NGW & NGW-S Series Planetary Gear Reducers Single-stage efficiency can reach 97% - 98%

I. Product Introduction

The NGW series reducer is an involute spur gear planetary reducer based on the 2K-H negative drive mechanism. It is the most standard and widely used planetary reducer series in China. Its name comes from Chinese Pinyin (N: Neihe = Internal Meshing; G: Gongyong = Common; W: Weihe = External Meshing), and its design complies with the Chinese Machinery Industry Standard JB/T 9043.1-1999.

• NGW Series: Single-stage or multi-stage series-connected standard planetary gear reducers.

• NGW-S Series: A derivative series, often indicating a shrunken or compact design for a more compact structure at equivalent torque, or denoting specific mounting forms.

Its core structure consists of a sun gear, multiple planet gears, an internal ring gear, and a planet carrier. Power can be input through the sun gear and output from the carrier (reduction), or vice versa (increase). This series is renowned for its significant features: compact size, light weight, high load capacity, and high efficiency.

II. Main Technical Parameters

1. Model Designation: Usually represented by a specification number and number of stages, e.g., NGW11 (single-stage), NGW52 (two-stage), NGW103 (three-stage), or NGW-S71.

2. Specification Definition: The specification number relates to the gear module and size. A larger number indicates a larger size.

3. Number of Stages: Single-stage, two-stage, three-stage, or four-stage. Larger ratios are achieved by connecting multiple planetary stages in series.

4. Ratio Range (i):

   • Single-Stage: 2.8 ~ 12.5

   • Two-Stage: 14 ~ 160

   • Three-Stage: 180 ~ 630

   • Four-Stage: 710 ~ 2800

5. Input Power (kW): Covers an extremely wide range, from fractional kW to several thousand kW.

6. Output Torque (N·m): Ranges from several hundred N·m to millions of N·m.

7. Gear Accuracy: Requires high gear precision, typically achieving Grade 6 or better per GB/T 10095.1 (comparable to ISO 1328).

8. Gear Material: Gears are made from high-quality alloy steel (e.g., 42CrMo, 20CrMnTi, 35CrMo), treated by processes like quenching & tempering and case carburizing.

9. Efficiency: Very high transmission efficiency. Single-stage efficiency can reach 97% - 98%. Efficiency decreases by about 1% per additional stage. Three-stage efficiency can still be maintained above 94%.

III. Key Advantages & Features

1. Small Size & Light Weight: Power is split and transmitted by multiple planet gears simultaneously, resulting in a very compact structure. It is far smaller and lighter than ordinary fixed-shaft gear reducers under equivalent load.

2. High Load Capacity: The load is shared among several planet gears, reducing the moment on each gear, thus achieving extremely high torque density.

3. High Transmission Efficiency: The symmetrical planetary structure minimizes frictional losses, resulting in higher efficiency than most other types of reducers.

4. Large Reduction Ratio: A single stage provides a relatively large ratio. Multi-stage series connection allows for very large ratios while maintaining a compact structure.

5. Smooth Operation & Strong Impact Resistance: Multiple planet gears increase the number of engaged teeth and balance the force, ensuring smooth transmission and high reliability.

6. Symmetrical Structure & High Adaptability: Coaxial input and output shafts facilitate machine layout. Can operate in both clockwise and counterclockwise directions.

IV. Primary Application Fields

The NGW series planetary reducer is suitable for almost all fields requiring compact, efficient, and high-torque transmission:

• Lifting & Transportation: Hoisting, luffing, and slewing mechanisms of cranes, port handling machinery.

• Mining & Metallurgy: Drives for rolling mills, sintering machines, rod mills, mine hoists, etc.

• Construction Machinery: Winch, slew, and travel mechanisms for excavators, tunnel boring machines, pavers, concrete mixer trucks.

• Wind Power: Yaw and pitch drives (often using derivative series).

• Petrochemical Industry: Drives for large agitators, extruders, compressors.

• Light & Textile Industry: Equipment requiring high precision and high speed.

• Military & Aerospace: Applications with extremely high demands for volume, weight, and reliability.