Raise Cutting Units
A three section gear pump is coupled to the piston (trac-
tion) pump. The gear pump section (P3) farthest from
the piston pump supplies hydraulic flow to the lift/lower
control valve and the steering control valve. Hydraulic
flow from this pump section is delivered to the two cir-
cuits through a proportional flow divider. The gear pump
takes its suction from the hydraulic reservoir. Maximum
lift/lower circuit pressure (1500 PSI) is limited by a relief
valve inthepower downand traction assist control man-
ifold (RV7).
To raise a side cutting unit on the Groundsmaster
4700--D (deck #6 or #7), the appropriate outer lift lever
on the lift/lower control valve is pulled toallow valve shift
in the lift/lower control. This valve change allows hy-
draulic pressure to the rod end of the cylinder and
causes the liftcylinder shafttoretract, raising thecutting
unit. Oil from the piston end of the cylinder returns to the
tractionchargecircuit.Whentheliftleverisreleased,the
lift cylinder is held in position.
An adjustable counterbalance valve (RV1) in the power
down and traction assist control manifold maintains
back pressure on the lift cylinders. This counterbalance
pressure transfers cutting unit weight to the machine to
improve traction. Excess circuit flow is routed to the oil
filter and then to the traction charge circuit.
OntheGroundsmaster4500--D,asingleliftleverisused
toliftandlower thefivecuttingdecks.TheGroundsmas-
ter 4700--D has three lift levers to control the cutting
decks: the center lever is for the five center decks, the
left lever controls the left, rear deck, and the right lever
controls the right, rear deck.
Pressure to the lift/lower control valve can be monitored
at a port on the end of the gear pump.
#4 Deck
#1 Deck
#5 Deck
When the cutting units are in a stationary position, flow
from the gear pump is by--passed through the lift/lower
control valve, power down and traction assist control
manifold, oil filter, and traction charge circuit.
To raise the center five cutting decks, the lift lever on the
lift/lower control valve is pulled to allow valve shift in the
lift/lower control valve. This valve change allows hy-
draulic pressure to the rod end of the lift cylinder and
causes the shaft to retract, raising the cutting units. Oil
from the piston end of the cylinder flows to the traction
charge circuit. When the lift lever is released, the lift cyl-
inders are held in position.
#
2
#3
Deck
#
(GM4700)
6 Deck
#7 Deck
(GM4700)
Deck
CUTTING DECK LOCATIONS
Figure 11
2200
PSI
GM 4700--D
RAISE DECK #6 SHOWN
Figure 12
Page 4 -- 13
Groundsmaster 4500--D/4700--D
Hydraulic System (Rev. A)
| Categories | Lawn Mower Manual, Sprinkler and Irrigation Manuals, Toro Sprinkler and Irrigation Manuals |
|---|---|
| Tags | Toro Groundsmaster 4500 D, Toro Groundsmaster 4700 D |
| Download File |
|
| Document Type | Service Manual |
| Language | English |
| Product Brand | Toro. Customer Service Representatives are available by phone:
Monday - Friday 7:30 a.m. to 9:00 p.m. (CDT) - Saturday 8:00 a.m. to 8:00 p.m. (CDT) - Sunday 10:00 a.m. to 8:00 p.m. (CDT)
Canada 1-888-225-4886 USA 1-888-384-9939, Lawn Mower |
| Document File Type | |
| Publisher | toro.com |
| Wikipedia's Page | Toro Company |
| Copyright | Attribution Non-commercial |
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