Patent ID: 9458842
Filing Date: 2016-10-04
CPC Classification: B60T,E02F,F04B,F15B,F16H

Claim Text:
1. A hydrostatic drive system for a vehicle, comprising: an open circuit including: a closed circuit configured to propel the vehicle including: an electronic controller connected to the speed sensor and the main variable displacement hydraulic pump, the electronic controller being configured to run a strong braking mode in which the electronic controller at least partially increases the displacement of the main variable displacement hydraulic pump such that hydraulic fluid is discharged via the pressure relief valve into the reservoir if an engine speed is determined, based on a signal received from the speed sensor, which is higher than a predetermined maximum engine speed, wherein the electronic controller is configured to control the displacement of the main variable displacement hydraulic pump by increasing and decreasing the displacement during the strong braking mode such that the engine speed varies within a predetermined engine speed range including the predetermined maximum engine speed, and wherein the electronic controller is additionally configured to control at least one of the displacement of the auxiliary variable displacement hydraulic pump and a displacement of the hydraulic motor by increasing and decreasing the displacements during the strong braking mode such that the engine speed varies within a predetermined engine speed range including the predetermined maximum engine speed.