TB is a compact series of spiral bevel gearboxes with an aluminum alloy housing and factory-filled grease. The catalog permits mounting in any orientation and lists single-ended and double-ended shaft arrangements. Its three frames are available with 1:1 and 2:1 ratios.

Models and ratio options
| Model | Ratios in the catalog rating tables |
|---|---|
| TB12 | 1:1, 2:1 |
| TB17 | 1:1, 2:1 |
| TB20 | 1:1, 2:1 |
Construction and ordering codes
| Parameter | Specification |
|---|---|
| Gear construction | Case-hardened chromium-molybdenum steel spiral bevel gears with lapped tooth surfaces |
| Housing | Cast aluminum alloy |
| Bearings | Deep-groove ball bearings |
| Lubrication | Factory-filled grease |
| Shaft arrangement codes | 2 for single-ended, 3 for double-ended |
| Key specification | Flat key on TB12. JIS B 1301:1996 on TB17 and TB20. |
| Example designation | TB122-2 identifies size 12, shaft arrangement 2 and ratio 2:1. A final T identifies a special configuration. |
Mounting and replacement
The catalog permits mounting in any orientation. Confirm the direction of rotation from the shaft layout drawing. For replacement, check the shaft and key geometry, bolt pattern, shaft extension and coupling clearance. A stainless shaft can be specified for applications that require corrosion resistance.
Reading the torque columns
The 2:1 rating table lists separate A- and B-shaft torque values. The 1:1 table gives a single output torque value. For a three-shaft unit, apply the catalog note that the B-shaft torque is half the table value.
Catalog rating points at 400 and 600 rpm
These values are for the stated A-shaft speed and a service factor of 1. OHL means allowable overhung load. The dash indicates that the 1:1 table reports one output torque value. For a different operating speed, use the rating row for that speed and ratio.
| Model | Ratio | A-shaft speed (rpm) | Rated input (kW) | A-shaft torque or single output torque (N·m) | B-shaft torque (N·m) | A-shaft OHL (N) | B-shaft OHL (N) |
|---|---|---|---|---|---|---|---|
| TB12 | 1:1 | 400 | 0.07 | 1.8 | — | 200 | 260 |
| TB17 | 1:1 | 400 | 0.27 | 6.5 | — | 240 | 330 |
| TB20 | 1:1 | 400 | 0.56 | 13.3 | — | 570 | 660 |
| TB12 | 1:1 | 600 | 0.11 | 1.8 | — | 160 | 220 |
| TB17 | 1:1 | 600 | 0.38 | 6.0 | — | 190 | 270 |
| TB20 | 1:1 | 600 | 0.78 | 12.3 | — | 400 | 540 |
| TB12 | 2:1 | 400 | 0.03 | 0.7 | 1.3 | 210 | 380 |
| TB17 | 2:1 | 400 | 0.11 | 2.5 | 5.0 | 260 | 560 |
| TB20 | 2:1 | 400 | 0.18 | 4.3 | 8.4 | 740 | 960 |
| TB12 | 2:1 | 600 | 0.04 | 0.7 | 1.3 | 170 | 320 |
| TB17 | 2:1 | 600 | 0.15 | 2.4 | 4.6 | 210 | 470 |
| TB20 | 2:1 | 600 | 0.25 | 4.0 | 7.8 | 620 | 900 |
Information for selection and ordering
Provide the required power or torque, input and output speeds, running hours, load variation and reversal frequency. Specify the exact shaft layout and rotation direction for each shaft, the mounting orientation, and the magnitude and point of application of overhung loads. Check the applicable speed limit and thermal rating for the selected configuration.






