A variable mechanical lubricant pump provides a pressurized lubricant for an internal combustion engine. The lubricant pump includes a delivery port which is fluidically connected to the engine, a control ring which shifts between a maximum and a minimum eccentricity position, a pump rotor having slidable vanes which rotate in the control ring, a control ring preload spring which pushes the control ring into the maximum eccentricity position, a hydraulic control chamber which pushes the control ring into the minimum eccentricity position, a pressure galley pump port fluidically connected to the engine, and an overpressure valve fluidically associated with the delivery port. The pressure gallery pump port charges the hydraulic control chamber with a gallery pressure to control a remote gallery pressure of the engine via a control chamber pressure in the hydraulic control chamber. The overpressure valve opens if an applied lubricant pressure exceeds a predefined maximum pressure limit.

An engine lubrication system including: an oil pump configured to be driven by an engine; an oil jet mechanism configured to inject oil pressure-fed by the oil pump to a piston; and circuitry configured to set a target hydraulic pressure of the oil injected from the oil jet mechanism according to an operation state of the engine; determine a hydraulic pressure state of the oil injected from the oil jet mechanism; and change a gear stage of the automatic transmission to a lower gear stage in a case that a predetermined condition between the determined hydraulic pressure state and the target hydraulic pressure is satisfied.

A gerotor pump assembly, and a system and method for operating a gerotor pump assembly, result in a lubrication strategy for operating in a loss-of-prime mode. An inner drive gear may be rotated in a first direction and in a second opposite direction about an axis of rotation. The inner drive gear has a number of projections extending outwardly therefrom. An outer driven gear surrounds the inner drive gear and defines a number of recessions along an inner surface configured to engage with the projections of the inner drive gear. The outer driven gear and the inner drive gear further define at least one dynamically-changing fluid cavity therebetween. The inner drive gear and the outer driven gear define an oil transfer volume clearance between a projection and a recession in a fully engaged position. Oil is maintained within the oil transfer volume clearance as the inner drive gear is rotated.

An oil pump includes a housing defining a pump cavity having an inner circumferential wall with a first segment located in a low-pressure side of the pump cavity. The first segment defines a recessed cutout. A gerotor pump set is disposed in the cavity and includes an inner drive rotor and an outer driven annulus. An outer circumferential wall of the outer annulus and the cutout cooperate to form an increased radial clearance to reduce friction losses between the outer annulus and the housing.

A variable mechanical lubricant pump provides a pressurized lubricant for an internal combustion engine. The lubricant pump includes a delivery port which is fluidically connected to the engine, a control ring which shifts between a maximum and a minimum eccentricity position, a pump rotor having slidable vanes which rotate in the control ring, a control ring preload spring which pushes the control ring into the maximum eccentricity position, a hydraulic control chamber which pushes the control ring into the minimum eccentricity position, a pressure galley pump port fluidically connected to the engine, and an overpressure valve fluidically associated with the delivery port. The pressure gallery pump port charges the hydraulic control chamber with a gallery pressure to control a remote gallery pressure of the engine via a control chamber pressure in the hydraulic control chamber. The overpressure valve opens if an applied lubricant pressure exceeds a predefined maximum pressure limit.

An internal combustion engine assembly includes a crankcase and a cam housing. The crankcase includes a crankcase cavity configured to receive a counterweight. The cam housing includes a cam housing cavity configured to receive a camshaft. A pump is positioned within the cam housing. The pump is configured to draw oil from an oil reservoir defined by the cam housing cavity. A crankshaft supports the counterweight for rotation therewith. The crankshaft is rotatably supported within the cam housing and is coupled to drive the pump. A bearing supports the crankshaft between the crankcase cavity and the cam housing cavity. The bearing includes an outer race. A seal is positioned between the pump and the bearing. The seal is positioned against the outer race to block the transmission of pressure fluctuations between the crankcase cavity and the oil reservoir.

A scavenge pump includes: a pump housing including a housing body and a cover member, the housing body having a rotor chamber in which an inlet port, an outlet port, and a bearing hole formed by shaft holes with varying diameters with a stepped surface therebetween are provided; an outer rotor housed in the rotor chamber and having inner teeth; an inner rotor having outer teeth and a shaft support hole; and a drive shaft inserted or fixedly attached to the shaft support hole. The bearing hole includes a stepped inner circumferential part having a larger diameter than that of the drive shaft at an open peripheral edge on one side facing the rotor chamber, and a groove that extends through between a point close to a trailing end of the outlet port and the stepped inner circumferential part is formed.

Methods and systems are provided for indicating degradation of a variable displacement oil pump. In one example, an engine method comprises indicating degradation of the oil pump based on a fuel usage change of the engine, responsive to a commanded change in displacement of the variable oil pump. In response to an indicated degradation, engine wear may be avoided and fuel economy may be improved by adjusting engine operation.

A machine includes a liquid lubrication system and a shaft, the shaft being rotatable about a rotation axis, the shaft including a first part, a second part engaged coaxially with the first part, and a journal bearing between the first part and the second part, the first part being rotatable relative to the second part about the rotation axis, a helical feature disposed between the first part and the second part and configured to define a helical pump between the first part and the second part, the pump being hydraulically connected to the liquid lubrication system, the journal bearing being disposed adjacent to the helical feature.

A variable displacement vane pump is described. The pump includes a control chamber provided between a housing and a control slide. A pressure-controlled relief valve is in fluid communication with the outlet path and moves to block or unblock a relief port based on output pressure of the lubricant. A feedback channel fluidly connects the control chamber to an inlet path of the pump. The feedback channel further connects to a control port that is connected to a main control valve. The relief valve and control valve are distinct and not fluidly connected. The relief valve moves once the pressure in the outlet path exceeds a predetermined amount, opening the relief port, and thus delivers a portion of the output lubricant to the control chamber via the relief port, thereby pressurizing the control chamber and reducing eccentricity of the pump by displacing the control slide.