Operating Parameters; Input Speed; System Pressure - Danfoss H1P 045 Service Manual

Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps

Operating Parameters

Input Speed

System Pressure

© Danfoss | June 2020
Minimum
is the lowest input speed recommended during engine idle condition. Operating below
speed minimum speed limits the pump's ability to maintain adequate flow for lubrication and
power transmission.
Rated speed is the highest input speed recommended at full power condition. Operating at or
below this speed should yield satisfactory product life.
Operating conditions between rated and maximum speed should be restricted to less
than full power and to limited periods of time.
Maximum
is the highest operating speed permitted. Exceeding maximum speed reduces product
speed life and can cause loss of hydrostatic power and braking capacity. For most drive
systems, maximum unit speed occurs during downhill braking or negative power
conditions.
W
Warning
Never exceed the maximum speed limit under any operating conditions.
During hydraulic braking and downhill conditions, the prime mover must be capable of providing
sufficient braking torque in order to avoid pump over speed. This is especially important to consider for
turbo-charged and Tier 4 engines.
For more information please see Pressure and Speed Limits, BC152886484313, when determining speed
limits for a particular application.
Independent Braking System
Unintended vehicle or machine movement hazard. Exceeding maximum speed may cause a loss of
hydrostatic drive line power and braking capacity.
Machine manufacturer is responsible to provide a braking system, redundant to the hydrostatic
transmission, sufficient to stop and hold the vehicle or machine in the event of hydrostatic drive power
loss. The braking system must also be sufficient to hold the machine in place when full power is applied.
Hydraulic unit life depends on the speed and normal operating — or weighted average — pressure that
can only be determined from a duty cycle analysis.
System pressure is the differential pressure between high pressure system ports. It is the dominant
operating variable affecting hydraulic unit life. High system pressure, which results
from high load, reduces expected life.
Application is the high pressure relief or pressure limiter setting normally defined within the
pressure
order code of the pump. This is the applied system pressure at which the drive line
generates the maximum calculated pull or torque in the application.
Maximum
is the highest recommended application pressure and is not intended to be a
working
continuous pressure. Propel systems with application pressures at, or below this
pressure pressure should yield satisfactory unit life given proper component sizing.
Application pressures above maximum working pressure will only be considered
with duty cycle analysis and factory approval.
Pressure spikes are normal and must be considered when reviewing maximum
working pressure.
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