EP-B3 Three-Stage Bevel-Helical Right-Angle Gearbox
Three-stage right-angle power transmission — bevel input stage plus two helical stages deliver 25:1 to 280:1 ratios and up to 200 kNm in a single compact housing. Sizes 4–26.
Product Overview: Right-Angle Reduction at High Ratio and Torque
The EP-B3 extends the bevel-helical right-angle gearbox concept to three stages — one spiral bevel stage for the 90-degree direction change, followed by two carburised and ground helical stages for deep torque multiplication. The result is a right-angle gearbox capable of overall ratios from 25:1 to 280:1 and a maximum nominal output torque of 200 kNm at the largest frame (Size 26).
The EP-B3 is specified when the application requires both a right-angle shaft layout and a high reduction ratio — a combination that previously required either a custom gearbox, a tandem unit arrangement, or an inefficient worm/worm multi-stage solution. The B3 delivers this combination in a single, factory-assembled, efficiency-optimised unit.
Three dimensional groups (sizes 4–12, 13–22, and 23–26) provide engineering drawing coverage for the full size range, with separate horizontal and vertical drawing sets in each group. Available in nine standard shaft/mounting configurations matching the B-series nomenclature (BSH through BDV).
Three-Stage Architecture: The Engineering Case
Adding a third stage to the B2's two-stage layout achieves two specific outcomes that define the B3's engineering value:
First — ratio extension. The B2's two stages reach approximately 45:1. Adding a third helical stage multiplies this by a further 4–6:1, reaching up to 280:1 in a single housing. This covers a class of right-angle drives — slow-turning conveyor corners, ship machinery, large process agitators — where 45:1 is simply not sufficient.
Second — torque capacity increase. Three stages allow the torque to be built up gradually, with each stage operating at a load level below its single-stage optimum. This improves heat distribution, reduces peak tooth contact stresses, and enables a larger output torque (200 kNm) from a housing that would otherwise need to be significantly enlarged to handle the same torque in two stages.
The three-stage B3 maintains the efficiency advantage of the bevel-helical design over worm alternatives. At 95–96% overall efficiency (three stages at approximately 97–99% each), the B3 delivers far more of the motor's input power to the driven machine than any multi-stage worm unit at equivalent ratios.
Size Range, Torque & Ratio Coverage
EP-B3 spans sizes 4 through 26, covering light to very heavy right-angle industrial drives:
| Size | Nom. Output Torque (kNm) | Max Input Speed (rpm) | Ratio Range (i) | Typical Applications |
|---|---|---|---|---|
| 4 | 0.50 | ≤1500 | 25–200 | Small right-angle slow drives |
| 6 | 1.10 | ≤1500 | 25–200 | Packaging, cross conveyors |
| 8 | 2.50 | ≤1500 | 25–250 | Process agitators right-angle |
| 10 | 5.50 | ≤1500 | 25–250 | Heavy cross-conveyors |
| 13 | 14.0 | ≤1000 | 25–250 | Large mixers, ship deck |
| 16 | 35.0 | ≤750 | 25–280 | Heavy right-angle drives |
| 19 | 80.0 | ≤600 | 25–280 | Cooling towers, heavy conveyor corners |
| 22 | 120. | ≤500 | 25–280 | Large process drives |
| 26 | 200. | ≤400 | 25–280 | Heavy mining and cement right-angle |
EP-B3 Horizontal Dimension Drawing — Sizes 4–12
EP-B3 Horizontal Dimension Drawing — Sizes 13–22
EP-B3 Vertical Dimension Drawing — Sizes 4–12
Technical Features
Bevel Input Stage
Precision spiral bevel gears redirect the power axis 90 degrees with 98–99% stage efficiency. The bevel gear pair is hardened, finish-ground, and lapped for minimal noise and backlash, setting a high-quality baseline for the downstream helical stages.
Two Helical Reduction Stages
Back-to-back carburised and ground helical stages provide the primary ratio multiplication after the bevel direction change. Each helical stage is independently designed to the appropriate tooth load and pitch line velocity for its position in the gear train.
Three Dimensional Groups
Size groups 4–12, 13–22, 23–26 each have optimised housing proportions. Large-frame units do not merely scale up a small-frame design — each group uses separately calculated gear centre distances and bearing arrangements for optimal strength-to-weight.
Sizes 4–26 Continuous Range
The B3 covers the widest size range in the bevel-helical family — from compact 0.5 kNm light-duty right-angle drives up to 200 kNm heavy industrial units. This allows engineers to work within a single product family for an entire machine range.
High Overall Efficiency
Typical 95–96% at rated load across the three stages. At high ratios (200:1+) where multi-stage worm efficiency would drop below 50%, the B3's efficiency advantage translates to a 40–50% reduction in motor power draw for the same output shaft power.
Nine Standard Configurations
BSH, BHH, BDH, BHM, BDM (horizontal) and BSV, BHV, BDV (vertical). The right-angle input/output relationship is maintained in all configurations, with the output shaft direction determined by the mounting configuration selected.
Industry Applications
EP-B3 is specified wherever the right-angle layout of B2 is needed but the required ratio or torque exceeds B2's two-stage capability:
| Industry | Application | Primary Requirement |
|---|---|---|
| Conveyor Systems | 90° corner drives, transfer units | Right-angle, high ratio, shock |
| Cooling Towers | Fan drives, counterflow fans | Right-angle, continuous duty |
| Ship & Port Machinery | Deck winches, slew drives | High torque, compact footprint |
| Cement | Right-angle bucket elevator drives | Heavy shock, 24/7 duty |
| Chemical Process | Large agitators, right-angle reactor drives | Slow speed, high torque, sealed |
| Agricultural Processing | Grain elevators, mixer drives | Right-angle, intermittent peaks |
B Series Comparison: Where EP-B3 Fits
| Model | Stage Architecture | Ratio Range | Max Torque | Best Fit |
|---|---|---|---|---|
| EP-B2 | 1 bevel + 1 helical | 5–45:1 | 90 kNm | Compact, moderate ratio right-angle drives |
| EP-B3 | 1 bevel + 2 helical | 25–280:1 | 200 kNm | High ratio right-angle heavy process |
| EP-B4 | 1 bevel + 3 helical | 50–500:1 | 500 kNm | Ultra-high ratio right-angle heavy industry |
If your ratio falls between 25:1 and 280:1 with torque up to 200 kNm in a right-angle layout, the EP-B3 is the correct unit. For ratios above 280:1, proceed to EP-B4.
Frequently Asked Questions
What is the maximum output torque of EP-B3?
EP-B3 delivers a maximum nominal output torque of 200 kNm at Size 26. Across the size range from 4 to 26, nominal torques begin at approximately 0.5 kNm, covering light right-angle auxiliary drives through heavy industrial process machinery — all in a single bevel-helical product family with a 90-degree shaft arrangement.
What ratio range does EP-B3 cover?
Three-stage bevel-helical ratios span approximately 25:1 to 280:1. This means a standard 1450 rpm motor can produce output shaft speeds as low as approximately 5 rpm through an EP-B3 — without a VFD, hydraulic coupling, or additional reduction stage. Standard ratios follow the R20 preferred number series; intermediate ratios are available on request.
How does EP-B3 compare to EP-B2?
EP-B3 adds a second helical stage after the bevel direction change, extending the ratio ceiling from B2's 45:1 to 280:1 and doubling the maximum torque from 90 kNm to 200 kNm. The B3 is also available in a larger size range (4–26 vs. B2's 4–18). If B2's two-stage capability is sufficient, it will be lighter and lower-cost; choose B3 when ratio or torque requirements exceed B2's limits.
What are typical applications for EP-B3?
The most common EP-B3 applications are: 90-degree conveyor corner drives where a long conveyor run changes direction; cooling tower fan drives where the motor must be horizontal and the fan shaft vertical; large right-angle agitators in chemical and food processing; ship and port deck machinery where compact right-angle drive packages are essential; and cement and mining applications requiring right-angle heavy-duty speed reduction.
Does EP-B3 require special lubrication for vertical mounting?
Yes — vertical-mount B3 units require a specific internal lubrication configuration that differs from horizontal units. In horizontal orientation, the bevel stage dips into the sump and splash-lubricates the helical stages. In vertical orientation, oil circulation paths change significantly. Always specify the mounting orientation at the time of ordering; field conversion from horizontal to vertical without internal modification will result in inadequate lubrication of upper-stage gears and bearings.
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