Nested Planetary Speed Reducer for Low Backlash Server Torque

Solution Overview

Problem

Conventional speed reducers in servers suffer from excessive backlash, leading to power loss, defective assemblies, and increased manufacturing costs due to inefficient power transmission.

Innovation Solution

A speed reducer design featuring a first planetary gear set with a sun gear, planet gear carrier, and internal gear, coupled with an output gear, which reduces backlash and enhances power transfer efficiency by maintaining low backlash and high speed ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional reducing gears are used in speed reducers, then power transmission can be achieved, but excessive backlash occurs leading to power loss and defective assemblies

Engineering Contradiction:

Improvepower lossVSAvoidbacklash

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The speed reducer is divided into multiple planetary gear sets (first planetary gear set and second planetary gear set) with distinct functions. The first planetary gear set primarily reduces speed, while the second planetary gear set further reduces speed and maintains coaxial alignment. This segmentation allows each gear set to be optimized for specific functions, reducing overall backlash and improving power transmission efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first planetary gear set is nested within the second planetary gear set, with the first planet gear carrier positioned inside the second planet gear carrier. The internal gear of the first planetary gear set is surrounded by the second planet gears. This nested configuration compactly arranges multiple gear sets while maintaining coaxial relationships, reducing backlash through precise alignment and enabling high speed ratios in a compact space.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Speed

If multiple reducing gears are used to achieve high speed ratio, then speed reduction is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvespeed ratioVSAvoidstructure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The first planetary gear set is nested within the second planetary gear set, with the first planet gear carrier positioned inside the second planet gear carrier. The internal gear of the first planetary gear set is surrounded by the second planet gears. This nested configuration compactly arranges multiple gear sets while maintaining coaxial relationships, reducing backlash through precise alignment and enabling high speed ratios in a compact space.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

Each planetary gear set serves multiple functions: speed reduction, torque multiplication, and maintaining coaxial alignment between input and output shafts. The internal gear of the first planetary gear set acts as both a gear element and a structural support for the second planetary gear set. This multi-functionality reduces the need for additional components, simplifying the overall structure while achieving high speed ratios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If conventional speed reducers are used, then power transmission is achieved, but assembly is labor-consuming and production yields decrease

Engineering Contradiction:

Improveassembly efficiencyVSAvoidassembly difficulty

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The speed reducer is divided into modular components including the first planetary gear set, second planetary gear set, internal gear, and output gear, each with specific functions. The first planet gear carrier and second planet gear carrier are separately manufactured and then assembled in a nested configuration. This modular segmentation enables standardized manufacturing processes and simplifies assembly operations, improving production yields.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first planetary gear set is nested within the second planetary gear set, with the first planet gear carrier positioned inside the second planet gear carrier. The internal gear of the first planetary gear set is surrounded by the second planet gears. This nested configuration compactly arranges multiple gear sets while maintaining coaxial relationships, reducing backlash through precise alignment and enabling high speed ratios in a compact space.

Inventive Principle:

Principle #7Nested doll (Nesting)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively reduces power transfer loss, increases output torque, and extends the service life of the speed reducer while enabling high-speed ratios and improved assembly yields.

Implementation Method 1

The first planetary gear set includes a first sun gear mounted on the motor output shaft, a first planet gear carrier, and at least one first planet gear pivotally coupled to the first planet gear carrier and meshed with the first sun gear

Methodology Applied

Scientific EffectGear meshing: Gear

Data Source

PatentUS10138987B2Speed reducer and server using same

Publication Date: 2018.11.27 TRICORE CORP

AI summary

A speed reducer used in a server is disclosed to include a first planetary gear set, a planet gear carrier, an internal gear surrounding the first planetary gear set, and an output gear. The first planet gear includes a first sun gear mounted on the motor output shaft, at least one first planet gear pivotally coupled at the first planet gear carrier and meshed with the first sun gear and the internal gear for driving the first planet gear carrier and the output gear to rotate. Thus, the first planetary gear set reduces the revolving speed of the rotary driving force outputted by the motor output shaft, and effectively transfer the rotary driving force to the output gear, achieving the advantages of low backlash and long service life, reducing power transfer loss, increasing server output torque, and providing high speed ratio, high design flexibility and high assembly yields.