Harmonic Drive CHA - Page 82

82 1018854 12/2015 V01
Rated voltage U
N
[V
rms
]
Supply voltage for operation with rated torque and rated speed.
Ratio i [ ]
The ratio is the reduction of input speed to the output speed.
Note for Harmonic Drive® Gears: The standard version has the Wave Generator as the input element, the Flexspline as the
output element and the Circular Spline is fixed to the housing. Since the direction of rotation of the input (Wave Generator)
is opposite to the output (Flexspline), a negative ratio should be used for calculations in which the direction of rotation is to
be considered.
Repeatability [arcmin]
The repeatability of the gear describes the position dier-
ence measured during repeated movement to the same
desired position from the same direction. The repeatability
is defined as half the value of the maximum dierence
measured, preceded by a ± sign.
Repeatable peak torque T
R
[Nm]
Specifies the maximum allowable acceleration and braking
torques. During the normal operating cycle the repeatable
peak torque T
R
should be not be exceeded.
Resistance (L-L, 20° C) R
L- L
[Ω]
Winding resistance measured between two conductors at a winding temperature of 20° C.
Size
1) Actuators / Gears with Harmonic Drive® gears or Harmonic Planetary gears
The frame size is derived from the pitch circle diameter of the gear teeth in inches multiplied by 10.
2) CHM Servo motor series
The size of the CHM servo motors is derived from the stall torque in Ncm.
3) Direct drives from the TorkDrive® series
The size of the TorkDrive® series is the outer diameter of the iron core of the stator.
Static load rating C
0
[N]
Maximum static load that can be absorbed by the output bearing before permanent damage may occur.
Static tilting moment M
0
[Nm]
With the bearing stationary, this is the maximum allowable radial load with no additional axial forces or tilting moments
applied.
Tilting moment stiness K
B
[Nm/arcmin]
Describes the relationship between the tilting angle of the output bearing and an applied moment load.
Torque constant (motor) k
TM
[Nm/A
rms
]
Quotient of stall torque and stall current.
Repeatability = ±x /2 = ±x /2
φ1
φ7
φ2
x
x/2
x/2