Starter Pinion Toothing Profiles to Prevent Engagement Jamming
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Solution Overview
Problem
Starter devices for internal combustion engines often jam due to burrs and surface irregularities on the toothings, leading to costly mechanical reworking to prevent jamming, which is undesirable in terms of production costs.
Innovation Solution
The starter device is designed with a driveshaft and pinion shaft having different toothing profiles, such as involute and trapezoidal profiles, to prevent contact between burrs and irregularities, ensuring smooth operation and eliminating the need for mechanical reworking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical reworking (grinding) is used to remove burrs and surface irregularities, then jamming is prevented, but production costs increase
Solution Approach 1:
The invention changes the geometric parameters of the toothings by providing different toothing profiles (e.g., involute for external toothing, trapezoidal for internal toothing) between the pinion wheel and transmission device. This parameter change ensures that burrs and surface irregularities on the pinion wheel teeth do not contact the transmission device teeth during engagement, preventing jamming without requiring costly mechanical reworking or burr removal processes
2Reliability
If different toothing profiles are used, then burr contact is prevented and jamming is avoided, but manufacturing complexity increases
Solution Approach 1:
The invention applies different toothing profile parameters to the pinion wheel and transmission device teeth. Specifically, the pinion wheel has an external toothing with one profile type (e.g., involute) while the transmission device has an internal toothing with a different profile type (e.g., trapezoidal, convex, spline, or serration). This parameter differentiation prevents burr contact while maintaining relatively simple manufacturing processes for each component
Data Source
Figure 1~2
AI summary
The present invention relates to a starter device (1) for cranking an internal combustion engine (2) having a driveshaft (4), which comprises an external toothing (5), having a pinion shaft (6), which comprises a driveshaft receptacle (7), in which the driveshaft (4) is slidably received, having a transmission device (8) equipped for transmitting a torque (29) from the driveshaft (4) to the pinion shaft (6), which transmission device (8) comprises an internal toothing (9), wherein the transmission device (8) and the pinion shaft (6) are jointly adjustable in an actuation movement (10) between an engaged position (11), in which the internal toothing (9) and the external toothing (5) engage into one another, and a disengaged basic position. It is substantial for the invention that the external toothing (5) and the internal toothing (9) have different toothing profiles. The invention relates in particular to an internal combustion engine (2) having such a starter device (1).