Shaft Encoder Mounting via Transverse Grooves and Bearing Lock
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Solution Overview
Problem
Existing methods for fastening transmitters to electric drive shafts are prone to unintentional loosening, especially in aggressive media environments, and often require additional components or increased space, leading to reduced signal strength and complex assembly processes.
Innovation Solution
A device featuring two parallel transverse grooves at the shaft end for a form-fitting connection with the transmitter, utilizing the existing bearing for securement and minimizing additional parts, allowing a captive and non-rotatable connection without increasing radial space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If adhesive bonding is used to attach sensor elements to shaft ends, then the mounting process is simple, but the connection is prone to unintentional loosening especially in aggressive media environments
Solution Approach 1:
The connection is divided into two independent positive-locking connections: one preventing axial displacement and another preventing radial displacement. This segmentation allows each connection to specialize in preventing specific loosening modes, significantly improving reliability while maintaining simple implementation through basic geometric features rather than complex adhesive processes
Solution Approach 2:
The adhesive bonding system is replaced with a purely mechanical positive-locking connection system using transverse grooves and ribs. This substitution eliminates the reliability issues of adhesive degradation in aggressive media while maintaining ease of manufacture through simple geometric interlocking features that can be implemented during standard machining operations
2Measurement precision
If the sensor element is moved away from the shaft to avoid magnetic field interference, then the magnetic field strength at the sensor is improved, but the installation space requirement increases
Solution Approach 1:
The sensor mounting position is optimized by utilizing the axial dimension (along the shaft axis) rather than only the radial dimension. The transverse grooves are positioned at specific axial locations where the sensor can achieve optimal distance from the shaft end for signal strength while remaining within the existing radial boundaries of the bearing assembly, thus improving measurement precision without increasing overall installation space
3Reliability
If additional fastening components are added to secure the encoder, then the connection reliability is improved, but the device complexity and number of parts increase
Solution Approach 1:
Multiple fastening functions are merged into the shaft structure itself through integrated transverse grooves and ribs. The shaft geometry is designed to provide both axial and radial positive-locking connections without requiring separate fastening components. This merging approach maintains high connection reliability while minimizing the number of parts and simplifying the overall device structure
Solution Approach 2:
The shaft structure is designed with multi-functionality, where the same shaft component serves both as the rotational element and as the mounting structure for the encoder. The transverse grooves and ribs are integrated into the shaft geometry, allowing the shaft to simultaneously perform its primary function and provide secure encoder retention, thereby reducing the need for additional dedicated fastening parts
4Ease of manufacture
If the magnetic assembly increases the shaft diameter, then the sensor can be properly mounted, but the space requirement and installation complexity increase
Solution Approach 1:
The encoder mounting structure is nested within the existing shaft and bearing geometry rather than adding external protrusions. The transverse grooves are cut into the shaft end surface, and the encoder is seated within the space defined by these grooves and the bearing inner contour, allowing proper sensor mounting without increasing the overall shaft diameter or radial space requirements
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 provides a robust, secure, and simplified assembly method for the transmitter, maintaining signal strength and reducing the risk of loosening, while minimizing the number of components and space requirements.
Implementation Method 1
The shaft end has two recesses into which the encoder engages, thereby forming a positive-locking connection that acts at least in the direction of one shaft axis
Implementation Method 2
the bearing of the electric drive serves as a locking element to prevent the positive-locking connection from loosening
Implementation Method 3
During assembly, the sensor is pushed into the transverse grooves perpendicular to the shaft's longitudinal direction (axial direction) and positively connected to the shaft
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
The invention relates to a sensor element for attachment to one end of a shaft of an electric drive. "Sensor element" refers to a sensor or a component consisting of a carrier part and a sensor. The object of the invention is to provide a sensor element of this type that is particularly simple in design, has a low number of parts, and allows for particularly simple and secure assembly, thereby enabling a captive and rotationally fixed connection. This object is achieved according to the invention by providing a sensor element (1) for attachment to one end of a shaft (2) of an electric drive, wherein the shaft end has at least one recess (3) into which the sensor element (1) engages, thereby forming a positive-locking connection acting at least in the direction of a shaft axis (9), and wherein a bearing (4) of the electric drive serves as a locking means against loosening of the positive-locking connection.Alternatively, a snap-fit device (21) or a clamping device of the transmitter device (1) serves as a safety device against loosening of the positive locking connection.