LM Guide THK - Industrial Technologies

Индастриал Технолоджис www.industrial‐technologies.com.ua +38 044 498 21 94Characteristics of Models NR and NRS[Increased Rigidity in Major Load Directions]The structure with a contact angle of 90° used inmodel NR differs from that with a 45° contactangle also in rigidity. Under the same radial loadP, the displacement in the radial direction withmodel NR having a contact angle of 90° is 44%less than the 45°.Fig.2 shows the difference in radial load and displacement.Accordingly, where high rigidity inthe radial direction is required, model NR ismore advantageous.[Increased Rigidity in the Lateral and ReverseradialDirections]Since with LM Guide model NR, the distance"H" between the rail bottom and the lowergrooveballs (balls receiving lateral loads) isshort, the ratio between the rail width "W" andthe distance "H" is small, and the distance "T"between the LM rail mounting bolt seat and theLM rail bottom is short. Accordingly, the deformationof the LM rail under a lateral load is minimal,and the rigidity in the lateral directions isincreased.Since the dimension "B" of the LM block is shortand the thickness "A" is large, the lateral extensionof the LM block under a reverse radial orlateral load is minimized. This structure allowsthe rigidity in the reverse radial direction to beincreased.In comparison to the old model with the samemodel number, the ball diameter of NR issmaller and the number of effective balls isapproximately 1.3 times greater, thus increasingthe static rigidity.Deflection in radial direction δ’1Deflection δ 190°P P P1Deflection δ 245°Deflection in radial direction δ’2Contact structure of 90° Contact structure of 45°(Model NR)Fig.1 Deflection under a Radial LoadLoad and deflection when contact angles are not the same (Da=6.35mm)(deflection per 24 balls)25When the contact angle is 45°2015105When the contact angle is 90°0 2 4 6 8 10Applied load (kN)Deflection (µm)Fig.2 Radial Load and Deflection (normal clearance, no preload)HWRadial type structureAFig.3 Cross Section of Model NRTBIndustrial TechnologiesA1-172