Parker GVM Series User Manual

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18-06-08 PVD3668_GB_GVM_June_2018
3. TECHNICAL DATA
3.1. Motor selection
3.1.1. Altitude derating
From 0 to 1000 m : no derating
From 1000 to 4000 m : torque derating of 5% for each step of 1000 m for GVM motors.
3.1.2. Cooling temperature
Water cooled motor
Standard datasheets are available for water cooling without Glycol and inlet temperatures of
25°C or 65°C (see total flow required if Glycol is added on § 3.6.3).
Parker can provide a specific datasheet for a different coolant type or coolant temperature.
3.1.3. Thermal equivalent torque (rms torque)
The selection of the correct motor can be made through the calculation of the rms torque
M
rms
(i.e. root mean squared torque) (sometimes called equivalent torque).
This calculation does not take into account the thermal time constant. It can be used only if
the overload time is much shorter than the copper thermal time constant.
The rms torque M
rms
reflects the heating of the motor during its duty cycle.
Let us consider:
- the period of the cycle T [s],
- the successively samples of movements i characterized each ones by the maximal torque
M
i
[Nm] reached during the duration  t
i
[s].
So, the rms torque M
rms
can be calculated through the following basic formula:
Example:
For a cycle of 2s at 0 Nm and 2s at 100Nm, the rms torque is
The maximal torque M
i
delivered by the motor at each segment i of movement is obtained by
the algebric sum of the acceleration-deceleration torque and the resistant torque.
Therefore, M
max
corresponds to the maximal value of M
i
.



n
i
iirms
tM
T
M
1
2
*
1
NmM
rms
7,702*100*
4
1
2


Parker GVM Series Specifications

General

Brand	Parker
Model	GVM Series
Category	Engine
Language	English