MGB EN

MGB | Data sheet

STATIC LOAD AND SERVICE LIFE

■ Calculating the applied load The MGB rail and block are capable of receiving loads and moments in all directions whether they are generated by the mounting orientation and position, the location of the center of gravity of the moving object, the position of the thrust, the acceleration, or an additional effort, for example the cutting resistance.

M X

C C 0ax

M Y

Axial load

Radial load

Radial load

C C 0rad

M Z

M Y moment in pitching direction M Z moment in the yawing direction M X moment in the rolling direction

Fig.25

Fig.26

■ Moment equivalence When the space to install the MGB guide is limited, you may have to use only one MGB block, or two MGB blocks in close contact with each other. In such a setting, the load distribution is not uniform. As a result, an excessive load is applied in localized areas (i.e., both ends) as shown in Fig. 27. Continued use under such conditions may result in flaking in those areas, consequently shortening the service life. In such a case, calculate the actual load by multiplying the moment value by any one of the equivalent-moment factors. Close contact refers to a center distance between blocks less than twice the block length L.

Moment load

Moment load

Rows of balls under a load

Rows of balls under a load

MGB rail

Ball displacement line

Load distribution curve

Load distribution curve

Ball displacement line

Maximum ball deflection

Maximum applied load on a ball

Fig.27

Ball load when a moment is applied.

An equivalent-load equation applicable when a moment is applied to an MGB guide is shown below.

P: equivalent load per MGB guide (N) K: equivalent moment factor M: applied moment (Nm)

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