Flow-bypassing structure of grinding tool and grinding tool having the same

Abstract

The present invention relates to a flow-bypassing structure and a grinding tool having the same. The main body has an intake passage and an exhaust passage. A cylinder is disposed in an interior of the main body and has an air inlet communicated with the intake passage and an air outlet communicated with the exhaust passage to form an airflow pathway. A rotor is disposed in the cylinder, and a rotational axle base is rotatably disposed though the cylinder and in a rotational cooperative relationship with the rotor. An end of the rotational axle base is extended and formed with a rotational working portion outside the cylinder. The surroundings of the rotational working portion define a space. A flow-bypassing passage is communicated with the airflow pathway and the space, and an end of the flow-bypassing passage is open toward the space.

What is claimed is: 
     
         1 . A flow-bypassing structure of a grinding tool adapted for being assembled to a main body of the grinding tool, the main body having an intake passage and an exhaust passage, a cylinder disposed in an interior of the main body and having an air inlet and an air outlet, the air inlet communicated with the intake passage, the air outlet communicated with the exhaust passage, an airflow pathway defined to be communicated with the interior of the cylinder, the air outlet and the exhaust passage, a rotor being disposed in the cylinder, a rotational axle base rotatably disposed though the cylinder and in a rotational cooperative relationship with the rotor, an end of the rotational axle base extended and formed with a rotational working portion which is operable from an outside of the cylinder, the surroundings of the rotational working portion defining a space, an abutting ring neighboring the space abutted against the main body and the cylinder so as to fixedly position the cylinder in the main body, a flow-bypassing passage disposed through a side wall of the cylinder and communicated with the airflow pathway, an end of the flow-bypassing passage being open toward the abutting ring and a venting pathway disposed through the abutting ring and communicated with the space and the flow-bypassing passage. 
     
     
         2 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the cylinder includes a tubular member and a lid member, an end of the tubular member remote from the space has a first axle hole, the other end of the tubular member is an open end, the lid member is disposed on the open end of the tubular member and has a second axle hole corresponding to the first axle hole, and the rotational axle base is rotatably disposed in the first and second axle holes. 
     
     
         3 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the cylinder includes a tubular member and a lid member, an end of the tubular member near the space is an open end, the other end of the tubular member has a first axle hole, the lid member is disposed on the open end of the tubular member and has a second axle hole corresponding to the first axle hole, and the rotational axle base is rotatably disposed in the first and second axle holes. 
     
     
         4 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the cylinder includes a tubular member and two lid members, the two corresponding ends of the tubular member are open ends, the two lid members are respectively disposed on the two corresponding ends of the tubular member and has corresponding first and second holes, and the rotational axle base is rotatably disposed in the first and second axle holes. 
     
     
         5 . The flow-bypassing structure of the grinding tool of  claim 2 , wherein the flow-bypassing passage is disposed at the end of the tubular member near the space and substantially along an axis of the rotational axle base. 
     
     
         6 . The flow-bypassing structure of the grinding tool of  claim 3 , wherein the flow-bypassing passage is disposed on the lid member and substantially along an axis of the rotational axle base. 
     
     
         7 . The flow-bypassing structure of the grinding tool of  claim 4 , wherein the flow-bypassing passage is disposed on the lid member near the space and substantially along an axis of the rotational axle base. 
     
     
         8 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the flow-bypassing passage is communicated with the interior of the cylinder and the venting pathway. 
     
     
         9 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the flow-bypassing passage is communicated with the exhaust passage on the exterior of the cylinder and the venting pathway. 
     
     
         10 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein part of the main body surrounds the rotational working portion, and the space is formed among the part of the main body, the cylinder and the rotational working portion. 
     
     
         11 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein the abutting ring and the cylinder define the venting pathway. 
     
     
         12 . The flow-bypassing structure of the grinding tool of  claim 1 , wherein a side of the abutting ring facing the cylinder is formed with an outer ring protrusion and an inner ring recession which is relatively remote from the cylinder, and the end of the flow-bypassing passage is open toward the inner ring recession. 
     
     
         13 . The flow-bypassing structure of the grinding tool of  claim 12 , wherein a sealing ring member is further surroundingly disposed between the outer ring protrusion and the inner ring recession, and the sealing ring member is air-tightly abutted against the cylinder and the inner ring recession. 
     
     
         14 . A grinding tool, including the flow-bypassing structure of  claim 1 .