STS M2-H, Operator'S Manual

Page: 65 / 71

65
Group 2 Gear Motors Technical Information
System Requirements
Hydraulic fluids
Ratings and data for gear motors are based on operating with premium hydraulic fluids containing
oxidation, rust, and foam inhibitors. These fluids must
possess good thermal and hydrolytic
stability to prevent wear, erosion, and corrosion of internal components. They include:

Hydraulic fluids following DIN 51524, part 2 (HLP) and part 3 (HVLP) specifications•

API CD engine oils conforming to SAE J183•

M2C33F or G automatic transmission fluids•

Certain agricultural tractor fluids•
Use only clean fluid in the motor and hydraulic circuit.
Caution
Never mix hydraulic fluids.
Please see Sauer-Danfoss publication
Hydraulic Fluids and Lubricants Technical Information,
520L0463
for more information. Refer to publication
Experience with Biodegradable Hydraulic
Fluids Technical Information, 520L0465
for information relating to biodegradable fluids.
Temperature and viscosity
Temperature and viscosity requirements must be concurrently satisfied. Use petroleum / mineral-
based fluids.
High temperature l
imits apply at the inlet port to the motor. The motor should run at or below the
maximum continuous temperature. The peak temperature is based on material properties. Don’t
exceed it.
Cold oil,
generally, doesn’t affect the durability of motor components. It may affect the ability of oil
to flow and transmit power. For this reason, keep the temperature at 16 °C [60 °F] above the pour
point of the hydraulic fluid.
Minimum
(cold start)
temperature
relates to the physical properties of component materials.
Minimum viscosity
occurs only during brief occasions of maximum ambient temperature and
severe duty cycle operation. You will encounter maximum viscosity only at cold start. During this
condition, limit speeds until the system warms up. Size heat exchangers to keep the fluid within
these limits. Test regularly to verify that these temperatures and viscosity limits aren’t exceeded.
For maximum unit efficiency and bearing life, keep the fluid viscosity in the recommended viscosity
range.
Fluid viscosity Temperature
Maximum (cold start)
mm
2
/s
[SUS]
1000 [4600]
Recommended range
12-60 [66-290]
Minimum
10 [60]
Minimum (cold start)
°C
[°F]
-20 [-4]
Maximum continuous
80 [176]
Peak (intermittent)
90 [194]