Danfoss Series 90, Техническая информация

Страница: 10 / 91

Overview
This section defines the operating parameters and limitations for Series 90 pumps with regard to input
speeds and pressures. For actual parameters, refer to the Operating parameters for each displacement.
Input Speed
Minimum speed is the lowest input speed recommended during engine idle condition. Operating below
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.
Maximum speed is the highest operating speed permitted. Exceeding maximum speed reduces product
life and can cause loss of hydrostatic power and braking capacity. Never exceed the maximum speed
limit under any operating conditions.
Operating conditions between Rated speed and Maximum speed should be restricted to less than full
power and to limited periods of time. For most drive systems, maximum unit speed occurs during
downhill braking or negative power conditions.
For more information consult Pressure and Speed Limits , BLN-9884, when determining speed limits for a
particular application.
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
turbocharged and Tier 4 engines.
Independant Braking System
W
Warning
Unintended vehicle or machine movement hazard
Exceeding maximum speed may cause a loss of hydrostatic drive line power and braking capacity. You
must provide an independant 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.
System Pressure
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. Hydraulic unit life depends on the speed and normal operating, or weighted
average, pressure that can only be determined from a duty cycle analysis.
Application pressure is the high pressure relief or pressure limiter setting normally defined within the
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 working pressure is the highest recommended Application pressure. Maximum working
pressure is not intended to be a continuous pressure. Propel systems with application pressures at, or
below, this pressure should yield satisfactory unit life given proper component sizing.
Maximum pressure is the highest allowable Application pressure under any circumstance. 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.
Technical Information Series 90 Axial Piston Pumps
Operating Parameters
10 520L0603 • Rev 0804 • March 2016