A lubricant vane pump for providing a pressurized lubricant for an internal combustion engine includes a pump housing, a pump chamber, a shiftable control ring comprising a pressure-relief-valve, a pump rotor, a pretensioning element which pushes the control ring into a high pumping volume position, a control chamber, and a pump outlet cavity fluidically connected to the control chamber. The pump chamber comprises pump compartments which rotate from a charge to discharge zone. The control ring envelops the pump chamber. The pump rotor comprises radially slidable vanes which rotate in the control ring to provide the pump chamber with the pump compartments. A high lubricant pressure in the control chamber moves the control ring into a low pumping volume direction against the pretensioning element. The pressure-relief-valve of the control ring connects or disconnects the control chamber with one of the pump compartments between the charge zone and the discharge zone.

A lubricant pump includes a housing having a shiftable control ring which radially confines a pumping chamber, an outlet chamber, a rotor, a pumping chamber pressure section, and a slide bearing. An interface between the outlet chamber and the control ring defines an outside pressure surface of the control ring. An interface between the pumping chamber pressure section and the control ring defines an inside pressure surface of the control ring. The slide bearing supports the control ring within the housing and includes a first slide bearing surface defined by the housing and which extends in a slide plane, and a second slide bearing surface defined by the control ring. An outside projection area defined by an orthographic projection of the outside pressure surface onto the slide plane is smaller than a maximum inside projection area defined by an orthographic projection of the inside pressure surface onto the slide plane.

An oil pump includes a pump component, a valve container, a valve mechanism, and a circumvention passage. The valve container includes a through hole establishing communication between an inside and an outside of the valve container. The valve mechanism includes: a valve body contained in the valve container; a valve element contained movably in the valve body; a back pressure chamber disposed to face a first valve end of the valve element; a drive mechanism disposed to face a second valve end of the valve element and structured to generate a drive force to move the valve element; and an aperture positioned higher in a vertical direction than the through hole and formed in the valve body so as to establish communication between the back pressure chamber and the inside of the valve container. The circumvention passage establishes communication between the through hole and the aperture.

A system for controlling a variable oil pump is provided. The system includes a variable oil pump that varies a discharge pressure of oil and an actuator that is operated to vary the discharge pressure of the oil of the variable oil pump. A controller turns the actuator on or off based a relationship between an outdoor temperature and a cooling water temperature of an engine.

One embodiment of a pump may include an idler gear having a plurality of idler gear teeth extending radially outward, wherein at least one of the idler gear teeth may be formed with an idler gear cavity therein. The pump may include a drive gear having a plurality of drive gear teeth extending radially outward that may be intermeshed with the idler gear teeth during use. The drive gear may be formed with a recess at on axial end thereof, and the axial position of the recess may correspond to the axial position of the idler gear cavity. In one embodiment of a pump, each idler gear tooth may be formed with an identical idler gear cavity at the same relative position on each idler gear tooth.

A power unit includes at least one drive source that outputs rotational power to a drive target other than pumps; a first pump rotationally driven by the rotational power of the drive source; a second pump rotationally driven by the rotational power of the drive source, the second pump being different form the first pump; and a power transmission structure that transmits the rotational power of the drive source to the first and second pumps. The power transmission structure includes transmission components and transmits the rotational power to the first pump through one of the transmission components and to the second pump through another of the transmission components.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A lubricant holder for vertical conveying of lubricant using a crankshaft of a coolant compressor includes a sleeve element having a clear cross-section delimited by an inside wall, which cross-section extends along a longitudinal axis, from an upper end to a lower end, an inner element that has a mantle surface that extends along a longitudinal axis of the inner element, from a lower end to an upper end, wherein in an operating state the inner element is arranged within the clear cross-section with its mantle surface, at least in certain areas. At least one groove of the inside wall and/or of the mantle surface, which groove runs in spiral shape, has a varying angle of inclination, which preferably increases from the lower end to the upper end of the mantle surface.

Variable displacement pump has first control hydraulic chamber 21 giving force to cam ring 5 in direction that decreases volume variation of each pump chamber 13 by internal pressure, second control hydraulic chamber 22 giving force to cam ring in direction that increases volume variation of each pump chamber by internal pressure, first seal surface 44 formed on both end surfaces of cam ring, which are in sliding-contact with both opposing inside surfaces of pump body 1 and cover member 2, and sealing gap between each pump chamber and first control hydraulic chamber, and second seal surface 45 sealing gap between each pump chamber and second control hydraulic chamber at outlet section side. Radial direction width W2 of second seal surface is greater than that W1 of first seal surface. Increase in weight of the pump can be suppressed while suppressing increase in pump control pressure against intention of control.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.