초록 ▼

A system for monitoring the charge flow in a hydrostatic system. The system provides a sharp edge orifice restriction in the drain from the hydrostatic pump, creating a back pressure in the drain that is proportional to the fluid flow through the drain. A pressure switch mounted in the pump case, or

A system for monitoring the charge flow in a hydrostatic system. The system provides a sharp edge orifice restriction in the drain from the hydrostatic pump, creating a back pressure in the drain that is proportional to the fluid flow through the drain. A pressure switch mounted in the pump case, or in the drain, detects the back pressure in the drain. The pressure switch is designed to be activated at a back pressure that corresponds to the intended charge flow at a specific engine speed. During operation, if the back pressure is not sufficient to cause the pressure switch to be activated at the predetermined engine speed or at a faster engine speed, the charge flow is not sufficient and a warning signal is generated.

대표청구항 ▼

1. A hydrostatic system comprising:a hydrostatic pump and motor in fluid communication with one another; a charge pump providing a flow of fluid to the hydrostatic pump and motor, the charge pump receiving fluid from a sump; a fluid drain from the hydrostatic pump and motor to the sump, the drain fl

1. A hydrostatic system comprising:a hydrostatic pump and motor in fluid communication with one another; a charge pump providing a flow of fluid to the hydrostatic pump and motor, the charge pump receiving fluid from a sump; a fluid drain from the hydrostatic pump and motor to the sump, the drain flow being generally equal to the charge pump flow; an orifice in the drain the orifice being of a size selected to create a drain back pressure proportional to the charge and drain flow; and a pressure sensor to monitor the drain back pressure and thereby the charge pump flow, the sensor providing a warning signal when the charge pump flow drops below a predetermined level.