RD Square Guideway

DLY RD Series is a heavy-duty roller linear guideway designed for machine tools and industrial equipment requiring high rigidity, high load capacity and stable precision motion. Unlike conventional ball-type guideways, the RD Series uses cylindrical rollers as the rolling elements. The resulting line-contact structure reduces elastic deformation under load and improves the rigidity of the linear motion system.

The series includes RDH square-type blocks and RDW flange-type blocks in sizes 15, 20, 25, 30, 35, 45, 55 and 65. Standard and long blocks are available for different load and mounting requirements. Typical applications include CNC machining centers, grinding machines, heavy-duty cutting equipment, injection molding machines and large gantry machines.

As a linear guideway manufacturer, DLY can supply matched rails and blocks, customized rail lengths, multiple accuracy grades and preload options. For other heavy-load motion solutions, see our Heavy Duty Linear Guide Rails range.

Product Specifications

Model Code

A complete model code identifies the block shape, nominal size, block length and mounting method. Supplying the complete code helps DLY confirm the correct rail-and-block assembly.

Examples: RDH25CA identifies a size 25 square-type standard block mounted from the top. RDW35HC identifies a size 35 flange-type long block that can be mounted from the top or bottom.

Block Types

RDH Square-Type Specifications

RDH blocks are available in standard CA and long HA configurations. Long blocks provide higher dynamic and static load ratings by increasing the effective roller contact length.

RDW Flange-Type Specifications

RDW blocks use a wider flange body and support mounting from the top or bottom. CC is the standard-length block, while HC is the long block for applications requiring increased load capacity.

The listed load ratings and dimensions are product selection data. Final rail length, mounting-hole position, accuracy and preload should be confirmed before ordering.

Rail Specifications

Roller Guideway Structure

Cylindrical rollers form line contact with the hardened raceways, while steel balls mainly form point contact. Under external load, the roller contact structure produces less elastic deformation and gives the guideway greater rigidity.

The raceways are arranged with a 45-degree contact angle so that the guideway can carry radial, reverse-radial and lateral loads. This four-row arrangement provides high load capacity and rigidity in all four principal directions.

• Rolling circulation system: guide rail, block body, cylindrical rollers, end caps and return paths.
• Lubrication system: grease nipple and internal lubrication passages for periodic maintenance.
• Sealing system: end seals and bottom seals help reduce the entry of dust and machining debris.
• Optional protection: additional scrapers or protection accessories can be selected according to the working environment.

Product Advantages

RD and HD Selection

RD and HD are both suitable for load-bearing linear motion, but they use different rolling elements and are intended for different rigidity requirements.

RD is generally selected when rigidity and deformation control are the main concerns. HD may be more suitable when the application requires smooth general-purpose motion without the higher rigidity of a roller guideway.

Accuracy and Preload

RD Series roller linear guideways are available in H, P, SP and UP accuracy grades. The required grade should be selected according to positioning accuracy, running parallelism, machine structure and assembly conditions.

Preload affects system rigidity, running resistance and service life. The appropriate preload should be confirmed according to the load, mounting accuracy, operating speed and required rigidity rather than selected only by the highest available level.

Applications

Production and Inspection

DLY controls guide rail processing and block assembly to maintain consistent running performance. The production process includes raw material preparation, drilling, heat treatment, straightening, profile grinding, surface grinding, cleaning, assembly and inspection.

Inspection focuses on rail width, rail height, block assembly height, raceway condition, running parallelism, straightness and surface quality. Matched rail-and-block assemblies are also checked for smooth movement, stable preload and abnormal roller jamming before packaging.

Guideways receive anti-rust protection and suitable packaging for long-distance transportation. Long rails can be packed in reinforced wooden cases according to their length and order quantity.

Ordering Information

To select and quote an RD roller linear guideway, please provide the following information:

• Complete block model, such as RDH25CA or RDW35HC
• Required rail length
• Number of blocks per rail
• Number of rails
• Accuracy grade
• Preload or rigidity requirement
• Mounting-hole arrangement or drawing, when specified
• Machine application, operating load and speed if selection assistance is required

For customers without a complete model, DLY can recommend a suitable configuration after confirming the load direction, moving mass, mounting space, required rigidity and operating conditions.

FAQ