Coffee Machine Brewing Spindle Support Against Pressure Bending
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Solution Overview
Problem
The existing brewing devices for coffee machines experience spindle bending due to high pressure forces during the brewing process, leading to undesirable changes in the brewing chamber conditions.
Innovation Solution
The spindle is supported by additional support means fixed to the frame, which prevents bending by providing optimal engagement of the trapezoidal thread and maintaining the spindle's position, thereby preventing the brewing cylinder with the lower piston from moving away from the upper piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the spindle is made of elastic material (POM) to enable injection molding production, then the ease of manufacture is improved, but the spindle bends under high pressure forces during brewing
Solution Approach 1:
The spindle is divided into two functional segments: a supported portion that remains stationary and engages with the threaded part, and a free portion that can rotate. The support means creates a segmentation point that allows the spindle to be both manufacturable (using elastic POM material) and stable (preventing bending under pressure) during the brewing process.
Solution Approach 2:
The support means acts as an intermediary element between the spindle and the frame. This intermediary provides the necessary support to prevent spindle bending while allowing the spindle to maintain its elastic properties for manufacturing purposes. The support means mediates between the conflicting requirements of manufacturability and stability.
2Adaptability or versatility
If the spindle is allowed to bend under pressure, then the brewing cylinder can lower to change brewing chamber conditions, but this causes undesirable changes in brewing conditions
Solution Approach 1:
The support means applies a preliminary counteracting force to prevent the spindle from bending under pressure. By providing this anti-action before the bending occurs, the support means ensures that the spindle remains stable and the brewing conditions remain reliable, while still allowing the brewing cylinder to be lowered through the proper rotational mechanism.
Solution Approach 2:
Instead of allowing the spindle to bend to achieve brewing chamber changes, the invention inverts the mechanism: the brewing cylinder is lowered by rotating the spindle in the other direction (opening direction), while the support means prevents bending during the brewing process. This inversion separates the functions of pressure resistance and position adjustment.
3Force
If the threaded part engages the spindle over a large area, then the force distribution is improved, but the spindle bending increases due to greater leverage
Solution Approach 1:
The support means extracts the burden of force resistance from the entire spindle length by providing localized support opposite the threaded part. This allows the threaded part to engage over a larger area for better force distribution, while the support means counteracts the resulting bending moment, effectively separating the force distribution function from the stability function.
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 ensures stable operation during brewing, maintaining the integrity of the brewing chamber conditions and preventing the spindle from deflecting, ensuring consistent coffee production.
Implementation Method 1
a spindle (9) provided with a trapezoidal thread (8), the ends of which are rotatably mounted in the frame (2) on both sides, and a motor (10), in which the trapezoidal thread (8) of the spindle (9) engages a threaded part (7a)
Implementation Method 2
the spindle (9) is supported on the area opposite the threaded part (7a) by support means (31), which can be fastened to the frame (2)
Implementation Method 3
Due to the inclined thread flanks of the trapezoidal thread, a force component is generated on the spindle, which acts transversely to its axis and which would like to push the spindle away from the threaded part
Implementation Method 4
Due to the choice of material used for production, the spindle has a certain elasticity, so that the spindle bends under the influence of this force component
Data Source
Figure 1
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Figure 3
AI summary
The unit (1) has a brewing cylinder (6) with a cylindrical bore and upper and lower pistons (3, 4). The cylinder and the pistons are held in a frame (2) and are driven by a spindle (9) including a trapezoidal thread (8). A coffee powder feeding device fills a brewing chamber with coffee powder. A stripping element (19) serves to strip off the residual coffee powder that is discharged from the chamber through the lower piston after the brewing process. The spindle is supported by supporting units (31) on a region opposite to a threaded part (7a), where the units are attached to the frame.