Engine cooling system for motorcycle

Abstract

An engine cooling system for a motorcycle of the present invention includes an engine that includes a crankcase and a cylinder, a water pump to supply cooling water to the engine, and a radiator that dissipates heat of internally circulating cooling water by receiving a travelling wind. The water pump is an electrically operated type including a driving motor, and disposed independently of the crankcase.

1 . An engine cooling system for a motorcycle, comprising:
 an engine that includes a crankcase and a cylinder;   a water pump to supply cooling water to the engine; and   a radiator that dissipates heat of internally circulating cooling water by receiving a travelling wind, wherein   the water pump is an electrically operated type having a driving motor, and disposed independently of the crankcase.   
     
     
         2 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the water pump is disposed such that a pump shaft of the water pump is separated from a pump shaft of an oil pump in a side view of the vehicle body, and   in a vehicle body width direction, the water pump is disposed such that at least apart of the water pump is lying inside outer ends of the crankcase, the cylinder, or the radiator.   
     
     
         3 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the water pump is disposed ahead of the crankcase or the cylinder and rear of a rear end portion of a front wheel, and disposed downward of the radiator in the side view of the vehicle body.   
     
     
         4 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the crankcase includes a balancer shaft holder ahead of a shaft of an internal crankshaft, and   at least a part of the water pump overlaps with respect to the balancer shaft holder in the vertical direction, and the water pump is disposed ahead of the crankcase and downward of the balancer shaft holder in the side view of the vehicle body.   
     
     
         5 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the crankcase includes a balancer shaft holder ahead of a shaft of an internal crankshaft, and   at least a part of the water pump overlaps with respect to the balancer shaft holder in the vertical direction, and the water pump is disposed ahead of the cylinder and upward of the balancer shaft holder in the side view of the vehicle body.   
     
     
         6 . The engine cooling system for the motorcycle according to  claim 4 , wherein
 the water pump is disposed such that a longer side direction of the water pump is disposed to extend approximately parallel to an axis line of a balancer shaft in the front view of the vehicle body.   
     
     
         7 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the cylinder includes a cylinder block and a cylinder head, internally includes a coolant passage space that covers a peripheral area of a combustion chamber, and includes a cooling water inlet and a cooling water outlet to communicate with outside of the cylinder from the coolant passage space, and   both the cooling water inlet and the cooling water outlet of the cylinder are disposed on an identical one side in the vehicle body width direction.   
     
     
         8 . The engine cooling system for the motorcycle according to  claim 7 , wherein
 the coolant passage space communicates with the outside of the cylinder block by the cooling water inlet and the cooling water outlet only.   
     
     
         9 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the water pump includes a cooling water discharge port and a cooling water suction port on one side and another side in the vehicle body width direction respectively in the front view of the vehicle body, and   the radiator includes a cooling water intake and a cooling water supply port on one side and another side in the vehicle body width direction respectively.   
     
     
         10 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the cylinder includes a cam chain chamber on the other side in the vehicle body width direction.   
     
     
         11 . The engine cooling system for the motorcycle according to  claim 1 , wherein
 the engine includes an oil cooler in the crankcase, the oil cooler includes a cooling water inlet, a cooling water outlet, and a coolant passage to perform heat exchange with engine lubricating oil,   the oil cooler is disposed in the crankcase, and includes the cooling water outlet and the coolant passage on the other side in the vehicle body width direction, and   the cooling water inlet side of the oil cooler is coupled to the radiator, and the cooling water outlet side is coupled to the water pump.