Vacuum pump

Abstract

The invention relates to a heat insulation structure having the function of retaining a high temperature in a vacuum exhaust chamber in a rotary type vacuum pump and the function of cooling bearings at the same time, and particularly has for its object the provision of a structure for preventing bearings or shaft seals from becoming so high in temperature as to be damaged when a high temperature is to be retained in an exhaust chamber with respect to a vacuum pump for exhausting reactive gases as in a semiconductor process. As a means to achieve the object, in a vacuum pump comprising an introduction means having a vacuum exhaust chamber and adapted to introduce a process gas into the vacuum exhaust chamber, an exhaust means for exhausting the process gas out of the vacuum exhaust chamber, a housing for separating the vacuum exhaust chamber from outside, with a rotor installed fro rotation in the housing through a bearing, a heat insulation means is provided between the vacuum exhaust chamber and the bearing. Further, a metal whose thermal conductivity is higher than that of the material of the housing is incorporated as a heat transmission means into the housing.

Description

technical field [0001] The present invention relates to a structure for protecting bearings and the like from heat generated in an exhaust chamber of a vacuum pump, and more particularly to a vacuum pump for exhausting reactive gases in semiconductor processing, keeping the exhaust chamber It is a structure that does not cause damage to bearings or shaft seals due to high temperatures at the same time. Background technique [0002] Conventional rotary vacuum pumps that flow reactive gases have the problem of accumulating reaction products in the exhaust passage, clogging the exhaust passage of the exhaust port and preventing exhaust, or causing the products to adhere In the exhaust chamber or on the rotating impeller, etc., there is a problem that the impeller (rotor) etc. cannot be rotated. In order to solve these problems, it is possible to use the heat generated during vacuum exhaust to make the casing high temperature or wrap the heater around the outer periphery of the...

AI Technical Summary

Problems solved by technology

[0003] However, in the case of the above-mentioned conventional vacuum pump with a rotating shaft, in order to cool the bearing, a passage for cooling water is provided near the bearing, and the cooling water flows, thereby cooling the casing, so there is a possibility that the high temperature will be maintained. The heat in the exhaust chamber is also taken away from the problem

In order to prevent the product from adhering to the casing or impeller in the exhaust chamber, it is necessary to keep the exhaust chamber at a high temperature; in order to cool the bearings and raise the temperature in the exhaust chamber, it is necessary to heat the exhaust chamber There is a problem of causing a so-called vicious circle in which the consumed energy is also increased because more than the heat lost is supplied to the casing.

Furthermore, in the case of a shaft structure with a shaft seal, there may also be a problem that the shaft seal is destroyed by heating

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