Rotary pump and cam ring therefor
AssigneeLucas Industries Limited
InventorGraham Paul Boyd Balfour
Life of this patent
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Abstract
A rotary pump such as a rotary fuel injection pump comprises a pump body; a rotor rotatably supported by the pump body and responsive to mechanical pulses to pump a fluid; and a stator ring (208) supported by the pump body and having a ring of projections (209) arranged to deliver mechanical pulses to the rotor when the rotor rotates relative to the stator ring. The stator ring (208) has a vibrational mode which is induced by delivering the mechanical pulses to the rotor. The pump body supports the stator ring across an interface which is a complete annulus or a partial annulus. In order to reduce the transmission of vibration from the stator ring to the pump body, the interface and/or stator ring incorporate cavities at the antinodes of the vibrational mode of the stator ring.
Claims21
A rotary pump comprising:
- a pump body;
- a rotor rotatably supported by the pump body and responsive to mechanical pulses to pump a fluid;
- and
- a stator ring supported by the pump body and having a ring of projections arranged to deliver mechanical pulses to the rotor when the rotor rotates relative to the stator ring;
- wherein;
- the stator ring has a vibrational mode which is induced by delivering the mechanical pulses to the rotor;
- the pump body supports the stator ring across an interface which is a complete annulus or a partial annulus;
- and
- at the interface, and/or in the stator ring, there are cavities positioned at the antinodes of the vibrational mode of the stator ring so as to reduce the vibrational transmission from the stator ring to the pump body across the interface and wherein the interface comprises a first surface of the stator ring and a second surface of the pump body;
- the second surface lies on a notional interface circle;
- the first surface has along its length a series of peaks and a series of depressions located between the peaks;
- and
- the peaks lie on the notional interface circle so as to abut the second surface, whereby the stator ring is supported by the pump body, and the depressions extend away from the notional interface circle so as to form the cavities at the interface.
A rotary pump comprising:
- a pump body;
- a rotor rotatably supported by the pump body and responsive to mechanical pulses to pump a fluid;
- and
- a stator ring supported by the pump body and having a ring of projections arranged to deliver mechanical pulses to the rotor when the rotor rotates relative to the stator ring;
- wherein:
- the stator ring has a vibrational mode which is induced by delivering the mechanical pulses to the rotor;
- the pump body supports the stator ring across an interface which is a complete annulus or a partial annulus;
- and
- at the interface, and/or in the stator ring, there are cavities positioned at the antinodes of the vibrational mode of the stator ring so as to reduce the vibrational transmission from the stator ring to the pump body across the interface and wherein the stator ring comprises inner and outer component rings which are rigidly fixed together and the cavities are formed as gaps in the annular joint between the component rings.
A cam ring for a rot wherein:
- the cam ring has an annular inner surface which faces radially inwards and includes a ring of cam lobes for driving pump plungers of a pump rotor;
- the cam ring has an annular outer surface which faces radially outwards and has, along part or all of its length, a series of peaks and a series of depressions located between the peaks;
- and
- each depression is radially aligned with a respective one of the cam lobes
- wherein each peak has a curved top which lies on a notional circle common to all of the curved tops of the peaks and has the same curvature as the notional circle.
A cam ring for a rotary pump, wherein:
- the cam ring comprises inner and outer component rings which are rigidly fixed together:
- the inner component ring has an annular inner surface which faces radially inwards and includes a ring of cam lobes for driving pump plungers of a pump rotor;
- and
- at least one cavity is present in an annular joint between the component rings.
Dependencies are inferred from the claim text.