Motor Case Sealing Design for Waterproof Drive Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drive apparatuses require multiple sealing locations and increased manufacturing steps to ensure waterproofing, particularly in electric power steering systems, where rainwater and other fluids can intrude, complicating the sealing process and reducing reliability.
Innovation Solution
A drive apparatus design featuring a motor unit, control device, motor case, and control device cover with a primary seal between the motor case and installation subject, and a secondary seal between the control device cover and motor case, using an O-ring and bonding agent respectively, to reduce the number of sealing locations and simplify assembly, while maintaining effective waterproofing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sealing locations are used to ensure waterproofing at all connection points, then waterproof reliability is improved, but device complexity and number of sealing components increase
Solution Approach 1:
The motor case integrates multiple functions: it serves as both the motor housing and the mounting structure fixed to the installation subject (e.g., gear box). By combining these functions into a single component, the patent eliminates the need for separate sealing locations at the motor case connections, reducing the total number of sealing points while maintaining waterproof reliability through the primary seal at the motor unit connection.
2Reliability
If multiple sealing locations are used to ensure waterproofing, then waterproof reliability is improved, but the number of manufacturing steps increases
Solution Approach 1:
The motor case integrates multiple functions: it serves as both the motor housing and the mounting structure fixed to the installation subject (e.g., gear box). By combining these functions into a single component, the patent eliminates the need for separate sealing locations at the motor case connections, reducing the total number of sealing points while maintaining waterproof reliability through the primary seal at the motor unit connection.
3Stability of the object's composition
If radially outward flanges and dedicated fixing elements are used to secure the drive apparatus, then structural stability is improved, but the outer diameter of the drive apparatus increases
Solution Approach 1:
Instead of using radially outward flanges that increase the outer diameter, the patent employs axial connection structures. The motor case has an opening at one end where the motor unit is inserted, and the control device cover is fixed to this end portion. This axial arrangement allows for secure structural stability without requiring radial extensions, thereby minimizing the outer diameter of the drive apparatus.
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
This design reduces the number of sealing locations, improves waterproof reliability, and minimizes the outer diameter of the drive apparatus, eliminating the need for radially outward flanges and dedicated fixing elements, thus enhancing assembly efficiency and reducing the risk of water intrusion.
Implementation Method 1
a primary seal, which fluid-tightly seals between the motor case and the installation subject
Implementation Method 2
a secondary seal, which fluid-tightly seals between the control device cover and the motor case
Data Source
AI summary
In a drive apparatus, a motor unit is received in an inside of a tubular section of a motor case, and a bottom plate section is fixed to a gear box. A closure is fitted to an inner wall of the tubular section on an inner side of an opening edge part of the motor case. A control device cover is fixed to an end part of the motor case, which is opposite from the gear box, to cover a control device. An O-ring fluid-tightly seals between the motor case and the gear box, and a bonding agent fluid-tightly seals between the control device cover and the motor case.