Gear units - Introduction
Type of construction
Helical gear units
Foot mounted version
Example: G02A
Flange mounted version
Example: G33C
Foot-flange mounted version
Example: G22E
Double gearbox
Example: G33G12A
Shaft mounted helical gear units
Shaft mounted version
Hollow shaft with keyway
Example: F42A
Shaft mounted version
Hollow shaft with keyway
Example: F53B
Shaft mounted version
Hollow shaft with shrink disc
Rubber elements
Example: F32BSG
Flange mounted version
Hollow shaft with keyway
Example: F33C
Flange mounted version
Output shaft with key
Example: F42CV
Flange mounted version
Hollow shaft with shrink disc
Example: F52CS
Shaft mounted version + side areas
Hollow shaft with keyway
Example: F43D
Shaft mounted version + side areas
Output shaft with key
Example: F32DV
Flange mounted version + side areas
Hollow shaft with keyway
Example: F42E
Double gearbox
Example: F33G12A
Helical bevel gear units
Foot mounted version
Hollow shaft with keyway
Example: K43A
Foot mounted version
Output shaft with key
Example: K33AV
Shaft mounted version
Hollow shaft with keyway
Example: K53B
Shaft mounted version
Hollow shaft with shrink disc
Torque arm T1
Example: K53BT1S
Flange mounted version
Hollow shaft with keyway
Example: K43C
Flange mounted version
Output shaft with key
Example: K33CV
Flange mounted version
Hollow shaft with shrink disc
Example: K43CS
Shaft mounted version + foot area
Hollow shaft with keyway
Example: K53D
Flange mounted version + foot area
Hollow shaft with keyway
Example: K33E
Double gearbox
Example: K43G12A
Helical worm gear units
Foot mounted version
Hollow shaft with keyway
Example: S32A
Foot mounted version
Output shaft with key
Example: S12AV
Shaft mounted version
Hollow shaft with keyway
Example: S22B
Shaft mounted version
Hollow shaft with shrink disc
Torque arm T1
Example: S22BT1S
Flange mounted version
Hollow shaft with keyway
Example: S22C
Flange mounted version
Output shaft with key
Example: S12CV
Flange mounted version
Hollow shaft with shrink disc
Example: S32CS
Shaft mounted version + foot area
Hollow shaft with keyway
Example: S22D
Flange mounted version + foot area
Hollow shaft with keyway
Example: S32E
Double gearbox
Example: S32G12A
Mounting position
Mounting face
For helical-worm and helical bevel geared motors with flange, with solid shaft or with shrink disk the position of mounting face has to be specified.
Example: Mounting face R
Direction of rotation Gear unit
The direction of rotation of the gear unit depends on the type of gear unit, the number of stages of the gearbox and for the gear units K23..K93 on the position of the mounting face.
For the bevel gearboxes K2..K9, the direction of rotation can also be selected contrary to the normal version.
In the versions hollow shaft with shrink disc and solid shaft with key a modified output shaft is required for this.
Order information in this case, i. e .: Mounting face :L, Direction of rotation as R
Efficiency of gearbox
The efficiency of the gear unit for helical gear units G, shaft mounted helical gear units F and helical bevel gear units K depends on the number of gear stages, 2-stage (0.96) and 3-stage (0.94).
The efficiency of helical worm gear units S depends on the ratio of the worm gear stage, the input speed into the gear unit and the temperature of the gear unit.
The efficiency of helical worm gear units S is shown in the selection table for gear units.
The efficiency of helical worm gear units S for back driving is significantly lower than the normal efficiency. In certain cases the worm gear unit can be self-locking.
At certain mounting positions the gearbox is completely filled with lubricant. At high input speed, mixing losses can reduce the efficiency of the gear unit.
Drive selection
Selection conditions
The following conditions must be considered in the selection of the geared motor:
T2 ≥ TA
cG ≥ fB
- T2 [Nm]
- Torque of geared motor (see selection table)
- TA [Nm]
- Counter-torque of driven machine
- cG
- Gear coefficient (see selection table)
- fB
- Application factor of driven machine
Further, the selection of the geared motor is influenced by the following factors:
- Duty cycle of the motor
- Application of forces on the output shaft
- Ambient temperature and altitude
- Environment conditions
Please consult the manufacturer in the case of complicated drive applications.
Application factor fB
The service factor of the driven machine is given from the shock grade, the average operating time / day and the number of switches per hour. The shock grade is given from the mass acceleration factor of the driven machine.
- FJ = Jred / Jmot
- Mass acceleration factor
- Jred
- All external inertias corrected to motor input
- Jmot
- Inertia (Motor)
| Shock grade | FJ | Operating time hours/day | Operations per hour | |||
| < 10 | 10 ... 100 | 100 ... 200 | > 200 | |||
| I - uniform | 0 … 0.2 | < 8 | 0.8 | 1.0 | 1.2 | 1.3 |
| 8 ... 16 | 1.0 | 1.2 | 1.3 | 1.4 | ||
| 16 ... 24 | 1.2 | 1.3 | 1.4 | 1.5 | ||
| II - moderate shocks | 0.2 … 3 | < 8 | 1.1 | 1.3 | 1.4 | 1.5 |
| 8 ... 16 | 1.3 | 1.4 | 1.5 | 1.7 | ||
| 16 ... 24 | 1.5 | 1.6 | 1.7 | 1.8 | ||
| III - severe shocks | 3 … 10 | < 8 | 1.4 | 1.6 | 1.7 | 1.8 |
| 8 ... 16 | 1.6 | 1.7 | 1.8 | 2.0 | ||
| 16 ... 24 | 1.8 | 1.9 | 2.0 | 2.1 | ||
Radial force on gear output shaft
- FR [N]
- Radial force on gear output shaft
- M2 [Nm]
- Torque of geared motor (see selection table)
- d0 [mm]
- Effective diameter of fitted drive element
- fz
- Incremental factor (see table)
| Transmission element | fz | Remarks |
| Gears | 1.1 | < 17 teeth |
| Sprockets | 1.4 | < 13 teeth |
| 1.2 | < 20 teeth | |
| Toothed belt pulleys | 1.5 | Influence of initial pretensioning force |
| V-belt pulleys | 1.7 | Influence of initial pretensioning force |
| Flat belt pulleys | 2.5 | Influence of initial pretensioning force |
The radial force determined must not exceed the permissible radial force for the gear unit.