Predicting the Rigidity
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Selection Criteria Predicting the Rigidity Predicting the Rigidity Selecting a Radial Clearance (Preload) Preload is an internal load applied in advance to the rolling elements (balls, rollers, etc.) of an LM block in order to increase its rigidity. Table 12: Types of Radial Clearance Normal clearance Clearance C1 (light preload) Clearance C0 (medium preload) ● The loading direction is fixed, ● An overhang load or moment ● High rigidity is required and impact and vibrations are miniload is applied. vibrations and impact are apmal and 2 rails are installed in ● The LM Guide is used in a plied. parallel. single-rail configuration. ● Heavy-cutting machine tools ● Ve r y h i g h p r e c i s i o n i s n o t ● Light load and high accuracy required, and the sliding resisare required. tance must be as low as possible. • • • • • • • • • Beam-welding machines Book-binding machines Automatic packaging machines XY axes of general industrial machinery Automatic sash-manufacturing machines Welding machines Flame cutting machines Tool changers Various kinds of material feeders • Grinding machine table feed axes • Automatic coating machines • Industrial robots • Various kinds of high-speed material feeders • NC drilling machines • Vertical axes of general industrial machinery • Printed circuit board drilling machines • Electric discharge machines • Measuring instruments • Precision XY tables • Machining centers • NC lathes • Grinding stone feed axes of grinding machines • Milling machines • Vertical/horizontal boring machines • Tool rest guides • Vertical axes of machine tools Since the radial clearance of an LM Guide greatly affects the running accuracy, load carrying capacity, and rigidity of the LM Guide, it is important to select an appropriate clearance according to the application. In general, the service life and accuracy are favorably affected by selecting a negative clearance (i.e., applying a preload1) while taking into account possible vibrations and impacts generated from reciprocating motion. For specific radial clearances, contact THK. We will help you select the optimal clearance according to the conditions. The clearances of all LM Guide models (except models HR, GSR, and GSR-R, which are separate types) are adjusted as specified before s

Service Life with a Preload Considered When using an LM Guide under a medium preload (clearance C0), it is necessary to calculate the service life while taking into account the magnitude of the preload. To identify the appropriate preload for any selected LM Guide model, contact THK. Rigidity When a load is applied to an LM Guide, the bearings and LM block will undergo elastic deformation within the allowable load range. The ratio of displacement to applied load is referred to as “rigidity.” The radial internal clearance (preload) for the LM Guide can be specified in order to reduce...

Selection Criteria Predicting the Rigidity Radial Clearance Standard for Each Model Radial Clearances for Model SSR Radial clearance Indication symbol Light preload Radial Clearances for Models SHS and SCR Unit: m Indication symbol Light preload Medium preload Radial Clearances for Models SVR/SVS, NR-X/ NRS-X, and NR/NRS Unit: m Indication symbol Light preload Note) Model RSX includes types 5, 7, 9, 12, and 15. The Model RSX-M1 is available in models 9, 12, and 15. Radial Clearances for Model SHW Indication symbol Light preload Medium preload Indication symbol Light preload

Radial Clearances for Models HSR, CSR, HSR-M1, and HSR-M1VV Unit: m Indication symbol Model No. 8 Indication symbol Model No. 45 Radial Clearances for Models SR and SR-M1 Radial Clearances for Model HRW Indication symbol Model No. 15 Indication symbol Model No. 12 Radial Clearances for Models RSR, RSR-W, and RSR-M1 Unit: m Indication symbol Model No. 2

Selection Criteria Predicting the Rigidity Radial Clearances for Model JR Radial Clearances for Models HCR and HMG Unit: m Indication symbol Model No. 12 Light preload Radial Clearances for Model NSR-TBC Indication symbol Model No. 20 Radial Clearances for Model HSR-M2 Unit: m Indication symbol Model No. 15 Light preload Radial Clearances for Models SRG and SRN Unit: m Indication symbol Model No. 15 Super heavy preload CN2 — Note) Heavy preload and super heavy preload are available only for Model SRG-C/LC/ SLC and Model SRN-C/LC/SLC. Contact THK if you desire a heavy preload or super...