PTO transmission system in a work vehicle

摘要

A PTO transmission system in a vehicle for transmitting power to a PTO shaft driving an implement comprises a planetary drive unit having first and second input and output coupled to the PTO shaft. The first and second input means are coupled to an output shaft of the vehicle engine and to an output shaft of a drive motor, respectively. A control system controls the transfer of power from a power source to the drive motor. The power source is a variable power generating source driven by the PTO shaft. The drive motor is configured and adapted to decrease or increase the rotational speed of the output of the planetary drive unit on an increase or decrease of the power transferred to it, respectively.

主权项

1. A power take-off (PTO) transmission system in a work vehicle configured to transmit power to a PTO shaft driving an implement, the work vehicle comprising an engine and ground drive wheels driven by a main transmission comprising a continuously variable transmission (CVT) or a powershift transmission;
the PTO transmission system comprising:
a planetary drive unit having a first input, a second input, and an output, the first input being adapted to be coupled to an output shaft of the engine, the second input being adapted to be coupled to an output shaft of a drive motor, and the output being adapted to be coupled to the PTO shaft;a control system operable to control a speed of the engine, a transmission ratio of the main transmission, and the drive motor;an engine speed sensor and a PTO shaft speed sensor, operable to measure the speed of the engine and a speed of the PTO shaft, respectively, and communicatively coupled to the control system; wherein the control system is operable to control the speed of the engine, the transmission ratio of the main transmission, and the drive motor such that the speed of the PTO shaft corresponds to a target PTO shaft speed, and the PTO transmission system comprises a torque sensor operable to measure a load on the PTO shaft and communicatively coupled to the control system; wherein the control system in one working mode is operable to reduce the target PTO shaft speed when a target PTO load is below a first threshold value, the control system is operable to automatically reduce the target PTO shaft speed on a sudden increase of the load on the PTO shaft to avoid stall when the speed of the engine is below a second threshold value, or a combination thereof.