This is a new idea of a mechanism of transmission that can change its speed ratio continuously (not stepped) and as well geared. It can be applied in many moving applications, especially in vehicles.
This presentation demonstrates the parts and mechanism as well as the advantages and disadvantages and possible modifications.
Table of Contents
Introduction
1 – changeable length rod
2 – Couple of Ratchets
2.1 – derivation of the relationship between the angular speed of the changeable length rod and the angular speed of the ratchets
3 – Accumulator
Advantages and Disadvantages
Modifications
Research Objectives and Key Topics
The objective of this work is to present the concept and mechanical design of a geared continuously variable transmission (CVT) system. The research focuses on overcoming the limitations of traditional transmissions by providing a mechanism that enables smooth speed ratio adjustments without the delays associated with conventional clutch engagement.
- Mechanical design of a changeable length rod mechanism
- Kinematic analysis and derivation of angular speed relationships
- Utilizing ratchet couples for motion transformation
- Implementation of an accumulator for output synchronization
- Efficiency and performance advantages over standard gearboxes
Excerpt from the Book
1 – changeable length rod:
This is the first part in the mechanism as it transfers the power from the engine by its rotating axis to he next part (connecting rod).
This part contains of a slider connected to a worm gear which is rotated by the servo motor and according to that the slider changes its distance from the main rotating center of rode.
According to this change of distance the torque and speed transmitted are changed since the torque ratio decrease and the speed increase with the increase of the distance and vice versa.
Summary of Chapters
Introduction: Defines the geared transmission system and its capability to change speed ratios smoothly across a range of limits.
1 – changeable length rod: Describes the primary component responsible for power transfer and explains how slider adjustments modify torque and speed ratios.
2 – Couple of Ratchets: Explains the conversion of rotational motion to reciprocating motion and the necessity of using a ratchet pair to maintain a continuous output.
2.1 – derivation of the relationship between the angular speed of the changeable length rod and the angular speed of the ratchets: Provides the mathematical foundation and kinematic formulas governing the transmission's speed behavior.
3 – Accumulator: Details the integration of a differential-based mechanism to synchronize the output of the two transmission systems.
Advantages and Disadvantages: Evaluates the performance benefits, such as instant gear ratio changes, against the complexity of the design.
Modifications: Proposes technical improvements, including the use of hydraulic systems and multistage rods, to further enhance the mechanism.
Keywords
Geared Transmission, Continuously Variable Transmission, CVT, Torque Ratio, Speed Ratio, Slider Mechanism, Worm Gear, Ratchet, Accumulator, Kinematic Analysis, Mechanical Engineering, Power Transmission, Servo Motor, Automotive Engineering
Frequently Asked Questions
What is the primary purpose of this geared transmission?
The system is designed to act as a continuously variable transmission that allows for smooth, stepless changes in speed ratios without the typical delays found in conventional manual or automatic gearboxes.
What are the core components of the mechanism?
The system consists of a changeable length rod, a set of ratchets for motion transformation, and an accumulator used to merge the output from different transmission stages.
How is the speed ratio adjusted?
The speed ratio is adjusted by changing the distance of a slider from the main rotating center using a worm gear driven by a servo motor.
What mathematical approach is taken to analyze the system?
The author derives kinematic formulas based on time-dependent functions to define the relationship between the angular speed of the input rod and the output ratchets.
Why are ratchets used in the transmission?
Ratchets are utilized to transform rotational input into a consistent output motion; a pair is required to handle both directions of rotation effectively.
What is the role of the accumulator?
The accumulator functions as a differential mechanism that merges the output of two separate systems, which otherwise could not be combined due to phase angle differences.
How does this design compare to traditional gearboxes?
Unlike traditional transmissions with fixed ratios, this design allows for any speed ratio, which helps keep the engine at its optimum efficiency point, thereby reducing fuel consumption.
What are the suggested modifications to improve the current design?
The author suggests using rack-and-pinion systems as substitutes for connecting rods, implementing hydraulic systems for better actuation, and adding multistage rods to broaden the range of available speed ratios.
- Arbeit zitieren
- Yahya Alsalman (Autor:in), 2019, Geared Continuously Variable Transmission, München, GRIN Verlag, https://www.grin.com/document/535129
