Audible noise is evidence to investigate, but fault location depends on whether the sound tracks speed, torque or the machine structure.
EP-K77 Right-Angle Helical Bevel Gear Reducer
Input Power 0.18–15 kW | Max. Output Torque 3000 N·m | Gear Ratio 5.36–192 | Right-Angle Output • Multiple Mounting Types
Product Overview
The EP-K77 is a helical-bevel gear reducer designed for industrial applications that require a
right-angle (90°) change of transmission direction. The drive combines
two stages of helical cylindrical gears with one stage of spiral bevel gears
in a compact three-stage arrangement, delivering precise directional change, wide ratio coverage,
and high efficiency in a single robust housing.
All gears are machined from 20CrMnTi low-carbon alloy steel, carburised and case-hardened to a
tooth-flank hardness of HRC 58–62, with contact fatigue strength σH ≥ 1,500 MPa and bending
fatigue strength σF ≥ 450 MPa. Ground tooth flanks achieve GB/T 10095.1 accuracy grade 6,
minimising noise and vibration and maximising transmission smoothness.
The EP-K77 covers an input power range of 0.18–15 kW and a maximum permitted
output torque of 3000 N·m. The standard gear ratio range is 5.36–192,
giving output speeds from 7.4–486 rpm with a 4P / 6P / 8P induction or servo motor.
Six mounting types — foot (K), B5-flange (KF), shaft-mounted hollow-bore (KA, KAF),
GK-housing hollow-bore (KAB), and torque-arm shaft-mounted (KAT) — cover virtually
every installation requirement. Standard ingress protection is IP55, with IP65 available on request.
The housing is precision-cast from HT250 high-strength grey cast iron and stress-relief aged
to ensure long-term dimensional stability. All rolling-element bearings are sourced from
premium manufacturers, designed to an L10h service life of ≥ 20,000 hours.
A balanced internal pressure system and high-integrity shaft seals prevent lubricant leakage
and exclude external contamination.
Key Technical Specifications
| Parameter | Value | Notes |
|---|---|---|
| Frame Size | 77 | K77 series |
| Rated Input Power | 0.18–15 kW | Mating motor power range |
| Max. Output Torque | 3000 N·m | Permitted maximum |
| Gear Ratio Range | 5.36–192 | Standard ratio series |
| Output Speed Range | 7.4–486 rpm | With standard motor speeds |
| Permitted Radial Force | 18,905 N | At output shaft end |
| Unit Weight | 62–82 kg | Varies with motor configuration |
| Mounting Positions | M1–M6 (6 positions) | Any mounting orientation |
| Motor Pole Count | 4P / 6P / 8P | Standard 50 Hz configuration |
| Gear Accuracy Grade | Grade 6 | GB/T 10095.1 |
| Ingress Protection | IP55 standard / IP65 optional | GB/T 4942.1 |
| Lubrication | Splash + pressure-balanced breather | Mineral oil standard |
| Ambient Temperature | −10 °C to +40 °C | Synthetic oil for low-temp. sites |
| Duty Cycle | Continuous (S1) | Intermittent duty also supported |
| Noise Level | ≤78 dB(A) | No-load, rated speed |
Mounting Types & Installation Positions
The EP-K77 is available in the following mounting configurations, each designed for a specific
installation requirement:
- K77 (foot-mounted, solid output shaft)
- KF77 (B5 flange-mounted, solid output shaft)
- KA77 (shaft-mounted, hollow output shaft)
- KAF77 (B5 flange + hollow output shaft)
- KAB77 (GK housing, hollow output shaft)
- KAB77 — GK-housing shaft-mount type with hollow output shaft; designed for high radial loads (available on selected sizes)
- K77SZ — input-shaft-only variant (no motor); accepts a customer-supplied coupling or pulley
- K77R — combination of K77 and R-series helical reducer for very high overall ratios
- KAT77 — KA type with integrated anti-rotation torque arm for rigid shaft-mount installations
All mounting types support six standard mounting positions (M1 to M6):
| Position | Definition | Typical Use |
|---|---|---|
| M1 | Motor horizontal, housing feet down (standard position) | Suits the majority of horizontal drive applications |
| M2 | Motor horizontal, motor below housing | For upward-facing output shaft or suspended installation |
| M3 | Motor horizontal, housing feet up | For overhead platform mounting |
| M4 | Motor above housing | Saves horizontal floor space in side-drive layouts |
| M5 | Motor horizontal, housing left side down | For drives mounted on a vertical face |
| M6 | Motor horizontal, housing right side down | Mirror image of M5 for opposite-hand mounting |
Model Designation Guide
A complete EP-K77 series model number encodes all key configuration data.
The fields are defined in the table below:
| Field | Example | Meaning |
|---|---|---|
| Mounting type | KAF | B5-flange + hollow output shaft |
| Frame size | 77 | Housing size number |
| Motor type & power | Y0.75 | Y-series motor, 0.75 kW |
| Pole count | 4P | 4-pole motor (approx. 1,450 rpm) |
| Gear ratio | 35.57 | Exact ratio from standard series |
| Mounting position | M1 | Standard horizontal, feet down |
| Output shaft direction | B | Output shaft hand (A or B) |
| Terminal box position | 90° | Motor terminal box orientation |
Order example: KAF77-Y0.75-4P-35.57-M1-B-90°
— KAF-type, frame 77, Y-series 0.75 kW motor, 4-pole, ratio 35.57, M1 mounting, B-hand output, terminal box at 90°.
Typical Industry Applications
| Industry | Typical Application |
|---|---|
| Power Generation | Cooling fan drives and auxiliary pump sets in power plants. |
| Petrochemical | Pipeline pumps, agitator vessels, and screw conveyors in chemical plants. |
| Construction | Aggregate conveyors at concrete batching plants. |
| Grain Processing | Bucket elevators and drag-chain conveyors in grain terminals. |
The 90° right-angle output shaft of the EP-K77 gives it a decisive advantage wherever
space is constrained or the transmission direction must change. From precision low-speed
processes to continuous heavy-duty industrial operations, the EP-K77
delivers a reliable and efficient drive solution across a wide range of sectors.
Case Study: Fine Chemical Agitator
A 5,000-litre ATEX Zone 1 reactor at a specialty chemical plant was fitted with an EP-K77 at a ratio of 97:1, giving 15 rpm output. Seal integrity has been maintained for five years with zero leakage, and the unit carries full ATEX certification for use in the hazardous area.
Key Product Advantages
High Efficiency
Three-stage combined drive achieves 94–97% unit efficiency. Ground spiral bevel flanks minimise mesh losses and heat generation.
High Torque Density
Compact housing achieves an excellent torque-to-weight ratio. The K77 frame delivers up to 3000 N·m in a package weighing only 62–82 kg.
Long Service Life
L10h bearing life target ≥ 20,000 hours. Premium rolling bearings, engineered lubrication and robust sealing support a 15–20 year equipment life.
Versatile Installation
Foot, flange, shaft-mount and torque-arm types with M1–M6 positions cover virtually every spatial constraint and layout requirement.
Low Noise & Vibration
Grade 6 ground gears and precision-balanced spiral bevel stage keep sound pressure below 78 dB(A), suitable for noise-sensitive production environments.
Wide Ratio Range
Standard ratio series 5.36–192 covers a broad output speed range in one frame size, eliminating the need for separate gearbox families for different applications.
Selection Guide
Confirm the following parameters before finalising your EP-K77 selection:
| Selection Criterion | Guidance | EP-K77 Limit |
|---|---|---|
| Required output torque | Calculate from load and duty cycle | ≤ 3000 N·m |
| Service factor fB | 1.0 smooth; 1.25–1.75 moderate shock | Apply to required torque before comparing |
| Required gear ratio | Motor speed ÷ output speed | Select nearest standard value in 5.36–192 |
| Motor input power | Rated motor power | Within 0.18–15 kW range |
| Mounting type | Match to equipment layout | K / KF / KA / KAF / KAB / KAT |
| Output radial force | Include belt/chain tension | ≤ 18,905 N |
About Ever Power
Ever Power is a specialist manufacturer and global supplier of industrial power transmission equipment,
including helical-bevel gear reducers, helical gear reducers, worm gear reducers, planetary gearboxes,
bevel gearboxes, and matched gearmotors. Our manufacturing facilities operate under ISO 9001 quality
management systems, and our products carry CE certification as standard.
With customers across mining, cement, steel, paper, port, food processing, and general industrial sectors,
Ever Power combines engineering depth with responsive global logistics. Our technical team provides
full selection calculations, dimensional drawings, and application engineering support —
typically within one working day.
We supply sample quantities of 1–5 units for evaluation and prototype projects.
Mixed-model orders are accepted from approximately USD 1,500. Standard production lead time is
10–25 working days; priority scheduling is available for urgent requirements.
Learn more about Ever Power.
Frequently Asked Questions
How much higher is the permitted radial load on the K87 compared with the K77?
The K87 permits approximately 27,455 N radial force at the output shaft, versus 18,905 N for the K77 — about 45% higher. When belt tension or chain pull is large, select the larger frame to protect the output-shaft bearing.
How should I select the K77 for an application with more than 20 start-stop cycles per day?
Multiply the required torque by a start-stop factor of 1.25 before comparing it with the K77's rated torque. If the resulting value exceeds the K77 limit, move up to the K87. Also consider specifying a soft-starter or VFD to limit inrush torque and extend gear life.
Is the B5 flange on the KAF77 to a standard interface?
Yes. The B5 flange dimensions on all KAF37–157 types comply with IEC 72; hollow bore diameter and keyway dimensions follow GB/T 3362. The flange is directly compatible with the majority of IEC-frame motors.
How should the K77 be protected in a dusty environment?
Specify IP65 or IP66 protection. Fit a labyrinth seal at the output shaft. Check and clean the breather filter regularly to prevent dust clogging that would cause pressure build-up inside the housing.
What is the difference between the grease lubrication of the bearings and the oil fill of the gearset?
Bearings are packed with sealed, lifetime grease that requires no maintenance. The gear cavity is filled with mineral or synthetic gear oil that must be changed at the specified intervals (typically every 10,000 hours or two years). The two lubricants must never be mixed. Specify the oil grade — mineral or synthetic — at the time of order.
Request a Quote or Technical Support
Need technical data sheets, CAD drawings, or a custom selection service for the EP-K77?
Our engineering team is ready to assist:
- Full selection parameter tables (constant-power and constant-torque duty)
- Free 2D and 3D installation dimension drawings
- Custom gear ratios, ingress protection levels, and surface treatments
- Samples: 1–5 units; mixed orders from approx. USD 1,500; 10–25 working days lead time