Abstract: A working fluid supply system is provided with: a first oil pump and a second oil pump driven by an engine; a switching valve configured to cause a discharge passage of the second oil pump to communicate with at least one of a supply passage and a first drain passage; and a controller configured to switch the switching valve. The controller is configured to switch the switching valve by spending a switching time that is set in accordance with a degree of pressure variation predicted to be caused in the supply passage when the switching valve is switched instantaneously.

Abstract: A working fluid supply system is provided with: a first oil pump and a second oil pump driven by an engine; a switching valve configured to cause a discharge passage of the second oil pump to communicate with at least one of a supply passage and a first drain passage; and a controller configured to switch the switching valve. The controller is configured to switch the switching valve by spending a switching time that is set in accordance with a degree of pressure variation predicted to be caused in the supply passage when the switching valve is switched instantaneously.

Abstract: A working-fluid supply system includes: a first pump and a second pump driven by an engine; a first switching valve capable of switching a supply target of the second pump to either one of the discharge side and the suction side of the first pump; a first switching control unit configured to perform a switching control of the first switching valve; and a first pressure control unit configured to perform a control such that pressure on the suction side of the first pump becomes a predetermined first pressure when the first switching valve is switched such that the supply target of the second pump becomes the suction side of the first pump.

Abstract: A working fluid supply device is provided with: a first oil pump and a second oil pump driven by an engine; a third oil pump driven by an electric motor; a first unloading valve configured to shift the second oil pump to a no-load operation state; and a controller configured to control a supply state of working oil to an automatic transmission. The controller sets the supply state to a supply state selected from: a first supply state in which the working oil is supplied only from the first oil pump; a second supply state in which the working oil is supplied from the first oil pump and the third oil pump; a third supply state in which the working oil is supplied from the first oil pump and the second oil pump; and a fourth supply state in which the working oil is supplied from the first oil pump, the second oil pump, and the third oil pump.

Abstract: A working fluid supply device is provided with: a first oil pump and a second oil pump driven by an engine; a third oil pump driven by an electric motor; a first unloading valve configured to shift the second oil pump to a no-load operation state; and a controller configured to control a supply state of working oil to an automatic transmission. The controller sets the supply state to a supply state selected from: a first supply state in which the working oil is supplied only from the first oil pump; a second supply state in which the working oil is supplied from the first oil pump and the third oil pump; a third supply state in which the working oil is supplied from the first oil pump and the second oil pump; and a fourth supply state in which the working oil is supplied from the first oil pump, the second oil pump, and the third oil pump.

Abstract: In a control device for an automatic transmission having a flow control mechanism that causes a part of a working oil discharged from a mechanical oil pump to flow into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrowed portion increases beyond a predetermined value, the narrowed portion being provided in a discharge passage through which the working oil discharged from the mechanical oil pump flows, a line pressure is raised when an oil temperature of the working oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or smaller than a predetermined engine torque.

Abstract: A control device for automatic transmission includes a flow control mechanism for introducing a part of hydraulic oil discharged from a mechanical oil pump into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrow part provided in a discharge passage in which hydraulic oil discharged from the mechanical oil pump flows becomes larger than a predetermined value. Air mixed into the hydraulic oil is compressed by increasing a line pressure as a differential rotation speed increases when oil temperature of the hydraulic oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or lower than a predetermined engine torque.

Abstract: A control device for automatic transmission includes a flow control mechanism for introducing a part of hydraulic oil discharged from a mechanical oil pump into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrow part provided in a discharge passage in which hydraulic oil discharged from the mechanical oil pump flows becomes larger than a predetermined value. Air mixed into the hydraulic oil is compressed by increasing a line pressure as a differential rotation speed increases when oil temperature of the hydraulic oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or lower than a predetermined engine torque.

Abstract: In a control device for an automatic transmission having a flow control mechanism that causes a part of a working oil discharged from a mechanical oil pump to flow into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrowed portion increases beyond a predetermined value, the narrowed portion being provided in a discharge passage through which the working oil discharged from the mechanical oil pump flows, a line pressure is raised when an oil temperature of the working oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or smaller than a predetermined engine torque.

Abstract: A transmission includes a shaft, a sleeve receiving the shaft and including a first sleeve portion and a second sleeve portion. A drum is rotatably supported on a bearing by a bearing support which is formed on the first sleeve portion. Seal ring grooves are formed on the second sleeve portion. The first and second sleeve portions have walls which define first and second bore sections, respectively. The inner diameter of the second bore section is larger than the inner diameter of the first bore section. The first sleeve portion is firmly engaged with the shaft while the second sleeve portion is in spaced relationship with the shaft with clearance fit.

Abstract: A novel hydraulic system for an automotive automatic power transmission improves efficiency of working fluid supply for controlling transmission operation and for lubricating transmission components. The hydraulic system employs independently fabricated lubrication circuit for lubricating transmission components and a hydraulic control circuit for controlling operation of transmission components. The hydraulic system employs a first fluid pump connected to the hydraulic control circuit for supplying working fluid thereto, and a second fluid pump connected to the lubrication circuit for supplying working fluid thereto, and operative independently of the first fluid pump.

Abstract: A variable volume type vane pump comprises a housing, a rotor having a plurality of vanes, a cam ring disposed to be adjacent to said rotor, and a cover. A control piston is arranged for slidably displacing the cam ring relative to the housing and the cover. The housing, the cam ring, the control piston, and the cover cooperating to define an oil reservoir. A pressure within the oil reservoir is adjusted by a check valve.

Abstract: An automatic transmission for use in an automotive vehicle is comprised of an oil pump assembly adapted to discharge hydraulic oil as operating oil for the automatic transmission. The oil pump assembly is disposed around a stator shaft connected to the stator of a torque converter. The oil pump assembly includes a pump element drivably disposed in a pump housing and covered with a pump cover secured to the pump housing. The pump cover is made of light alloy and integrally formed with a boss inside which the stator shaft is fitted. The boss protrudes in a direction opposite to the pump housing. Additionally, a rigid ring is fitted on the outer periphery of the boss, thereby increasing the rigidity of the boss and preventing the outer peripheral section of the boss from being worn.

Abstract: A pump housing is formed with a recess receiving therein pump elements, and a pump cover is secured to the pump housing to close the recess. The pump cover and the pump housing define an interface area therebetween formed with a pump discharge port. The pump casing is provided with a predetermined passage which normally serves as an oil pressure delivering passage, but serving as a drain passage under a condition when the oil pump discharge pressure increases. The predetermined passage is open within said interface area via a groove extending around the pump discharge port.

Abstract: An oil pump cover includes an annular rib receiving therein an oil pump housing and a flange section extending radially outward of the annular rib. The flange section is formed with a cutout to receive a final drive pinion on a counter shaft of an automatic transaxle. Thus, the final drive pinion is disposed in the vicinity of the annular rib.