Floating Bearing Roller Profile for Concrete Mixer Drum
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing roller profiles for truck mixer floating bearings experience high Hertzian pressure due to deformations, leading to potential damage and premature wear, as the constant radius design results in a small contact surface and increased risk of edge pressure during axis tilting.
Innovation Solution
A novel roller profile with a crowned surface featuring at least two different radii, where the central area has a larger radius and the end areas have a smaller radius, reducing the contact pressure and minimizing edge contact risk through a larger contact surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a constant radius profile is used for the roller tread, then the manufacturing is simple, but the contact surface is small leading to high Hertzian pressure and premature wear
Solution Approach 1:
The roller tread profile is divided into different zones with different radii: a central zone with a larger radius (5000-10000mm) to increase contact surface and reduce Hertzian pressure, and edge zones with smaller radii (1000-3000mm) to prevent edge contact during axis tilting. This local differentiation optimizes both durability and manufacturing feasibility.
2Strength
If the crowning radius is increased to reduce Hertzian pressure, then the contact surface is larger, but the probability of edge contact increases during axis tilting
Solution Approach 1:
Different zones of the roller tread are assigned different radii to simultaneously achieve large contact surface in the central zone and edge contact prevention in the side zones, resolving the contradiction between durability and reliability.
Solution Approach 2:
The profile transitions from symmetric constant radius to asymmetric variable radius, with the apex of the tread profile offset from the center axis to account for expected axis tilting under load, optimizing both contact surface and edge contact prevention.
3Reliability
If a smaller radius is used for the roller tread, then the risk of edge contact is reduced, but the contact surface is smaller leading to higher Hertzian pressure
Solution Approach 1:
The roller tread uses small radii (1000-3000mm) only in the edge zones to prevent edge contact during tilting, while the central zone maintains a large radius (5000-10000mm) to ensure sufficient contact surface and low Hertzian pressure, thus resolving the contradiction between reliability and strength.
4Duration of action of stationary object
If the roller profile is optimized with multiple radii, then the Hertzian pressure is reduced and service life is extended, but the manufacturing complexity increases
Solution Approach 1:
The profile is divided into a limited number of zones (typically 2-3 zones) with different radii, which can be manufactured using conventional rolling or grinding processes with multiple passes, balancing service life extension with manufacturing complexity.
Solution Approach 2:
The roller profile parameters (radii, zone widths, apex offset) are optimized within specific ranges to achieve the desired performance while remaining compatible with standard manufacturing processes, thus extending service life without excessive complexity.
Data Source
Figure 1
Figure 2
Figure 3a~3c
AI summary
The invention relates to a roller for a floating bearing (30) of a truck mixer, which rolls on a running ring of the mixing drum. According to the invention, the running surface profile is partially convex with a specific radius, and at least a further area of the running surface is convex with a different radius or with a different profile shape.