How to assemble the gears and how to set the transmission relationship?

I have never assembled a gear before, today I consulted some others, and roughly learned the method as follows: the first step, the gear end face alignment of the second step, showing the indexing circular surface of the gear, use it to add the tangent relationship of the third step, if the tooth shape interference is to use the gear's own default datum, cooperate with each other to ensure that the gear does not interfere, after this step is done, this constraint should be suppressed and then use the indexing circular surface to carry out gear relationship assembly, the assembly relationship will automatically help you find the correct transmission ratio, Right-click to confirm the end of the gear assembly relationship, if the set is out of order, the relationship is uninhibited, and the gear will be restored to its original state. I did a GIF animation tutorial with SolidEdge ST **Way 1:

The method is as follows: the first step, the gear end face is aligned in the second step, showing the indexing circular surface of the gear, use it to add the tangent relationship in the third step, if the tooth shape interference is to use the gear's own default datum, cooperate with each other to ensure that the gear does not interfere, after this step is completed, this constraint should be suppressed and then use the indexing circular surface to carry out gear relationship assembly, the assembly relationship will automatically help you find the correct transmission ratio, right-click to determine the end of the gear assembly relationship, if the gear assembly relationship is messed up, the relationship will be uninhibited, The gears are restored to their original state. I made a gif animation tutorial with SolidEdge ST way:

The assembly method of the gear transmission is as follows: judgment.

1. The gear is fixed on the shaft and is mostly connected by keys, after the gear is installed, its center line should coincide with the axis line, and the gear end face should be perpendicular to the axis line;

2. The gears that are reassembled into the gearbox after disassembly, cleaning and reassembly should be loaded into the box in the reverse order of the gears, shafts and other parts and components;

3. The high-speed and precise synchronous gear must be assembled according to the manufacturer's mark; The rolling mill herringbone gear should also be hardness checked;

4. The gear meshing clearance and tooth surface contact spots must comply with the provisions of the specification or equipment technical documents, if the number of tooth surface contact points is insufficient, the cause should be found out and countermeasures should be taken.

1. The coordination between the gear hole and the shaft should be appropriate to meet the requirements of use.

1) The empty set of gears shall not shake on the shaft;

2) The slip gear should not be bitten or blocked;

3), the fixed gear shall not be eccentric or skewed.

2. Ensure that the gear has an accurate installation center distance and appropriate tooth side clearance.

1), tooth side clearance refers to the normal direction distance of the non-working surface of the gear pair;

2) The backlash is too small, the gear rotation is not flexible, and it is easy to jam the teeth during thermal expansion, which aggravates the wear;

3) If the side clearance is too large, it is easy to produce shock vibration.

3. Ensure that the tooth surface has a certain contact area and correct contact position.

1. The coordination between the gear hole and the shaft should be appropriate to meet the requirements of use.

1) The empty set of gears shall not shake on the shaft;

2) The slip gear should not be bitten or blocked;

3), the fixed gear shall not be eccentric or skewed.

2. Ensure that the gear has an accurate installation center distance and appropriate tooth side clearance.

1), tooth side clearance refers to the normal direction distance of the non-working surface of the gear pair;

2) The backlash is too small, the gear rotation is not flexible, and it is easy to jam the teeth during thermal expansion, which aggravates the wear;

3) If the side clearance is too large, it is easy to produce shock vibration.

3. Ensure that the tooth surface has a certain contact area and correct contact position.

Belts, teeth, allowable movement speed is faster so in the front, snails, chain movement speed is slower, so put in the back.

The chain drive should be arranged in the low-speed stage, the chain drive has a strong bearing capacity, and the load of the low-speed stage is generally larger. The motorcycle is applied, the gear is arranged in the high-speed stage, and after the reducer is decelerated, the rear wheel of the motorcycle is driven by the chain drive.

The belt drive can be arranged in the high-speed stage, and the general belt drive can be directly connected to the power part, which is very common in life, and many electric motor diesel engines drive the next level of equipment directly through the belt drive.

The belt drive is arranged in the high-speed stage, when the actual transmission power exceeds the allowable rated power, it can be overload protected, so as to protect important parts, and the chain drive should be arranged in the low-speed stage, because the speed is too high, it will cause additional dynamic load, which will aggravate the chain vibration, impact and noise.

Gear assembly.

After the fixed immobility is generally assembled by interference fit, and the assembly of sliding gear is generally assembled with clearance fit.

There are three basic mating relationships in mechanical design: interference fit, transition fit, and gap fit.

The assembly of interference fit generally adopts the hot assembly method, and the gear is heated and assembled. There are generally two heating methods: oil heating and electric heating. The cold assembly method is generally assembled by a press, and can also be hammered with copper rods.

The assembly of sliding gears is generally carried out with gears for trial assembly first, and the inappropriate places are generally filed for repair and then assembled.

In actual assembly, there are only two types of fitting, clearance and interference, which are easy to understand. Transition fit is the possibility of both clearance fit and interference fit, and only after the part is processed and formed, it can be decided at the time of assembly. Transition fits can be appropriately selected, such as those with large gap fit or interference fit.

The fixed form of gear and gear shaft assembly is generally adopted:

key assembly fit;

Cone sleeve assembly fit;

Interference assembly fit.

Gear is a power transmission mechanism that requires high precision for mechanical transmission, and is also a speed changing device, in order to ensure that the lubrication of the gear is the best, the temperature is the lowest, the noise is the smallest, and the transmission power is the largest, and the coordination between the gear and the shaft is quite critical.

1. Key fit is the most commonly used form of fit, which is divided into single key, double bond, spline, etc. The assembly requirements are low, and it can be assembled with a copper hammer to meet the general mechanical transmission.

Second, the taper sleeve is relatively high, the taper sleeve and the gear bore are required to be very accurate, and when assembling, special hydraulic tools are required to complete, and there are more applications in more important mechanical devices.

Third, interference fit is also called tight fit, the gear needs to be heated during assembly, so that after the gear bore is expanded, it is easy to set on the gear shaft that has been processed, and it is fixed on the shaft after cooling, and half of the disassembly is difficult, and the methods of heating the gear are: oil boiling method and electromagnetic heating method.

Tell low load with belt drive, low speed distance with chain drive, but poor transmission accuracy gear suitable for heavy load.