Abstract: The first piston of the first cylinder and the second piston of the second cylinder are connected so that the first piston and the second piston have the same displacement. The cross-section area of one side of the first piston is the smallest, and the cross-section area on the same side of the second piston is the third smallest. The two air chambers of the first cylinder and the two air chambers of the second cylinder are referred to as a first air chamber, a second air chamber, a third air chamber, and the fourth air in ascending order in the cross-section area. The control valve connects the air pressure source to the first air chamber, connects the second air chamber to the third air chamber, and opens the fourth air chamber to the atmosphere in the forward stroke.

Abstract: A method of controlling steering loads on a marine propulsion system of a marine vessel is provided. The marine vessel has at least two sets of marine drives, each set having at least an inner marine drive and an outer marine drive, and a steer-by-wire steering actuator is associated with each set of marine drives. The method includes determining a maximum required actuator pressure on each steer-by-wire steering actuator, and determining a pressure reduction amount based on the maximum required actuator pressure. A link toe angle has been determined based on the pressure reduction amount. A mechanical link connecting each inner marine drive to the respective outer marine drive is adjusted to achieve the link toe angle.

Abstract: A control system for a hydraulic steering cylinder utilizes a supply valve and a drain valve. The supply valve is configured to supply pressurized hydraulic fluid from a pump to either of two cavities defined by the position of a piston within the hydraulic cylinder. A drain valve is configured to control the flow of hydraulic fluid away from the cavities within the hydraulic cylinder. The supply valve and the drain valve are both proportional valves in a preferred embodiment of the present invention in order to allow accurate and controlled movement of a steering device in response to movement of a steering wheel of a marine vessel.

Abstract: A gas turbine engine includes an epicyclic gear train that drives a turbo fan. The epicyclic gear train employs a one-piece carrier in which the spaced side walls are interconnected with circumferentially spaced apart mounts to form a unitary structure. Baffles are secured to the carrier near the mounts and provide lubrication passages that spray oil onto the sun gear and/or intermediate gears arranged between the baffles. The baffles can be constructed from a different material than the carrier since the baffles are not structural components in the gear train.

Abstract: Methods and apparatus for driving a positive displacement pump disposed within a wellbore are disclosed herein. Embodiments of the present invention provide a drive mechanism for driving the downhole positive displacement pump. In embodiments of the present invention, the positive displacement pump is hydraulically driven and mechanically counterbalanced. The drive mechanism may be mechanically or electrically controlled, or may be controlled by a combination of mechanical and electrical controls.

Abstract: The invention contemplates oil-well pumping apparatus (a) in which a traction cylinder is mounted at the well-head for direct reciprocating operation of the polish rod from which a pumping piston is suspended in a well casing, and (b) in which hydraulic-counterweight principles of copending application, Ser. No. 601,481, filed Apr. 18, 1984 are employed to reduce lift-capacity requirements which would otherwise be imposed on the prime mover.

Abstract: The preferred embodiment is directed to an oil well pumping apparatus incorporating a walking beam having a horsehead at one end which connects to the sucker rods in the oil well. The opposite end of the walking beam is supported on a fixed pivot. A hydraulic and pneumatic combination unit connects from a supporting platform to a central point on the beam to raise and lower the beam. The improved apparatus utilizes air pressure to balance the static load on the apparatus and dynamically strokes the sucker rod string by imparting a reciprocating motion through hydraulic power applied at a specified rate to raise and lower the walking beam. A pump and motor system for a closed hydraulic loop is included. Alternate preferred embodiments are disclosed. In one form, a lubricating system is incorporated. First and second alternate forms of pickoff apparatus which powers the pneumatically balanced pumping apparatus is also included.

Abstract: An oil well pump drive including a drive unit that is hydraulically actuated by a double-acting hydraulic cylinder to reciprocate vertically. An endless chain is entrained over vertically spaced sprockets carried by the unit, with one flight of the chain anchored against vertical movement and the other flight is secured to the pump polish rod so that the vertical motion imparted to the polish rod is double that hydraulically imparted to the drive unit. The polish rod load on the chain is opposed by a counterweight connected thereto by a chain extending over an elevated pulley. The output of the hydraulic pump supplying the hydraulic cylinder is cam controlled so that the motion of the drive unit is smoothly decelerated and accelerated as the unit approaches and moves from the upper and lower limits of its movement.

Abstract: A system is provided for maintaining a permanent reciprocatory movement of a mechanical arrangement, particularly a pump unit. A main driving wheel is coupled to the mechanical arrangement and fastened on the shaft of a hydraulic motor which is supplied by a variable delivery pump provided with control means. The control means is coupled to the wheel by a drive mechanism which comprises a rocking lever coupled to the control means and a cam carrier wheel rotationally fixed to the wheel. As the mechanical arrangement moves in one direction, the rotation of the driving wheel causes the cam wheel to change the position of the rocking lever thus permitting the control means to direct the flow of fluid from the variable delivery pump to the hydraulic motor to reverse the direction of travel of the mechanical arrangement.