Oil Pump; Oil Strainer; Relief Valve - Kubota EA330-E4 Series Workshop Manual

EA330-E4, WSM

[2] OIL PUMP

[3] OIL STRAINER

[4] RELIEF VALVE

The oil pump is of trochoid pump type, whose rotors
have trochoid lobes. The inner rotor (3) has 4 lobes and
the outer rotor (4) has 5 lobes, and they are eccentrically
engaged with each other. The inner rotor, which is driven
by the crankshaft through the gears, rotates the outer
rotor in the same direction, varying the spaces between
the lobes.
While the rotors rotate from (A) to (B), the space
leading to the inlet port increases, which causes the oil
to flow through the inlet port.
When the rotors rotate to (C), the port to which the
space leads is changed from inlet to outlet.
At (D), the space decreases and sucked oil is
discharged from the outlet port.
(1) Inlet
(2) Outlet
Entry of foreign material such as iron chips, dirt, etc.
into the lubricating system may damage the lubricated
parts. To prevent this, an oil strainer is equipped prior to
the oil pump. This strainer has a double wound stainless
steel net (50 meshes) at the outside, and four magnets
(2) are mounted inside.
This stainless steel net (screen (4)) removes small
dirt in the lubricating oil. Further, fine iron chips passing
through this net are attracted by these magnets to
prevent them from entering the lubricating system.
(1) Plug
(2) Magnet
(3) Spacer
The relief valve consists of ball (4), spring (3), and
plug (1), which holds them, and is built into the lower part
of the gear case.
The relief valve (5) is used to adjust the lubricating oil
pressure to a proper level (200 to 390 kPa, 2.0 to
2
4.0 kgf/cm , 29 to 56 psi).
The oil which has passed through the relief valve
falls to the cylinder block.
If this regulated pressure is too low, the delivery of
lubricating oil to various portions will become deficient
and may cause seizure. Too high oil pressure may cause
oil leakage.
(1) Plug
(2) Gasket
(3) Spring
(4) Ball
1-M11
ENGINE
(3) Inner Rotor
(4) Outer Rotor
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(4) Stainless Steel Net
(5) Spring
(6) End Plate
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(5) Relief Valve
(6) Trochoid Pump
(7) Oil Strainer
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KiSC issued 05, 2015 A