A rotating head assembly includes a body, an implement, a clamp assembly, a drive member, a hydraulic motor, and a bypass circuit. The drive member is threadingly connected to a first clamp member and a second clamp member. The hydraulic motor is connected to the drive member to cause the drive member to rotate in a selected direction. An inlet of the bypass circuit is in fluid communication with an inlet of the hydraulic motor to receive a portion of the pressurized hydraulic fluid passing to the hydraulic motor. An outlet of the bypass circuit is in fluid communication with the outlet of the hydraulic motor. At least one bypass valve is interposed between the inlet of the bypass circuit and the outlet of the bypass circuit. The bypass valve has an actuator positioned adjacent one of the first clamp member and the second clamp.

A hydraulic control device that reduces the loss of the power of a pump in combined operation of boom lowering and arm pushing. A controller performs single control of increasing capacity of a first pump in accordance with increase in an operation amount of a boom operation member, in a single operation of the boom lowering. On the other hand, the controller restricts the capacity of the first pump compared to capacity in the single control, during a restriction control period when the combined operation of boom lowering and arm pushing is detected, and the operation amount of the boom operation member is a prescribed operation amount or more.

A pneumatic control device includes a functional assembly that has an interruption valve device for the selective opening or interruption of at least one main working channel used for the pneumatic control of a pneumatic actuator. The functional assembly also contains a manually actuatable valve device that is connected to the interruption valve device by means of at least one auxiliary working channel and which enables manual pneumatic control of the connected actuator, if the at least one main working channel is interrupted by the interruption valve device at the same time. A process control device can also be equipped with a control device of this type.

A rotating head assembly includes a body, an implement, a clamp assembly, a drive member, a hydraulic motor, and a bypass circuit. The drive member is threadingly connected to a first clamp member and a second clamp member. The hydraulic motor is connected to the drive member to cause the drive member to rotate in a selected direction. An inlet of the bypass circuit is in fluid communication with an inlet of the hydraulic motor to receive a portion of the pressurized hydraulic fluid passing to the hydraulic motor. An outlet of the bypass circuit is in fluid communication with the outlet of the hydraulic motor. At least one bypass valve is interposed between the inlet of the bypass circuit and the outlet of the bypass circuit. The bypass valve has an actuator positioned adjacent one of the first clamp member and the second clamp.

A hydraulic system includes a first electric machine connected to a first hydraulic machine and a second electric machine connected to a second hydraulic machine. An output side of the second hydraulic machine is connected to an input side of the first hydraulic machine. A hydraulic consumer is hydraulically coupled to an output side of the first hydraulic machine via a supply line and is powered by the first hydraulic machine. A return line hydraulically couples the hydraulic consumer to an input side of the first hydraulic machine. The second hydraulic machine provides a flow of hydraulic fluid to the input side of the first hydraulic machine if a requested flow from the first hydraulic machine exceeds a flow of the return line and recuperates energy if the requested flow from the first hydraulic machine is lower than the flow of the return line.

Method for controlling a hydraulic system for a working machine, the system including a first electric machine connected to a first hydraulic machine the first hydraulic machine including an input side and an output side a second electric machine connected to a second hydraulic machine the second hydraulic machine including a high-pressure side and a low-pressure side the high-pressure side connected to the input side; a hydraulic consumer coupled to the output side via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side and to the high-pressure side; wherein the method includes detecting a return flow from the hydraulic consumer through the first return line; and controlling the second hydraulic machine to maintain a pressure in the first return line at a pressure level higher than a predetermined minimum pressure level.

An unloading valve includes a valve body, a valve trim, a return spring, a damping hole, and an unloading groove. A combined valve includes the unloading valve and a throttling valve. The throttling valve includes a buffer stopper and a buffer chamber. A piston rod assembly of the combined valve type buffer cylinder is provided in a cylinder body. The cylinder body includes a cylinder head flange, a cylinder bottom, and a cylinder barrel. The piston rod assembly includes a guide sleeve, a piston, and a piston rod. The combined valve is provided on the cylinder. The system is located in an unloading state in a buffering process to reduce the energy loss and heat buildup of the system, prevent the pressure impact of buffering on the system, make the system more reliable, and lower the difficulty of the original buffer valve in performance matching, installation and debugging.

A hydraulic system includes a first electric machine connected to a first hydraulic machine and a second electric machine connected to a second hydraulic machine. An output side of the second hydraulic machine is connected to an input side of the first hydraulic machine. A hydraulic consumer is hydraulically coupled to an output side of the first hydraulic machine via a supply line and is powered by the first hydraulic machine. A return line hydraulically couples the hydraulic consumer to an input side of the first hydraulic machine. The second hydraulic machine provides a flow of hydraulic fluid to the input side of the first hydraulic machine if a requested flow from the first hydraulic machine exceeds a flow of the return line and recuperates energy if the requested flow from the first hydraulic machine is lower than the flow of the return line.

A pneumatic control device includes a functional assembly that has an interruption valve device for the selective opening or interruption of at least one main working channel used for the pneumatic control of a pneumatic actuator. The functional assembly also contains a manually actuatable valve device that is connected to the interruption valve device by means of at least one auxiliary working channel and which enables manual pneumatic control of the connected actuator, if the at least one main working channel is interrupted by the interruption valve device at the same time. A process control device can also be equipped with a control device of this type.

A pneumatic control device includes a functional assembly that has an interruption valve device for the selective opening or interruption of at least one main working channel used for the pneumatic control of a pneumatic actuator. The functional assembly also contains a manually actuatable valve device that is connected to the interruption valve device by means of at least one auxiliary working channel and which enables manual pneumatic control of the connected actuator, if the at least one main working channel is interrupted by the interruption valve device at the same time. A process control device can also be equipped with a control device of this type.