Centaur 2001 950, Руководство по обслуживанию, Страница: 427 / 450

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Axial Piston Pumps, Motors, and Transmissions Series 70 / 15 Series
Description of Operation for Series 70 and 15 Series Products (Continued)
Implement Circuit – Series 70-BDU-21L
TO
CASE
DRAIN
INPUT
CHARGE
PUMP
CHARGE
RELIEF
IMPLEMENT
VALVE
PV PF
FROM
INLET
FILTER
IMPLEMENT
RELIEF
PRESSURE
FILTER
TO
CASE
DRAIN
INPUT
IMPLEMENT
RELIEF
CHARGE
PUMP
CHARGE
RELIEF
IMPLEMENT
VALVE
PV PF
TO
CASE
FROM
INLET
FILTER
HEAT EXCHANGER
(OPTIONAL)
Implement Circuit – 15 Series
Implement Pump
Implement (auxiliary) flow capability is offered on the
Series 70 21 cc transmission and on 15 Series units.
Charge (implement) pump sizes available are .18 in
3 /
Rev. (3 cc/rev.) for the Series 70 BDU-21L transmis-
sion, .30 in
3 /Rev. (4.9 cc/rev.) for the 15 U transmis-
sion and .33 in 3 /Rev. (5.4 cc/rev.) for the 15 PV, 15
PT, or 15 in-line transmission.
The implement circuit must be of the “open center”
type that allows oil from the charge pump circulating
through the control valve to return to the transmis-
sion.
There are two styles of implement circuits depending
upon whether the Series 70 or the 15 Series is used.
In the Series 70 BDU-21 implement circuit, flow from
the charge (implement) pump flows first to the imple-
ment circuit control valve, then to the charge relief
and charge check valves. The implement circuit must
be designed to return the implement flow to the
transmission. (A check valve is provided to allow oil to
be drawn into the charge circuit should the flow
returning from the implement circuit be momentarily
insufficient to charge the closed loop.) The customer
must provide an implement circuit relief valve in
addition to the implement control valve. It is also
recommended that the customer provide a charge
pressure filter between the implement control valve
and the transmission to prevent any contaminants
created in the implement circuit actuator(s) from
entering the charge circuit.
In the 15 Series implement circuit, flow from the
charge (implement) pump flows to the charge check
valves and charge relief. Once charge pressure is
established, the charge relief allows oil to flow to the
implement control valve, and on to the transmission
case drain. (If an oil cooler is required in the circuit, it
may be installed between the implement control
valve and the case connection.) The implement relief
valve limits the pressure in the implement circuit (and
charge circuit) when the implement valve is actuated.