Compressor Connecting Rod Bearing Preload for Noise Reduction
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Solution Overview
Problem
Existing reciprocating piston compressors used in compressed air supply systems for vehicles, such as passenger cars, face challenges with noise levels due to structure-borne noise transmission through the connecting rod drive, which affects the acoustics and reliability of the compressor, especially in passenger car applications.
Innovation Solution
The compressor design incorporates a connecting rod bearing system where the connecting rod axis is tilted relative to the cylinder axis, reducing bearing play and noise emissions by applying a predetermined force to the connecting rod bearing, thereby reducing the free bearing clearances and manufacturing-related tolerances, ensuring a balanced preload that minimizes noise and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the connecting rod bearing has standard clearance design, then the compressor can be manufactured with standard tolerances, but structure-borne noise transmission increases and acoustics deteriorate
Solution Approach 1:
The patent applies parameter changes by preloading the connecting rod bearing with a predetermined force, which reduces the bearing clearance from standard values to optimized values. This changes the physical state of the bearing clearance parameter to minimize noise transmission while maintaining manufacturability through the predefined preload force approach
2Object-affected harmful factors
If bearing clearance is reduced to minimize noise, then acoustics improve, but the connecting rod bearing requires precise positioning and preload application
Solution Approach 1:
The patent applies preliminary action by preloading the connecting rod bearing during the assembly process before the compressor enters service. The predetermined force is applied in advance to set the optimal bearing clearance, eliminating the need for complex adjustment mechanisms during operation while achieving the desired noise reduction
3Reliability
If a predetermined force is applied to preload the bearing, then bearing play and noise are reduced, but additional assembly steps and force application mechanisms are required
Solution Approach 1:
The patent applies self-service by designing the bearing preload system to be self-regulating through the predetermined force. The bearing clearance is automatically optimized by the preload force without requiring complex external adjustment mechanisms, and the system self-maintains the optimal clearance through the predefined force application
Data Source
Figure 1
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Figure 3A~3B
AI summary
The invention relates to a reciprocating piston machine, in particular a one-, two-, or multi-stage piston compressor (400) or a one-, two-, or multi-cylinder compressor, having: at least one cylinder (410, 420) and at least one piston (K1, K2) each assigned to a cylinder (410, 420), wherein, during operation, the piston (K1, K2) is deflected along a radially oriented cylinder axis (Z) in a cylinder displacement space (411, 421) of the cylinder (410, 420); a crankshaft (430) that can be driven during operation and has a crankshaft journal (432), which is arranged eccentrically in relation to a shaft axis (E) of the crankshaft, and a drive shaft coupling (431), which is designed for coupling a drive shaft (501) for driving the crankshaft (430); at least one connecting rod (P1, P2), each designed to deflect the at least one piston (K1, K2) and extending along a connecting rod axis (Pa, Pb), which can be moved by means of the crankshaft journal (432), wherein the crankshaft journal (432) and/or the drive shaft coupling (431) is/are oriented along an axially aligned shaft axis (E) which extends at right angles to the radially oriented cylinder axis (Z). The connecting rod axis (Pa) of the connecting rod (P1) is located in a position in which at least one connecting rod bearing (L1, L2) is braced with respect to the crankshaft journal (432) by a predetermined force (Fk) acting on the at least one connecting rod bearing (L1, L2) along the direction of the shaft axis (E), in particular in such a way that the bearing play of the at least one connecting rod bearing (L1, L2) is reduced. The connecting rod axis (Pa) of the connecting rod (P1) is moved into the position in which a force acting along the direction of the shaft axis (E) is applied to the at least one connecting rod bearing (L1), until a predetermined opposing force is reached.