The bevel-T gearbox is one of the most mechanically elegant solutions in industrial drive engineering — yet it remains one of the least understood outside the engineering community. The “T” describes the physical configuration: a single input shaft meets a through-shaft that exits from both sides of the housing, forming a T-junction in the drivetrain. One motor drives two output axes simultaneously, with inherent mechanical synchronisation. This guide explains what a bevel-T gearbox is, how it works, why it outperforms alternative two-motor arrangements in many applications, and where Ever Power bevel-T gearboxes are used worldwide.
1. What Is a Bevel-T Gearbox?
A bevel-T gearbox is a spiral bevel gearbox in which the output (crown gear) shaft extends through both sides of the housing simultaneously, rather than exiting from only one side as in a standard bevel gearbox. The housing has three external shaft connections — one input (the bevel pinion shaft) and two outputs (the left and right extensions of the crown gear shaft) — forming a T-shape when viewed from above.
Because both output shafts are on the same physical shaft (the crown gear shaft), they rotate at exactly the same speed and in the same direction simultaneously. No electronic synchronisation, no secondary shaft coupling, no differential mechanism — the T-configuration provides inherent mechanical synchronisation as a fundamental geometric property of the design.
In Ever Power’s product designation, this is the C-configuration (3-shaft arrangement): one input shaft + two output shafts. The D-configuration extends this further with three output shafts (four total connections), driving three driven components simultaneously from one input.
2. How It Works: Torque Distribution to Two Outputs
The spiral bevel pinion on the input shaft drives the crown gear, which rotates on the through-shaft. Both extensions of the through-shaft rotate at the crown gear speed simultaneously. The total output torque available across both shaft ends equals the input torque multiplied by the gear ratio and transmission efficiency.
Torque distribution depends on the load applied to each output shaft:
- If both outputs carry equal loads, each shaft carries 50% of the total output torque. The bearing loads on both sides of the crown gear shaft are symmetric and the gear mesh load is centred on the tooth face width.
- If the outputs carry unequal loads, the more heavily loaded output shaft draws more torque. The gear mesh contact pattern shifts toward the more loaded side. This is acceptable up to an asymmetry ratio of approximately 70:30 without special bearing modification — beyond this, Ever Power engineering specifies asymmetric bearing selection to maintain adequate life on the more loaded side.
3. Bevel-T vs Two-Motor Arrangement: Why T-Configuration Wins
| Criterion | Bevel-T Gearbox (1 Motor) | Two Separate Motor-Gearbox Units |
|---|---|---|
| Synchronisation | Inherent — mechanical | Electronic — requires encoders and closed-loop control |
| Synchronisation Reliability | Cannot fail — no electronics involved | Can fail due to encoder fault, signal loss, or control error |
| Component Count | 1 motor, 1 gearbox, 1 VFD | 2 motors, 2 gearboxes, 2 VFDs, encoders, synchronising controller |
| Capital Cost | Lower — one drive system | Higher — duplicated drive system plus synchronising hardware |
| Maintenance Points | One gearbox oil change, one motor service | Two of everything |
| Speed Accuracy | Exact — same physical shaft | Near-exact — limited by control system resolution and encoder accuracy |
| Unequal Load Handling | Up to 70:30 asymmetry standard | Fully independent load management per motor |
4. Key Applications for Bevel-T Gearboxes
Both screws must rotate at identical speed for uniform material flow. A bevel-T gearbox from one motor guarantees exact speed equality and eliminates the risk of one screw outrunning the other — which causes material bridging and uneven discharge in powder and granule handling systems.
Dual spinner discs must rotate at equal speed for a symmetric spread pattern. Any speed difference produces asymmetric fertilizer distribution — directly measurable in yield maps as differential crop growth on either side of the pass.
Stage lifts with two columns (one on each side of the stage) must rise and fall in perfect level synchronisation. A bevel-T gearbox drives both columns from one motor — inherently level without encoders or control loops. Used in theater stage machinery worldwide.
Steel rolling mill runout tables use bevel-T gearboxes to drive multiple roll table sections from one motor. The T-configuration fans out the drive power to adjacent table sections without additional gearboxes or chain drives.
Very wide belt conveyors require drive at both ends of the head pulley shaft. A bevel-T gearbox positioned at the centre of the head pulley drives both ends simultaneously — eliminating the overhung load that a single-end drive would impose on the pulley shaft and bearings.
Underground longwall conveyors use bevel-T gearboxes at drive stations where a single motor must power belt sections on both sides of the structure — a space-efficient solution where running a second motor would require impractical access space in a restricted tunnel environment.
5. Ever Power Bevel-T Gearbox Specifications
| Parameter | Standard C-Configuration | Heavy Duty C-Configuration |
|---|---|---|
| Available Ratios | 1:1, 1.5:1, 2:1, 3:1 | 1:1, 1.5:1, 2:1, 3:1 |
| Housing Material | Cast iron HBS 190–240 | Ductile iron GGG50 |
| Gear Material | 20CrMnTi, HRC 58–62 | 20CrMnTi, HRC 58–62 |
| Output Shaft Options | Equal length both sides (standard); custom lengths available | Asymmetric lengths on request |
| Load Asymmetry Tolerance | Up to 70:30 (standard bearing) | Up to 80:20 (asymmetric bearing option) |
| Transmission Efficiency | 94% – 96% | 94% – 96% |
| Noise Level | 60 – 68 dB | 60 – 68 dB |
| การรับรอง | CE, ISO 9001 | CE, ISO 9001, EN 10204 3.1 available |
| Lead Time | 20 – 35 working days | 30 – 45 working days |
6. Custom Bevel-T Gearboxes from Ever Power
Ever Power designs and manufactures custom bevel-T gearboxes with non-standard shaft extensions, asymmetric output shaft lengths, custom ratios, and special bearing arrangements for asymmetric loading. Our Netherlands-registered company serves industrial customers across Europe and worldwide with CE-certified bevel-T units designed to your installation drawing.
We also supply the D-configuration (four-shaft: one input, three outputs) for applications requiring three simultaneously driven output points from one motor — stage machinery with three lift columns being the most common application for this configuration.
Customer Cases
Poland — Agricultural Equipment OEM
Ever Power bevel-T gearboxes replaced a two-gearbox arrangement on a new fertilizer spreader design. The machine became 12 kg lighter, eliminated a synchronising driveshaft, and reduced the parts count by 23 components. Symmetric spread pattern verified in field tests — equal rotational speed confirmed by optical measurement on both discs. “The inherent synchronisation gave our agronomist the pattern consistency he needed without any control system calibration.” — Lead Mechanical Designer
Japan — Steel Plant, Nagoya
Bevel-T gearboxes in a hot strip mill runout table drive. Shock factor of 3x nominal specified due to strip front-end impact loads. Ever Power provided full shock factor documentation required by the plant’s engineering review board. 30 months in continuous hot mill service — no gearbox-related downtime reported. “The documentation was accepted by our review board without modification.” — Rolling Mill Project Engineer
UK — Powder Handling, Yorkshire
Twin-screw powder conveyor with a requirement for inherent speed synchronisation — no closed-loop control budget available for the project. Ever Power bevel-T gearbox provided exact synchronisation without electronics. “Single gearbox, single motor, perfectly synchronised — exactly what our budget and our process needed.” — Systems Engineer
FAQ
Need a bevel-T gearbox for a synchronized twin-drive application?
Ever Power C and D configuration bevel-T gearboxes: inherent mechanical synchronisation, one motor, CE certified, fast European delivery.
