Decentered Axial Oil Passage in Open Compressor
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Solution Overview
Problem
In open-type compressors, the oil supply amount decreases due to increased flow-path pressure loss at high rotational speeds, particularly because the axial-direction oil supply passage is structurally pierced in a radial direction, leading to reduced lubrication performance.
Innovation Solution
The axial-direction oil supply passage is decentered by a predetermined dimension, and a radial-direction oil supply passage is provided on the decentered side, reducing the passage length and flow-path pressure loss, while maintaining or improving oil supply performance through centrifugal pump effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the axial-direction oil supply passage is provided on the axis of the drive shaft, then the structure is simple and easy to manufacture, but the flow-path pressure loss increases at high rotational speeds, reducing oil supply amount
Solution Approach 1:
The axial-direction oil supply passage is decentered from the drive shaft axis by a predetermined dimension, creating an asymmetric configuration. This asymmetry reduces the passage length from the pump chamber to the axial-direction oil supply passage, thereby reducing flow-path pressure loss and improving oil supply amount at high rotational speeds while maintaining manufacturing feasibility
2Productivity
If the rotating speed of the drive shaft increases, then the centrifugal force and oil supply performance improve, but the flow-path pressure loss increases, reducing the oil supply amount
Solution Approach 1:
By decentering the axial-direction oil supply passage from the drive shaft axis, the passage length is reduced. This asymmetric positioning ensures that as rotational speed increases and centrifugal force increases, the shorter passage length prevents excessive flow-path pressure loss, maintaining oil supply amount despite higher operating speeds
3Loss of energy
If the passage length of the radial-direction oil supply passage is reduced, then the flow-path pressure loss decreases, but the structural complexity increases due to decentering
Solution Approach 1:
The axial-direction oil supply passage is positioned asymmetrically (decentered) relative to the drive shaft axis. This creates a shorter radial-direction oil supply passage that connects the pump chamber to the axial-direction passage, reducing flow-path pressure loss. The decentering is by a predetermined dimension, balancing the trade-off between reduced passage length and increased structural complexity
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 minimizes flow-path pressure loss and maintains or enhances oil supply performance, particularly at high rotational speeds, thereby improving lubrication reliability in open-type compressors.
Implementation Method 1
a centrifugal-type oil supply pump, a displacement-type oil supply pump, or the like is provided on the end of a drive shaft, a lubricant which fills a sealed vessel is pumped up by the oil supply pump
Implementation Method 2
the axial-direction oil supply passage is provided at a position which is decentered by a predetermined dimension with respect to the axis of the drive shaft, and the radial-direction oil supply passage is provided on a side toward which the axial-direction oil supply passage is decentered
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
Provided is an open-type compressor with which it is possible to prevent a reduction in oil supply amount caused by an increase in flow-path pressure loss particularly in a high rotational speed range, and to improve reliability in lubrication performance. Disclosed is an open-type compressor (1) comprising: a drive shaft (9) having one end protruding outside a housing (2); an oil supply pump (37) provided in an outer circumferential section of the drive shaft (9); a pump chamber (39) that is formed around the drive shaft (9), and into which oil pumped up by the oil supply pump (37) is discharged; an axial-direction oil supply passage (41) that is pierced inside the drive shaft (9) along the direction of the axis L thereof, and that supplies the oil from the pump chamber (39) to a sliding part; and a radial-direction oil supply passage (40) that guides the oil in the pump chamber (39) to the axial-direction oil supply passage (41). The axial-direction oil supply passage (41) is provided in a position that is decentered by a predetermined dimension Δh with respect to the axis L of the drive shaft (9). The radial-direction oil supply passage (40) is provided on a side toward which the axial-direction oil supply passage (41) is decentered.