Significant advantages of the THK SHW Caged Ball LM Guides

November 9, 2022

THK's SHW wide, low centre of gravity type caged ball LM guides set the new benchmark for LM guides due to its four-way equal load, self-adjustment capability and low dust generation. 

An LM rail and LM block hold four rows of raceways in which the ball bearings are housed. Ball cages and endplates in the LM block allow the ball bearings to circulate. 

Its wide LM rail and low centre of gravity makes it suitable for space saving locations and large Mc moment rigidity. 

Its four-way equal load allows the LM guide to be used in all orientations and in various applications as each row of balls are placed at a contact angle of 45 degrees so that the LM block's rated loads are uniform in the radial, reverse-radial and lateral directions. 

A highly accurate, smooth linear motion is achieved through the LM guide's self-adjustment capability via a face-to-face configuration of THK's unique circular-arc grooves, which allows a mounting error to be absorbed even under a preload. 

Additionally, friction is removed between the balls and lubricant is retained due to the use of ball cages, resulting in low dust generation. 

The SHW is able to receive a large moment with a single rail and the geometrical moment of inertia of the LM rail is large while the lateral rigidity is high. 

Further, the SHM model's major applications include: 

  • Loader 
  • Machining centre 
  • NC lathe 
  • Robot 
  • Wire-cut electric discharge machine 
  • APC 
  • Measuring instrument 
  • Construction equipment