Audible noise is evidence to investigate, but fault location depends on whether the sound tracks speed, torque or the machine structure.
Helical Gearbox Noise Diagnosis by Speed and Load
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EP-S97 Helical-Worm Gear Reducer
The EP-S97 is a 2 (1 helical + 1 worm) helical-worm gear reducer with right-angle output, delivering up to 3,500 N·m from 0.55–15 kW across gear ratios 8.74–196.11. Available in foot-mount (S), flange-mount (SF), hollow-bore (SA), flange+hollow (SAF), and torque-arm (SAT) configurations — quieter and more efficient than conventional worm reducers.
MOQ: flexible. Minimum order value USD 1,500; mixed orders and trial quantities welcome.
Product Overview — EP-S97 Helical-Worm Gear Reducer
The EP-S97 is the flagship model of the Ever Power S-series helical-worm programme, engineered for the heaviest right-angle drive applications in the range. With up to 3,500 N·m continuous output torque from motor powers of 0.55–15 kW and ratios covering 8.74–196.11, the EP-S97 serves the most demanding installations in paper and board manufacturing, heavy material handling, steel service centres, and marine deck equipment.
At this torque class, thermal management and structural integrity are as important as gear geometry. The EP-S97 housing is designed with generous fin area on the worm-face, providing natural-convection heat dissipation of up to 3.5 kW in free air at 20 °C ambient — sufficient for the majority of continuous-duty applications without supplementary cooling. An external oil-to-air cooler is available as an accessory for the most thermally demanding installations.
Every EP-S97 unit is built to order from high-quality components and undergoes a full factory run-in test at rated load before despatch. The test record — oil temperature rise, noise level, and bearing vibration — is included in the documentation pack. For project-critical installations, third-party inspection and extended documentation are available. Contact our project engineering team to discuss your requirements.
Technical Specifications — EP-S97
| Parameter | Specification |
|---|---|
| Gear Type | Helical pre-stage + worm gear set (right-angle output) |
| Number of Stages | 2 (1 helical + 1 worm) |
| Motor Power Range | 0.55–15 kW |
| Max Output Torque | 3,500 N·m |
| Gear Ratio Range | 8.74–196.11 |
| Output Speed Range | 7–161 rpm |
| Approximate Unit Weight | 140–205 kg |
| Max Output Radial Load | 27,000 N |
| Overall Efficiency | 75–82% (vs 55–65% for equivalent single-stage worm) |
| Lubrication | Oil bath; ISO VG 220 synthetic-blend worm gear oil (factory fill) |
| Housing Material | Close-grained cast iron (HT250) |
| Worm Shaft Material | 20CrMnTi alloy steel, case-hardened HRC 58–62, profile ground Ra ≤ 0.4 µm |
| Worm Wheel Material | Centrifugally cast phosphor-bronze (ZCuSn10P1) |
| Helical Stage Material | 20CrMnTi alloy steel, case-hardened, precision ground DIN 6 |
| Protection Rating | IP55 standard; IP65 optional |
| Ambient Temperature | −25 °C to +40 °C (standard lubricant) |
| Noise Level | ≤ 68 dB(A) at rated load (1 m, free-field) |
| Standards Compliance | ISO 14521 worm gear rating; ISO 281 bearing life; CE Machinery Directive |
Structural Types & Mounting Configurations — S97 Series
The S97 series is produced in five structural types plus an input-shaft-only SA-SZ variant. All share the same internal helical-worm gear train and achieve identical output torque and efficiency ratings. The structural type determines the mounting method and driven-machine interface.
| Type Code | Description |
|---|---|
| S97 | foot-mounted, solid output shaft |
| SF97 | B5 flange-mounted, solid output shaft |
| SA97 | shaft-mounted, hollow output bore |
| SAF97 | B5 flange + hollow output bore |
| SAT97 | torque-arm, hollow output bore |
| SA97-SZ | input shaft only, no motor flange |
SF and SAF Mounting Positions
Flange-mounted SF97 and SAF97 variants support all six standard mounting positions. Oil fill level and breather plug position must be adjusted per mounting position — refer to the position-specific lubrication table in the installation manual.
SA and SAT Torque-Arm Mounting Positions
The SA97 shaft-mounted and SAT97 torque-arm variants mount directly onto the driven shaft, reacting torque through the torque arm rather than a baseplate. This eliminates shaft-to-shaft coupling alignment and is particularly suited to conveyor head drives and drum agitators.
Key Advantages of the EP-S97 Helical-Worm Reducer
Superior Efficiency vs. Worm-Only Drives
The helical input stage of the EP-S97 achieves ≥98% per-stage efficiency, contributing directly to the 75–82% overall efficiency of the complete unit — 15–25 percentage points above conventional single-stage worm reducers. In continuous-duty applications this margin translates to measurable energy cost reduction and lower operating heat, reducing cooling requirements and extending lubricant life.
Right-Angle Compact Form Factor
The S-series right-angle configuration delivers 3,500 N·m from a housing sized for 0.55–15 kW — a torque density comparable to much larger parallel-shaft units. The perpendicular input-to-output layout is inherently suited to machine geometries where the motor and driven shaft cannot share the same axis, eliminating additional bevel stages or chain-and-sprocket drives that add cost and maintenance.
Significantly Quieter Operation
By pre-reducing speed in the helical stage before it reaches the worm mesh, the EP-S97 reduces worm sliding velocity at any given overall ratio. Lower sliding velocity directly reduces worm-mesh friction noise, yielding typical noise levels 6–10 dB(A) below equivalent single-stage worm reducers — an advantage valued in food production halls, pharmaceutical facilities, and any environment with operator occupancy near the drive.
Wide High-Reduction Ratio Range
Ratios from 8.74 to 196.11 in a single housing are achievable with the EP-S97, covering applications from moderately fast conveyor drives at the lower end to very slow-rotation stirring and positioning drives at the upper end. This breadth eliminates the need to cascade multiple reducers in most applications, simplifying the drivetrain and reducing total installation length.
Multiple Structural Types
Five structural types — S, SF, SA, SAF, SAT — plus the SA-SZ input shaft variant address every practical machine interface without custom engineering. SA and SAF hollow-bore types allow direct shaft mounting, eliminating flexible couplings and their associated alignment requirements. The SAT torque-arm type simplifies drum and conveyor installations further by reacting torque through a single rubber-buffered arm rather than a rigid baseplate.
Long-Life Worm Gear Materials
The EP-S97 worm wheel is manufactured from centrifugally cast phosphor-bronze (ZCuSn10P1), chosen for its combination of high load capacity, low friction against hardened steel, and resistance to adhesive wear under boundary-lubrication conditions during start-up. The hardened and profile-ground worm shaft (Ra ≤ 0.4 µm) maintains an elastohydrodynamic oil film across the full operating speed range, extending tooth-surface life to typically 25,000–40,000 hours.
Structural Type Diagrams — S97 Series
Use the diagrams below to confirm the external geometry, mounting interface, and connection dimensions of each S97 structural type before finalising your machine design. Certified dimensional drawings in DXF and PDF are available on request.
S97 Foot-Mount, Solid Output Shaft
SF97 B5 Flange, Solid Output Shaft
SA97 Shaft-Mounted, Hollow Bore
SAF97 B5 Flange + Hollow Bore
SAT97 Torque-Arm, Hollow Bore
SA97-SZ Input Shaft Only
Industry Applications — Where the EP-S97 Excels
| Industry Sector | Typical Application |
|---|---|
| Paper & Board | Board-making felt-guide roll drives, board cutter feed drives, and pulper auxiliary agitator drives. |
| Heavy Material Handling | Screw conveyor head-end drives for fertiliser granule and mineral powder handling. |
| Steel Service Centres | Coil car travel drives, leveller in-feed roll auxiliary drives, and press-brake back-gauge drives. |
| Marine & Offshore | Deck hatch actuator drives and anchor-chain guide fairlead rotation drives on smaller vessels. |
Application Case Study: Paper Board Felt-Guide Roll
A corrugated board mill replaced six plain worm gear drives on its wet-end felt-guide rolls with EP-S97 units. The helical pre-stage reduced total drivetrain losses from 38% to 21%, and the lower oil temperature extended seal life — previous seals required replacement every 8 months; after 20 months with the EP-S97, no seal replacements have been needed.
Model Designation Guide — How to Order an EP-S97
Every element of the S-series order code defines a specific product attribute. The example below shows a 1.5 kW, torque-arm, hollow-bore unit in mounting position M1:
EP - S97 - SAT - Y - 2 - 1.5 - 4P - M1
| Code Element | Meaning |
|---|---|
| EP | Brand identifier — Ever Power |
| S97 | Series and frame size — S-series helical-worm |
| SAT | Structural type: torque-arm, hollow-bore output |
| Y | Motor type: Y-series IEC standard induction motor |
| 2 | Number of gear stages (helical + worm) |
| 1.5 | Motor rated power in kW |
| 4P | Motor pole count (1,450 rpm at 50 Hz) |
| M1 | Mounting position (1 of 6 standard positions) |
Frequently Asked Questions — EP-S97
Mission-Ready Torque for Heavy Industrial Applications
The EP-S97 brings the efficiency and compact footprint of helical-worm design to the highest torque class in the S-series. Our engineering team specialises in large-installation projects requiring documentation packages, third-party certification, and project scheduling. Discover Ever Power's engineering capability, or contact us directly for a formal project proposal.
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