JPS6214380B2 - - 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 denotes first and second spindle devices of the machine tool, which are arranged at an interval of span P. 2, 21 are main shafts, 3, 31 are bearings, 4, 41 are bearing stands, 5, 5
1 is a pulley and 6 is a 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 fluctuation of the positions 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. 3 and 4. Fig. 3 is a block diagram showing the functional system, and Fig. 4 is a cross-sectional side view. In these figures, 7 and 71 are annular hollow chambers formed inside the bearing stands 4 and 41, and 8 is a heat dissipation device. and
It is cooled by a cooling fan 9. 10,10
Reference numeral 1 denotes first and second steam pipes that guide the vapor of the working liquid that is vaporized in the hollow chambers 7 and 71 to the heat radiating device 8, respectively, and 12 and 121 the working liquid that is condensed and liquefied in the heat radiating device 8 to the bearing mounts 4 and 41. These are first and second liquid pipes that are guided to hollow chambers 7 and 71, respectively. Reference numeral 13 denotes a communication pipe that communicates the first liquid pipe 12 and the second liquid pipe 121.

In addition, the hollow chambers 7 and 71 and the heat dissipation device 8, the first
Second steam pipe 10, 101, first and second liquid pipe 1
After reducing the pressure inside 2,121, a predetermined amount of working liquid such as ammonia or chlorofluorocarbon is sealed therein.

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 steam pressure, the steam is moved to the heat radiating device 8 through the first and second steam pipes 10 and 101, respectively,
It is cooled by ambient air by a cooling fan 9.
At this time, vapors such as fluorocarbons condense and return to liquid, but the latent heat of condensation is released to the surrounding air, and the bearings 3, 31
of heat is radiated to the surrounding air. The condensed working liquid passes through the first and second liquid pipes 12, 121 and returns to the hollow chambers 7, 71 of the bearing stands 4, 41 using gravity.
By repeating such operations, the amount of heat in the bearing stands 4, 41 is transported to the heat radiating device 8 and efficiently cooled.

By the way, when the temperature rise (heat amount) of the bearing pedestal 4 is larger than that of the other bearing pedestal 41, the working liquid in the hollow chamber 7 of the bearing pedestal 4 becomes the working liquid in the hollow chamber 71 of the bearing pedestal 41 when vaporized. Compared to this, the amount of steam, pressure, and temperature are greater. Therefore, as the amount of steam becomes larger, the latent heat of vaporization is taken away to a greater extent, and the temperature of the bearing pedestal 4 increases.
It works to prevent it from becoming larger than 1. The high temperature steam vaporized in the hollow chamber 7 of the bearing stand 4 moves to the heat radiating device 8 via the first steam pipe 10 and is condensed and liquefied. On the other hand, the temperature rise of the bearing pedestal 41 is smaller than that of the bearing pedestal 4, and the working liquid in the hollow chamber 71 of the bearing pedestal 41 has a vapor amount and vapor pressure when vaporized compared to the working liquid in the hollow chamber 7 of the bearing pedestal 4.・Steam temperature is low. Therefore, the low temperature steam vaporized in the hollow chamber 71 of the bearing stand 41 is transferred to the second steam pipe 101.
The liquid then moves to the heat dissipation device 8 where it is condensed and liquefied.

However, high temperature steam has a high temperature when condensed and liquefied, and low temperature steam has a low temperature when condensed and liquefied. The respective working liquids condensed and liquefied in the heat dissipation device 8 pass through the first liquid pipe 12 and the second liquid pipe 121 to the hollow chambers 7 and 71 of the bearing stands 4 and 41.
However, the two working liquids are mixed by the communication pipe 13 and returned to the hollow chambers 7, 71 as a working liquid having an average temperature. That is, the working fluid at a lower temperature returns to the hollow chamber 7 of the bearing pedestal 4, is cooled by the lowered temperature, and the temperature rise of the bearing pedestal 4 is reduced, and the working fluid returns to the hollow chamber 71 of the bearing pedestal 41 at a higher temperature. The working fluid at the lower temperature returns and is warmed by the increased temperature, increasing the temperature rise of the bearing pedestal 41, and suppressing the difference in temperature rise between the two bearing pedestals 4, 41 to a small value. Further, the communication pipe 13 serves to keep the amount of both working liquids returning to the hollow chambers 7, 71 at a predetermined amount. By repeating such an operation, when the heat generation amount and temperature rise of either of the bearing stands 4, 41 starts to increase, it works to suppress the difference in temperature rise of both the bearing stands 4, 41 to a small value, Bearing stand 4, 41
is effectively cooled on average. Therefore, in the machine tool, thermal deformation and distortion of the bearing portion can be minimized, and machining accuracy can be improved.

In the above embodiment, the case where the cooling fan 9 is used has been described, but the cooling fan 9 may not be used and natural air cooling may be used, or cooling water or oil other than the cooling air may be used as the cooling source. The effect of this can be obtained.

Further, in the above embodiment, the hollow chambers 7, 71 are provided in the bearing pedestals 4, 41, respectively, but the hollow chambers 7, 71 are provided between the bearings 3, 31 and the bearing pedestals 4, 41, respectively. You can do it like this.

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 three or more spindle devices, and the same effects as in the above embodiment can be obtained.

As explained above, this invention has annular hollow chambers formed inside the bearing part and filled with working fluid, and the first and second bearings are mounted on the same machine.
a main shaft device, a heat radiating device for dissipating the heat of the first and second main shaft devices, and a first and second main shaft device for guiding the vapor of the working liquid vaporized in the hollow chambers of the first and second main shaft devices to the heat radiating device, respectively. 2 steam pipes, first and second liquid pipes that guide the working liquid that is condensed and liquefied in the heat dissipation device to the hollow chambers of the first and second main shaft devices, and the first liquid pipe and the second liquid pipe. By providing a communicating pipe and transporting the heat of the bearing from the hollow chamber to the heat radiating device, the heat of the bearing can be rapidly removed and cooled efficiently and evenly, reducing thermal deformation of the bearing.・It has an extremely large practical effect of suppressing distortion to a minimum and improving the machining accuracy of machine tools.

[Brief explanation of the drawing]

1 and 2 are a cross-sectional side view and a front view showing a conventional multi-shaft cooling device, and FIG. 3 and FIG. 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. It is. In the figure, 1 and 11 are first and second main shaft devices, 4 and 41 are bearing stands, 7 and 71 are hollow chambers, 8 is a heat dissipation device, 10 and 101 are first and second steam pipes,
12 and 121 are first and second liquid pipes. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. First and second spindle devices each having an annular hollow chamber formed inside a bearing portion and filled with a working liquid, and mounted on the same machine, and the first spindle; A heat radiator that radiates the heat of the device; first and second steam pipes that guide the vapor of the working liquid vaporized in the hollow chambers of the first and second main shaft devices to the heat radiator, respectively; and condensation in the heat radiator. first and second liquid pipes that guide the working liquid to be liquefied into the hollow chambers of the first and second main shaft devices, the first liquid pipe and the second liquid pipe;
A multi-axis cooling device, comprising a communication pipe that communicates the liquid pipes of the working liquid, and the heat of the bearing portion is transported from the hollow chamber to the heat radiating device by the evaporation and condensation action of the working liquid. 2. The multi-axis cooling device according to claim 1, wherein the hollow chamber is formed in a bearing stand. 3. The multi-shaft cooling device according to claim 1, wherein the hollow chamber is formed between the bearing stand and the bearing.