A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A transfer pump configured to move a hydraulic fluid in a hydraulic fluid management system of a hydraulic system of a vehicle including a transmission. In one embodiment, the transfer pump moves the fluid from a differential case to a hydraulic reservoir coupled to the transmission. The transfer pump is a positive displacement pump including an unloading device, such as a sealing plate, that is resiliently biased against the pump during a normal operation but is moved away from the pump upon the application of a pilot pressure. The result is an open chamber for the pump gears to turn without developing pressure, to thereby reduce parasitic losses.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

A device is described for transmitting mechanical power that allows variable output-speed to input-speed ratios. Gear sets such as epicyclic gear sets have components that rotate about a common axis selectively at the same rotational speed and at different relative rotational speeds as determined by at least one of fluid flow and fluid pressure. One or more inlet ports and fluid passageways introduce a working fluid into one or more volume spaces between the components. The internal pressure and flow of the working fluid through the device is controlled to provide substantially infinite variability of the output-speed to input-speed ratios for applications where, for example, an engine provides the mechanical power for propelling a vehicle.

The invention relates to a downhole tool for use in a petroleum well. The downhole tool (100) comprises a first part (110) comprising a driving unit (8), and second part (120) comprising a driven unit (9), wherein the drive unit (8) is configured for driving the driven unit (9). The downhole tool (100) comprises a coupling unit (1) having an input side (S1) coupled with the driving unit (8) and an output side (S2) coupled with the driven unit (9), wherein the driving unit (8) is configured for driving the driving unit (9) via the coupling unit (1) comprising a torque limiting coupling having a first operational mode, the coupling unit (1) transfers all torque from the input side (S1) to the output side (S2), the coupling unit (1) further having a second operational mode, wherein the coupling unit (1) slips such that less torque is transferred form the input side (S1) to the output side (S2), wherein the second operational mode is automatically activated when the torque load on the input side exceeds a predefined level, and wherein the first operational mode is automatically activated when the torque load on the input side reduces to a level below a further predefined level. The coupling unit (1) comprises a displacement pump (2), wherein the displacement pump (2) is activated by opening of a pressure-limitation valve (4), for facilitating slipping of the coupling unit (1) when the coupling unit (1) is switching to the second operational mode, and wherein the displacement pump (2) is deactivated by closing of the pressure-limitation valve (4), for locking the coupling unit (1) when the coupling unit (1) is switching to the first operational mode.

The invention relates to a downhole tool for use in a petroleum well. The downhole tool (100) comprises a first part (110) comprising a driving unit (8), and second part (120) comprising a driven unit (9), wherein the drive unit (8) is configured for driving the driven unit (9). The downhole tool (100) comprises a coupling unit (1) having an input side (S1) coupled with the driving unit (8) and an output side (S2) coupled with the driven unit (9), wherein the driving unit (8) is configured for driving the driving unit (9) via the coupling unit (1) comprising a torque limiting coupling having a first operational mode, the coupling unit (1) transfers all torque from the input side (S1) to the output side (S2), the coupling unit (1) further having a second operational mode, wherein the coupling unit (1) slips such that less torque is transferred form the input side (S1) to the output side (S2), wherein the second operational mode is automatically activated when the torque load on the input side exceeds a predefined level, and wherein the first operational mode is automatically activated when the torque load on the input side reduces to a level below a further predefined level. The coupling unit (1) comprises a displacement pump (2), wherein the displacement pump (2) is activated by opening of a pressure-limitation valve (4), for facilitating slipping of the coupling unit (1) when the coupling unit (1) is switching to the second operational mode, and wherein the displacement pump (2) is deactivated by closing of the pressure-limitation valve (4), for locking the coupling unit (1) when the coupling unit (1) is switching to the first operational mode.

A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.