Removable Encoder Assembly for Micro-Fluidic Valve Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current micro-fluidic valve actuator systems face challenges in precise positioning and alignment due to tight tolerances, leading to increased costs and complexity in assembly, with existing encoder assemblies requiring precise angular relation and concentricity, which can result in misalignment and incorrect encoding.
Innovation Solution
A removable, stand-alone encoder assembly with a support structure that allows minute movement in three degrees of freedom, enabling pre-alignment and pre-calibration before installation, reducing assembly complexity and cost by accommodating misalignments within the actuator housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the encoder assembly is rigidly coupled to the actuator housing, then the alignment and concentricity are maintained, but the assembly complexity and cost increase due to tight tolerances
Solution Approach 1:
The encoder assembly is designed with dynamic characteristics that allow it to float or shift slightly within the actuator housing. The support structure includes features such as tapered bore fittings and clearance gaps that enable the encoder assembly to self-align and accommodate misalignments dynamically, rather than requiring rigid fixed-position mounting.
Solution Approach 2:
The invention changes the mounting parameters from fixed rigid coupling to flexible coupling with controlled movement. The support structure allows for minute movements in three degrees of freedom, changing the physical state from static to dynamically adjustable, which simplifies assembly while maintaining operational precision.
2Measurement precision
If the encoder assembly requires precise angular relation and concentricity, then the positioning accuracy is improved, but the assembly cost and difficulty increase
Solution Approach 1:
The encoder assembly is pre-assembled as a complete unit with the encoder wheel and encoder module mounted on the support structure before installation into the actuator housing. This preliminary assembly allows for pre-alignment and pre-calibration, ensuring positioning accuracy is achieved before the final installation step.
Solution Approach 2:
The support structure acts as an intermediary between the encoder assembly and the actuator housing. It provides a mounting interface that allows the encoder assembly to float and self-align, mediating the connection in a way that simplifies assembly while maintaining the required positioning accuracy through its dynamic adjustment capability.
3Ease of manufacture
If the encoder wheel is secured with a set screw, then the assembly is simplified, but the encoder wheel may move relative to the shaft causing incorrect encoding
Solution Approach 1:
The encoder wheel is merged with the encoder shaft through interference fit or key-way connections integrated into the encoder assembly design. This combining of components eliminates the need for separate set screws while ensuring the encoder wheel remains securely fixed to the shaft, preventing relative movement and ensuring encoding reliability.
4Manufacturing precision
If tight tolerances are maintained throughout the drive train, then the valve positioning precision is improved, but the manufacturing cost and assembly difficulty increase
Solution Approach 1:
The encoder assembly is designed with dynamic characteristics that allow it to float or shift slightly within the actuator housing. The support structure includes features such as tapered bore fittings and clearance gaps that enable the encoder assembly to self-align and accommodate misalignments dynamically, rather than requiring rigid fixed-position mounting.
Solution Approach 2:
The invention changes the mounting parameters from fixed rigid coupling to flexible coupling with controlled movement. The support structure allows for minute movements in three degrees of freedom, changing the physical state from static to dynamically adjustable, which simplifies assembly while maintaining operational precision.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A multi-position micro-fluidic valve system (20) operably mounted to a drive motor (21) is described. The valve system comprises a housing (27) having an exterior wall and an interior wall defining an interior through-chamber (28). A drive assembly (24) is rotatably positioned within said chamber and has a drive axis of rotation (33) co-axial with a chamber axis (31) and is rotatably coupled to said drive motor. A removable, stand alone, self contained encoder assembly (36) includes a support structure (37), an encoder shaft (38) rotatably mounted to said support structure for rotation about an encoder shaft axis, and an encoder device (40) configured to determine the rotational position of the encoder shaft about the encoder shaft axis. Said support structure is positioned within said housing (27) at a mounting position, enabling rotational coupling of the encoder shaft to the drive assembly. A multi-position micro-fluidic valve device (22) has a valve shaft (25) rotating about a valve axis (26) between a plurality of discrete fluid distribution positions and is mounted to the housing to enable rotational coupling of the valve shaft to the encoder shaft. The support structure is free of rigid coupling directly to said actuator housing.