Dishwasher Spray Arm Linkage for Wider Wash Coverage
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Solution Overview
Problem
Conventional dishwashers have limitations in evenly spraying wash water onto dishes, leading to inefficient washing due to fixed spray arm angles and the need for separate driving devices to rotate the spray arm.
Innovation Solution
A dishwasher design featuring a spray arm with a main arm and auxiliary arm, where the auxiliary arm rotates and reciprocates using the rotational force of the main arm, allowing for varied spray angles without a separate driving device, and utilizing an eccentric gear system to convert rotational motion into reciprocating motion for the linker, which pushes the auxiliary arm to rotate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed spray arm structure is used, then the device complexity is reduced, but the sprayed area and washing efficiency deteriorate
Solution Approach 1:
The spray arm is designed with an auxiliary arm that can rotate relative to the main arm, transforming the fixed structure into a dynamic one. The auxiliary arm rotates to change spray angles and expand the sprayed area, while the main arm provides stable support. This dynamic configuration resolves the contradiction by allowing structural complexity only where needed to expand coverage.
Solution Approach 2:
The spray arm is divided into a main arm and an auxiliary arm that can rotate independently. The main arm contains nozzles for primary spraying, while the auxiliary arm adds additional nozzles that rotate to cover different areas. This segmentation allows the system to maintain a simple base structure while adding rotational capability to expand the sprayed area.
2Area of moving object
If a separate driving device is added to rotate the spray arm, then the sprayed area increases, but the device complexity and cost increase
Solution Approach 1:
The auxiliary arm utilizes the rotational motion of the main arm as its driving force, eliminating the need for a separate motor or actuator. The main arm's rotation naturally drives the auxiliary arm to rotate, creating a self-powered system that expands spray coverage without adding complex driving mechanisms.
Solution Approach 2:
The driving function for both the main arm and auxiliary arm is merged into a single rotational motion system. The main arm's rotation serves dual purposes: directly spraying water and simultaneously driving the auxiliary arm's rotation. This merging eliminates redundant driving devices and reduces overall system complexity.
3Productivity
If the auxiliary arm rotates freely, then the spray angles vary improving washing efficiency, but the reliability of water supply to the auxiliary arm deteriorates
Solution Approach 1:
The connection between the main arm and auxiliary arm is designed as a dynamic rotational joint with an integrated water supply passage. The passage rotates together with the auxiliary arm, ensuring continuous water supply regardless of the auxiliary arm's rotational position. This dynamic connection maintains reliability while allowing free rotation for varied spray angles.
Solution Approach 2:
The water supply passage is nested within the rotating connection structure, with the passage axis coinciding with the rotation axis. This nested configuration ensures that the water supply channel rotates synchronously with the auxiliary arm, maintaining proper alignment and continuous water flow to the nozzles throughout the rotation cycle.
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 increases the sprayed area of wash water, enhances washing efficiency by allowing water to be sprayed at various angles, and eliminates the need for a separate driving device to rotate the spray arm, resulting in improved cleaning performance.
Implementation Method 1
an eccentric gear engaged to the fixed gear to rotate by rotating the spray arm, and a linker connecting the eccentric gear to the spray arm. The linker may be moved by rotation of the eccentric gear to push each auxiliary arm to be rotated
Implementation Method 2
the spray arm may rotate using driving force by spraying the wash water without a separate driving device
Data Source
Figure 1
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Figure 4
AI summary
A dishwasher (1) is provided. The dishwasher (1) includes a washing tub (10) accommodating objects to be washed, a main arm (300, 300a, 300b) rotatably provided in the washing tub to form a main flow path (301a, 301b) to spray wash water to the object, an auxiliary arm (400a, 400b) rotatably mounted at the main arm to form an auxiliary flow path (301c, 301d) through which wash water flow, and an auxiliary arm connector (330a, 301b) extending from the main arm to rotatably support the auxiliary arm. The auxiliary arm is configured to rotate about the auxiliary arm connector as an axis. In the auxiliary arm connector, an auxiliary flow path guide (334) is inserted into the auxiliary flow path to secure pressure of the wash water of the auxiliary flow path.