What is Gear reduction: Definition and 13 Discussions

A transmission is a machine in a power transmission system, which provides controlled application of power. Often the term 5-speed transmission refers simply to the gearbox, that uses gears and gear trains to provide speed and torque conversions from a rotating power source to another device.The term transmission properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differential, and final drive shafts. In America the term is sometimes used in casual speech to refer more specifically to the gearbox alone, and detailed usage differs.
The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted.
Often, a transmission has multiple gear ratios (or simply "gears") with the ability to switch between them as the speed varies. This switching may be done manually (by the operator) or automatically (by a control unit). Directional (forward and reverse) control may also be provided. Single-ratio transmissions also exist, which simply change the speed and torque (and sometimes direction) of motor output.
In motor vehicles, the transmission generally is connected to the engine crankshaft via a flywheel or clutch or fluid coupling, partly because internal combustion engines cannot run below a particular speed. The output of the transmission is transmitted via the driveshaft to one or more differentials, which drive the wheels. While a differential may also provide gear reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at different speeds (essential to avoid wheel slippage on turns) as it changes the direction of rotation.
Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation. Alternative mechanisms include torque converters and power transformation (e.g. diesel-electric transmission and hydraulic drive system). Hybrid configurations also exist. Automatic transmissions use a valve body to shift gears using fluid pressures in response to engine RPM, speed, and throttle input.

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  1. Datt

    How Does Gear Count Affect the Efficiency and Size of Gearboxes?

    I have a question what is a difference or advantage for using two gears with high gear ratio or using three gears with lower gear ratio.Is there any advantage.
  2. P

    Misc. Display built with a rotating cube design

    Hello everyone, I want to build a rotating display cube (will be mounted on a wall, those cubes that has shops logos ect..), my problem is that I don't know where to start and how to attack the rotating mechanism. I have a 1400Rpm moteur (and it's a 1m per 1m cube that weights around 120kg-150kg...
  3. E

    3D Printer Stepper Motor Torque Requirements Using Gear Reduction

    I hope to explore mechanical engineering one day so I can answer these kinds of questions on my own, but until then, I appeal to anyone that knows how to do this to help me. I am building a core xy 3D Printer and I want to use a belt driven Z axis. I will have 3 or 4 stepper motors to drive...
  4. F

    B What is the entire gear reduction ratio of a vehicle?

    As I was looking in the caracteristics of an old tank, I found a number that I could not get anything of on the web. It is called "entire reduction ratio" and was presented just under the gearbox caracteristics. His value is 1:13.4. My question is : is it useful? Does this value have relation...
  5. T

    How does mechanical torque affect generator volts and amps?

    Hello! today I have a question regarding the most efficient way to generate electricity by moving a magnet across a coil. The theoretical magnet would be moving in a circular motion fixed to the outer circumference of a driver wheel like in many simple generators, how does the physical torque...
  6. M

    Calculating tq for incline / best practices for gear reduction

    I am calculating the amount of torque required to give mobility to a 7000 lbs oilfield service vehicle. The vehicle has a rectangular frame with fairly even weight distribution. The radius, from wheel center to edge of tire is 11.5 inches. These tires are treaded with various half-inch tall...
  7. J

    How can I increase output speed without a significant decrease in torque?

    For a project I am doing I need to increase out put speed to 515 rpm from 1rpm with no more than a 20% decrease in torque, I need help I have been trying a lot of things and can't figure it out.
  8. Gurfin321

    Automotive Electric Longboard Gear Ratio

    I would like to know what gear ratio i would need for my electric longboard. The goal is to run the longboard at 30 - 40 km/h at max power. Me and the longboards weight is approximately 65 kg. The brushless motor i am running has an rpm of approximately 18000 rpm (as it is an airplane engine)...
  9. Ty Harris

    How much weight/force to move gear reduction

    I need some math help. I am very good with my hands and building mechanical things, but not-so-good with math calculations. ( I got a D in high school physics but can fix damned near anything...) I would appreciate some help figuring this out. I have attached a diagram showing what I am trying...
  10. B

    Rotational force of motor + potential gear reduction

    I'm trying to determine how powerful of a stepper motor I need for a project. I am attempting to take a display that weighs 15lbs and transition it from laying flat to inclined (approximately 45 degrees) using a stepper motor. I had considered a linear actuator since it would have been an easier...
  11. A

    Load Acting on Robot Arm Driven by Electric Motor

    Hello all I have a doubt with the load concept acting on a beam. Consider a robot arm, actuated using Electric motor. When the arm is static and hold in position by the motor, Does the Gear ratio reduce the load acting on the motor due to the Gear ? Or when the arm is static, the Gear system...
  12. D

    Understanding Gear Reduction: How to Achieve Lower Angular Velocity in Gears

    hi everyone! i was wondering how gear reduction is done besides connecting a small gear to a larger gear (radius speaking)? In my problem i have a gear - radius:5cm, angular velocity: 1000rpm I have a second gear - radius:5 cm, anguler velocity required: 1 rpm How do i make this...
  13. R

    Gear Reduction Help for Kinetic Sculptor w/ Small Budget

    I am a kinetic sculptor in need of some gear reduction help. I have a 2250 rpm .5 hp electric motor. i need to reduce the rpms to less than 5. the gear drive will turn a 30" plywood wheel, and it must turn slowly. the electric motor is the only one I have, so i must use it. I have a small...