Novel Use of a U-Style Hydrostatic Transmission to Develop a Low-Power Dual-Mode Transmission

摘要

Rapid growth in developing economies has created a high demand for large quantities of small, low-cost, and low-tech agricultural equipment. Despite their small size, these machines are used in great quantities attributing to significant energy consumption. These machines could benefit from the gains in efficiency and performance provided by continuously variable hydrostatic (HST) and hydro-mechanical (HMT) transmissions typically found on larger, more advanced machines. This paper discusses the design of a dual-mode HST/HMT transmission based around a commercially available U-style integrated HST unit. The transmission was designed using off-the-shelf components to provide an efficient, cost effective solution for low-power agricultural equipment. Bench testing has demonstrated efficiency gains for the hydro-mechanical mode of five percent over the U-style HST unit alone. The transmission design is currently installed on two prototype tractors undergoing continued testing to refine the design and control system.