What Is a Gear Wheel?

Gear refers to the mechanical element on the rim with gears continuously meshing to transmit motion and power. The use of gears in transmission has been around for a long time. At the end of the 19th century, the principle of the gear cutting method and the special machine tools and tools that used this principle to cut teeth appeared one after another. With the development of production, the smoothness of gear operation has been valued.

Tooth (tooth)-each of the convex parts of the gear used for meshing. Generally speaking, these raised portions are arranged radially. The gear teeth on the paired gears contact each other, resulting in continuous meshing operation of the gears.

Cogging-the space between two adjacent teeth on a gear.

GB / T 14229-1993 Gear contact fatigue strength test method

GB / T 14230-1993 Gear bending fatigue strength test method

GB / T 14231-1993 Method for measuring gear device efficiency

GB / T 1840-1989 circular arc gear module

GB / T 15752-1995 Basic term of circular cylindrical gear

GB / T 15753-1995 arc cylindrical gear accuracy

GB / T 3481-1997 Gear wear and damage terms

GB / T 2362-1990 Basic profile of small modulus involute cylindrical gear

GB / T 2363-1990 Small modulus involute cylindrical gear accuracy

GB / T 3480-1997 Calculation method for bearing capacity of involute cylindrical gear

GB / T 6083-2001 basic type and size of gear hob

GB / T 6084-2001 General specifications for gear hobs

GB / T 1356-2001 Standard basic rack profile for cylindrical gears for general machinery and heavy machinery

GB / T 4459.2-2003 Mechanical drawing gear representation

GB / T 2821-2003 Gear geometric element code

GB / T 10062.1-2003 Bevel gear bearing capacity calculation method Part 1: Overview and general influence factor

GB / T 10062.2-2003 Bevel gear bearing capacity calculation method Part 2: Calculation of tooth surface contact fatigue (pitting) strength

GB / T 10062.3-2003 Bevel gear load capacity calculation method Part 3: Calculation of tooth root bending strength

GB / Z 6413.1-2003 Spherical gear, bevel gear and hypoid gears calculation method for cement load carrying capacity-Part 1: Flash temperature method

GB / Z 6413.2-2003 Spherical gears, bevel gears, and hypoid gears calculation method for cement bearing capacity-Part 2: Integral temperature method

GB / T 17879-1999 Etching test of surface tempering after gear grinding

GB / T 3374-1992 basic terms of gears

GB / T 19321-2003 Small boat steering gear gear transmission connection system

GB / T 19406-2003 Calculation method of load capacity of involute spur gear and helical gear

GB / Z 19414-2003 closed gear transmission for industry

GB / T 9205-2005 Insert gear hob

GB / T 19936.1-2005 Gear FZG test procedure. Part 1: Relative glue carrying capacity of oil FZG test method A / 8.3 / 90

GB / T 6404.1-2005 Acceptance specifications for gear units-Part 1: Test specifications for airborne noise

GB / T 6404.2-2005 Acceptance specifications for gear units-Part 2: Determination of mechanical vibration of gear units in acceptance tests

GB / T 14348-2007 double arc gear hob

GB / Z 18620.4-2008 Code for inspection of cylindrical gears Part 4: Inspection of surface structure and contact spots of gear teeth

GB / T 10095.2-2008 Cylindrical gear precision system Part 2: Definition and allowable value of radial comprehensive deviation and radial runout

GB / Z 18620.2-2008 Code for implementation of inspection of cylindrical gears Part 2: Inspection of radial comprehensive deviation, radial runout, tooth thickness and backlash

GB / T 6320-2008 lever gear comparator

GB / Z 18620.1-2008 Code for the implementation of inspection of spur gears-Part 1: Inspection of tooth surfaces on the same side of gear teeth

GB / Z 18620.3-2008 Code for inspection of cylindrical gears Part 3: Inspection of gear blanks, shaft center distance and axis parallelism

GB / T 10095.1-2008 Cylindrical gear precision system Part 1: Definition and allowable value of deviation of tooth surface on the same side of gear teeth

GB / T 13924-2008 Accuracy Inspection Rules for Involute Cylindrical Gears

GB / T 19073-2008 wind turbine gearbox

GB / T 21945-2008 CNC Fan Gear Gear Shaper Precision Inspection

GB / T 22161-2008 35mm film projector intermittent film transmission gear size

GB / T 22097-2008 Gear Measurement Center

GB / Z 22559.2-2008 Gear thermal power Part 2: Calculation of thermal load carrying capacity

GB / T 1357-2008 cylindrical gear module for general machinery and heavy machinery

GB / T 3480.5-2008 Calculation of load capacity of spur and helical gears Part 5: Strength and quality of materials

GB / Z 22559.1-2008 Thermal power of gears Part 1: Calculation of thermal balance of gears when oil pool temperature is 95

GB / T 22775-2008 Gear end gears for timing instruments

GB / T 6443-1986 Dimensional data for involute cylindrical gears

GB / T 11281-2009 General technical requirements for gear reducers for micromotors

GB / T 7631.7-1995 Classification of Lubricants and Related Products (Class L) Part 7: Group C (Gear)

GB / T 3374.1-2010 Gear terms and definitions Part 1: Geometric definition

GB / T 25509-2010 Reference dictionary for mechanical systems and gears

GB / T 25662-2010 Precision inspection of CNC bevel gear milling machine

GB / T 26090-2010 Gear pitch measuring instrument

GB / T 26091-2010 Gear single-sided meshing overall error measuring instrument

GB / T 6467-2010 Gear involute model

GB / T 26092-2010 Gear Spiral Measuring Instrument

GB / T 6468-2010 Gear Spiral Model

GB / T 26093-2010 Gear Double-sided Meshing Comprehensive Measuring Instrument

GB / T 8542-1987 Technical conditions of turbine gear transmission

GB 5903-2011 industrial closed gear oil

GB / T 3374.2-2011 Gear terms and definitions Part 2: Geometric definition of worm gear

GB / T 28252-2012 Gear hob before grinding

GB / T 28247-2012 disc gear milling cutter

GB / T 10063-1988 Simplified Calculation Method for Bearing Capacity of General Mechanical Involute Cylindrical Gears

GB / T 10098-1988 Technical conditions of marine medium speed diesel gearbox

GB / T 10224-1988 Basic tooth profile of small modulus bevel gear

GB / T 10225-1988 Small modulus bevel gear accuracy

GB / T 11365-1989 Accuracy of bevel gears and hypoid gears

GB / T 11572-1989 Marine gearbox bench test method

GB / T 12368-1990 bevel gear modulus

GB / T 12369-1990 Basic tooth profile of straight and helical bevel gears

GB / T 12370-1990 Terminology of bevel gears and hypoid gears

GB / T 12371-1990 Size data should be indicated on the bevel gear design

GB / T 12601-1990 Basic terms of harmonic gear transmission

GB / T 12759-1991 basic tooth profile of double arc cylindrical gear

GB / T 13672-1992 Test method for gear carrying capacity

GB / T 13799-1992 Calculation method for bearing capacity of double circular arc cylindrical gear

GB 13895-1992 heavy duty vehicle gear oil (GL-5)

Generally there are gear teeth, cogging, end face, normal surface, tooth top circle, tooth root circle, base circle,

Number of teeth Z

Closed

Classified according to specifications or sizes, gear models are divided into standard and non-standard;

According to different measurement units at home and abroad, the gear models are divided into metric and inch.

Metric gear model

The metric system / module (M / m) is mainly used in China, and the gear module = indexing circle diameter / number of teeth = gear outer diameter / (number of teeth + 2).

The main models of metric gears are: M0.4 M0.5 M0.6 M0.7 M0.75 M0.8 M0.9 M1 M1.25 M1.5 M1.75 M2 M2.25 M2.5 M2.75 M3 M3. 5 M4 M4.5 M5 M5.5 M6 M7 M8 M9 M10 M12 M14 M15 M16 M18 M20 M22 M24 M25 M26 M28 M30

Inch gear model

DP gear is an imperial gear (diameter gear) used in Europe, America and other countries. It refers to the number of teeth per inch of the index circle. The larger the value, the smaller the teeth. Diameter pitch DP = z / D (z number of teeth, D indexing circle diameter, inch). The unit of diameter DP is (1 / in). Its conversion relationship with the metric system is m = 25.4 / DP, which means that it is the same as our commonly used modulus.

The main models of inch gear are: DP1 DP1.25 DP1.5 DP1.75 DP2 DP2.25 DP2.5 DP2.75 DP3 DP4 DP4.5 DP5 DP6 DP7 DP8 DP9 DP10 DP12 DP14 DP16 ^[5]

Gears can be classified by tooth shape, gear shape, tooth line shape, surface on which the gear teeth are located, and manufacturing methods.

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 cycloid gears and arc gears have fewer applications.

In terms of pressure angle, the load capacity of small pressure angle gears is small; while the load capacity of high pressure angle gears is high, but the bearing load increases under 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 various types of machinery and equipment.

Commonly used steel for gear manufacturing

By transmission ratio:

Constant transmission ratio-round gear mechanism (cylindrical, cone)

Variable transmission ratio-good structure of non-circular gear machine (ellipse gear)

Divided by the relative position of the axle

Plane gear mechanism, spur gear transmission, external gear transmission, internal gear transmission, rack and pinion transmission, helical gear transmission, herringbone gear transmission, space gear mechanism, bevel gear transmission, staggered shaft helical gear transmission

There are two main types of involute gear machining methods. One is the profiling method, which uses a forming milling cutter to mill the cogging of the gear, which is "imitating the shape". The other is Fan Chengfa (

1.Tooth surface wear

For open gear transmission or closed gear transmission with unclean lubricant, due to the relative sliding between the meshing tooth surfaces, some hard abrasive particles enter the friction surface, which changes the tooth profile and increases the backlash. So that the gear is too thin and the teeth are broken. Under normal circumstances, only when the abrasive particles are mixed in the lubricating oil, the wear of the tooth surface abrasive particles will be caused during operation.

2.Tooth surface bonding

For high-speed and heavy-duty gear transmission,

A couple

The gear industry is mainly composed of three types of enterprises: vehicle gear transmission manufacturing enterprises, industrial gear transmission manufacturing enterprises and gear special equipment manufacturing enterprises. Among them, vehicle gear stands out, its market share reaches 60%; industrial gear consists of industrial general, special, and special gears, with market shares of 18%, 12%, and 8% respectively; gear equipment only accounts for 2% of the market share .

The purpose of the simple diagnosis is to quickly determine whether the gear is in a normal working state.

Gear accuracy refers to a grade divided by the comprehensive error of gear shape, which includes some important parameters such as tooth shape, tooth direction, runout, etc., where tooth shape refers to the radial shape of the tooth, and tooth direction refers to the longitudinal direction of the tooth Shape, run-out refers to the error of the distance between two adjacent teeth. Generally, the gears used in our cars can be determined by

Gear castings are also known as cast steel gears. This is because most gears are made of cast steel. Here, I share some information about the production of gear castings and related heat treatment. Gear castings usually weigh from a few kilograms to several tons.

Gear casting materials are usually made of high-carbon cast steel, and some alloy steels containing chromium, nickel, and molybdenum are used to achieve high tensile strength. Large gears usually have lower physical requirements than small gears.

Regarding the casting process, the floor molding process is usually suitable and can meet normal needs. As for cast steel gears such as driven gears, gears and idlers, the floor molding process using quartz sand is a good choice. Why, because most parts of the gear need to be processed. So you don't need to use a higher casting process. In addition, for medium and large steel castings, the floor molding process using quartz sand is almost the only option.

Regarding heat treatment, of course, all steel castings must be standardized to eliminate internal pressure. Gear castings can be welded in certain areas. If the foundry welds the casting, the weld location must be annealed. If the hardness is extremely high after hobbing, you can anneal again to reduce the hardness and eliminate internal hard spots. After processing and hobbing, the gear is quenched or hardened to increase the surface hardness of the gear teeth. For pinions, you can do carburizing. For large driven gears, you can do surface hardening. Gears that are not hardened have a short life, only a few weeks to a few months.

Because gear casting has higher requirements on materials, defects, machining and heat treatment. Moreover, orders for gear castings are relatively small. Therefore, many steel foundries are reluctant to manufacture.

Some gears are made by a forging process. Forged gears have better internal tissue density and higher strength. Forged gears can be used for more stringent working conditions. Casting gears have low strength but are widely used in general working conditions. The cost of forging gears is high, while the cost of casting gears is relatively low. The buyer should select the appropriate manufacturing process based on cost and conditions of use. ^[6]