Explanations of maxon terminology: Strain wave gear
Dimensional drawings Presentation of the views according to the projection method E (ISO). All dimensions in [mm]. Mounting in plastic Screwed connections on motors with plastic flanges require special attention. M A Max. tightening torque [Ncm] A torque screwdriver may be adjusted to this value. L Active thread depth [mm] The relation of the thread depth to the thread diame- ter must be at least 2:1. The screw-in depth must be less than the usable length of the thread! Gearhead data Values are based on an ambient temperature of around 25 °C (known as cold data). Gearhead data 1 Reduction ratio The reduction indicates the ratio by which the speed of the gear output shaft is smaller than the motor speed. 2 Max. continuous torque [Nm] The continuous torque provides the maximum load permanently applied to the output shaft. If it is ex- ceeded, the service life is significantly shortened. 3 Max. intermittent torque* [Nm] The short-time torque is the maximum torque that may be output on the output shaft for a short period of time without damaging it. 4 Max. overload torque [Nm] The maximum torque that may be applied for a short period of time without causing mechanical damage to the gearhead; for instance, in the event of a collision. 5 Max. continuous/intermittent* input speed [rpm] It is based on service life considerations. If this value is greatly exceeded, the service life can be shortened, the gear heats up more and more noise is generated. 6 Efficiency [%] The specified efficiency is a maximum value that ap- plies under continuous torque load (M N ). Under very small loads, the efficiency decreases (by a factor of V).
8 Mass inertia [gcm²] The gear moment of inertia is given at the motor shaft. It is required in order to calculate the additional torque needed for acceleration of the gear components in the case of highly dynamic drives. Variations may arise depending on how lubrication is distributed. 9 Gear length L1 [mm] L1 describes the gear length down to the motor’s axial mount area (reference C in motors). 10 Mech. positioning accuracy [arcmin] The mechanical positioning accuracy describes the absolute positioning error at the output. It is mea- sured over a full revolution (360°) at the output and shown as the maximum value of the bandwidth.
15 Starting torque, no load [mNm] The starting torque specifies the torque that must be applied at the gearhead input to set the gearhead in motion. No load is applied to the gearhead output in this case. 16 Backdriving torque, no load [Nm] The backdriving torque specifies the torque that must be applied at the gearhead output to drive the gear- head from the output side. No load is applied to the gearhead input in this case. 17 Ratcheting torque [Nm] The ratcheting torque describes the torque during operation at which the tooth contact between the flexspline and circular spline is lost and the teeth slide over each other. This results in asymmetric tooth meshing. Continued operation leads to increased wear and tear, ultimately destroying the gearhead. 18 Buckling torque [Nm] The buckling torque describes the torque at standstill at which the flexspline can plastically deform or even tear away from the base. The gearhead is irreparably damaged afterward. Technical data 20 Tilting rigidity [Nm/arcmin] The tilting rigidity describes the resistance of the out- put bearing to tilting. 21 Max. tilting torque [Nm] The specified value only refers to the tilting torque without axial/radial load in a static condition. 22/23 Max. axial/radial load [N] The specified value only refers to the axial/radial load without tilting torque in a static condition. 24/25 Dynamic/static load rating [N] The load ratings are specifications for calculating the expected service life of the output bearing. 26 Distance rolling bearing center to output [mm] This values describes the distance from the output to the center of the output bearing. 27 Pitch diameter [mm] The pitch diameter describes the diameter of the cir- cle along which the centers of the rolling elements move. 28 Ambient temperature [°C] Specifies the permissible ambient temperature for proper operation of the gearhead. The gearhead properties depend on the ambient temperature. Spe- cial lubricants are available on request. *intermittent Short-term operation is defined as follows: – during 1 second – during max. 10% of the operating cycle If these values are exceeded, a reduced service life must be expected.
Soll-Position Target position
11 Mech. repeatability [arcmin] The mechanical repeatability describes how accu- rately a position can be reached repeatedly from the same direction. It is defined as half of the maximum deviation and is expressed as a ± value. 12 Hysteresis loss [arcmin] The hysteresis loss describes the angular deviation (φ) resulting from fluctuating loads on the output shaft (T). It is measured while the gearhead input is blocked.
φ
Hystereseverlust Hysteresis loss
T
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.2
13 Torsional rigidity [104 Nm/rad] The torsional rigidity describes the elastic deforma- tion of the output under load. The torsional strength is presented in a linearized form, divided into three segments. C1: up to torque M1 C2: between torque M1 and M2 C3: higher than torque M2
φ
C3
50% M N
M N
7 Weight [g] The specified weight corresponds to the net weight, including motor add-on components.
C2
C1
M1
M2
M
454 maxon gear
© 2025 maxon. March 2025 edition / provisional data / subject to change
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