What is the gear ratio and speed ratio in epicyclic gearbox?
If the ring gear is held stationary and the sun gear is used as the input, the planet carrier will be the output. The gear ratio in this case will be 1/(1 + Nr/Ns) which can also be written as 1:(1 + Nr/Ns). This is the lowest gear ratio attainable with an epicyclic gear train.
What is the velocity ratio in gear train?
Velocity ratio: The ratio of the number of revolutions of the driving (or input) gear to the number of revolutions of the driven (or output) gear, in a unit of time. Pitch point: The point of tangency of the pitch circles of a pair of mating gears.
Which gear train is used for higher velocity ratio?
Which gear train is used for higher velocity ratios in a small space? Explanation: The epicyclic gear trains are useful for transmitting high velocity ratios with gears of moderate size in a comparatively lesser space.
How many speed ratios are in a single set of epicyclic gear train?
Two basic gear layout arrangements have dominated WTGS gearbox applications: (1) gears on parallel shafts and (2) planetary gear systems (also known as an epicyclic gear system). A typical gearbox speed ratio in large WTGS may be around 30:1 to 100:1.
How does an epicyclic gear train work?
A planetary or epicyclic gear train is one type of gear train used to transmit motion. Epicyclic gear trains consist of two or more gears mounted so that the center of one gear revolves around the center of the other. As the planet carrier turns, it delivers low-speed, high-torque output.
Is speed ratio same as gear ratio?
Gears have many properties, one of which is the speed ratio, often known as gear ratio. This is the ratio of the turning speed of the input gear to that of the output gear, in other words, how many time the input gear has to revolve to make the output gear revolve once.
Is velocity ratio same as gear ratio?
The reason bicycles are easier to cycle up a hill when the gears are changed is due to what is called Gear Ratio (velocity ratio). Basically, the ratio is determined by the number of teeth on each gear wheel, the chain is ignored and does no enter the equation.
What is the train value of gear train?
Explanation: Train value = Speed of the last driven or follower/Speed of the first driver. Explanation: When the axes of the first gear (i.e. first driver) and the last gear (i.e. last driven or follower) are co-axial, then the gear train is known as reverted gear train.
Which gear can be used to transmit rectilinear motion?
Explanation: Rack and pinion gear can be used to transmit rectilinear motion.
When do you use an epicyclic gear train?
The epicyclic gear train is useful for transmitting high-velocity ratio with a gear of moderate size and in less space. We use an epicyclic gear train in Wrist Watch. Table of Motions for Epicyclic gear trains: Suppose an Epicyclic Gear Train has 2 gears (Gear A and Gear B) and an Arm (Arm C).
How is carrier rotation affected in an epicyclic gear system?
Figure 1. A typical epicyclic planetary gear system By reason of the planet gears being connected to two other gears, carrier rotation is affected by two gear chains: (a) Sun-Planet-Carrier and (b) Ring-Planet-Carrier. Figure 2. Sun-Planet-Carrier
What kind of arm is used in epicyclic gears?
Only one planet-carrier /crank arm is used in a single epicyclic gear train. This complicated arrangement (see below) has a number of modes of operation depending on which members are locked.
How are gear trains used in compound gears?
In compound gears, each intermediate shaft has two-gears rigidly fixed to it. What is epicyclic gear trains? The epicyclic gear train is useful for transmitting high-velocity ratio with a gear of moderate size and in less space. What is an inverted gear train?