HIWIN RGH-CA High Rigidity Roller Linear Guideway Block

The HIWIN RGH-CA is the square, heavy load block of the RG series, a roller type linear guideway that uses rollers instead of steel balls. The rollers contact the raceway along a line at 45 degrees, which gives very high rigidity and load capacity in all four load directions, and the RG is aimed at CNC machining centres, heavy cutting machines and grinders.

A roller guideway for the highest rigidity and load

According to the catalog, the roller has a greater contact area than a ball, so the roller guideway has a higher load capacity and greater rigidity, and the elastic deformation under load is greatly reduced. The four rows are arranged at a 45 degree contact angle, which gives equal load ratings in the radial, reverse radial and lateral directions, and the contact pressure is spread over a line, which cuts stress concentration and lengthens the running life. HIWIN designed the block and rail with FEM analysis and a recirculation path for smooth motion.

Test data in the catalog: an RGH35CA at 15 kN with ZA preload ran 1135 km without fatigue flaking against a nominal life of 1000 km, and an RGW35CC ran 15000 km at 120 m/min with no flaking. HIWIN lists automation systems, transportation equipment, CNC machining centres, heavy duty cutting machines and CNC grinding machines as main applications.

Technical specifications

Size range and load ratings of the RGH block

H is the assembled height, W the block width, L the block length, then C and C0 and the block and rail mass. The RGL, RGW, RGS and RGF blocks are in the catalog extract.

Ordering code, preload and selection

The RG model number lists the series, block type, size, load type, block mounting, blocks per rail, rail mounting, rail length, accuracy, preload, rails per matched set and dust protection, as in RGW35CCE2R1640EZAPII+KK/E2+RC. Precision codes start at H, since there is no normal grade in this series.

Roller guideways run best with correct alignment, so check the flatness and parallelism of the mounting surfaces against the catalog. Choose ZA for machine tool axes, Z0 where load is light and the direction fixed, and ZB where super high rigidity is needed with vibration and impact. Before ordering, confirm the size, block type, preload, accuracy, rail length and E values, and send the label data of the guideway you replace.

Where the RGH-CA block is used

The RGH-CA block is chosen where a machine axis must carry heavy loads while staying stiff under cutting forces. Typical applications are the X, Y and Z axes of CNC machining centres, heavy duty cutting machines and CNC grinding machines, as listed by HIWIN, along with gantry axes, transfer units in automation systems and heavy transportation equipment. Because the rollers carry load along a line rather than at a point, the block deflects less under load than a ball type guide of similar size, which helps machining accuracy and surface finish and reduces chatter in heavy cuts.

The square RGH body mounts from the top, which suits machine tables and carriages where the block is bolted down into the moving part. Where the mounting must be made from below or space is limited in height, the flange and low body types in the same series are the alternatives to compare.

Selecting size, load type and preload

Start from the loads and moments on each block, including cutting forces, the weight of the moving part and acceleration forces, then compare them with the dynamic and static load ratings in the table. The C heavy load blocks suit most machine axes, while the H super heavy load blocks in the same size give higher ratings within the same rail and height. Choose the accuracy class to match the machine requirement, and the preload class according to the guidance above: lighter preload for lightly loaded axes and heavier preload where rigidity under vibration and impact is the priority.

When replacing an existing guideway, keep the same block type, size, load type and rail length so that the mounting holes and assembled height match the machine. The label data on the existing rail and block is the most reliable starting point.

Installation practice

Roller guideways are sensitive to mounting errors, so preparation of the machine base matters as much as the guideway itself. Clean the mounting surfaces, remove burrs, and check flatness and parallelism against the catalog values before fitting the rail. Push the rail against its reference edge, tighten the bolts in sequence, then fit the blocks and check that they move smoothly along the full length. Grease or oil the blocks before the first run and set up a routine to check lubrication at the interval given in the specification table.

Workshop and site conditions in Oman

Machine shops and fabrication plants in Oman often work in hot, dusty conditions, and fine sand and metal chips are the main enemies of linear guideways. Select the dust protection options listed in the specification table to suit the environment, keep the machine guarding in good condition, and clean the rail regularly. High temperature also shortens lubricant life, so a shorter relubrication interval is sensible during the hottest months, and spare rails and blocks should be stored in their packaging in a cool, dry place.

Documents and quotation

The linked PDF is the RG chapter of the HIWIN Linear Guideway Catalog G99TE24-2410, unchanged. More items are in our product range. Seven Star LLC is an independent supplier in Muscat; send the RG model number, rail length, quantity and delivery location with your RFQ.