands 4 and 41 increases, and various thermal deformations and strains occur in each part due to thermal expansion. For this reason, the positions of the main shafts 2 and 21 fluctuate,
There was a drawback that the machining accuracy decreased when machining the workpiece. Furthermore, there is a drawback that there is a difference in the positional fluctuations of the main shafts 2 and 21 between them, and at the same time, there is a difference in the machining accuracy when performing a plurality of machining operations.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and an object of the present invention is to provide a multi-shaft cooling device that can effectively and evenly cool the first and second main shaft devices. It is an object.

An embodiment of the present invention will be described below with reference to FIGS. 8 and 4. Fig. 8 is a block diagram showing the functional system, and Fig. 4 is a cross-sectional side view. Room, 8,
81 is a heat dissipation device, which is cooled by cooling fans 9 and 91. A pair of pipes 10 and 11 communicate the hollow chamber 7 and the heat radiating device 8, and serve as a steam pipe and a liquid pipe, respectively. 101,1
11 are a pair of pipes that communicate the hollow chamber 71 and the heat radiating device 81, and function as a steam pipe and a liquid pipe, respectively. 12 is a communication pipe that communicates the steam pipes 10 and 101 and has a flexible part 12a such as a bellows, and 13 is a communication pipe that communicates the liquid pipes 11 and 111 and has a flexible part 13a that can be extended and contracted such as a bellows. It's a tube. In addition, the hollow chambers 7, 71 and the heat dissipation devices 8, 8
1. After reducing the pressure inside the steam pipes 10, 101 and liquid pipes 11, 111, a predetermined amount of working liquid such as ammonia or fluorocarbon is sealed inside them.

Next, the operation will be explained. The heat of the bearings 3, 31 received by the bearing stands 4, 41 is taken away as latent heat of vaporization when the working liquid such as fluorocarbons in the hollow chambers 7, 71 is heated and vaporized, and the vapor of the vaporized fluorocarbons is Using the steam pressure, the steam is transferred through the steam pipes 10, 101 to the heat dissipation devices 8, 81, and the cooling fans 9,
91 to be cooled by ambient air. At this time, the vapor of fluorocarbon or the like is condensed and returned to liquid, but the latent heat of condensation is released to the surrounding air, and the amount of heat from the bearings 3 and 31 is radiated to the surrounding air. The condensed working liquid passes through the liquid pipes 11 and 111 and moves to the hollow chambers 7 and 7 using gravity.
Return to 1. By repeating these operations, the amount of heat in the bearing stands 4, 41 is reduced to the heat dissipation devices 8, 81.
The system transports heat to ensure efficient cooling.

By the way, if the temperature rise (heat amount) of the bearing pedestal 4 is larger than that of the other bearing pedestal 41, the amount of vapor, pressure, and temperature when the working liquid in the hollow chamber 7 on the bearing pedestal 4 side evaporates will be higher than that of the other bearing pedestal 41. growing. Therefore, a larger amount of latent heat of vaporization is absorbed to cool down the bearing pedestal 4 more strongly. Steam with high pressure and temperature flows in. As a result, when viewed from the bearing stand 4 side, the heat radiation area increases by the amount that flows into the other heat radiation device 81 via the communication pipe 12, and the cooling capacity increases. In addition, in the heat dissipation device 81, the high temperature steam flowing in from the hollow chamber 7 on the bearing stand 4 side mixes with the low temperature steam flowing in from the hollow chamber 71 on the bearing stand 41 side, and as a result, the hollow chamber on the bearing stand 41 side mixes with the low temperature steam flowing in from the hollow chamber 71 on the bearing stand 41 side. 71, the temperature of the steam flowing in becomes higher. The working fluid condensed and returned to liquid in the heat radiating devices 8, 81 returns to the hollow chambers 7, 71 via liquid pipes 11, 111. Although the working liquid condensed in the heat dissipation device 81 has a lower temperature than the other one,
Through the communication pipe 13 that communicates the liquid pipes 11 and 111,
The working liquid is mixed with the condensed working liquid in the heat dissipation device 8, the temperature is averaged, and the working liquid returns to the hollow chambers 7, 71.

By providing the communication pipes 12 and 13 in this way, if there is a difference in the amount of heat generated or temperature rise between the two, the heat dissipation and cooling capacity of the one with a higher temperature increase will increase, suppressing the temperature rise, and reducing the temperature rise difference. In addition, it is possible to raise the temperature of the working fluid with a lower temperature rise, reduce the heat radiation area, slightly increase the temperature rise, and suppress the difference in temperature rise to a small value. As a result, thermal deformation and distortion of the bearing portion can be suppressed to a minimum, and the machining accuracy of the machine tool can be improved. Further, the span P between the main shaft 2 and the main shaft 21 can be made variable within the range of expansion and contraction of the flexible portions 12a and 13a of the communication pipes 12 and 13.

In the above embodiment, the steam pipe 1 is connected to the steam pipe 1 by the communication pipe 12.
0 and 101 are connected, and the liquid pipe 11 is connected by the communication pipe 13.
Although the case has been described in which the steam pipes 10 and 101 or the liquid pipes 11 and 111 are communicated with each other, the communication pipe 12 or 13 may be provided to communicate with either the steam pipes 10 and 101 or the liquid pipes 11 and 111.

Further, in the above embodiment, the flexible portions 12a, 13a of the communication pipes 12, 13 are configured with bellows, but they may be configured to be expandable and retractable using a device other than the bellows.

Furthermore, although the above embodiment describes the case where the cooling fans 9, 91 are used, the cooling fans 9, 91
A similar effect can be obtained by performing natural air cooling without using cooling air, or by using cooling water, oil, etc. other than cooling air as a cooling source.

Incidentally, in the above description, the case where there are two spindle devices has been described, but the present invention can also be applied to a case where there are eight or more spindle devices, and the same effects as in the above embodiment can be obtained.

As described above, the present invention provides a first heat dissipation device that has an annular hollow chamber formed between a bearing and a bearing stand and in which a working liquid is sealed, and a heat dissipation device that communicates with the hollow chamber through a pair of pipes. , a second spindle device, and a communication pipe that communicates the piping of the first spindle device with the piping of the second spindle device is provided so that the amount of heat in the bearing stand is transported from the hollow chamber to the heat radiating device. This makes it possible to quickly remove heat from the bearing pedestal and cool it efficiently and evenly, which has an extremely large practical effect of suppressing thermal deformation and distortion of the bearing to a minimum and improving the machining accuracy of machine tools, etc. . Further, by providing the flexible part that can be expanded and contracted in the communication pipe, it is possible to have a structure in which the mutual positional relationship between the first spindle device and the second spindle device can be changed within the expansion and contraction range of the flexible portion.

[Brief explanation of the drawing]

1 and 2 are cross-sectional side views showing a conventional multi-shaft cooling device, and FIGS. 3 and 4 are a block diagram and a cross-sectional side view showing a multi-shaft cooling device according to an embodiment of the present invention. In the figure, 1 and 11 are the first and second spindle devices, 3 and 31 are bearings, 4 and 41 are bearing stands, and 7 and 7
1 is a hollow chamber, 8, 81 are heat dissipation devices, 10, 11 and 101, 111 are piping, 12, 13 are communication pipes, and 12a, 13a are flexible parts.
Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An annular hollow chamber formed between a bearing that supports the main shaft and a bearing stand that supports the bearing and in which a working fluid is sealed, and a heat dissipation device that communicates with this hollow chamber through a pair of piping. first and second spindle devices each having a device, a connecting pipe that communicates the piping of the first spindle device and the piping of the second spindle device, and the amount of heat generated in the bearing is transferred to the hollow chamber. A multi-axis cooling device characterized in that the cooling device is configured to transport the heat from the cooling device to the heat dissipation device. 2. Claim 1, wherein one of the pair of pipes is a steam pipe and the other is a liquid pipe.
Multi-axis cooling device as described in section. 3. The multi-axis cooling device according to claim 1 or 2, wherein the communication pipes communicate between the alternate steam pipes and between the liquid pipes. 4. The multi-axis cooling device according to claim 1 or 2, wherein the communication pipe communicates only between the steam pipes or between the liquid pipes. 5. The multi-axis cooling device according to claim 1 or 2, wherein the connecting pipe has a flexible part that can be expanded and contracted. 6. The multi-axis cooling device according to claim 5, wherein the flexible portion is constituted by a bellows.