Thursday, July 18, 2019

Types Of Gears?


What is gear?
The gears are a type of mechanical element whose teeth are cut around a cylindrical or conical surface with the same space. It is used for the rotation and transmission of force from the drive shaft to the driven shaft when coupling a pair of elements. The gears can be classified into spiral, cycloid and trochoidal gears according to their shape. It can also be classified as parallel shaft gear, transverse shaft gear and non-parallel and non-transverse shaft gear depending on the position of the shaft.

Various Types Of Gears:- They are different types of gears such as spur gears, helical gears, bevel gears, internal gears which are classified depend on the positions of the axes, such as parallel axes, transverse axes and non-transverse axes.

To achieve the required force transfer in the mechanical design, it is necessary to understand exactly the differences between the types of gears. It is important to take into account factors such as dimensions (module, dimension, helix angle, face width, etc.), precision standards (ISO, AGMA, DIN) and tooth sharpening requirements after choosing a common type. 

Spur Gear:-  A gear with a cylindrical pitch surface is called a spur gear. Spur gears are cylindrical gears that belong to the group of parallel shaft gears and have straight and straight teeth parallel to the shaft. Spur gears are the most used gears that can be achieved with high precision with relatively simple production processes. It has no axial load (thrust load). The largest of the pairs of mesh is called a gear and the smallest is called a pinion.




Gear Rack:- The teeth of the same size, cut to the same distance along a flat surface or straight bar, are called gear rack. The rack is a cylindrical gear with an infinite pitch radius. Converts the rotary movement into linear motion when coupled with a cylindrical pinion. Gear frames can be roughly divided into straight tooth frames and spiral frames, but both have straight lines. You can connect the end of the gear racks to the end of the gear rack  by machining the end of the gear rack.

Helical Gear:- The helical gears are cylindrical gears that are used with parallel shafts similar to the spur gears and have winding teeth. They have a better teeth  grip than spur gears, have excellent low noise and can carry higher loads, which makes them suitable for high speed applications. When helical gears are used, thrust bearings must be used because they generate thrust in the axial direction. The helical gears come with turns of the right and left hand that require the gear of the opposite hand to engage.

Bevel gear:- The bevel gears have a conical shape and are used to transmit forces between two intersecting axes at a point (intersection axis). The bevel gear has a cone on its step surface and its saw teeth are cut along the cone. Types of bevel gears include straight bevel gears, helical bevel gears, spiral bevel gears, bevel gears, angular bevel gears, bevel gears, null bevel gears and hypoidal gears.




Spiral Bevel Gear:-  The spiral bevel gear is a bevel gear with a serrated tooth. Due to the high contact rate of the teeth, efficiency, strength, vibration and noise are superior to straight bevel gears. On the other hand, they are more difficult to produce. In addition, since the tooth is bent, the thrust is generated in the axial direction. The zero conical gears with a turning angle of 0 in a helical bevel gear are called null bevel gears.
Screw Gear:- The screw gears are a pair of hand gears with a 45 ° angle of rotation on parallel axes that do not intersect. Since the contact of the tooth is a point, the load capacity is low and is not suitable for a high power transmission. Since the force is transmitted by the sliding of the tooth surface, it is necessary to pay attention to the lubrication when using the screw gear. There is no limit to the number of tooth combinations.
Miter Gear:- The miter gear is a bevel gear with a speed ratio of 1. It is used to change the direction of the power transmission without changing the speed. Miter straight and spiral miter gear. When using helical miter gears, the thrust bearings generate a pulse in the axial direction and must be considered for use. In addition to a common miter gear with a 90 ° shaft angle, a miter gear with a different shaft angle is called an angle miter gear.
Worm Gear:-  The screw shape that is cut on the shaft is a worm, the mesh gear is a helical gear, and the axes that do not intersect are called worm gears. The worm and worm wheels are not limited to cylindrical shapes. There is a type of hourglass that can increase the contact rate, but production becomes difficult. It is necessary to reduce the friction due to the sliding contact of the gear surface. For this reason, a hard material is generally used for the worm, and a soft material for the worm wheel. The rotation is smooth and quiet even if the efficiency is low due to the sliding contact. If the angle of advance of the worm is small, an automatic block is created.
Internal Gear:- The internal gears are teeth cut into a cylinder or cone and paired with external gears. The main uses of the internal gears are the planetary gears and the shaft couplings of the gear type. Due to in-volute interference, trochoid interference and cutting problems, there is a limit on the number of teeth between the difference between internal and external gears. When the two outer gears are engaged, the directions of rotation of the mesh of the internal and external gears are the same but opposite directions.