US 2009/0290997 A1 · Reduced flow pulsations in a tandem floating cup pump with an odd number of pistons

Abstract

A method for reducing the flow pulsations in a tandem floating cup pump having an odd number of pistons includes determining a low noise net index angle that produces reduced flow pulsations relative to those produced when the net index angle is either zero or half the separation angle and offsetting a first rotating group relative to a second rotating group by the low noise net index angle. The net index angle is the sum of a piston index angle and the port plate index angle. The piston index angle is the angle between a piston from a first rotating group and an adjacent piston from a second rotating group whereas the port plate index angle is the angle by which a first port plate is offset relative to a second port plate.

Claims20

Dependent claims

A method for reducing flow pulsations in a tandem floating cup pump having an odd number of pistons in each of a first and second rotating group, each piston on each rotating group spaced equally apart from an adjacent piston by a separation angle, comprising the steps of:

determining a low noise net index angle that corresponds to reduced flow pulsations with respect to the flow pulsations produced at a net index angle of zero and the flow pulsations produced at a net index angle of half the separation angle;
setting a net index angle between a top dead center orientation of the first rotating group relative to a top dead center orientation of the second rotating group to the low noise net index angle.

A floating cup pump, comprising:

a rotor, a first barrel plate and a second barrel plate, attached to a shaft;
a first rotating group comprising a first set of an odd number of floating cups, each floating cup swivelly attached to the first barrel plate, a first set of an odd number of pistons, each piston being equally spaced apart from an adjacent piston by a separation angle and each piston having a first end and a second end, the first end of each piston attached to the rotor, the second end of each piston received by a respective one of the first set of floating cups;
a second rotating group comprising a second set of the odd number of floating cups, each floating cup swivelly attached to the second barrel plate, a second set of pistons, having a same number of pistons as the first rotating group, each piston being equally spaced apart from an adjacent piston by the separation angle and each piston having a first end and a second end, the first end of each piston attached to the rotor, the second end of each piston received in a respective one of the second set of floating cups;
the first rotating group and the second rotating group having a first relative orientation, the first relative orientation defining a piston index angle;
a first port plate adjacent the first barrel plate defining a bottom dead center position of the first rotating group;
a second port plate adjacent the second barrel plate defining a bottom dead center position of the second rotating group;
the bottom dead center of the first rotating group and the bottom dead center of the second rotating group having a second relative orientation, the second relative orientation defining a port plate index angle;
a low noise net index angle being the sum of the piston index angle and the port plate index angle, wherein the low noise net index angle is different from zero and half of the separation angle.

5 more elements

A floating cup pump, comprising:

a rotor, a first barrel plate and a second barrel plate, attached to a shaft;
a first rotating group comprising a first set of an odd number of floating cups, each floating cup swivelly attached to the first barrel plate, a first set of an odd number of pistons, each piston being equally spaced apart from an adjacent piston by a separation angle and each piston having a first end and a second end, the first end of each piston attached to the rotor, the second end of each piston received by a respective one of the first set of floating cups;
a second rotating group comprising a second set of the odd number of floating cups, each floating cup swivelly attached to the second barrel plate, a second set of pistons, having a same number of pistons as the first rotating group, each piston being equally spaced apart from an adjacent piston by the separation angle and each piston having a first end and a second end, the first end of each piston attached to the rotor, the second end of each piston received in a respective one of the second set of floating cups;
the first rotating group and the second rotating group having a first relative orientation, the first relative orientation defining a piston index angle;
a first port plate adjacent the first barrel plate defining a bottom dead center position of the first rotating group;
a second port plate adjacent the second barrel plate defining a bottom dead center position of the second rotating group;
the bottom dead center of the first rotating group and the bottom dead center of the second rotating group having a second relative orientation, the second relative orientation defining a port plate index angle;
a net index angle being the sum of the piston index angle and the port plate index angle;
and
means, including setting the net index angle to a low noise net index angle different from zero and half the separation angle, for reducing noise due to flow pulsations.

7 more elements

Dependencies are inferred from the claim text.

Reduced flow pulsations in a tandem floating cup pump with an odd number of pistons

Life of this patent

Reduced flow pulsations in a tandem floating cup pump with an odd number of pistons

Life of this patent

Abstract

Claims20