Dryer Drum Support Roller Assembly Without Press-Fit Bearing Damage
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Solution Overview
Problem
Existing dryers face challenges in assembling and maintaining the front bearing rollers, as the press-fit method requires precise tolerances, leading to potential damage and reduced bearing lifespan, increasing maintenance and replacement costs.
Innovation Solution
The use of plastic casing with integrated hollow cylindrical sleeves and screws that allow for easy assembly of rollers without press-fit, providing axial fixation and compensating for forces acting on the rollers, thus eliminating the need for precise tolerances and reducing strain on bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If press-fit method is used to mount roller shaft to bearing, then roller can be securely connected, but manufacturing precision requirements increase and bearing lifespan decreases
Solution Approach 1:
A plastic sleeve is introduced as an intermediary component between the roller shaft and bearing. The sleeve has a through-hole that receives the roller shaft and an outer surface that contacts the bearing, eliminating the need for direct press-fit connection. This mediator absorbs dimensional tolerances and prevents damage to the bearing during assembly.
Solution Approach 2:
The original direct connection between roller shaft and bearing is segmented into three separate components: the roller shaft, the plastic sleeve, and the bearing. This segmentation allows each component to be manufactured independently with relaxed tolerances while maintaining overall assembly functionality and reliability.
2Ease of manufacture
If press-fit method is used to assemble roller, then roller is firmly fixed, but assembly process becomes complex and time-consuming
Solution Approach 1:
The plastic sleeve is pre-installed into the bearing before the roller shaft assembly. This preliminary action creates a ready-receive condition that simplifies the subsequent assembly step, allowing the roller shaft to be quickly inserted without requiring complex press-fit operations or specialized tooling.
Solution Approach 2:
The plastic sleeve acts as a mediator that simplifies the assembly process by providing a friction-fit or snap-fit interface instead of requiring precision press-fit. This intermediary component enables rapid assembly with standard tools while ensuring firm fixation of the roller.
3Strength
If press-fit method is used, then roller connection is secure, but risk of bearing damage increases during assembly
Solution Approach 1:
The plastic sleeve is installed beforehand as a protective cushion between the roller shaft and bearing. This cushioning element prevents direct impact and stress concentration during assembly, protecting the bearing from damage while still providing secure connection strength through its friction-fit or interference-fit design.
Solution Approach 2:
The plastic sleeve serves as a protective intermediary that distributes assembly forces evenly across the bearing surface, preventing localized stress concentrations that could cause bearing damage. The sleeve material properties are selected to provide both protection during assembly and secure connection during operation.
Data Source
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AI summary
The present invention relates to a dryer (1) having a drum (2) wherein the laundry to be dried is disposed and which is rotated around the horizontal axis (X1), an intake opening (3) which is located at the front side of the drum (2) and which provides the laundry to be loaded, a casing (4) which surrounds the intake opening (3), which is produced from plastic material and which provides the drum (2) to be borne from the front side, and rollers (8) which are mounted to the casing (4) inner side facing the drum (2), which support the drum (2) by being seated in the front support rim (6), which have a bearing bore (7) located at the center of the roller (8) and providing it to be borne in a rotatable manner, and which rotate around a rotational axis (X2) parallel to the horizontal axis (X1) of the drum (2) by the effect of the rotational movement of the drum (2).