Parker GVM Series - Page 38

- 38 –
18-06-08 PVD3668_GB_GVM_June_2018
For a GVM motor, the mechanical time constant 
mech
represents the duration needed to
reach 63% of the final speed when applying a voltage step without any resistant torque, if the
electrical time constant is much smaller than the mechanical time constant.
An overall summary of motor time constants is given later.
3.2.2.3. Thermal time constant of the copper:
copperambientcoppertherm
CthRth *
_
 
]/[
][]/[
389*
KkgJ
Kg
copper
KJ
copper
MassCth



With:
Rth
copper_anbient
thermal resistance between copper and ambient [°K/W]
Cth
copper
thermal capacity of the copper [J/°K]
Mass
copper
mass of the copper (winding) [kg]
Overall summary of motor time constants:
Type
Electric time
constant (ms)
Mechanical time
constant (ms)
Thermal time
constant of
copper (s)
GVM142-050 6.5 1.80 24.4
GVM142-075 7.3 1.58 21.6
GVM142-100 8.0 1.37 20.3
GVM210-050 12 1.87 66
GVM210-100 16 1.29 50
GVM210-150 18 1.15 45
GVM210-200 19 1.09 43
GVM210-300 20 1.01 40
GVM210-400 21 0.97 39