JP3425774B2 - Cooling control device for rotating shaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling control device for a rotating shaft, such as a main shaft of a machining center of a machine tool, which rotates at high speed.

[0002]

2. Description of the Related Art Generally, in a high-speed rotating shaft, heat generation of the bearing causes thermal deformation of the rotating shaft and the bearing, resulting in deterioration of mechanical accuracy. When such a state progresses, seizure damage of the bearing occurs. There is.

In order to solve the above situation, it is already known to inject air into a bearing or a joint between the bearing and a rotary shaft for cooling.

The cooling method by various jets of air according to the prior art merely makes approximately uniform jets of air to each bearing or a joint between the bearing and the rotary shaft.

However, the amount of heat generated by friction at each bearing and the joint between the bearing and its rotary shaft differs depending on each position.

Despite this, the conventional cooling method using air injection does not take into consideration the fact that the amount of heat generated differs depending on the position of each bearing as described above. The existing bearing and its joint with the rotary shaft are not sufficiently cooled, and there is an unavoidable drawback that damage occurs at the position of this portion.

As another method of cooling the rotating shaft, there is a so-called jet lubrication system in which a lubricating oil for cooling is sprayed, which enables efficient cooling.

However, when the lubricating oil for cooling is used, the lubricating oil is inevitably agitated in the rotating shaft and the bearing portion, and the viscosity of the lubricating oil causes friction, which results in power loss. The above loss is large.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooling control device that overcomes the above-mentioned drawbacks of the conventional techniques and that is efficient and has less power loss.

[0010]

In order to solve the above-mentioned problems, according to the structure of the invention, a temperature sensor is attached to each bearing with respect to the rotating shaft, and cooling air is jetted to each bearing or a joint portion between the bearing and the rotating shaft. In order to do so, a temperature control chamber is interposed in the cooling air supply path branched from the cooling air supply source, and each temperature control chamber is connected to a controller that receives an input signal from each temperature sensor. It consists of a temperature control device for the rotating shaft.

As is apparent from the structure based on the above-mentioned solution means, in the present invention, the cooling air blown to each bearing which is a heat source or the joint portion between the bearing and the rotary shaft is There is a basic technical idea in that the temperature of the supplied air itself is individually supplied to each bearing via a controller.

That is, the present invention has a feature of the present invention in that the supply amount or temperature of the cooling air is individually adjusted in accordance with the site to perform appropriate cooling.

[0013]

EXAMPLES The constitution of the present invention will be specifically described with reference to the following examples.

FIG. 1 shows an embodiment of the present invention.

A temperature sensor 3 is provided for each bearing 2, and the controller 4 and the temperature sensor 3 are joined to each other and have a common compressed air source, and cooling air is supplied to each bearing 2 and its joining portion. Because of the injection, the cooling air supply path is branched.

In the branched cooling air supply path, temperature control chambers 7 are interposed, and each temperature control chamber 7 is joined to the controller 4.

That is, in the embodiment, control is performed to adjust the temperature itself of the cooling air to be supplied according to the temperature of each bearing 2 or the joint between the bearing 2 and the rotary shaft 1.

On the other hand, when the rotational speed of the rotary shaft 1 rises or falls, the temperatures of the bearings 2 and their joints rise and fall uniformly. However, in order to prepare for such a situation, the second embodiment is adopted. In a common compressed air supply source, a flow rate adjusting valve 6 is attached to adjust the supply amount of cooling air.

That is, when the rotation speed of the rotary shaft 1 is increased, the supply amount of the entire cooling air is increased, and when it is decreased, the supply amount of the entire cooling air is decreased. However, attaching the flow rate adjusting valve is not an essential requirement of the invention.

The relationship between the NC device 8 and the rotary shaft 1 and the controller 4 is the same as in the first embodiment, and when the temperature sensor 3 attached to each bearing 2 indicates an abnormal temperature, an alarm ( It can be designed to send a machine stop signal) to the NC device 8.

[0021]

As described above, according to the present invention, it is possible to appropriately control the cooling according to the heat generation state of each bearing 2 and its joint. Therefore, even if the rotating shaft 1 becomes extremely high in speed, the respective bearings 2 and their joints are appropriately cooled without causing local cooling insufficiency while preventing heat generation of the entire rotating shaft 1. It becomes possible to maintain high speed rotation. Further, efficient and economical cooling can be achieved by individually controlling the cooling of each bearing 2 and its joint. Moreover, since cooling is performed by air instead of lubricating oil while performing such efficient cooling, the power loss of the rotary shaft 1 can be made smaller than that of the conventional jet lubrication method. . As described above, the present invention has various advantages as compared with the conventional cooling system for the rotating shaft 1, and the effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

[Simple explanation of the sign]

1: Rotating axis 2: Bearing 3: Temperature sensor 4: Controller 5: Compressed air supply source 6: Flow control valve 7: Temperature control room 8: NC device 9: Air supply pipe

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Claims (2)

(57) [Claims] 1. A cooling air, which is branched from a cooling air supply source in order to attach a temperature sensor to each bearing for a rotating shaft and to inject the cooling air to each bearing or a joint portion between the bearing and the rotating shaft. A temperature control device for a rotary bearing by interposing temperature control chambers in the supply path of each of the temperature control chambers and each temperature control chamber is joined to a controller that receives an input signal from each of the temperature sensors. 2. A flow rate adjusting valve for adjusting the amount of air to be supplied, before the supply path is branched, is provided for the supply source of cooling air to each temperature adjusting chamber. Rotary axis temperature control device