Abstract: A controller for controlling a frequency inverter of a positive displacement pump motor of a positive displacement pump. The controller comprises a control unit configured to produce a control variable (Ys) for a frequency inverter of a positive displacement pump motor depending on a reference variable (W) and a first actual operating parameter (X). According to the invention, the control unit is associated with logical means having a first threshold value defining means that are designed to determine at least one first threshold value (YGrenzmax, YGrenzmin) depending on the first actual operating parameter (X) and/or at least one further actual operating parameter (XH, YH, YHH) that could lead to a failure state of the positive displacement pump when exceeded or fallen short of.

Abstract: A controller for controlling a frequency inverter of a positive displacement pump motor of a positive displacement pump. The controller comprises a control unit configured to produce a control variable (Ys) for a frequency inverter of a positive displacement pump motor depending on a reference variable (W) and a first actual operating parameter (X). According to the invention, the control unit is associated with logical means having a first threshold value defining means that are designed to determine at least one first threshold value (YGrenzmax, YGrenzmin) depending on the first actual operating parameter (X) and/or at least one further actual operating parameter (XH, YH, YHH) that could lead to a failure state of the positive displacement pump when exceeded or fallen short of.

Abstract: An apparatus and a method for controlling the braking operation of a machine having a large moment of inertia. The machine is driven by a motor through a coupling device. The control circuitry initiates first an uncoupling of the coupling device followed by a braking of the input side of the coupling device. Thereafter, and after the input side of the coupling has come to a stop, the coupling device is reactivated to couple the output side to the input side. Since the input side is blocked, this will effectively bring the machine to a halt.

Abstract: A lubricating device for use with transmission gearing, particularly in the starting phase of the transmission. A pair of oil reservoirs are provided with one being located higher than the other. The upper reservoir contains the transmission gearing therein. A pair of vertically spaced outlets are provided in the upper reservoir with both outlets being connected in fluid circuit with the lower reservoir. The fluid circuit for the lower outlet includes a valve controlling the flow of oil between the upper and lower reservoirs in response to the fluid pressure produced by a pump. The transmission gearing is immersed in the oil when the lower outlet is blocked by the valve, which will occur when the pump is off.