DESIGN AND EVALUATI ON OF A LOW–POWER PORTABLE TEST RIG FOR VIBRATION TESTS ON MOBILE AGRICULTURAL MACHINERY

摘要

Increased capacity of mobile agricultural machinery and higher driver comfort requirements force manufacturers to incorporate dynamic behavior explicitly into the design. Therefore, vibration tests should be carried out during the design phase. Because many of these manufacturers are small, they lack the know-how and equipment to perform these tests. Transportation to and from specialized companies to evaluate the vibrational characteristics is costly and time-consuming because of the size and weight of most agricultural machinery. A low-power mobile electro-hydraulic shaker allows such analysis to be performed on the factory floor. Such a device can be created by putting an air spring parallel to the actuator of an electro-hydraulic shaker, resulting in considerable power savings. A shaker with and without a parallel spring is theoretically examined. Experiments on a one-degree-of-freedom vertical shaker showed good agreement with the theory and demonstrated that different mode shapes of an agricultural tractor can be sufficiently excited with a nominal hydraulic power of 500 W