Patent ID: 9243618
Filing Date: 2016-01-26
CPC Classification: F04B,F16N

Claim Text:
1. A pump device for lubricant comprising: a tank for storing lubricant; a block-shaped pump main body provided with a suction port, a suction path along which the lubricant stored in the tank is suctioned from the suction port, a discharge port, and a discharge path along which the suctioned lubricant is discharged from the discharge port; a cylinder part provided with an introduction port which is formed in the pump main body and is intercommunicated with the suction path and introduces the lubricant from the suction path, and a derivation port which is intercommunicated with the discharge path and leads the lubricant to the discharge path; a piston which is inserted into the cylinder part to move forward and backward within the cylinder part, and arranged to suction the lubricant from the introduction port when moved backward and discharge the lubricant from the derivation port when moved forward; an actuator which allows the piston to move forward to a 1st position at which the lubricant is discharged from the derivation port, move backward from the 1st position to a 2nd position at which the lubricant is suctioned from the introduction port and further move backward from the 2nd position to a 3rd position at which the suction and discharge of the lubricant is stopped; a driving control device which drives and controls the actuator such that when the lubricant is supplied, the piston is allowed to move from the 3rd position to the 1st position and allowed to move between the 1st position and the 2nd position, and when the lubricant is not supplied, the piston is allowed to move to the 3rd position and stop; a 1st detection part which detects that the piston is positioned at the 1st position; a 2nd detection part which detects that the piston is positioned at the 2nd position; and a 3rd detection part which detects that the piston is positioned at the 3rd position; wherein the driving control device drives and controls the actuator based on each of start command signals, detection signals from the 1st detection part, the 2nd detection part and the 3rd detection part, and stop command signals, the cylinder part of the pump main body is formed with a 1st opening and a 2nd opening which are blocked when the piston moves between the 1st position and the 2nd position and is opened when the piston is allowed to move back to the 3rd position and the pump main body is formed with a 1st path which connects the 1st opening and the discharge path a 2nd path which connects the 2nd opening and the suction path, and a decompression path which reaches the suction path after passing the discharge path, the 1st path, the cylinder part and the 2nd path when the piston is allowed to move backward to the 3rd position.