mechanicalcheck.com

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mechanicalcheck.com is a software calculator that helps you to design and verify machine elements according standard. These calculations are often tedious, error-prone and in sum very time-consuming. The online calculator offers remedy: With mechanicalcheck all converting calculations can be done quickly, properly and well documentated.

General information about the user interface

Please fill in all input boxes. Output boxes in grey ('output') are only for information and are locked. But you may choose the unit for the output value. All input data which are confirmed by enter will be immediatly send to the system and and start the calculation. But to safe time it is recommended not to start the calculation by pressing the enter-key or by clicking the 'calculate'-Button before all input-data have been entered.

Materials

The data base of the online calculator includes the materials listed in DIN 6892

DIN EN 10025 (Structural steel),
DIN EN 10277-5 (Bright steel),
DIN EN 10083-1 (Quenched and tempered steel),
DIN EN 10083-2 (Quenched and tempered steel),
DIN EN 1563 (Spheroidal graphite cast iron),
DIN EN 10293 (Cast steel, previously DIN 1681),
DIN EN 1561 (Grey cast iron)

and additionally

DIN EN 10083-3 (Quenched and tempered steel),
DIN EN 10277-2 (Bright steel) and
DIN EN 10277-3 (Bright steel).

For materials according DIN EN 10084 (Case hardened steels, previously DIN 17210) no generally accepted data has been found.

Mechanical properties

For ductile materials the yield strength is provided yield strength, for brittle material (grey cast irons) tensile strength. Because for many materials the mechanical properties are influenced by the mechanical or heat treatment, information about the treatment is added:

+C (cold drawn),
+N (normalized),
+QT, +QT1 oder +QT2 (quenched, tempered),
+QT+C, (quenched, tempered and cold drawn),
+C+QT, (cold drawn and quenched, tempered)

The field 'Shaft'

Please fill in data for shaft here. From the diameter and material name the online calculator calculates the allowable strength limit for the shaft. Furthermore the choice of the appropriate parallel key and the allowable torque is influenced by the diameter.

The Field 'Parallel Key'

Please fill in data for the parallel key here.

Number of keys: You can select 1 or 2 keys. It is possible to select 2 keys, though it is quite unusual. If you are not sure just select 1 (this is also the default value).

Standard: You can select parallel keys according standard DIN 6885-1 or DIN 6885-3. It is possible to select standard 6885-3, though it is quite unusual. If you are not sure just select 6885-1 (this is also the default value).

Shape: You can select shape A, B, C, D, E, F, G, H, or J. Please consider that keys according DIN 6883-3 exist only with shapes A, B, C, E. If you are not sure just select A (this is also the default value).

Length: Please enter the length (overall) of the key. If using method B (professional) the ratio between length and diameter (l_tr/d) should not increase the value of 2.0.

Material: According standard 6885-1 the following materials are suggested

E295GC +C für h < 25 mm
E335GC +C für 25 < h < 50 mm

or according standard 6885-3:

E335GC +C für h < 12 mm.

Nevertheless it is quite usual to select also other materials. If you are not sure, just select C45 +C (this is also the default value), because this material is very popular for keys.

The field 'Hub'

Please enter the data for hub here. From the property value D and material name the online calculator calculates the allowable strength limit for the hub. If the hub is produced by machining from solid, you should enter the outer diameter as a conservative approach for the property value D. If the hub is produced by casting, you should enter the wall thickness of the raw cast part. For forged or heat treated hubs the property value D should be chosen due to your experience, but as a conservative approach you can enter the outer diameter.

The field 'Loads'

Please enter the nominal torque, the extreme peak torque,the number of peaks and the operational characteristic from the drive and the driven machine. Operational characteristic of drive and driven machine influences the fatigue strength of the connection. This is the reason for the introduction off the application factor.

The field 'Allowable Loads'

This is the field for output of allowable equivalent torque and allowable peak torque.

The field 'Fit'

If you use an interference fit between shaft and hub, you can enter a minimum friction torque here. Thus loads on the parallel key will be reduced and safety of connection be increased.

But an interference fit will also complicate disassembling of the connection and is in contrast to the design rule 'Clarity'. If you want to use the advantages of interference fits (high torque transmission), use interference, if you want to use the advantages of parallel keys (good torque transmission and easy to assembly) use parallel keys.

Because of this it is not recommended to use interference fits and the default value is 0.

Nevertheless interference fits could be used. Minimal friction torque can be calculated according DIN 7190.

The field 'Safety'

The load capacity of the connection is proven, if the value for every safety is >1.