Vacuum pump, protective net, and contact part

Abstract

A vacuum pump that is small in height (length) is configured to bring a rotating body and a protective net as close to each other as possible by causing the rotating body to actively support the protective net. The vacuum pump is provided with a mechanism that causes a rotating body (a shaft or a rotor) to actively support a protective net when the protective net becomes deformed (bent) toward the vacuum pump side due to a change in pressure or temperature of the vacuum pump. Specifically, instead of preventing the protective net from being caught in the rotating body by increasing the distance therebetween, the entanglement of the protective net is prevented by actively supporting the protective net by bringing the protective net and the rotating body closer to each other. Accordingly, the height (length) of the vacuum pump can be reduced more.

1 . A vacuum pump, comprising:
 a housing in which an inlet port is formed;   a protective net provided at the inlet port;   a gas transfer mechanism provided with a rotating body in the housing; and   an entanglement prevention mechanism that prevents the protective net from being caught in the rotating body when the protective net is deformed.   
     
     
         2 . The vacuum pump according to  claim 1 , wherein the entanglement prevention mechanism has a contact support structure in which, when the protective net is deformed, the protective net and the rotating body are brought into contact with each other to support each other. 
     
     
         3 . The vacuum pump according to  claim 2 , wherein the contact support structure forms, in a part of the rotating body that comes into contact with the protective net, a shape having a small contact resistance. 
     
     
         4 . The vacuum pump according to  claim 3 , wherein the shape having a small contact resistance is provided on a shaft of the rotating body. 
     
     
         5 . The vacuum pump according to  claim 3 , wherein the shape having a small contact resistance is provided on a rotor of the rotating body. 
     
     
         6 . The vacuum pump according to  claim 3 , wherein a part of the protective net that comes into contact with the rotating body is provided with a hole corresponding to the shape having a small contact resistance that is formed in the part of the rotating body. 
     
     
         7 . The vacuum pump according to  claim 6 , wherein the hole provided on the protective net is configured to narrow a contact point coming into contact with the shape having a small contact resistance that is formed on the rotating body. 
     
     
         8 . The vacuum pump according to  claim 3 , wherein the shape having a small contact resistance that is formed on the rotating body is coated so as to lower a friction coefficient. 
     
     
         9 . The vacuum pump according to  claim 3 , wherein the part of the protective net that comes into contact with the rotating body is provided with a plane corresponding to the shape having a small contact resistance that is formed on the rotating body. 
     
     
         10 . The vacuum pump according to  claim 6 , wherein a distance between the hole provided on the protective net and the shape having a small contact resistance that is formed on the rotating body is made smaller than a mesh of the protective net. 
     
     
         11 . The vacuum pump according to  claim 1 , wherein the entanglement prevention mechanism is a non-mesh portion that is formed in a part of the protective net that comes into contact with the rotating body, by leaving a base material. 
     
     
         12 . A protective net that is provided at an inlet port of a vacuum pump including a housing in which the inlet port is formed, and a gas transfer mechanism provided with a rotating body in the housing, the protective net comprising: an entanglement prevention structure that prevents the protective net from being caught in the rotating body at the time of deformation. 
     
     
         13 . A contact part that is installed in a vacuum pump comprising a housing in which an inlet port is formed, a protective net provided at the inlet port, and a gas transfer mechanism provided with a rotating body in the housing, the contact part being installed in a part of the rotating body that comes into contact with the protective net when the protective net is deformed, and having a shape configured to have a small contact resistance.