Preferred operating direction of BB motors
The preferred operating direction applies to BB motors with 2-speed valve.
The preferred operating direction is the rotating direction of the motor when the flow
direction is from port A to B.
• 2 = CW motor (For the right side of a vehicle.)
• 3 = CCW motor (For the left side of a vehicle.)
The rotating direction of the BBC motor and the flow direction in the working lines is
given in the table below.
Table 2: Rotating direction and flow direction of BBC motors.
ROTATING DIRECTION
flow direction
A
→
B
B
→
A
No preferred rotating
direction
CW
CCW
Freewheeling
Hydrostatic freewheeling and mechanical freewheeling are options for BB and BBC
series motors.
Black Bruin motors can be freewheeled without energy loss or overheating problems
(stationary cylinder block - no centrifugal forces), even at high speeds. The motors
can be re-engaged or disengaged during movement.
Hydrostatic freewheeling
Hydrostatic freewheeling requires a drain line check valve with 0.5 bar (8 psi) opening
pressure and active feed between the check valve and the drain port of the motor.
A check valve in the drain line regulates the pressure in the case. To limit the pressure
spikes in the case, the drain line and its check valve have to be sized to correspond
with the maximum flow rate at the time of engagement.
In order to create the freewheeling pressure into the case, fluid must be supplied to
case drain line C (all BB motors without flush port C1) between the motor and the
check valve.
Hydrostatic freewheeling of a multispeed BBC motor
In a multispeed (2- and 4-speed) BBC motor without freewheeling springs, the
freewheeling pressure is supplied to the motor case through case flushing line C1.
Multispeed BBC motor has an in-built check valve and thus no external check valve in
case drain line is required.
The freewheeling valve should be positioned as close to the motor as possible to
ensure smooth and rapid mode change.
3.8
3.8.1
Motor Description
26
Product Manual
