20-43HRC Double Helical And Herringbone Gears 1650 Mpa Tensile Strength

20-43HRC Double Helical And Herringbone Gears 1650 Mpa Tensile Strength

Gear is a mechanical element that continuously meshes with gears on the rim to transmit motion and power
Tooth (teeth) - Each raised part of a gear used to mesh. Generally, these raised portions are arranged in a radial pattern. The teeth on the mating gears contact each other, resulting in a continuous meshing operation of the gears.
Cogging - The space between two adjacent teeth on a gear.

20-43HRC Double Helical And Herringbone Gears 1650 Mpa Tensile Strength
End face - a plane perpendicular to the axis of the gear or worm on a cylindrical gear or cylindrical worm.
Normal plane - On a gear, the normal plane refers to the plane perpendicular to the tooth line of the gear teeth.
Addendum Circle - The circle where the tooth tips are located.
Root circle - the circle where the groove bottom is located.
Base circle—a circle on which the occurrence line forming the involute is made pure rolling.
Index circle—a reference circle for calculating the geometric dimensions of the gear in the end face. For spur gears, the modulus and pressure angle on the index circle are standard values.
Tooth surface - the side surface of the gear tooth between the top cylindrical surface and the tooth root cylindrical surface.
Tooth Profile—The line where the tooth flank is intercepted by a specified surface (a plane for cylindrical gears).
Tooth line - the intersection of the tooth surface and the indexing cylindrical surface.
End face tooth pitch pt——the indexing arc length between the tooth profiles on the same side of the adjacent two teeth.
Modulus m——The quotient obtained by dividing the tooth pitch by pi, in millimeters.
Diameter P—the reciprocal of the modulus, in inches.
Tooth thickness s——The length of the indexing arc between the tooth profiles on both sides of a gear tooth on the end face.
Slot width e——The length of the indexing arc between the tooth profiles on both sides of a tooth slot on the end face.
Addendum height hɑ——The radial distance between the addendum circle and the index circle.
Root height hf——The radial distance between the index circle and the root circle.
Total tooth height h——The radial distance between the tip circle and the root circle.
Tooth width b——the size of the gear teeth along the axial direction.

End face pressure angle ɑt── the acute angle formed by the radial line passing through the intersection of the end face tooth profile and the index circle and the tooth profile tangent passing through this point.
Standard Rack: Only the dimensions of the base circle, tooth shape, full tooth height, tooth crown height and tooth thickness are in line with the standard spur gear specification, and the rack is cut according to its standard gear specification. It is called the reference rack.
Standard Pitch Circle: It is used to determine the reference circle of the size of each part of the gear. It is the number of teeth x modulus
Standard Pitch Line: A specific pitch line on the rack or the tooth thickness measured along this line, which is one-half of the pitch.
Action Pitch Circle: When a pair of spur gears mesh, each has a tangent to make a rolling circle.
Standard Pitch: The selected standard pitch is used as the benchmark, which is equal to the standard rack pitch.
Pitch Circle: The track left on each gear at the occlusal contact point on the connecting center line of the two gears is called the pitch circle.
Pitch Diameter: The diameter of the pitch circle.
Effective tooth height (Working Depth): the sum of the crown height of a pair of spur gears. Also known as the working tooth height.
Addendum: the difference between the tip circle and the pitch circle radius.
Backlash: The gap between the tooth surface and the tooth surface when the two teeth are engaged.
Clearance: When two teeth are engaged, the gap between the top circle of one gear and the bottom of the other gear.
Pitch Point: The point where a pair of gears meshes with the pitch circle.
Pitch: The distance between the corresponding point arcs between two adjacent teeth.
Normal pitch (Normal Pitch): the pitch of the involute gear measured along the same vertical line of a specific section.
Transmission ratio ( ): The ratio of the speed of the two meshing gears. The speed of the gear is inversely proportional to the number of teeth. Generally, n1 and n2 represent the speed of the two meshing teeth.
Gears can be classified by tooth shape, gear shape, tooth line shape, surface on which the gear teeth are located, and manufacturing method.
The tooth profile of the gear includes tooth profile curve, pressure angle, tooth height and displacement. Involute gears are relatively easy to manufacture, so among the gears used in modern times, involute gears account for the absolute majority, while cycloidal gears and arc gears are used less frequently.
In terms of pressure angle, the bearing capacity of small pressure angle gear is small; while the bearing capacity of large pressure angle gear is higher, but the load of the bearing increases under the condition of the same transmission torque, so it is only used in special cases. The tooth height of the gear has been standardized, and the standard tooth height is generally used. Displacement gears have many advantages and have been used in all kinds of mechanical equipment.
In addition, gears can also be divided into cylindrical gears, bevel gears, non-circular gears, racks, and worm gears according to their shapes; spur gears, helical gears, herringbone gears, and curved gears according to the shape of the tooth line; The surface is divided into external gears and internal gears; according to the manufacturing method, it can be divided into casting gears, cutting gears, rolling gears, sintering gears, etc.
The gear's manufacturing material and heat treatment process have a great impact on the gear's load-carrying capacity and dimensional weight. Before the 1950s, carbon steel was used for gears, alloy steel was used in the 1960s, and case-hardened steel was used in the 1970s. According to the hardness, the tooth surface can be divided into two types: soft tooth surface and hard tooth surface.
Gears with soft tooth surfaces have lower bearing capacity, but are easier to manufacture and have good running-in properties. They are mostly used in general machinery with no strict restrictions on transmission size and weight, as well as small-scale production. In the paired gears, the small wheel has a heavier burden, so in order to make the working life of the large and small gears roughly equal, the hardness of the tooth surface of the small gear is generally higher than that of the large gear.
The hardened gear has a high bearing capacity. It is quenched, surface quenched or carburized and quenched after the gear is finely cut to increase the hardness. However, during heat treatment, the gear will inevitably deform, so grinding, grinding or fine cutting must be carried out after heat treatment to eliminate errors caused by deformation and improve the accuracy of the gear.
The steels commonly used in the manufacture of gears are quenched and tempered steel, quenched steel, carburized and quenched steel and nitrided steel. The strength of cast steel is slightly lower than that of forged steel, and it is often used for gears of larger size; gray cast iron has poor mechanical properties and can be used in light-load open gear transmission; ductile iron can partially replace steel to make gears; plastic gears are mostly used In places where light loads and low noise are required, steel gears with good thermal conductivity are generally used for their matching gears.
In the future, gears are developing in the direction of heavy load, high speed, high precision and high efficiency, and strive to be small in size, light in weight, long in life and economical and reliable.
The development of gear theory and manufacturing process will further study the mechanism of gear tooth damage, which is the basis for establishing a reliable strength calculation method, and is the theoretical basis for improving gear bearing capacity and prolonging gear life; the development is represented by arc tooth profile. new gear shape; research new gear materials and new gear manufacturing processes; research gear elastic deformation, manufacturing and installation errors and distribution of temperature field, gear teeth modification, to improve the smoothness of gear operation, and at full load At the same time, the contact area of ​​the gear teeth is increased, thereby improving the bearing capacity of the gear.
Friction, lubrication theory and lubrication technology are the basic work in gear research. Studying elastic hydrodynamic lubrication theory, promoting the use of synthetic lubricating oil and adding extreme pressure additives to the oil can not only improve the bearing capacity of the tooth surface, but also Also improve transmission efficiency

By transmission ratio:
Fixed transmission ratio - circular gear mechanism (cylindrical, conical)
Variable transmission ratio - non-circular gear mechanism (oval gear)

According to the relative position of the axle
Plane gear mechanism, spur gear transmission, external gear transmission, internal gear transmission, rack and pinion transmission, helical cylindrical gear transmission, herringbone gear transmission, space gear mechanism, bevel gear transmission, staggered shaft helical gear transmission, Worm gear drive

By process
Bevel gears, rough semi-finished gears, helical gears, internal gears, spur gears, worm gears
There are two types of involute gear processing methods, one is the copying method, which uses a forming milling cutter to mill out the tooth slot of the gear, which is "imitation shape". The other is Fan Chengfa (Development Method).
(1) Gear hobbing machine: it can process helical teeth with modules below 8
(2) Milling machine teeth: straight racks can be processed
(3) Slotting machine: can process internal teeth
(4) Cold punching machine: can be processed without chips
(5) Gear planing machine: can process 16-module large gears
(6) Precision cast teeth: cheap pinions can be processed in large quantities
(7) Gear grinding machine: it can process the gears on the precision mother machine
(8) Casting gear of die casting machine: most non-ferrous metal gears are processed
(9) Gear shaving machine: It is a metal cutting machine tool for gear finishing

High Precision Customized spur herringbone helical double gears forged shaft

Main Testing and Inspection Device