8 Parallel key calculation according DIN 6892

[Next Chapter] [Previous Chapter] [Previous Chapter (End of Page)] [End of Page] [Contents]

Chapter 8
Parallel key calculation according DIN 6892

    8.1   General
    8.2   The field of application of DIN 6892
    8.3   Geometry
    8.4   The loads
    8.5   Hints for method C
    8.6   Example: Parallel keys according to DIN 6892

8.1 General

A parallel key is a positive shaft-hub-connection. The torque is transmitted from the shaft to the hub via the parallel key. The main purpose of the parallel key is to transmit static and quasi-static torques. The parallel key can be used with limitations also for swelling and alternating torques. In case a good assembly and disassembly of the shaft-hub-connection are required or necessary (e.g., replacement or repair), then a parallel key may be used. A shearing off of the parallel key does not happen very often and occurs only in the event of overloading. The fretting corrosion due to rotating bending and/or torsional oscillation has been proven in numerous endurance tests and is usually the crucial factor which leads to the failure of the shaft-hub-connection. For the proof of strength of parallel keys, it is necessary to check the following factors:

Surface pressure on the shaft, parallel key and hub
Design strength of the shaft for
Torsional stress, normally (quasi-) static
Bending load, normally dynamic
Consideration of notch effects, for that the strength calculation for the shaft according to DIN 743 is usually used
Design strength of the hub

In DIN 6892 a distinction is made between different methods for the proof of strength for parallel keys: method A, B and C.

Method A: This method is an experimental proof of strength under conditions of practice and/or an extensive stress analysis of the entire parallel key connection, consisting of shaft, parallel key and hub.
Method B: The dimensioning takes place due to a detailed consideration of the occurring surface pressures. In addition, the proof of strength for the shaft is carried out according to the nominal-stress concept.
Method C: An approximate calculation of the surface pressures and resulting estimation for the stress of the shaft.

The methods B and C, according to the standard, are integrated and available for the calculation.

8.2 The field of application of DIN 6892

For parallel keys whose parts are made of metallic materials
Mainly for parallel keys used in mechanical engineering for the temperature range of -40^∘C to 150^∘ C

8.3 Geometry

There is a selection of parallel key geometry according to DIN 6885-1, DIN 6885-2 and DIN 6885-3. This geometry selection includes the standard lengths of parallel keys. The supporting length is determined from the standard length and the chosen parallel key type. There are various types of parallel keys. Hence, the types A to J are available.

Figure 8.1:

Types of parallel keys (A to J)

This applies for round-ended parallel keys (type A, E, C) $ltr = lPF - b$
This applies for straight-ended parallel keys (type B, D, F, G, H, J) $ltr = lP F$
This applies for combined parallel keys (AB) $ltr = lPF - b∕2$

where

$ltr$

is the supporting length

$lPF$

is the standard length

$b$	is the width

For nonstandard parallel keys, it is possible to define an individual parallel key geometry and supporting lengths. The different keyway depths in shaft and hub as well as the chamfer of the parallel key are taken into consideration for the calculation. For method B, the chamfer on the shaft and hub keyway is additionally integrated into the calculation.

If the supporting length is set to the manual input, the supporting length $l2tr$ of the hub keyway can be smaller than $ltr$ of the parallel key. For this case, according to DIN 6892, the length $l1tr$ of each extended part may be calculated as carrying up to maximum $1× b$ . The eAssistant uses the most conservative case as a basis for a save calculation and this exceptional case is not considered automatically by the eAssistant.

8.4 The loads

Surface pressure

The effective surface pressure between parallel key and shaft or hub keyway wall must not exceed the permissible value. The permissible values result from the material strength - for ductile materials from the yield point ( $Rp0,2$ and/or $Re$ ) and for brittle materials from the tensile strength $Rm$ . The calculation can be accomplished by using unusual metallic materials. The following strength criteria have to be fulfilled with the appropriate safeties:

p1,2eq < fW ⋅pzul

p1,2max < fL ⋅pzul

where

$fW$	is the changes of load direction factor

$fL$	is the load peak frequency factor

The calculation method applies for one-sided stress and with restriction for an alternating stress of the parallel keys. The surface pressure is determined from the torque that is transmitted.

Figure 8.2:

Geometry and surface pressure on the parallel key connection

The supporting keyway depth between parallel key and shaft as well as hub keyway wall are given by the following equations. Therefore, a 45^∘ chamfer and radius on the parallel key as well as on the shaft and hub keyway edge are considered according to the figure above:

For shaft keyway wall $1( ∘-------------) t1tr = t1 - (r + s1)- - d - d2 - (b + 2s1)2 2$
For hub keyway wall $1 ( ∘ -2----------2) t2tr = h - t1 - (r+ s2)+ 2 d- d - (b+ 2s1)$

Permitted surface pressure

For ductile material: $pzul = fS ⋅fH ⋅Re an d fS ⋅fH ⋅Rp0,2$

according to the specifications in the standard sheets for the respective materials.
For brittle material: $pzul = fS ⋅Rm$

where

$f S$

is the support factor

$f H$

is the hardness factor

The application factor

The application factor $KA$ is determined for the calculation of the equivalent torque $Teq$ similarly to the gear calculation according to DIN 3990 with the following table:


Application factors $K A$ according to DIN 3990-1: 1987-12

Working characteristics	Working characteristics of the driven machine

of the driving machine	Uniform	Light shocks	Moderate shocks	Heavy shocks

Uniform	1,0	1,25	1,5	1,75

Light shocks	1,1	1,35	1,6	1,85

Moderate shocks	1,25	1,5	1,75	2,0

Heavy shocks	1,5	1,75	2,0	2,25 or higher


Examples for driving machines with various working characteristics
according to DIN 3990-1: 1987-12

Working characteristics	Driving machine

Uniform	Electric motor (e.g., d.c. motor), steam or gas turbine with uniform operation¹ (small rarely occurring starting torques)

Light shocks	Steam turbine, gas turbine, hydraulic motor or electric motor (large, frequently occurring starting torques)

Moderate shocks	Multiple-cylinder internal combustion engines

Heavy shocks	Single-cylinder internal combustion engines

¹ Based on vibration tests or on experiences gained from similar installations.


Examples of working characteristics of driven machines
according to DIN 3990-1: 1987-12

Working characteristics	Driven machines

Uniform	Steady load current generator; uniformly loaded conveyor belt or platform conveyor; worm conveyor; light lifts; packing machinery; feed drives for machine tools; ventilators; lightweight centrifuges; centrifugal pumps; agitators and mixers for light liquids or uniform density materials; shears; presses; stamping machines¹; vertical gears; running gear².

Light shocks	Non-uniformly (e.g., with piece or batched components) loaded conveyor belts or platform conveyors; machine tool main drives; heavy lifts; crane slewing gear; industrial and mine ventilator; heavy centrifuges; centrifugal pumps; agitators and mixers for viscous liquids or substances of non-uniform density, multi-cylinder piston pumps, distribution pumps; extruders (general); calenders; rotary kilns; rolling mill stands³ (continuous zinc and aluminium strip mills, wire and bar mills).

Moderate shocks	Rubber extruders; continuously operating mixers for rubber and plastisc; ball mills (light); woodworking machine (gang saw, lathes); billet rolling mills³,⁴; lifting gear; single-cylinder piston pumps.

Heavy shocks	Excavator (bucket wheel drives), bucket chain drives; sieve drives; power shovels; ball mills (heavy); rubber kneaders; crushers (stone, ore); foundry machines; heavy distribution pumps; rotary drills; brick presses; debarking mills; peeling machines; cold strip³,⁵; briquette presses; breaker mills.

¹ Nominal torque: maximum cutting, pressing or stamping torque.
² Nominal torque: maximum starting torque.
³ Nominal torque: maximum rolling torque.
⁴ Torque from current limitation.
⁵ $KA$ up to 2,0 because of frequent strip cracking.

The load factor

Due to deviation in form and position of a single parallel key, an unbalanced or uneven carrying of two parallel keys, that are arranged evenly around the circumference, occurs. Thus, the reduced load capacity of the parallel key is considered by the load factor $Kv$ . In practice, not more than two parallel keys are used because of the load distribution that is difficult to determine.

Kv = 1- iφ

One parallel key ( $i = 1$ ): $f = 1$
Two parallel keys ( $i = 2$ ): $f = 0,75$ for the determination of the equivalent surface pressure, $f=0,9$ for the determination of the maximum surface pressure

Compared to the calculation of the equivalent surface pressure, a higher load part $f$ can be estimated for the determination of the maximum surface pressure because a torque occurring in several load peaks leads to a higher load part by deformation on the parallel key and keyway ground. Using these load parts, ductile materials with pronounced yield point as well as sufficient manufacturing accuracy are required. For brittle materials (e.g., gray cast iron), there is no established knowledge about the load capacity using two parallel keys.

Load distribution factor

The load distribution factor $K λ$ takes an uneven load distribution into consideration along the keyway length as well as the ratio of load in and output. For using two parallel keys, the unbalanced carrying is considered by the following assumption:

One parallel key: $K λ = K λe$
Two parallel keys: $Kλ = 2⋅K λe - 1$

The factor $Kλ$ is dependent upon the kind of load in and output position. Regardless of the torque flow direction, three cases are distinguished. For a stepped hub, it means:

$D1$	Small outer diameter of stepped hub

$D2$	Large outer diameter of stepped hub

$a0$	Distance between the axial cutting planes through N and W

$c$	Width of the hub with $D2$ within the carrying part of the parallel key, i.e., $c ≤ ltr$

$D$ is the outer diameter of the hub or the outer diameter of the alternative cylinder with equal torsional stiffness. The alternative outer diameter is calculated as follows:

D = ∘--------D2---------- 4( D2)4(1 - c-)+ c- D1 ltr ltr

Depending on $a∕l 0 tr$ , the factor $K λe$ is determined by using the figures 3, 4 and 5 in DIN 6892. These diagrams are integrated into the calculation module and are valid for a specific ratio $a ∕l 0 tr$ $(a∕l=0;0,5;1) 0tr$ . For other ratios $a ∕l 0 tr$ , the values are determined from two diagrams by interpolation.

Friction factor

For an interference fit, part of the torque is transmitted by friction. The friction factor $KR$ considers that. But it is taken into consideration only for the calculation of the maximum effective surface pressure $pmax$ . For a dynamic load, an interference fit stops the occurrence of fretting corrosion. A clearance fit or interference fit adversely affects the shaft strength. For the determination of the friction factor, a minimum friction torque $TRmin$ of the interference fit is assumed. According to DIN 7190, this can be obtained for a hole without keyway. The joint pressure, that is reduced due to the parallel key in comparison to the hole without keyway, is considered by the factor $q$ . Thus, the friction torque, effective for the power transmission, is decreased. As a first approximation, $q = 0,8$ can be specified for a parallel key. With the maximum load peak torque $Tmax$ , occurring during the entire operation time, it applies:

Tmax > q⋅TRmin

KR = Tmax---q⋅TRmin- Tmax

For

Tmax ≤ q⋅TRmin

the load peak torque is transmitted by friction. In this case, the surface pressure, occurring in the parallel key, is not relevant. A check of the maximum surface pressure $pmax$ is not necessary according to DIN 6892. However, it is integrated into the calculation.

Please note: For brittle materials (e.g., gray cast iron), no interference fit is allowed.

Load direction change factor

Parallel key connections are only conditionally usable during changing the direction of torque. However, the rating life is limited if it comes to constant slipping between shaft and hub and thus to a deflection of the parallel key connection. There are two different cases:

Case 1: One-sided load of the parallel key during alternating load direction. The maximum torques in reverse direction (against the main load direction) do not exceed the effective part of the minimum friction torque. $TmaxR ¨uck ≤ q⋅TRmin : fW = 1$
Case 2: Alternating load of the parallel key during alternating load direction. The maximum torques exceed the effective part of the minimum friction torque in both directions. $Tmax > q ⋅TRmin and TmaxR¨uck > q ⋅TRmin : fW ≤ 1$

In case 2, the changes of load direction factor $fW$ is dependent upon the frequency $NW$ of changes of load direction for the parallel key. It can be determined according to DIN 6892, figure 6. Two cases are differentiated:

For alternating torques with a slow torque increase (e.g., reversing operation for carriages)
For alternating torques with a fast torque increase (e.g., high-dynamic servo drives using in robots for industrial environments)

Load direction changes, that occur due to special cases, have to be considered as well.

Load peak frequency factor

Load peaks occur when the torque clearly exceeds the equivalent torque $Teq$ . Special cases may occur due to starting impacts, short-circuit torques, emergency breaking torques, abrupt blockings etc. The frequency $NL$ of the load peaks has to be estimated during the entire operating time. For a single load peak, depending on the ductility of the material, the 1,3 to 1,5 times the permanent surface pressure is allowed. The progress of $fL$ for ductile and brittle materials over the frequency is shown in figure 5 according to DIN 6892.

Figure 8.3:

Load peak frequency factor $fL$

The support factor

Using the support factor $fS$ , a supporting effect can be considered that occurs for compressive stress components. From experience, the supporting effect for hubs is larger due to the higher stressed material volume than for shafts and parallel keys (see table: support and hardness factors for different materials).

The hardness influence factor

The hardness influence factor $fH$ is determined from the ratio of surface strength to core strength for case-hardened components. By the hardness influence factor, an increasing of the permissible surface pressure is considered (see table: support and hardness factors for different materials).


Support and hardness influence factors for different materials

Component	Material	$fs$	$fH$

Parallel key	Structural steel according to DIN EN 10 025	1,0	1,0
	Bright steel according to DIN 1652-4	1,0	1,0
	Heat-treated steel according to DIN EN 10 083-1 and DIN EN 10 083-2	1,0	1,0
	Case-hardened steel according to DIN 17210	1,0	1,15

Shaft	Structural steel according to DIN EN 10 025	1,2	1,0
	Heat-treated steel according to DIN EN 10 083-1 and DIN EN 10 083-2	1,2	1,0
	Case-hardened steel according to DIN 17 210	1,2	1,15
	Gray cast iron with lamellar graphite according to DIN 1693-1 and DIN 1693-2	1,2	1,0
	Steel casting according to DIN 1681	1,2	1,0

	Gray cast iron with lamellar graphite according to DIN 1691	1,0	-

Hub	Structural steel according to DIN EN 10 025	1,5	1,0
	Heat-treated steel according to DIN EN 10 083-1 and DIN EN 10 083-2	1,5	1,0
	Case-hardened steel according to DIN EN 17 210	1,5	1,15
	Gray cast iron with spheroidal graphite according to DIN 1693-1 and DIN 1693-2	1,5	1,0
	Steel casting according to DIN 1681	1,5	1,0

	Gray cast iron with lamellar graphite according to DIN 1691	2,0	-

8.5 Hints for method C

The calculation method C according to DIN 6892 is suitable only for a rough calculation of parallel keys. The method is based on the following simplifications:

Constant surface pressure over the keyway length and height of keyway wall
No consideration of chamfers or radii for the determination of supporting surfaces

Limitations:

$ltr≤1,3⋅d$ ; a length going beyond it does not make a considerable contribution for the torque transmission.
Number of parallel keys $i ≤ 2$
For an inversion of the torque direction, method C cannot be used. The method B has to be applied.

8.6 Example: Parallel keys according to DIN 6892

The calculation example shall support you with a fast start into the parallel key calculation module with its numerous possibilities. We prepared the following example for an introduction to this calculation module (see DIN 6892, Example E.2).

8.6.1 Start the calculation example

Please login with your user name and your password. Select the module ‘Parallel key’ through the tree structure of the Project Manager by double-clicking on the module or clicking on the button ‘New calculation’.

The calculation module is opened in a new window.

Figure 8.4:

A general overview

8.6.2 The input values

A strength calculation for the following shaft-hub-connection has to be accomplished. Please enter the following values into the input fields:

Diameter of shaft

= 60 mm

Application factor

= 1.75

Outer diameter hub $D 2$

= 120 mm

Calculation method

= B

Input data method B:

Kind of load

= Alternating torque with a slow torque increase

Changes of load direction

= $106$

Max. reverse torque $T maxRev$

= 3900 Nm

Small outer diameter of stepped hub $D 1$

= 120 mm

Big outer diameter of stepped hub $D 2$

= 120 mm

Width of hub with $D 2$ internal $l tr$ ( $c$ )

= 91 mm

Axial distance between load in and output position $a 0$

= 45.5 mm

Chamfer or radius on the shaft keyway edge $s 1$

= 1.0 mm

Chamfer or radius on the hub keyway edge $s 2$

= 1.0 mm

Operation nominal torque $T nom$

= 1.950 Nm

Min. frictional torque $T Rmin$

= 1.250 Nm

Max. load peak torque $T max$

= 3.900 Nm

Load peaks $N L$

= 500

Material shaft

= C45 hardened and tempered

Material hub

= 34CrNiMo6 hardened and tempered

Parallel key

= DIN 6885.1 AB 18 x 11 x 100

Material parallel key

= 34CrNiMo6 hardened and tempered

Standard length parallel key

= 100 mm

Number of parallel keys

= 1

8.6.3 The calculation

Please note: While you enter the data into the input fields, the calculations are accomplished. Thereby it can happen that the input fields are marked in red. Nevertheless, continue to enter the complete input data.

Figure 8.5:

Input value

Please note: If you right-click into an input field, you can change the unit of measurement. A context menu is opened. The both arrows mark the current setting. The current field value will be converted automatically into the selected unit.

Calculation method B

Because of the reversal of the direction, a rough calculation according to method C is not possible. Select the calculation method B.

Figure 8.6:

Calculation method B

When selecting the calculation method for the first time, the window ‘Input data method B’ opens immediately.

Enter the further values here and confirm your inputs with ‘OK’. If you would like to change your input values later, please click on the button ‘Input values method B’ and the input mask appears again.

Figure 8.7:

Values for the calculation method B

Input of load peaks

The number of load peaks is ‘500’. Select ‘User defined input’ from the listbox and enter the value ‘500’.

Figure 8.8:

Specification of load peaks

Inputs for the shaft

Define a material for the shaft. For our example the material ‘C45 hardened and tempered’ is required.

Figure 8.9:

Shaft

The calculation module offers an easy possibility to choose the material directly from the listbox. But if you click on the button ’Material’, you will get to the material database. Here you will receive further information about the material source, kind of material, yield point, hardness factor $f H$ as well as the support factor $f H$ . After you have selected the material ‘C45 hardened and tempered’, please confirm with the button ‘OK’. Then you will get to the main mask.

Figure 8.10:

Material database

User defined material

Use the possibility to specify your own defined material. Select the entry ’User defined’ from the listbox. You can add a comment or change the kind of material. Enter your own input values for the hardness factor $f H$ or for the support factor $f S$ .

Figure 8.11:

User defined inputs

Inputs for the hub

Determine the material of the hub. The required material is here ‘34CrNiMo6 hardened and tempered’. You can select the material directly from listbox. In case you need further information, please click on the button ‘Material’. Then you get to the material database of the hub. Select the material ‘34CrNiMo6 hardened and tempered’ and confirm with the button ‘OK’.

The material is taken over to the main mask.

Figure 8.12:

Hub

The button ‘Material’ allows you to define your own material.

Input data for the parallel key

For a comfortable working, a parallel key selection according to DIN 6885 sheet 1 to 3 is available. Here you can choose the parallel key geometry as well as the size. Find all appropriate standardized lengths for the parallel keys. The dimensions of the parallel key are as follows:

Parallel key: DIN 6885.1 AB 18 x 11 x 100

Standard length

To determine the standard length of the parallel key, select the value ‘100’ from the listbox.

Figure 8.13:

Standard length

The length is taken over to the geometry of the parallel key.

Figure 8.14:

Geometry

Selection of the parallel key geometry

Click on the button ‘Parallel key’ to select the shape of the parallel key.

Figure 8.15:

Button ‘Parallel key’

A new window is opened. The appropriate parallel key will be displayed immediately.

Figure 8.16:

Selection dialog for the parallel key

Select the parallel key geometry ‘DIN 6885 sheet 1-8/1968’ as well the shape ‘AB’ from the appropriate listbox.

Figure 8.17:

Selection of the parallel key

Confirm with the button ‘OK’ to take over the values into the main mask.

Figure 8.18:

Dimensions of the parallel key

Please note: The input of non-standard parallel keys

You have got the possibility to calculate non-standard parallel keys. You can define parallel keys different from the standard. The parallel keys A to J are also available here. In case you would like to define a non-standard parallel key, click on the button ‘Parallel key’ and you will get to the selection dialog again. Now activate the option ‘Own input’ and choose the appropriate dimension from the list or enter the dimensions directly.

Figure 8.19:

Option ‘Own input’

Selection of a material

Select the material ‘34CrNiMo6 hardened and tempered’ directly from the listbox.

Figure 8.20:

Material for the parallel key

If you need further information on the material, click on the button ‘Material’ and you will get to the material database.

Figure 8.21:

Button ‘Material’

The supporting length $l tr$ is calculated automatically from the already specified standard length.
You can use the listbox to select the number of parallel keys. For our calculation example we specify one parallel key.

Figure 8.22:

The supporting length and number of parallel key

Please note: The supporting length for non-standard parallel keys

It is possible to define a supporting length for non-standard parallel keys. Select the option ‘User defined input’ from the listbox for the standard length. Now you can enter your own value into the input field for the supporting length.

Figure 8.23:

User defined input

It is possible to specify different supporting lengths for the shaft and for the hub. Activate the input field for the supporting length for shaft and hub.

Figure 8.24:

The supporting length for shaft and hub

8.6.4 The calculation results

The safeties of the operation load and at the maximum load for all three components (shaft, hub, and parallel key) are determined and displayed immediately in the result panel during the input. Which means that after every input of data, the results are calculated again. You will get the results for the equivalent pressure and for the pressure at load peak as well as the safety at operation load and the safety at peak load.

Figure 8.25:

The calculation results

You can find also some additional information about your results in the message window.

Figure 8.26:

The message window

In our calculation example the safeties for the shaft, the hub and the parallel key are marked in red. This means that the minimum safeties are not fulfilled. In addition, you get also an appropriate message in the message window. The parallel key is not suitable for our calculation example.

8.6.5 The documentation: The calculation report

Use the button ‘Report’ to generate the calculation report very fast. This report contains the calculation method, all input values as well as the detailed results.

Figure 8.27:

The button ‘Report’

The calculation report contains a table of contents. You can navigate through the report via the table of contents that provides links to the input values, results and figures. The report is available in HTML and PDF format. Calculation reports, saved in HTML format, can be opened in a web browser or in Word for Windows.

Figure 8.28:

The calculation report for the parallel key

To save the report in the HTML format, please select ‘File’ $→$ ‘Save as’ from your browser menu bar. Select the file type ‘Webpage complete’, then just click on the button ‘Save’.
If you click on the symbol ‘Print’, then you can print the report very easily.
If you click on the symbol ‘PDF’, then the report appears in the PDF format. If you right-click on the PDF symbol, you should see the ‘Save Target As’ option. Click on that option and you will see the dialog box for saving the report.

8.6.6 How to save the calculation

After the accomplishment of your calculation, save the calculation either on the eAssistant server or on your own workstation locally. Click on the button ‘Save’.

Figure 8.29:

The button ‘Save’

If you have activated the option ‘Enable file save local’ in the Project Manager and the option ‘Local’ in the calculation module, a standard Windows dialog for saving the file on your workstation appears.

Please note: You must not forget that the calculation module has to be closed to activate the option ‘Enable file save local.’

Figure 8.30:

Windows dialog to save the file

In case you have not activated this option, a new window is opened and you can save the calculation on the eAssistant server (find further information in the chapter ‘The general functions’).

Figure 8.31:

Save the calculation

Please enter a name into the input field ‘Filename’ and click on the button ‘Save’. Then click on the button ‘Refresh’ in the Project Manager. Your saved calculation file is displayed in the window ‘File’.

8.6.7 The dimensioning functions

The button for the dimensioning functions is marked by a calculator symbol and is located next to the input fields. If you click on the dimensioning buttons, you get a suggestion for an appropriate input value. There the calculation of the value takes place that the given minimum safety is just fulfilled.

By the following dimensioning buttons you are optimally supported:

Dimensioning of the shaft diameter

Dimensioning of the operation nominal torque

Dimensioning of the maximum load peak torque

Dimensioning of the standard length

Dimensioning of the supporting length

Minimum safety: The dimensioning of the shaft diameter

The shaft diameter has to be determined so that the given safety of ‘1.2’ for the parallel key connection is achieved. Click on the dimensioning button (calculator) for the shaft diameter.

Figure 8.32:

The dimensioning button for the shaft diameter

Now the new shaft diameter is determined.

Figure 8.33:

New shaft diameter

The shaft diameter is now $d$ = 111.88 mm. With it the minimum saftey of ‘1.2’ is achieved and the parallel key is suitable for this application.

Figure 8.34:

The result

Because of its larger diameter, a new parallel key size is determined automatically.

Figure 8.35:

Parallel key

In case you click on the button ‘Parallel key’, the larger parallel key is displayed automatically.

Figure 8.36:

New parallel key

8.6.8 The button ‘Redo’ and ‘Undo’

The button ‘Undo’ allows you to reset your input to an older state. The button ‘Redo’ reverses the undo.

Figure 8.37:

The ‘Redo’ and ‘Undo’ button

8.6.9 The button ‘Options’

Click on the button ‘Options’.

Figure 8.38:

The ‘Options’ button

The ‘Options’ button allows you to change some general settings such as the minimum safety as well as the number of decimal places.

Figure 8.39:

Options

Our manual is improved continually. Of course we are always interested in your opinion, so we would like to know what you think. We appreciate your feedback and we are looking for ideas, suggestions or criticism. If you have anything to say or if you have any questions, please let us know via telephone +49 (0) 531 129 399-0 or email eAssistant@gwj.de.

[Next Chapter] [Previous Chapter] [Previous Chapter (End of Page)] [Top of Page] [Contents]

Chapter 8Parallel key calculation according DIN 6892

8.1 General

8.2 The field of application of DIN 6892

8.3 Geometry

8.4 The loads

Surface pressure

Permitted surface pressure

The application factor

The load factor

Load distribution factor

Friction factor

Load direction change factor

Load peak frequency factor

The support factor

The hardness influence factor

8.5 Hints for method C

Limitations:

8.6 Example: Parallel keys according to DIN 6892

8.6.1 Start the calculation example

8.6.2 The input values

8.6.3 The calculation

Calculation method B

Input of load peaks

Inputs for the shaft

User defined material

Inputs for the hub

Input data for the parallel key

Standard length

Selection of the parallel key geometry

Selection of a material

8.6.4 The calculation results

8.6.5 The documentation: The calculation report

8.6.6 How to save the calculation

8.6.7 The dimensioning functions

Minimum safety: The dimensioning of the shaft diameter

8.6.8 The button ‘Redo’ and ‘Undo’

8.6.9 The button ‘Options’

Chapter 8
Parallel key calculation according DIN 6892