Pressure Relief Device for a Gear Box

Abstract

A pressure relief device for a gear box which is disposed in the gear box and comprises a body, a blocking member and a spring. The body is defined with a penetrating hole. The spring pushes the blocking member and makes it seal the penetrating hole. When the pressure rises since the temperature therein is risen, and when the gas pressure in the gear box is larger than the force of the spring, the gas can push the blocking member and compress the spring, and then discharge from the penetrating hole of the body, thus reducing the pressure and the temperature of the gear box.

1 . A pressure relief device for a gear box being disposed in the gear box, comprising:
 a body being passed through the gear box and defined with a penetrating hole, both ends of the penetrating hole being in communication with an inner part and an outer part of the gear box;   a blocking member being disposed in the penetrating hole of the body; and   an elastic member being disposed in the penetrating hole of the body and pushes the blocking member and makes it seal the penetrating hole, when gas pressure in the gear box which is enough to compress the elastic member, the gas will push the blocking member and compress the elastic member, and then will discharge from the penetrating hole of the body, thus relieving the pressure.   
   
   
       2 . The pressure relief device for a gear box as claimed in  claim 1 , wherein the penetrating hole of the body comprises three orderly connected portions, that is, an inlet portion, a ventilating portion and an outlet portion, the inlet portion is in communication with the inner part of the gear box, the outlet portion is in communication with the outer part of the gear box, and the blocking member and the elastic member are disposed in the ventilating portion of the penetrating hole of the body. 
   
   
       3 . The pressure relief device for a gear box as claimed in  claim 2 , wherein a caliber of the inlet portion is smaller than that of the ventilating portion, a caliber of the outlet portion is also smaller than that of the ventilating portion, the blocking member is ball-shaped, a diameter of the blocking member is larger than the caliber of the inlet portion, one end of the elastic member is pressed against the outlet portion of the penetrating hole, and the other end of the elastic member is pressed against the blocking member in such a manner that the blocking member will be pushed by the elastic member to move towards the inlet portion and provide a sealing effect between the inlet portion of the penetrating hole and the ventilating portion. 
   
   
       4 . The pressure relief device for a gear box as claimed in  claim 2 , wherein the body is provided with a funnel structure having a contracting end with a smaller caliber and an expanding end with a larger caliber, and the funnel structure is connected to and is in communication with the outlet portion of the penetrating hole by the contracting end. 
   
   
       5 . The pressure relief device for a gear box as claimed in  claim 4 , wherein a sponge is disposed in the funnel structure. 
   
   
       6 . The pressure relief device for a gear box as claimed in  claim 1 , wherein the elastic member is a spring.