What Is Gear?- Principle of Gear & part

 

What Is Gear?

This method are conducting power is used in a place where the space between the soft is very less, it is fitted on the top of the soft shaft, it is like an iron circular wheel and the teeth are cut on its circumference. shapes are cut parallel to each other and equally spaced.

Principle of gear

Gear works on the fundamental principle of thermodynamics, the law of conservation, or the first law of thermodynamics, which states that energy can neither be created nor destroyed. We can say it is conservative. It can be transformed from one form to another. We know that power is the function of the shaft's torque (force in rotary motion) and speed (P = TV). Therefore, when we connect a small gear on the driving shaft and a larger gear on the driven shaft, the driven shaft speed decreases per unit rotation of the driving shaft.

As we know, power is conservative, so according to this, the torque of the driven shaft increases according to the ratio of driving gear to driven gear, or we can say, according to the ratio of driving shaft velocity to driven shaft velocity. Therefore, by using various gear designs, we can obtain various torque and speed combinations of the driven member.

Parts Of A Gear

There are a few different terms that you need to know when you are just starting out with gears, as listed below. So that the gears can mesh, the diametrical pitch and the pressure angle must be the same.

• Axis: The axis of revolution of the gear, where the shaft passes through
• Teeth: The jagged faces projecting outward from the circumference of the gear, used to transmit rotation to other gears. The number of teeth on a gear must be an integer. Gears only transmit rotation when their teeth mesh and have the same profile.
• Pitch Circle: The circle that defines the “size” of the gear. The pitch circles of two intermeshing gears must be tangential so that they can intermesh. If the two gears were instead two disks driven by friction, the circumference of those disks would be the pitch circle.
• Pitch Diameter: The pitch diameter refers to the working diameter of the gear, a.k.a., the diameter of the pitch circle. You can use the pitch diameter to calculate how far away two gears should be: The sum of the two pitch diameters divided by 2 corresponds to the distance between the two axes.
• Diametral Pitch: The ratio of the number of teeth to the pitch diameter. Two gears must have the same diametrical pitch to mesh.
• Circular Pitch: The distance from a point on one tooth to the same point on the adjacent tooth, measured along the pitch circle. (so that the length is the length of the arc rather than a line).
• Module: The module of gear is simply the circular pitch divided by pi. This value is much easier to handle than the circular pitch because it is a rational number.
• Pressure Angle: The pressure angle of a gear is the angle between the line that defines the radius of the pitch circle and the point where the pitch circle intersects a tooth, and the line tangent to that tooth at that point. Standard print angles are 14.5, 20, and 25 degrees. The pressure angle affects how the gears touch and how the force is distributed along with the tooth. Two gears must have the same contact angle for meshing.