Linde Aktiengesellschaft

Alfred Langen

Horst Deininger

Wolfgang Backe

Marcus Jarchow

Wolfgang Kraft

The invention relates to a drive axle (A) for a self-propelled work machine, in particular an industrial truck, in which two traction motors (EF, EF) spaced apart from each other and an electric motor (E) arranged axially in between them and provided to drive a hydraulic pump (P) are integrated. In order to utilize the installation space available optimally, according to the invention the electric motor (E) is arranged at right angles to the traction motors (EF, EF), as based on the longitudinal center line of the drive axle (A).

Drive axle with integrated electric motor for a hydraulic pump

A hydrostatic drive system with an adjustable pump in the delivery flow has at least one consuming device connected to the pump. Associated with each consuming device are actuation devices that specify the direction of movement and the speed of movement. A control valve device controls the direction of movement and the speed of movement. The delivery flow of the pump can be adjusted to the hydraulic flow required by the actuated consuming devices. The hydrostatic drive system makes possible the operation of the consuming devices independently of the load and the operation of the consuming devices independently of the direction of the load, in a simple manner and with lower energy losses. Associated with each consuming device is a delivery flow sensor that measures the hydraulic flow discharged from the consuming device to a reservoir, and/or a delivery flow sensor that measures the hydraulic flow from a delivery line of the pump to the consuming device. Each delivery flow sensor is connected to an electronic control. The electronic control is connected to the actuation device, to the control valve device and to a delivery flow setting device of the pump. The electronic control controls the control valve device and/or the delivery flow setting device of the pump as a function of the direction of movement and the speed of movement specified at the actuation device and of the hydraulic flow discharged from the consuming device measured at the delivery flow sensor and/or the hydraulic flow admitted to the consuming device measured at the delivery flow sensor.

Hydrostatic drive system

A hydrostatic drive system with a pump and at least one consuming device that is connected to the pump can be actuated by a control valve. The control valve can be actuated as a function of an actuator that specifies a desired speed of movement and a direction of movement of the consuming device. The control valve in the center position, makes possible an unpressurized circulation of the pump. The control valve can be actuated electrically, and there is a sensor that measures the actual speed of movement of the consuming device. The control valve, the speed-of-movement sensor and the actuator are connected with an electronic control that controls the control valve as a function of the direction and speed of movement specified by the deflection of the actuator and of the actual speed of movement of the consuming device as measured by the speed-of-movement sensor. The speed-of-movement sensor may be a delivery flow sensor.

This invention relates to a device to reduce pulsations on a hydrostatic positive displacement unit, such as an axial piston machine or a radial piston machine which can be used both as a pump and as a motor. The direction of rotation of the positive displacement unit is reversible and at least one piston is mounted so that it can move longitudinally in a cylinder bore forming a cylinder chamber. The device has a buffer element which can be brought into communication with the cylinder chamber by a connecting channel. It is possible to further optimize the reversing action of the cylinder chambers from the inlet side to the outlet side and to effectively minimize pulsations in a broad bandwidth of operating conditions by increasing the capacity of the buffer element compared to the capacity of an oil-filled buffer element and/or by providing at least one additional connecting channel which connects the cylinder chamber with the buffer element or with a control nodule of the positive displacement unit, whereby a throttling device is located in the other connecting channel. The buffer element may be a hydropneumatic buffer.

Device to reduce pulsations on a hydrostatic positive displacement unit

A hydrostatic drive system including a pump and a hydraulic motor in an open circuit which includes a feed line and a control valve in the feed line on the inflow side of the hydraulic motor to control the quantity of hydraulic pressure medium supplied to the hydraulic motor. A brake valve is located in the open circuit on the outflow side of the hydraulic motor to receive hydraulic pressure medium flowing out of the hydraulic motor. The control valve and the brake valve are constructed for independent actuation so that the functions of the control valve and the brake valve can be reversed when the direction of rotation of the hydraulic motor is reversed and the actuating pressure on the brake valve in the braking phase depends on the inflow pressure to the hydraulic motor independently of the actuating pressure on the control valve.

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Goldbach, Germany

Alfred Langen