Flow Control Valve Poppet With Needle for Low-Flow Accuracy
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Solution Overview
Problem
Existing stepper motor actuated flow control valves face challenges in maintaining accuracy and repeatability due to power loss and complexity in drive systems, as well as wear and deformation of rubber components, which affect flow resolution, especially at low fluid flowrates.
Innovation Solution
A flow control valve design featuring a valve member with a poppet and flow control needle, where the flow control needle's position is adjusted by a stepper motor to fine-tune fluid flow, separating the sealing and flow control interfaces to prevent wear and deformation from affecting flow accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a gear system or multi-directional drive system is used to translate the valve member, then the stepper motor can control the valve position, but power loss increases and position accuracy decreases due to multiple moving parts
Solution Approach 1:
The patent extracts the gear system and multi-directional drive components from the valve actuation mechanism, using only the stepper motor's rotational output directly to drive the valve member through a simplified linear translation mechanism, eliminating unnecessary intermediate components that cause power loss
Solution Approach 2:
The patent replaces the complex mechanical gear system with a direct-drive mechanism where the stepper motor's rotational motion is converted to linear valve member translation through a simpler mechanical linkage, reducing friction and power loss while maintaining control capability
2Ease of operation
If a gear system or multi-directional drive system is used to translate the valve member, then the valve can be actuated, but position accuracy and repeatability decrease due to multiple moving parts
Solution Approach 1:
The patent removes intermediate gear components and multi-directional drive elements that introduce cumulative errors and reduce positioning precision, maintaining only the essential stepper motor-to-valve-member transmission path
Solution Approach 2:
The patent segments the drive system into distinct functional zones: the stepper motor provides precise rotational positioning, which is then directly translated to linear valve member position through a simplified mechanism, allowing each component to operate in its optimal precision range
3Reliability
If the valve member includes rubber overmold and rubber valve seat for sealing, then fluid-tight seal is achieved, but wear and deformation occur over time reducing flow resolution
Solution Approach 1:
The patent segments the valve member into distinct functional zones: a wear-resistant needle portion that maintains precise flow control geometry, and a separate sealing portion with rubber components. This allows the flow control interface to remain precision-stable while the sealing components handle the wear from cyclic operation
Solution Approach 2:
The patent uses composite construction for the valve member, combining hard wear-resistant materials for the flow control needle with flexible rubber materials for sealing surfaces, allowing each material to perform its optimal function while protecting the precision flow control geometry from degradation
4Device complexity
If the flow control interface uses the same surface as the sealing interface, then structure is simplified, but wear and deformation affect both sealing and flow accuracy
Solution Approach 1:
The patent divides the valve member's interaction surfaces into separate functional zones: the sealing interface and the flow control interface. This segmentation allows wear to occur at the sealing interface without affecting the precision geometry of the flow control interface, maintaining flow accuracy over time
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 enhances flow resolution by isolating the sealing and flow control interfaces, maintaining accuracy and repeatability even at low fluid flowrates, and allows for adjustments to accommodate manufacturing tolerances and wear, improving performance compared to traditional systems.
Implementation Method 1
a bellows shaped diaphragm can be used to provide a seal between the valve body and the valve member. Such diaphragms can prevent contaminants from working their way into the motor housing while permitting longitudinal movement of the valve member.
Implementation Method 2
The flow control needle defines an outlet flow orifice with the inner surface of the outlet port. The flow control needle defines a needle bore in fluid communication with the outlet port.
Implementation Method 3
The flow control needle is adjustable relative to the poppet by rotating the flow control needle within the poppet bore. The flow control needle includes a tool interface permitting rotational adjustment of the flow control needle within the poppet bore.
Data Source
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AI summary
A flow control valve (10) including a valve body (11), stepper motor (41), and valve member (28). The valve member includes a poppet (30) that can slide longitudinally within a bore (19) of the valve body when the stepper motor receives electricity. A diaphragm (48), extending inwardly from the valve body to the valve member, deflects in response to movement of the valve member. A flow control needle (49), mounted to the poppet of the valve member, is at least partially received in an outlet port (23) of the valve body. The flow control needle cooperates with an inner surface (25b) of the outlet port to define an outlet flow orifice that varies in size when the valve member moves between open and closed positions. In the closed position, a seat engagement surface (46) of the valve member contacts a valve seat (18) of the valve body to create a fluid-tight seal.