A hydraulic drive unit includes: a pump; a pair of supply-discharge lines; a valve block; a sealed tank; a suction line that leads hydraulic oil in the sealed tank to the pump; a connecting line that connects an air vent port of the pump to the suction line; and a gas-liquid separator that separates air and the hydraulic oil flowing through the connecting line from each other. The pump is disposed upward of the valve block and the sealed tank in a vertical direction.

A mechanical activation system including a first mechanical device mechanically connectable to and controllable by an external device, with a rotational orientation of the first mechanical device controllable by the external device, the rotational orientation representative of a parameter of the external device. The first mechanical device and second mechanical device having interacting surfaces for controlling a valve for preventing the parameter of the external device from reaching a critical value. An operator actuation device interacts with a surface of the first mechanical device, permitting a single operator input that is automatically resettable by the system.

An apparatus includes a bootstrap accumulator having multiple fluid expansion volumes each configured to receive fluid. The bootstrap accumulator also includes a piston assembly configured to move within the fluid expansion volumes based on pressures within the fluid expansion volumes. The piston assembly includes (i) a fluid pathway that couples the fluid expansion volumes and (ii) a bypass valve configured to selectively open or block the fluid pathway. The piston assembly could also include multiple pistons and a connecting rod coupling the pistons. The fluid pathway could include a narrower path through a first portion of the connecting rod and a wider path through a second portion of the connecting rod. The bypass valve could include a ball and a spring configured to push the ball to block the narrower path through the first portion of the connecting rod.

A modular electrohydraulic actuator including an electric motor, a hydraulic pump driven by the electric motor, and a hydraulic actuator in fluid communication with the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder supporting a pressure sleeve in which a piston and rod is adapted for reciprocating motion in response to a supply of pressurized fluid to a first side or a second side of the piston, wherein at least one of the electric motor, hydraulic pump, hydraulic cylinder, piston, piston rod or the pressure sleeve supported in the hydraulic cylinder is selectively removable and replaceable with a different component to vary at least one performance characteristic of the electrohydraulic actuator.

A control system can include a resettable chamber and a bidirectional valve. The bidirectional valve can be switchable between (i) a first configuration for enabling fluid flow from the control line into a first port of a well tool and from a second port of the well tool into the resettable chamber, and (ii) a second configuration for enabling fluid flow from the control line into the second port of the well tool and from the first port of the well tool into the resettable chamber. The bidirectional valve can be switched from the first configuration to the second configuration in response to pressure being applied to the control line.

A bootstrap hydraulic reservoir includes a bootstrap chamber to hold hydraulic fluid, a piston chamber fluidly connected to a pressure line of the hydraulic fluid system, a piston having a bootstrap end portion held within the bootstrap chamber and a pressure end portion held within the piston chamber, and a hydraulic accumulator fluidly connected to the pressure line of the hydraulic fluid system. The hydraulic accumulator accumulates pressurized hydraulic fluid from the pressure line. The bootstrap hydraulic reservoir also includes a valve fluidly connected to the pressure line of the hydraulic fluid system between the hydraulic accumulator and an outlet of a pump of the hydraulic fluid system. The valve includes an actuator selectively moves the valve to an open position when the pressure line of the hydraulic fluid system is de-pressurized.

A reservoir for a hydraulic system has a housing with an interior space and a fluid outlet, a hydraulic driving device coupled to a shaft extending in the housing to introduce a torque, and a separating device in the housing, for dividing the interior space into two separate sections. The fluid outlet is fluidically connected to a first section. The separating device extends along the shaft in the housing and sets the size ratio of the two separate sections by pivoting at least one first surface, coupled to the shaft, of the separating device about an axis defined by the shaft. The separating device is coupled to the hydraulic driving device such that the at least one first surface exerts a pressure on a fluid in the first section which is dependent on a surface area of the first surface and the torque.

There is described a device for adjusting a seat position of a bicycle seat. The device allows a rider of a bicycle to adjust the tilt of their bicycle seat while the bicycle is in motion, without the rider having to first dismount. In some embodiments, the rider may also adjust the height of their bicycle seat at substantially the same time as the seat's tilt is an adjusted, again without the rider having to first dismount. There are described a motorized embodiment in which one or more motors are used to drive a tilt actuator and a linear actuator, and a mechanized embodiment in which a source of pressurized air may be used to drive the linear actuator which in turn drives the tilt actuator.

A technique facilitates wellbore operations and utilization of wellbore equipment, e.g. equipment comprising actuation devices for downhole tools. According to an embodiment, the system comprises a pump solution for an electrically control device, e.g. an electrically controlled valve. The system may comprise hydraulic circuitry which utilizes bellows to effectively enclose the hydraulic circuitry. Consequently, the system enables an electrically control downhole system having components hydraulically actuated via a closed loop hydraulic system.

A technique facilitates rapid transitioning of a valve, e.g. a gate valve. According to an embodiment, a system comprises a valve actuator constructed for coupling with a valve to actuate the valve between closed and open positions. Hydraulic actuation fluid may be supplied to the valve actuator under pressure via a hydraulic supply system to enable selective shifting of the valve actuator, and thus the valve, from a closed position to an open position. The system also comprises a dump tank coupled to the valve actuator in a manner to receive hydraulic fluid. In a rapid valve actuation operation, e.g. closing operation, the dump tank receives hydraulic fluid from the valve actuator rather than returning the hydraulic fluid to the hydraulic supply system. This, in turn, enables rapid shifting of the valve actuator and thus rapid shifting of the valve.