Abstract
Transmission systems are crucial components of many machines and mechanisms. Ken Hurst (1998) highlights that whether you are designing power plants, cars, or washing machines, the power transmission system is an integral component responsible for product success or failure. The components that comprise a power transmission system include those that transfer power directly (coupling and shaft), speed and torque multiplication components (gears, belt drives, etc.), and the related mechanisms (clutches, brakes, etc.; see Freeman & Velinsky, 1995). Transmission system design is a multistage iterative process of sequential generation and modification of design decisions. These decisions define in many respects the technical and economic characteristics of future products. Searching for suitable design decisions is a highly complex and time-consuming problem due to the necessity to consider and analyze many heterogeneous functional, technical, and economic factors. However, extensive computations, including solving very complex optimization tasks, are needed. As a rule, the design procedures are provided only by a very competent and experienced designer. With ever more complex and combinatorial decisions to be made, even the best designer will need competent design support, of which there is little. Therefore, the design of transmission systems is a wide open area for development and application of decision-making and decision support technologies.
Key Terms in this Chapter
Transmission Gear Ratio: This is the ratio of the speed of the driving shaft to the speed of the driven shaft.
Kinematic Chain: It is the sequence of gears such that the driven shaft of the previous gear is the driving shaft of the next gear.
Longevity of Transmission Element (Gear, Shaft): This is the duration of the element’s ability to work.
Transmission System: The transmission system is an assembly of gears (not obligatorily sequentially interconnected) that transmits a rotary motion and power from the input shafts to the output shafts.
Gear: A gear is a mechanism that transmits a rotary motion and power from a driving shaft to a driven shaft with possible changes in the speed, direction, and torque.
Total Life of the Transmission System: This is the duration of operation for all elements.
Transmission Ratio of Kinematic Chain: It is the ratio of the speed of the driving shaft for the first gear and the speed of the driven shaft for the last gear.
Gearbox: A gearbox is the system of gears with changeable connections that results in alternative kinematic chains from the input shaft of the gearbox to its output shaft with different transmission ratios.
Load Conditions for a Kinematic Chain: These are the speed and the torque of the output shaft of the chain as well as (if necessary) the operation time (total or relative) of the chain during the total life of the transmission.