Abstract: A method and apparatus are disclosed for selectively providing a fluid communication path between a plunger element and a contact region of an intermediate element that drives the plunger element. The fluid communication path is suitable for lubricant flow to enable a contact zone to occasionally be lubricated. The apparatus includes an elongate plunger element comprising a first end region, an intermediate element comprising a contact region arranged to selectively abut with and thereby urge a further end region of the plunger element and a spring seat member at the further end region of the plunger element. The spring seat member biases the further end region of the plunger element away from the intermediate element during a portion of a cycle of motion of the plunger element. A fluid communication path is thereby provided between an abutment surface of the further end region and the contact region.

Abstract: A pump head for a high-pressure fuel pump is disclosed. The pump head comprises a head housing including a body portion, and a turret portion extending from the body portion, a pumping chamber defined within the body portion, a pumping element bore for receiving a pumping element in use, the pumping element bore extending from the pumping chamber and through the turret portion, and a leakage return passage. The pump head further comprises a sleeve arranged around the turret portion to define a leakage flow path to allow fuel flow from the pumping element bore to the leakage return passage. The pump head is suitable for use in a fuel pump of the type in which a cam drive arrangement of the pump is lubricated by engine oil, since contamination of the engine oil with fuel can be minimised.

Abstract: A roller vane pump for fluid includes a carrier which is rotatable in a housing about an axis of rotation, the carrier carrying a plurality of roller vanes which are each received in a respective slot which extends inwardly of a periphery of the carrier and permits the roller to move inwardly and outwardly in use, the housing surrounding the carrier, pumping chambers being formed between the rollers, the carrier and the housing, the rollers engaging with the housing and moving inwardly and outwardly of their respective slots as the carrier rotates, in response to the configuration of the housing so that the pumping chambers change in volume as the carrier rotates, to effect pumping of the fluid, from an inlet to an outlet of the pump, and wherein in each of the slots in which the rollers are received, there is provided a restrictor element which restricts movement of the roller inwardly of its respective slot.