Planet Carrier Assembly With Press-Fit Locking for Heavy Door Loads

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Solution Overview

Problem

Existing planet carrier assemblies for vehicle door closing actuators face high manufacturing costs, complex assembly procedures, and insufficient mechanical strength due to excessive shaft connections or reliance on small screws, which are prone to failure under heavy loads.

Innovation Solution

A planet carrier assembly with a disc portion, cover portion, and output shaft portion, featuring rotatably mounted planetary gears, a press-fit mounting mechanism, and a rotation locking device with protrusions and recesses, reducing the number of shafts and eliminating the need for screws, while enhancing structural strength and compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple shafts are used to connect the disc portion and cover portion, then the mechanical strength is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvemechanical strengthVSAvoidassembly complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines multiple shaft connections into a single integrated connection structure. The mounting shaft not only supports the planetary gear but also serves as the primary connection element between the disc portion and cover portion, eliminating the need for separate connecting shafts while maintaining structural strength.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mounting shaft is designed to perform multiple functions simultaneously: it supports the planetary gear rotation, connects the disc portion to the cover portion, and provides structural reinforcement. This multi-functional design replaces what would otherwise require multiple dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If multiple shafts are used to connect the disc portion and cover portion, then the mechanical strength is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

By merging the connection function into the existing mounting shaft structure, the patent reduces the total number of parts that need to be manufactured, inventory-managed, and assembled. This consolidation directly reduces manufacturing costs while maintaining the required mechanical strength through optimized shaft design.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If screws are used to fix the disc portion and cover portion, then the assembly is simplified, but the reliability decreases due to screw failure under heavy load

Engineering Contradiction:
Improveassembly easeVSAvoidconnection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the connection function from the screw-based fastening system and implements it through the integrated mounting shaft structure. This eliminates screws from the connection mechanism, thereby removing the reliability issues associated with screw failure under heavy door closing loads while maintaining assembly simplicity.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If an integral type planet carrier is used, then the structural strength is improved, but the manufacturing cost increases and component replaceability decreases

Engineering Contradiction:
Improvestructural strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent segments the planet carrier into separable components (disc portion and cover portion) that are connected through the mounting shaft structure. This modular design maintains structural strength through the integrated shaft connection while enabling individual component replacement and reducing manufacturing complexity compared to a fully integral design.

Inventive Principle:
Principle #1Segmentation

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 decreases manufacturing costs, simplifies assembly, and improves mechanical strength, enabling effective operation under heavy load conditions while maintaining a compact design, thus addressing the limitations of prior art.

Implementation Method 1

one end of the mounting shaft protruding from a central hole of the planetary gear being pressed into a corresponding receiving hole on the cover portion

Methodology Applied
Scientific EffectPress-fit: Mechanical Fastener

Implementation Method 2

the rotation locking device comprises at least two protrusions protruding from a periphery of the cover portion toward the disc portion and at least two recesses recessed radially from a periphery of the disc portion, wherein the protrusions are engaged with the recesses

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Data Source

PatentEP3816476B1Planet carrier assembly for vehicle door closing actuator
Publication Date: 2023.08.30 GUANGDONG ZHAOQING L&V CO LTD
  • EP3816476B1 patent drawingFigure 1(a)~1(b)
  • EP3816476B1 patent drawingFigure 1(c)~2
  • EP3816476B1 patent drawingFigure 3

AI summary

The present application relates to a planet carrier assembly for a vehicle door closing actuator. The planet carrier assembly comprises a plurality of planetary gears and a planet carrier body. The planet carrier body comprises a disc portion, a cover portion and an output shaft portion, wherein the plurality of planetary gears are rotatably mounted on the disc portion via a corresponding number of mounting shafts fixed to the disc portion, one end of the mounting shaft protruding from a central hole of the planetary gear is pressed into a corresponding receiving hole on the cover portion, and the planet carrier body is further provided with a rotation locking device to prevent the cover portion from rotating circumferentially relative to the disc portion. The planet carrier assembly according to the present application has the advantages such as low cost, high strength, and simple assembly.