Plastic Driver Wear Reduction in Pumping Units
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conveyor units with steel drivers experience wear issues due to the interaction between the drive shaft and the driver opening, leading to increased manufacturing costs and noise, which are not effectively mitigated by existing technologies.
Innovation Solution
A plastic driver with glass fibers is used, where the distance between the drive shaft's flattened area and the drive axis is minimized to prevent wear, and elastic projections are incorporated for improved torque transmission and noise decoupling, with a D-shaped cross section and injection molding for cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a steel driver is used, then the driver has high strength, but wear occurs at the interaction between the drive shaft and driver opening
Solution Approach 1:
The driver is made from a composite material consisting of plastic and glass fibers. The glass fibers (20-80% by weight, preferably 30-50%) provide the necessary strength and wear resistance, while the plastic matrix provides toughness and damping properties. This composite structure resolves the contradiction by achieving both high strength and wear resistance simultaneously.
Solution Approach 2:
The distance H of the first flattening to the drive axis is optimized to be between 0 and 0.25 times the diameter D of the drive shaft. This parameter optimization reduces the lever arm for wear forces, minimizing wear at the driver opening while maintaining sufficient torque transmission capability.
2Power
If the distance H of the first flattened section is increased, then torque transmission is improved, but wear at the driver opening increases
Solution Approach 1:
The distance H is optimized to be between 0 and 0.25 times the diameter D of the drive shaft. This optimized parameter range achieves the necessary torque transmission while minimizing the wear lever arm, preventing excessive wear at the driver opening throughout the service life.
3Ease of manufacture
If a plastic driver is used, then manufacturing costs are reduced, but wear resistance is insufficient
Solution Approach 1:
The plastic driver is reinforced with glass fibers to create a composite material that maintains the cost advantages of plastic manufacturing while achieving the wear resistance required for long service life. The glass fiber reinforcement provides the necessary mechanical properties.
Solution Approach 2:
Optimizing the distance H parameter reduces wear, which compensates for the inherently lower wear resistance of plastic compared to steel, allowing plastic drivers to achieve adequate wear resistance for their intended service life.
4Power
If an interference fit is used between drive shaft and driver opening, then torque transmission is improved, but noise increases
Solution Approach 1:
The drive shaft is designed with a specific flattening geometry (distance H and width B within specified ranges) that enables effective torque transmission through a clearance fit while minimizing relative motion and noise. The optimized parameters ensure sufficient contact area for power transmission without the need for interference fit.
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 solution reduces wear and manufacturing costs, achieves noise reduction through mechanical decoupling, and enhances the driver's strength and service life, while maintaining efficient torque transmission.
Implementation Method 1
the driver (4) is made in one piece from plastic and contains glass fibers
Implementation Method 2
the first flattening (9) of the drive shaft (5) has a predetermined distance H to a drive axis (6) of the drive shaft (5)
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to pumping units, comprising a pump chamber, in which a rotor is rotatably arranged, which rotor is rotatably supported on a drive shaft and is driven by the drive shaft by means of a driver coupled to the drive shaft, wherein the driver has a through-opening, into which the drive shaft at least partially protrudes, wherein the drive shaft has a first flat portion and the through-opening of the driver has a second flat portion that interacts with the first flat portion of the drive shaft, wherein the first flat portion of the drive shaft has a predetermined distance H from a drive axis of the drive shaft and a predetermined width B measured transversely to the drive axis, which pumping units are already known. The driver comprises a first driver element composed of steel and a second driver element composed of plastic, which is coupled to the first driver element, wherein the drive shaft is coupled only to the first driver element and not to the second driver element. The first driver element transmits the torque of the drive shaft to the second driver element, which is mechanically coupled to the rotor. In the case of the pumping unit according to the invention, the production costs of the driver are reduced. According to the invention, the driver (4) is produced from plastic as a single piece and contains glass fibers, and the distance (H) of the first flat portion (9) of the drive shaft (5) lies in the range between zero and 0.25 times the diameter (D) of the drive shaft (5), wherein the drive shaft (5) has a radius (R) and the cross-section of the drive shaft (5) in the region of the first flat portion (9) is larger than a cross-section of a semicircle having the radius (R).