Crankshaft Collar Sensor Layout for Compact Engine Packaging
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Solution Overview
Problem
The existing internal combustion engine designs face increased dimensions and weight due to the need for a larger journal diameter to maintain sufficient shaft diameter for power transmission, leading to inefficiencies and component misalignment.
Innovation Solution
The design incorporates a to-be-detected body on the outer periphery of a collar member between the bearing and power transmission gear, with a detection sensor and key groove system to maintain angular position, allowing for a smaller shaft diameter at the extremity and reducing engine dimensions, while separating the AC generator and detection sensor to minimize electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the shaft diameter at the extremity of the crankshaft is increased to ensure sufficient power transmission capability, then the power transmission capability is improved, but the journal diameter must be increased, causing an increase in the weight of the internal combustion engine
Solution Approach 1:
The invention divides the crankshaft structure into two distinct diameter zones: a larger journal diameter portion for bearing support and a smaller extremity diameter portion for power transmission. This segmentation allows each portion to be optimized independently, enabling sufficient power transmission with a smaller extremity diameter while maintaining the necessary journal diameter for structural integrity and bearing fitment.
Solution Approach 2:
The invention applies different diameter specifications to different locations of the crankshaft. The journal portion has a larger diameter to ensure proper bearing support and structural strength, while the extremity portion has a smaller diameter optimized for power transmission. This local differentiation of geometric properties allows the system to achieve both adequate power transmission and reduced overall weight.
2Measurement precision
If a step is formed on the crankshaft to position the detection member, then the detection function is achieved, but the length of the crankshaft is increased, causing an increase in the dimensions of the internal combustion engine
Solution Approach 1:
Instead of extending the crankshaft in the axial direction (length dimension) to create a step for positioning the detection member, the invention positions the detection member in the radial direction by utilizing the collar member that surrounds the crankshaft journal. This dimensional shift allows the detection function to be achieved without increasing the axial length of the crankshaft.
Solution Approach 2:
The invention introduces a collar member as an intermediary component between the crankshaft journal and the detection member. The collar member provides a mounting surface for the detection member and positions it appropriately without requiring modifications to the crankshaft geometry. This intermediary structure enables the detection function while maintaining the original crankshaft dimensions.
3Power
If the journal diameter is increased to maintain sufficient shaft diameter for power transmission, then the power transmission capability is ensured, but the engine dimensions increase
Solution Approach 1:
The invention segments the crankshaft diameter into two zones: a larger journal diameter for structural integrity and bearing support, and a smaller extremity diameter for power transmission. This segmentation allows the power transmission capability to be maintained with a smaller overall crankshaft size, reducing the engine volume without compromising the necessary structural dimensions.
Data Source
AI summary
An internal combustion engine includes a crankshaft that has a journal linked to a bearing and is rotatably supported on the crankcase, a power transmission gear fixed to an extremity of the crankshaft that has a smaller diameter than a diameter of the journal and projects outward of the crankcase, a to-be-detected body that is fixed on an outer periphery of a collar member disposed between the bearing and the power transmission gear and is relatively non-rotatably supported on the crankshaft, and a detection sensor that is made to face a trajectory of the to-be-detected body and detects movement of the to-be-detected body to generate a pulse signal. This provides a structure for disposing a to-be-detected body that enables any increase in the dimensions of an internal combustion engine to be avoided.