Variable Speed Drive Shift Spindle Impact Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing variable speed drives for internal combustion engines face challenges in achieving high-speed and high-accuracy shifting operations when the inputting and operation mechanisms are disposed on the same side of the transmission case, leading to potential impact transmission and accuracy issues due to short shift spindle length and temperature constraints on rotational angle sensors.
Innovation Solution
The design incorporates a shift spindle with a hollow cylindrical shape, an extension collar member, and a return spring system, where the master arm is positioned between the input and output ends of the spindle, and a rotational angle sensor is placed externally to detect the spindle's rotation accurately, with a spring guide collar and washer to manage diameter and torsional rigidity, and uses spring steel for increased twistability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the inputting mechanism and operation mechanism are disposed on the same side of the transmission case, then the layout flexibility is improved, but the shift spindle length becomes short and impact transmission increases
Solution Approach 1:
The extension collar member extends in the axial direction of the shift spindle, effectively increasing the functional length of the spindle without increasing the radial or axial footprint of the entire assembly. This dimensional extension allows the inputting and operation mechanisms to be disposed on the same side while maintaining sufficient twistability to suppress impact transmission.
Solution Approach 2:
The extension collar member is provided with a specific region having different torsional characteristics than the main spindle body. This local variation in torsional rigidity allows the spindle to twist selectively at the extension collar region, absorbing impact while maintaining overall structural integrity and precise angle transmission.
2Measurement precision
If the rotational angle sensor is attached to the operation mechanism side inside the transmission case, then the detection accuracy is improved, but the temperature management becomes difficult
Solution Approach 1:
The rotational angle sensor is extracted from the high-temperature transmission case interior and relocated to the exterior. The extension collar member serves as the detection target outside the transmission case, allowing the sensor to be positioned in a cooler environment while still accurately detecting the spindle's rotational angle through the extended structure.
3Reliability
If the shift spindle axial length is made long to suppress impact transmission, then the impact absorption is improved, but the device complexity and size increase
Solution Approach 1:
The extension collar member is integrally formed with or closely coupled to the shift spindle, merging the functions of the spindle and the extension structure into a unified component. This integration provides the benefits of increased effective length for impact absorption without the complexity of separate, loosely-coupled components.
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 configuration allows for high-accuracy and high-speed shifting operations by absorbing impact through torsional deformation and maintaining sensor accuracy, even when mechanisms are on the same side, while reducing spindle diameter and preventing displacement, thus enhancing operational precision and reliability.
Implementation Method 1
the shift spindle can be twisted readily thereby to suppress transmission of the impact to the inputting mechanism
Implementation Method 2
a return spring which biases the master arm in a direction in which the master arm returns to a position before operation
Data Source
AI summary
A variable speed drive wherein an impact to be transmitted to an inputting mechanism is absorbed. A shift spindle has an input side end portion to which an inputting mechanism is connected and an output side end portion supported for rotation at a transmission side supporting portion provided on a transmission case. A master arm is positioned between the input side end portion and the output side end portion in an axial direction of the shift spindle. An extension collar member is fixed integrally to the master arm. The extension collar member connects the master arm and a connection portion provided at a location of the shift spindle rather near to the input side end portion than the output side end portion. The extension collar member extends from the connection portion toward the master arm with a gap left from an outer circumferential face of the shift spindle.