Screw Compressor Control Slide Guidance to Prevent Piston Rod Jamming
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Solution Overview
Problem
Screw compressors face the challenge of precise guidance of the piston rod in the guide insert, which can lead to jamming due to existing play and canting issues when the control slide moves transversely to the displacement direction.
Innovation Solution
The piston rod is guided elastically using a guide element that moves transversely to the displacement direction, with a spring-elastic element providing prestressing to ensure precise alignment and prevent jamming, while multiple guide elements and a limiting element maintain precision and dampen vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the piston rod is guided rigidly in the guide insert to achieve high precision, then guidance precision is improved, but the piston rod can jam due to canting and play when the control slide moves transversely
Solution Approach 1:
The guide element is designed with elastic properties, changing its mechanical parameter from rigid to flexible. This allows the guide element to deform elastically in response to transverse movements and canting, preventing jamming while maintaining guidance precision through its elastic restoring force.
Solution Approach 2:
The guide element is made dynamically adaptable by introducing elasticity, allowing it to adjust its position and orientation in response to operational conditions. The spring-elastic element enables the guide element to dynamically compensate for movements and maintain contact with the piston rod without rigid constraints that cause jamming.
2Reliability
If the guide element is made elastically flexible to prevent jamming, then reliability is improved, but guidance precision may be compromised
Solution Approach 1:
The spring-elastic element is pre-loaded to apply a constant prestressing force on the guide element before operation begins. This preliminary action ensures that the guide element maintains optimal contact pressure with the piston rod throughout operation, preserving guidance precision despite the elastic flexibility that prevents jamming.
Solution Approach 2:
The elastic properties of the guide element are carefully controlled through material selection and geometric design, changing its stiffness parameter to an optimal value that provides sufficient flexibility to prevent jamming while maintaining enough rigidity to ensure precise guidance. The spring-elastic element's prestressing force is also calibrated to achieve the desired balance.
3Manufacturing precision
If multiple guide elements are used to improve guidance precision and damping, then guidance precision and vibration damping are improved, but device complexity increases
Solution Approach 1:
The guidance function is segmented into multiple guide elements distributed along the piston rod. Each guide element independently provides guidance and vibration damping, and their combined effect achieves high precision guidance. This segmentation allows the system to benefit from multiple contact points without requiring a completely complex guidance mechanism.
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 solution prevents jamming and maintains high precision in guiding the piston rod, effectively reducing noise and ensuring reliable operation by allowing elastic mobility without compromising the precision of the guidance.
Implementation Method 1
the guide element is acted upon by a spring-elastic element 252, which serves to prestress the guide element 242 in the direction of a peripheral surface of the piston rod 118
Implementation Method 2
the spring-elastic element 252 is designed to support the guide element 242 on a side facing away from the piston rod 118
Implementation Method 3
Such an elastically prestressed contact of the guide element on the circumferential surface allows vibrations occurring on the piston rod to be dampened
Data Source
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AI summary
The invention relates to a screw compressor comprising a compressor housing (12) with a screw rotor chamber (18), two meshing screw rotors (26, 28) which are arranged in the screw rotor chamber and are mounted each on the compressor housing so as to be rotatable about respective screw rotor axes, and at least one control slide (52, 54) which is arranged in a compressor housing slide channel (56), the compression wall surfaces (62, 64) of which adjoin both screw rotors (26, 28), and which can be moved in a slide direction (72) parallel to the screw rotor axes, is rigidly connected to a piston rod (118) that leads to a cylinder assembly (112) for moving the at least one control slide, and is guided relative to the compressor housing by means of a guide insert (172) that movably receives the piston rod (118) in the slide direction (112), wherein the piston rod (112) is guided transversely to the slide direction in the guide insert (172) in an elastically resilient manner by means of a guide element (242, 276, 278, 292).