Rolling Piston Compressor with Back Pressure Groove
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Solution Overview
Problem
Current 1-cylinder 2-compression chamber compressors face issues with high power loss, refrigerant leakage, and vibration noise due to eccentric loads, friction, and non-uniform torque distribution, which affect efficiency and stability.
Innovation Solution
A compressor design featuring a crank shaft supported by bearing plates, with an outer and inner cylinder portion connected by a vane portion to form compression spaces, and a rolling piston that slides between these portions, incorporating a back pressure groove to reduce friction and stabilize the rotating body, allowing for easy volume adjustment and improved discharge port alignment to minimize pulsation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a 1-cylinder 2-compression chamber compressor is used, then the productivity is improved by forming two compression spaces in one cylinder, but the power loss increases and refrigerant leakage occurs due to eccentric loads and friction
Solution Approach 1:
The compressor divides the single cylinder into two separate compression chambers (first compression space V1 and second compression space V2) with independent discharge ports, allowing simultaneous compression operations in both chambers while maintaining balanced mechanical forces through the rolling piston mechanism
Solution Approach 2:
Instead of rotating the heavy cylinder as in conventional compressors, this design keeps the cylinder fixed and rotates the lighter rolling piston, thereby reducing the moment of inertia and friction losses while achieving the same compression function through reversed rotational mechanics
2Productivity
If the cylinder rotates in conventional compressors, then the compression function is achieved, but the bearing area increases and friction loss occurs
Solution Approach 1:
The design inverts the conventional rotation mechanism by keeping the cylinder stationary and rotating the rolling piston instead, which significantly reduces the bearing area required and minimizes friction losses between moving and stationary parts
Solution Approach 2:
The harmful rotational movement is extracted from the heavy cylinder and transferred to the lighter rolling piston, eliminating the need for large bearing areas to support cylinder rotation while maintaining the essential compression function
3Device complexity
If discharge ports are aligned in the same direction, then the structure is simplified, but pulsation phenomenon increases causing vibration noise
Solution Approach 1:
The discharge ports are positioned asymmetrically in opposite directions rather than aligned in the same direction, creating balanced and opposite discharge flows that cancel each other's pulsation effects, thereby reducing vibration noise while maintaining structural simplicity
4Ease of manufacture
If compression chambers are at the same height, then the manufacturing is easier, but torque load becomes non-uniform causing instability
Solution Approach 1:
The compression chambers are positioned at different heights (first compression space V1 at upper side, second compression space V2 at lower side) to create uniform torque distribution throughout the rotation cycle, improving operational stability while maintaining ease of manufacture through the simple rolling piston 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
The design achieves low power loss, reduced refrigerant leakage, and decreased vibration noise by stabilizing the rotating body and optimizing discharge port alignment, enhancing the compressor's efficiency and operational stability.
Implementation Method 1
a rolling piston slidably coupled to the vane portion between the outer cylinder portion and the inner cylinder portion to divide the compression space into an outer compression space and an inner compression space while making a turning movement by the crank shaft
Implementation Method 2
a back pressure groove having a predetermined area and depth is formed on at least either one surface of the rolling piston and a bearing plate with which the rolling piston is brought into contact
Implementation Method 3
a crank shaft configured to transmit the rotational force of a motor drive provided within the casing
Data Source
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AI summary
A compressor according to the present disclosure may include a cylinder including an outer cylinder portion and an inner cylinder portion, and a vane portion connected between the outer cylinder portion and inner cylinder portion, which is fixed to a casing. Furthermore, a rolling piston may be slidably coupled to the vane portion to form an outer compression space and an inner compression space while making a turning movement between the outer cylinder portion and inner cylinder portion. Through this, the weight of a rotating body can be reduced to obtain a low power loss with respect to the same cooling power and a small bearing area, thereby reducing the refrigerant leakage as well as easily changing the capacity of a cylinder in an expanded manner. Moreover, refrigerant may be discharged in opposite directions to each other in each compression space, thereby reducing the vibration noise of the compressor. In addition, a back pressure groove may be formed on an upper surface of the drive transmission portion of the rolling piston, thereby reducing a friction area between the rolling piston and the upper bearing as well as reducing a friction loss between the rolling piston and the upper bearing due to oil filled into the back pressure groove.