Bellows-Sealed Fluid Machine for Low-Friction Piston Operation
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Solution Overview
Problem
In hydraulic cylinders, friction between the seal ring and backup wear rings causes reduced operability of the piston when operating fluid is introduced, leading to inefficiencies in power transmission.
Innovation Solution
The use of first and second bellows, with the first bellows sealed to the moving member and the container, and the second bellows fixed to the container, separates the fluids and reduces sliding friction, enhancing the operability of the moving member by utilizing non-compressible fluids and a guide portion to stabilize and guide the movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal ring and backup wear rings are used to hermetically divide the cylinder tube, then fluid sealing is improved, but friction between the seal components and cylinder tube increases
Solution Approach 1:
The patent extracts the sealing function from direct sliding contact between seal rings and the cylinder tube. By introducing a bellows structure that seals against the cylinder tube while the piston moves independently, the harmful sliding friction between seals and cylinder wall is eliminated, yet fluid sealing is maintained through the bellows' sealing action.
Solution Approach 2:
The bellows acts as an intermediary element between the piston and the cylinder tube sealing system. It provides the sealing interface with the cylinder tube while allowing piston movement, thereby mediating between the need for tight sealing and the need for low-friction operation.
2Reliability
If seal rings are slidably contacted with the inner periphery of the cylinder tube, then fluid sealing is achieved, but wear and friction increase
Solution Approach 1:
The patent replaces the traditional mechanical sliding seal system with a bellows-based sealing mechanism. The bellows provides sealing through its flexible structure that maintains contact with the cylinder tube without requiring sliding friction, thereby substituting a high-friction mechanical system with a low-friction alternative.
Solution Approach 2:
The bellows, being a flexible structure, serves as the sealing element. Its flexibility allows it to maintain sealing contact with the cylinder tube inner periphery while accommodating piston movement without generating significant friction, thus reducing energy loss compared to rigid sliding seals.
3Ease of operation
If the first bellows is introduced to separate fluids and reduce friction, then operability is enhanced, but device complexity increases
Solution Approach 1:
The bellows structure performs multiple functions simultaneously: it provides fluid sealing between different chambers, reduces friction by eliminating sliding seal contact, and allows for piston movement. This multi-functionality justifies the added structural element by consolidating several requirements into a single component.
Solution Approach 2:
The use of a flexible bellows structure provides an elegant solution that addresses multiple requirements (sealing, friction reduction, movement accommodation) without requiring multiple separate components, thereby limiting the increase in overall device complexity despite the functional improvements.
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 configuration prevents fluid mixing, reduces friction, stabilizes movement, and enhances the operability of the moving member, allowing for efficient energy transmission with reduced wear and increased maintainability.
Implementation Method 1
the first bellows whose the first end portion is closed by the moving member and the second end portion is fixed to the first axial end of the inner surface part of the container in the sealed state, and therefore, the first fluid flowing in or flowing out of the first fluid outlet/inlet path and the second fluid flowing in or flowing out of the second fluid outlet/inlet path in the container can be, in the sealed state, separated into the inside and outside of the first bellows
Implementation Method 2
a damper effect utilizing fluid resistance of the non-compressible second fluid moving between the container and the moving member in association with movement of the moving member can be obtained. Thus, movement of the moving member in the container can be stabilized
Data Source
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AI summary
{Technical Problem} Provided is fluid equipment capable of enhancing operability of a moving member in a container. {Solution to Problem} Fluid equipment 1 includes a container 2 capable of having first and second fluids F1, F2 housed therein, a first fluid outlet/inlet path 24 provided at the container 2 for outflow and inflow of the first fluid F1, a second fluid outlet/inlet path 26 provided at the container 2 for outflow and inflow of the second fluid F2, and a moving member 3 capable of moving in the container 2 in response to the pressure of the first fluid F1, the fluid equipment 1 transmitting energy from the first fluid F1 to the second fluid F2. The fluid equipment 1 further includes a first bellows 4 configured such that one end 4b is closed in a sealed state by the moving member 3, the other end 4a is fixed to an inner surface part of the container 2 in a sealed state, and the inside 40 of the first bellows 4 communicates with the first fluid outlet/inlet path 24.