Cross-Roller Ring Series Compact, Highly Rigid Swivel Bearings Achieving a Superb Rotation Accuracy For details, visit THK at www.thk.com Product information is updated regularly on the THK website. CATALOG No.382-3E

▼Cross-Roller Ring Series

Cross-Roller Ring Inner ring Spacer retainer Structure of the Cross-Roller Ring Model RB With the Cross-Roller Ring, cylindrical rollers are arranged crosswise, with each roller perpendicular to the adjacent roller, in a 90° V groove, separated from each other by a spacer retainer. This design allows just one bearing to receive loads in all directions including, radial, axial and moment loads. Since the Cross-Roller Ring achieves high rigidity despite the minimum possible dimensions of the inner and outer rings, it is optimal for applications such as joints and swiveling units of industrial robots,...

• Significantly Increased Rigidity (Three to Four times Greater) Unlike the thin angular ball bearings installed in double rows, the cross array of rollers allows a single Cross-Roller Ring unit to receive loads in all directions, increasing the rigidity to three to four times greater than the conventional type. Moment Rigidity Diagram Cross-Roller Ring Angular ball bearing • Large Load Capacity (1) Compared with the conventional steel sheet retainers, the spacer retainer allows a longer effective contact length of each roller, thus significantly increasing the load capacity. The spacer retainer...

Cross-Roller Ring Outline Cross-Roller Ring Product Overview Model RU (Integrated Inner/Outer Ring Type) Since the mounting holes are provided, this model does not require a presser flange or housing. In addition, because it has an integrated inner/outer ring structure and is equipped with washers, its performance is minimally affected by the mounting procedure, ensuring stable rotation accuracy and torque. This model can be used for both inner-ring rotation and outer-ring Model RB (Separable Outer Ring Type for Inner Ring Rotation) Being the basic model of the Cross-Roller Ring, its outer ring...

(^Selection of a Cross-Roller Ring The following diagram shows a typical procedure for selecting a Cross-Roller Ring. t Inner ring rotation — model RB t Outer ring rotation — model RE t Mounting space — models RA and RA-C ,.y # Selecting a bearing size service life mounting section ) Accuracy grade Rotational torque Lubrication method Rated Life The service life of a Cross-Roller Ring is obtained from the following equation. Rated life (The total number of revolutions that 90% of a group of identical Cross-Roller Ring units independently operating under the same conditions can achieve without...

CROSS ROLLER RING OUTLINE Cross-Roller Ring Product Overview Static Safety Factor The basic static load rating Co refers to the static load with constant direction and magnitude, under which the calculated contact stress in the center of the contact area between the roller and the raceway where the maximum load is applied is 4,000 MPa (if the deformation exceeds this level, it will affect the rotation). This value is indicated as Co in the dimensional table. When a load is statically or dynamically applied, it is necessary to consider the static safety factor as shown below. fs : Static safety...

(^Accuracy Standards The Cross-Roller Ring is manufactured with the accuracy and the dimensional tolerance showing in the Tables 4 to 13. Table 4 Rotation Accuracy of the Inner Ring of Model RU_unit: Mm Note: The standard rotation accuracy of model RU is grade P5 (not expressed in the model number) Table 5 Rotation Accuracy of the Outer Ring of Model RU Unit: ¿uní Note: The standard rotation accuracy of model RU is grade P5 (not expressed in the model number)

CROSS ROLLER RING OUTLINE Cross-Roller Ring Product Overview Table 6 Rotation Accuracy of the Inner Ring of Model RB_unit: Mm Table 7 Rotation Accuracy of the Outer Ring of Model RE Unit: yum Table 8 Rotation Accuracy of the Inner Ring of Models RA and RA-C unit: M m Note: If higher accuracy than the above values Is required for the Inner ring In rotation accuracy for models RA and RA-C, contact THK. Table 9 Rotation Accuracy of the Outer Ring of Model RA-C Unit: yum Note: The rotation accuracy of the outer ring for model RA-C Indicates the value before separation.

Table 10 Dimensional Tolerance of the Bearing Inner Diameter_unit: Mm Note 1 : The standard inner diameter accuracy of models RA, RA-C and RU is grade 0. For higher accuracy than grade 0, contact THK Note 2: "dm" represents the arithmetic average of the maximum and minimum diameters obtained in measuring the bearing inner diameter at two points Note 3: For accuracy grades of the bearing inner diameter with no values indicated in the table, the highest value among the low accuracy grades applies Table 11 Dimensional Tolerance of the Bearing Outer Diameter_unit: Mm Note 1 : The standard outer diameter...

CROSS ROLLER RING OUTLINE Cross-Roller Ring Product Overview Table 12 Tolerance of the Inner/Outer Ring Width of Model RU unit: M m Table 13 Tolerance of the Inner/Outer Ring Width of Models RB and RE (Common to All Grades)_unit: Mm Note: All B and B1 steps of models RA and RA-C are manufactured with tolerance between -0.120 and 0

(^Accuracy Standards for the USP Series [Example of Rotation Accuracy of the USP Series] The rotation accuracy of the USP-Grade Series achieves the ultra precision grade that surpasses the world's highest accuracy standards, such as JIS Class 2, ISO Class 2, DIN P2 and AFBMA ABEC9. Radial runout Axial runout Rotation accuracy of the inner ring of model RB50040CC0USP Axial runout Radial runout Rotation accuracy of the outer ring of model RE50040CC0USP [Accuracy Standards for the USP Series] The USP-Grade Series of the Cross-Roller Ring models RU, RB and RE are manufactured with the accuracy and...

CROSS ROLLER RING OUTLINE Cross-Roller Ring Product Overview Radial Clearance Tables 16, 17, 18 and 19 show the radial clearance of model RU, the standard type of models RB/RE, the USP-Grade Series of models RB/RE, and models RA/RA-C (thin type), respectively. Table 16 Radial Clearance of Model RU Note: Clearance CC0 of model RU Is expressed In starting torque. The starting torque value for clearance CC0 does not Include a seal Table 18 Radial Clearance of the USP-Grade Series ol Table 17 Radial Clearance of Models RB and RE Unil: Mm Table 19 Radial Clearance of Models RA and RA-C unit: Mm