Vacuum Pump Rotor Shaft Polygonal Connection
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Solution Overview
Problem
Existing vacuum pumps face challenges in achieving smooth operation at high speeds and maintaining balance due to loose feather key connections and large tolerances, which lead to imbalance and reduced performance.
Innovation Solution
A vacuum pump design featuring a rotor shaft with a rotationally symmetrical, polygonal receiving opening that eliminates the need for a feather key connection, ensuring a non-positive connection and balance-free operation, with the rotor shaft adapted to the receiving opening and secured with springs or spring washers, and permanent magnets embedded within a gas-tight receptacle for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a feather key connection is used to connect the rotor shaft to the steel sheet package, then the connection is simple to manufacture, but the loose feather key element causes imbalance and reduces smooth running at high speeds
Solution Approach 1:
The invention removes the feather key element from the connection system entirely. Instead of using a separate feather key component that connects the rotor shaft to the steel sheet package, the patent integrates the connection function directly into the rotor shaft structure through a polygonal receiving opening, eliminating the source of imbalance caused by the loose feather key element.
Solution Approach 2:
The invention employs a polygonal (non-circular) receiving opening in the rotor shaft instead of a traditional circular hole. This asymmetric shape provides form-fitting engagement with the steel sheet package, preventing relative motion and ensuring precise positioning without requiring additional balancing elements like feather keys.
2Ease of operation
If a feather key connection is used, then assembly is straightforward, but large tolerances in the connection reduce smooth running of the rotor at high speeds
Solution Approach 1:
The polygonal receiving opening with its specific non-circular geometry provides form-fitting engagement that inherently restricts tolerances. The shape itself acts as a precision feature, ensuring that the steel sheet package is positioned accurately relative to the rotor shaft without requiring tight manufacturing tolerances on separate components.
3Manufacturing precision
If a rotationally symmetrical receiving opening is used, then the connection is imbalance-free, but torque transmission may be insufficient without additional mechanical features
Solution Approach 1:
The polygonal receiving opening combines the benefits of rotational symmetry (balance) with asymmetric geometry (torque transmission). The non-circular shape provides form-fitting engagement that mechanically couples the rotor shaft and steel sheet package, enabling effective torque transmission while maintaining rotational balance due to the symmetric distribution of the polygonal features.
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 smooth operation at high speeds with reduced imbalance and improved torque transmission, allowing for efficient gas pumping and easier maintenance by eliminating the need for feather key connections and minimizing manufacturing complexities.
Implementation Method 1
an electric motor, in particular designed as a synchronous motor, for driving the pump mechanism, the electric motor having a stator and a rotor that can be rotated with an axis of rotation and interacts with the stator
Implementation Method 2
the at least one laminated core is fixed on the rotor shaft with at least one spring and/or at least one spring washer
Implementation Method 3
at least one pump mechanism for pumping a gas through the vacuum pump
Data Source
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AI summary
The invention relates to a vacuum pump (22) comprising at least one pumping mechanism for pumping a gas with a rotor (32) and a rotor shaft (36) and an electric motor (100) for driving the pumping mechanism, wherein the electric motor (100) has a stator (82) and a rotor (106), wherein the rotor has a core (107) formed from at least one stack of steel sheets (107a), wherein the core (107) has a receiving opening (120) for the positive-locking reception of the rotor shaft (22), wherein the receiving opening has a shape deviating from a full circle, wherein the rotor shaft (36) has a section on which the at least one stack of steel sheets (107a) is arranged, which has a shape adapted to the reception, wherein the receiving opening (120) is rotationally symmetrical.