SCARA Robot Shaft Waterproofing with Bellows and Packing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing industrial robots, such as SCARA robots, face challenges in maintaining a waterproof structure, particularly around the ball screw spline shaft, which allows liquids like water to enter the robot due to the lack of comprehensive sealing solutions for longitudinal grooves.
Innovation Solution
The implementation of a SCARA robot design featuring a shaft with helical and longitudinal grooves, equipped with ring-shaped packing and a labyrinthine structure, and waterproof bellows covers at both ends, which include flange-shaped end portions for enhanced sealing and protection against liquids, utilizing materials like urethane sheets and closed-cell silicon sponges for effective sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bellows cover member is used to prevent liquid entry, then waterproof performance is improved, but the structure becomes complex and assembly becomes difficult
Solution Approach 1:
The bellows cover member is constructed from flexible bellows structures that expand and contract to accommodate shaft movement while maintaining liquid tightness. This flexible membrane approach provides effective waterproofing without requiring complex rigid sealing mechanisms, thus improving waterproof performance while keeping the structure relatively simple.
Solution Approach 2:
The bellows cover member is fitted over the shaft in a nested configuration, where the bellows structure envelops the shaft while allowing relative movement. This nesting approach simplifies assembly by eliminating the need for complex fastening mechanisms, as the bellows cover simply slides over and secures to the shaft.
2Reliability
If a bellows cover member with liquid gasket and clamp band is used, then waterproof performance is improved, but assembly and maintenance time increase
Solution Approach 1:
The bellows cover member is designed with pre-formed sealing surfaces and integrated sealing features that are prepared during manufacturing. This preliminary preparation eliminates the need for complex on-site assembly procedures involving multiple components like liquid gaskets and clamp bands, significantly reducing assembly time while maintaining waterproof performance.
Solution Approach 2:
Multiple sealing functions are merged into the single bellows cover member structure. The bellows cover integrates the sealing, protective, and movement-accommodating functions into one component, eliminating the need for separate liquid gaskets, clamp bands, and other sealing elements. This consolidation simplifies both assembly and maintenance procedures.
3Adaptability or versatility
If longitudinal grooves are added to the shaft for movement, then operational flexibility is improved, but liquid entry into the robot increases
Solution Approach 1:
The bellows cover member acts as a flexible sealing shell that covers the longitudinal grooves on the shaft. As the shaft moves within the grooves, the bellows material flexes to maintain continuous contact and sealing, preventing liquid entry while preserving the full range of motion enabled by the longitudinal grooves.
Solution Approach 2:
The bellows cover member serves as an intermediary barrier between the shaft's longitudinal grooves and the external liquid environment. It mediates between the need for shaft movement through the grooves and the requirement to prevent liquid entry, allowing motion while blocking liquid penetration.
Data Source
AI summary
A robot having a shaft extending in vertical directions at an end of an arm pivoting in horizontal directions around a pivot axis parallel to the vertical directions and performing work using an end effector attached to a lower end of the shaft, the shaft having a helical groove and a longitudinal groove to enable upward and downward motion in the vertical directions and pivot around an axis of the shaft, includes a ring-shaped packing having a convex portion to engage with the longitudinal groove, fitted on the shaft, and sandwiched and fixed by a stopper portion and a collar portion in an extension direction of the shaft.