Abstract: A nutating or wobble type pump has at least one flexible member connected to the pump's yoke and the pump's housing. The flexible member does not have any sliding joints therein. The member flexes in a manner that allows the yoke to tilt relative to the pump's axis while restraining the yoke from rotating.

Abstract: A nutating pump for creating pressure or a vacuum. The nutating pump includes a housing with a center support positioned within said housing. The center support includes a semi-spherical recess. The pump also includes a drive shaft adapted to be connected to an electric motor and an eccentric adapted to be connected to the drive shaft. The pump further includes a ball adapted to form a ball joint and is adapted to be positioned within the semi-spherical recess of said center support. In addition the pump includes a nutating yoke positioned within the housing. The yoke includes a semi-spherical recess adapted to accept said pivot ball. The nutating yoke is adapted to be connected to the eccentric, such that rotation of the eccentric causes the yoke to move about the ball.

Abstract: A nutating pump for creating pressure or a vacuum. The nutating pump includes a housing with a center support positioned within said housing. The center support includes a semi-spherical recess. The pump also includes a drive shaft adapted to be connected to an electric motor and an eccentric adapted to be connected to the drive shaft. The pump further includes a ball adapted to form a ball joint and is adapted to be positioned within the semi-spherical recess of said center support. In addition the pump includes a nutating yoke positioned within the housing. The yoke includes a semi-spherical recess adapted to accept said pivot ball. The nutating yoke is adapted to be connected to the eccentric, such that rotation of the eccentric causes the yoke to move about the ball.

Abstract: A nutating pump has a cross-type universal joint connecting a nutating member to a pump housing, ball joints connecting the nutating member to piston rods, and the piston rods fixed to piston heads so that the piston heads wobble in pump cylinders.

Abstract: A piston pump or compressor has a dynamically balanced drive assembly in which nearly all of the rotational, oscillatory and axial forces on the rotating drive shaft are canceled. The piston is primarily balanced by adding an oscillating counter weight mounted to the connecting rod to convert oscillatory forces into rotational forces at the axis of an eccentric element mounting the piston to the drive shaft. The remaining unbalanced rotational forces are centered along the drive shaft by a rotating counter weight. A further counter weight is mounted to the drive shaft spaced along the drive shaft from the rotating counter weight to impart a counter moment on the drive shaft and essentially cancel the moment about a moment axis perpendicular to the drive shaft resulting from the axial spacing of the piston and the other two counter weights. A method of reducing vibration on a piston drive shaft is also disclosed.

Abstract: An oxygen concentrator is controlled during start-up to rapidly shuttle the sieve beds between communication with the pump and atmospheric pressure, so the pressure in the sieve beds is relieved while the pump motor is starting up. After the start-up period, the sieve beds are alternately connected to the pump and atmospheric pressure for longer continuous periods.

Abstract: A pump has wobble pistons rigidly connected to arms of a nutating plate that is mounted on a bearing eccentrically mounted to a drive shaft by a counterweight. The piston assembly is nearly perfectly balanced by the counterweight due to its precisely defined moment of inertia and mass components. In particular, the counterweight produces a counter moment equal to the average moment produced by the piston assembly, preferably with a mass moment of inertia component corresponding to the average mass moment of inertia of the piston assembly. It also has a mass component providing a counter balance force opposing a radial force arising from the piston assembly having a center of gravity spaced from the shaft axis, and it has a mass component providing a counter balance moment opposing the moment arising from the counter balance force and the center of gravity of the piston assembly being spaced apart axially.

Abstract: A pump has wobble pistons rigidly connected to arms of a nutating plate that is mounted on a bearing eccentrically mounted to a drive shaft by a counterweight. The piston assembly is nearly perfectly balanced by the counterweight due to its precisely defined moment of inertia and mass components. In particular, the counterweight produces a counter moment equal to the average moment produced by the piston assembly, preferably with a mass moment of inertia component corresponding to the average mass moment of inertia of the piston assembly. It also has a mass component providing a counter balance force opposing a radial force arising from the piston assembly having a center of gravity spaced from the shaft axis, and it has a mass component providing a counter balance moment opposing the moment arising from the counter balance force and the center of gravity of the piston assembly being spaced apart axially.