Design of pedestal for mounting of hydraulic grapple on skidder

Abstract

Skidders represent an important part of the forestry. They allow to perform timber harvesting in difficult conditions of forests in an effective way. In the Slovak republic, only one company currently produces several types of articulated steering skidders differing by the dimensions, operating weight, engine power etc., which are well-known and used in the region of central and Eastern Europe for many years. These products are exposed to the strong competition from other world producers. In comparison with earlier technical solution of skidders, which have used winches for pulling trees to a landing, skidders are recently most often equipped with a hydraulic grapple, which is controlled by an operator directly from a skidder cabin. Thus, the operator has not to get off the cabin in order to drag the cable to the logs and hook them up. Hence, the hydraulic grapple improves the user comfort of a skidder, mainly in bad weather conditions. Therefore, every skidder is currently required to allow mounting the hydraulic grapple. The content of this article is focused on presentation of the design of a pedestal, which is intended to be mounted on an articulated steering skidder. The pedestal is the structural unit of the smallest type of the skidders produced in the Slovak Republic. The designed pedestal will be mounted in the rear part of the skidder. Winches are located under it. Therefore, the pedestal has to be clapper for better access to winches during maintenance and repair processes. As the pedestal will be loaded by various types of loads resulting from its fundamentals in the real operating conditions, its structure has to be designed precisely. The article contains a CAD model of the pedestal. Based on the calculated forces, which will act on it during a real operation, strength analyses are carried out.