OIL PUMP [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))]
OIL PUMP [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))]
SM2565249
id0111u0002500
Outline
• A variable displacement oil pump has been adopted.
• To control the engine hydraulic pressure according to the driving conditions, the PCM adjusts the displacement of the variable displacement oil pump by operating the engine oil solenoid valve to switch the hydraulic pressure transmission passage.
• For details on the engine oil variable control, refer to the CONTROL SYSTEM. (See ENGINE OIL VARIABLE CONTROL [SKYACTIV-G (WITHOUT CYLINDER DEACTIVATION (US))].)
Purpose, Function
• The oil pump suctions the engine oil in the oil pan through the oil strainer and pumps engine oil into the oil gallery.
Construction
• The oil pump is installed on the lower part of the cylinder block (in oil pan).
SKYACTIV-G 2.0
ac5uun00003999
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SKYACTIV-G 2.5
ac5wzn00004661
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• A chain drive type vane pump has been adopted for the oil pump to variably adjust the engine oil discharge pressure.
• The operation chamber is formed between the 7 vanes, the slide, and the rotor.
• The oil pump consists of the following parts:
SKYACTIV-G 2.0
ac5uun00003839
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SKYACTIV-G 2.5
ac9uun00003034
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Operation
• When the rotor is rotated by the rotation of the shaft which is the driving shaft, the capacity of the operation chamber formed by the 7 vanes, the slide, and the rotor changes.
• The operation chamber capacity changes from minimum to maximum to minimum until the oil reaches the discharge outlet from the inlet and oil is pumped from the discharge outlet.
• When the engine oil supplied from the engine oil solenoid valve is not supplied, and hydraulic pressure is not applied to the slide in oil pump, the oil pump discharge pressure is at the maximum.
• The slide swings at the fulcrum point according to the high/low hydraulic pressure applied to the oil pump via the engine oil solenoid valve.
• The capacity of the operation chamber changes when the slide swings, therefore the discharge pressure from the pump is suppressed. By repeatedly performing this operation while the engine is running, the oil pump discharge pressure is controlled.
SKYACTIV-G 2.0
ac5uun00003840
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SKYACTIV-G 2.5
ac9uun00003035
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Hydraulic pressure supplied from engine oil solenoid valve is low
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― Because the swing amount of the slide inside the oil pump is small when the hydraulic pressure from the engine oil solenoid valve is low, the operation chamber capacity is maintained at large. As a result, the oil pump discharge pressure increases.
ac5uun00003841
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Hydraulic pressure supplied from engine oil solenoid valve is high
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― Because the swing amount of the slide inside the oil pump is large when the hydraulic pressure from the engine oil solenoid valve is high, the operation chamber capacity is reduced. As a result, the oil pump discharge pressure decreases.
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• The oil discharged from the oil pump flows to the oil gallery and is applied to the slide which composes the operation chamber. Therefore, the swing is automatically applied to the slide during pump operation, and the oil pump itself controls the discharge amount using its structure.
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• The bypass valve opens if the hydraulic pressure increases excessively in a case such as when starting an extremely cold engine. Engine oil flows to the oil pan when the bypass valve is open. As a result, excessive hydraulic pressure increase is suppressed.
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