Patent ID: 7172257
Filing Date: 2007-02-06
Classification: B62D

Abstract:
1. A crawler track tension adjusting device for adjusting tension on a crawler belt of a crawler unit, the device comprising: (a) a hydraulic actuator which is operable with operating oil to control the tension on the crawler belt, wherein an inflow of the operating oil to the hydraulic actuator is equal to an outflow of the hydraulic oil from the hydraulic actuator such that the hydraulic actuator is operable both in a direction to increase tension on the crawler belt and in a direction to decrease tension on the crawler belt under a same condition; (b) an electric motor; (c) a hydraulic pump driven by the electric motor; (d) an operating condition detector which is disposed in a hydraulic circuit that connects the hydraulic pump to the hydraulic actuator, and which detects an operating condition of the hydraulic actuator; and (e) a casing housing the hydraulic actuator, the electric motor, the hydraulic pump and the operating condition detector; wherein the electric motor is controlled in accordance with a signal from the operating condition detector.