KM Series Helical Hypoid Gear Units are the latest generation of compact, high-efficiency gear reducers developed by NUODUN. Designed with advanced hypoid gear technology, the KM series delivers high torque density, smooth transmission, long service life, and superior energy efficiency compared to conventional worm gear reducers.

Featuring lightweight aluminum housing, high-strength alloy steel gears, multiple installation options, and compatibility with NMRV worm gear mounting dimensions, the KM series is ideal for a wide range of automation and power transmission applications.

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Features

1. Hypoid Gear Drive with High Torque Output

Delivers large output torque with high transmission efficiency, making it suitable for demanding industrial applications.

2. Energy Saving & High Efficiency

Compared with worm gear units, hypoid gears reduce energy loss and enable smoother, quieter operation.

3. Lightweight & Corrosion-Free Housing

Manufactured from high-quality die-cast aluminum alloy, providing low weight, excellent thermal dissipation, and rust-free service life.

4. Smooth Operation & Low Noise

Stable running with minimal vibration, suitable for long-term continuous operation in harsh environments.

5. Compact Structure & Attractive Appearance

Small volume, easy installation, aesthetically clean exterior, and long operational life.

6. Wide Installation Flexibility

Supports all-round mounting positions (B3, B6, B7, etc.) and modular configurations.

7. NMRV Compatibility

Mounting dimensions compatible with NMRV worm gear reducers (except partial dimensions of NMRV050 vs. KM28).

8. Modular & Multi-Structure Options

Multiple gear stages (2-stage & 3-stage) and ratios support diverse industrial applications.

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Materials & Construction

Housing

• Die-cast aluminum alloy (Frame size 28–58)
• Shot-blasted, degreased, and coated with RAL5010 blue paint
• Custom colors available upon request

Gears

• Material: 20CrMnTiH1 alloy steel
• Heat treatment: carbonizing & quenching
• Surface hardness: 56–62 HRC
• Carburized layer thickness: 0.3–0.5 mm after precision grinding

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Technical Specifications

Below are simplified, catalog-style tables for each frame size.

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KM28 Series (160 Nm)

3-Stage

Model	Nominal i	Actual i	Output Speed n₂ (r/min)	Max Torque (Nm)	Fr (N)
KM28C	300	294.05	4.8	130	4100
KM28C	250	244.29	5.8	130	4100
KM28C	200	200.44	7.0	130	4100
KM28C	150	146.67	9.6	160	4000
KM28C	125	120.34	12	160	3770
KM28C	100	99.41	14	160	3560
KM28C	90	91.48	15.5	160	3330
KM28C	75	74.62	19	160	3220

2-Stage

Model	Nominal i	Actual i	Output Speed	Max Torque	Fr
KM28B	60	58.81	24	130	2960
KM28B	50	48.86	29	130	2790
KM28B	40	40.09	35	130	2610
KM28B	30	30.54	48	160	2350
KM28B	25	24.86	59	160	2200
KM28B	20	19.88	70	160	2080
KM28B	15	14.92	93	160	1880
KM28B	12.5	12.47	113	160	1770
KM28B	10	10.30	134	160	1670
KM28B	7.5	7.73	182	160	1510

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KM38 Series (200 Nm)

3-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM38C	300	302.5	4.7	160	4800
KM38C	250	243.57	5.8	160	4800
KM38C	200	196.43	7.2	160	4800
KM38C	150	151.56	9.3	180	4650
KM38C	125	122.22	12	180	4330
KM38C	100	101.27	14	180	4070
KM38C	90	91.25	16	180	3920
KM38C	75	73.33	20	180	3650

2-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM38B	60	60.50	24	160	3430
KM38B	50	48.71	29	160	3190
KM38B	40	39.29	36	160	2970
KM38B	30	30.31	47	180	2720
KM38B	25	24.44	58	180	2530
KM38B	20	20.25	70	180	2380
KM38B	15	15.71	96	180	2130
KM38B	12.5	12.67	111	180	2030
KM38B	10	10.50	134	180	1910
KM38B	7.5	7.60	185	180	1710

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KM48 Series (350 Nm)

3-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM48C	300	297.21	4.7	350	6500
KM48C	250	240.89	5.8	350	6500
KM48C	200	200.66	7.0	350	6500
KM48C	150	151.20	9.3	350	6360
KM48C	125	121.02	11.6	300	5980
KM48C	100	100.81	14	240	5520
KM48C	75	79.41	17.7	200	5040

2-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM48B	60	59.44	27.8	350	4660
KM48B	50	48.18	29	350	4340
KM48B	40	40.13	34.9	300	4080
KM48B	30	29.86	46.9	350	3720
KM48B	25	24.20	57.9	300	3500
KM48B	20	20.16	69.4	240	3230
KM48B	15	15.58	88.2	200	2950
KM48B	12.5	12.49	112	300	2770
KM48B	10	9.84	142.3	240	2550
KM48B	7.5	7.48	187.2	200	2330

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KM58 Series (500 Nm)

3-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM58C	300	295.18	4.7	500	8300
KM58C	250	240.89	5.8	500	8300
KM58C	200	200.66	7.0	480	8300
KM58C	150	151.20	9.3	500	8050
KM58C	125	125.95	11.1	480	7580
KM58C	100	99.22	14.1	380	7000
KM58C	75	75.45	18.5	300	6390

2-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM58B	60	59.04	23.7	500	5890
KM58B	50	48.18	29	500	5500
KM58B	40	40.13	34.9	480	5170
KM58B	30	30.24	46.3	500	4710
KM58B	25	25.19	55.6	480	4430
KM58B	20	19.84	70.56	380	4090
KM58B	15	14.99	93.3	300	3730
KM58B	12.5	12.49	112	480	3510
KM58B	10	9.84	142.3	400	3240
KM58B	7.5	7.48	187.2	300	2950

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KM68 Series (750 Nm)

3-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM68C	300	298.57	4.7	750	10000
KM68C	250	250.10	5.6	750	10000
KM68C	200	195.43	7.2	750	9740
KM68C	150	156.07	9	750	9040
KM68C	125	122.67	11.4	750	8340
KM68C	100	97.96	14.3	650	7740
KM68C	75	75.51	18.5	520	7090

2-Stage

Model	Nominal i	Actual i	n₂ (r/min)	M2max (Nm)	Fr (N)
KM68B	60	59.71	23	750	6560
KM68B	50	50.02	28	750	6180
KM68B	40	39.09	36	750	5690
KM68B	30	31.21	45	750	5280
KM68B	25	24.53	57	750	4870
KM68B	20	19.59	71	650	4520
KM68B	15	15.10	93	520	4150
KM68B	12.5	12.16	115	520	3860
KM68B	10	9.71	144	650	3580
KM68B	7.5	7.48	187	520	3280

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Application

KM series hypoid gear units are designed for low-speed, high-torque, compact transmission systems, widely used in:

Light Load

• Screw conveyors
• Fans & blowers
• Packaging lines
• Light-duty elevators
• Washing equipment
• Filters
• Control drives

Medium Load

• Hoists & lifts
• Woodworking feeders
• Winches
• Sliding gates
• Scraper conveyors
• Mixing equipment
• Calendering machines
• Gear pumps

Heavy Load

• Centrifuges
• Crushers & mills
• Press machines
• Rotary tables
• Excavation & mining machinery
• Heavy-duty winches & cranes

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Service Factor (fs) Selection Guide

Proper service factor ensures gearbox life & reliability.

Determine fs Based On:

• Daily operating hours
• Start/stop frequency
• Load type (light/medium/heavy)
• Inertia & acceleration factor

Example:

• Inertia acceleration factor = 2.5
• Operation = 14 hours/day
• Start-stop = 200 times/hour

From the service chart:
fs = 1.48
Therefore, the selected gearbox must have
fs (catalog) ≥ 1.48

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Lubrication & Maintenance

1. First Oil Change

After 300 hours (running-in period)

2. Regular Inspection

• Check oil condition & level every 3000 hours or every 6 months
• Inspect oil seals and replace if leaking
• For IEC input types, check the elastic coupling

3. Periodic Replacement

• Replace mineral oil at least every 3 years
• Replace output shaft oil seals based on actual working conditions

4. Important Notice

If a failure occurs, do not disassemble — contact NUODUN support with:

• Model
• Serial number
• Operating hours
• Host machine type
• Failure description

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Final Summary for Catalog

The NUODUN KM Series Helical Hypoid Gear Units offer:

• High torque, compact structure
• High efficiency & low noise
• Aluminum lightweight housing
• Hypoid gear technology
• Wide ratio range
• NMRV-compatible mounting
• Long life & easy maintenance