JPS6218311B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-shaft cooling device that cools the bearings of, for example, a plurality of main shafts of a machine tool, and particularly relates to a multi-shaft cooling device that has a structure in which the mutual positional relationship of a plurality of main shafts is variable. It is something.

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
is a bearing, 4, 41 is a bearing stand, 5, 51 is a pulley,
6 is bet.

The following 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, 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 each of these figures, 7 and 71 are annular hollow chambers formed inside the bearing stands 4 and 41, and 8 and 81 are annular hollow chambers formed inside the bearing stands 4 and 41. It is a heat dissipation device and is cooled by cooling fans 9 and 91. 10, 101 are hollow chambers 7, 71 and heat dissipation device 8
1 and 8, and includes extensible and contractible flexible parts 10a, such as bellows, etc.
101a. Reference numerals 12 and 121 are liquid pipes that communicate the hollow chambers 7 and 71 with the heat radiating devices 8 and 81, respectively.

In addition, the hollow chambers 7, 71 and the heat dissipation devices 8, 81,
After reducing the pressure inside the steam pipes 10, 101 and liquid pipes 12, 121, a predetermined amount of a 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 Utilizing the steam pressure, the steam is moved through the steam pipe 10 to the heat radiating device 81 and through the steam pipe 101 to the heat radiating device 8, respectively, and is cooled by the surrounding air by the cooling fans 9, 91. 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 12 and 121 and is transferred to the hollow chambers 7 and 71 of the bearing stands 4 and 41 using gravity.
Return to By repeating these operations, the amount of heat in the bearing stands 4, 41 is reduced to the heat dissipation devices 81, 8.
The system transports heat to ensure efficient cooling.

By the way, if the temperature rise (calorific value) of the bearing pedestal 4 is larger than that of the other bearing pedestal 41, the amount of vapor, vapor pressure, and vapor temperature during vaporization of the working liquid in the hollow chamber 7 of the bearing pedestal 4 will be higher than that of the other bearing pedestal 41. It becomes larger in comparison. Therefore,
A larger amount of latent heat of vaporization is taken away and the bearing pedestal 4 is cooled down to a greater extent, and the temperature rise of the bearing pedestal 4 is caused by the temperature rise of the other bearing pedestal 41.
It works to prevent it from getting bigger. The high temperature steam vaporized in the hollow chamber 7 of the bearing stand 4 moves to the heat radiator 81 via the steam pipe 10, and the working liquid condensed in the heat radiator 81 is the working liquid condensed in the heat radiator 8. The temperature is higher than that of the liquid, and the liquid flows into the hollow chamber 71 of the bearing stand 41 through the liquid pipe 121. Therefore, the bearing pedestal 41 is warmed by the higher temperature of the working fluid, increasing the temperature rise, and the difference in temperature rise between the two bearing pedestals 4, 41 is kept small.
In addition, 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 volume 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 lower temperature working liquid flows through the steam pipe 101, the heat radiating device 8, and the liquid pipe 12. As a result, the bearing pedestal 4 is cooled by the lower temperature of the working fluid, reducing the temperature rise, and the difference in temperature rise between the two bearing pedestals 4, 41 is kept small. By repeating such operations, if the heat generation amount and temperature rise of either of the bearing stands 4, 41 begins to increase,
It works to suppress the difference in temperature rise between the two bearing pedestals 4, 41 to a small level, and both the bearing pedestals 4, 41 are effectively cooled on the average. Therefore, in the machine tool, thermal deformation and distortion of the bearing portion can be minimized, and machining accuracy can be improved. Further, the span P between the main shaft 2 and the main shaft 21 can be made variable within the expansion/contraction range of the flexible portions 10a, 101a of the steam pipes 10, 101.

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

Further, in the above embodiment, the flexible portion 10a,
Although the case where 101a is configured with bellows has been described, it may be configured to be expandable and retractable by other than bellows.

Further, in the above embodiment, the case was described in which the steam pipes 10, 101 were connected to the other heat radiating device 81, 8, but conversely, the liquid pipe 12, 121 was connected to the other heat radiating device 81, 8, The liquid pipes 12, 12
1 may be provided with a flexible part that can be expanded and contracted, and the same effects as in the above embodiment can be expected.

As explained above, this invention has an annular hollow chamber formed inside the bearing stand and filled with a working liquid, and a heat dissipation device communicated with the hollow chamber through piping constituted by a steam pipe and a liquid pipe. A first main shaft device and a second main shaft device are installed on the same machine, and either one of the steam pipe or the liquid pipe of the first main shaft device and the second main shaft device is connected to the other heat radiating device. By providing a flexible part that can be expanded and contracted on either the steam pipe or the liquid pipe and transporting the heat of the bearing pedestal from the hollow chamber to the heat dissipation device, the heat of the bearing pedestal can be quickly removed efficiently and evenly. Since the bearing can be cooled down to a minimum, thermal deformation and distortion of the bearing part can be minimized and the machining accuracy of machine tools can be improved, which is extremely effective in practical terms.

[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, 4 and 41 are bearing stands, 7 and 71 are hollow chambers, 8,
81 is a heat dissipation device, 10, 101 is a steam pipe, 10
a and 101a are flexible parts, and 12 and 121 are liquid pipes. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. Each bearing has an annular hollow chamber formed inside the bearing pedestal and filled with a working liquid, and a heat dissipation device communicated with the hollow chamber through piping constituted by a steam pipe and a liquid pipe. and the first, which is installed on the same machine,
A second main shaft device is provided, and either one of the steam pipes or liquid pipes of the first main shaft device and the second main shaft device is connected to the other heat radiating device, and expands and contracts into either the steam pipe or the liquid pipe. 1. A multi-shaft cooling device, characterized in that a flexible portion is provided, and the amount of heat in the bearing pedestal is transferred 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 flexible portion is constituted by a bellows.