NSK7906A5TYDULP4Angular Contact Ball Bearing Pair – 30 mm Bore, 47 mm OD, 9 mm Wide, 25° Contact Angle, ABEC 7, Light Preload, Thin 719 Section

Product Description

What this part is:

NSK 7906A5TYDULP4 super-precision angular contact ball bearings, supplied as a universally ground matched pair. Bore Diameter: 30 mm. Outside Diameter: 47 mm. Overall Width: 9 mm per bearing, 18 mm across the pair. Contact Angle: 25°. Precision Class: ABEC 7 / P4. Preload: Light, 78 N. Cage Type: Ball-guided. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. Number Of Rows: 1 per bearing. Item Weight: 0.05 kg (0.11 lb) each. Series: 19. Unit Quantity: 2 Pcs. GTIN: 029176075063.

Decoding the designation:

79 — ISO dimension series 19, the extra-thin spindle section. A 30 mm bore inside a 47 mm outside diameter and only 9 mm wide.

06 — bore code. Multiplied by five it gives the 30 mm bore.

A5 — 25° contact angle, the steeper of NSK’s two standard super-precision angles.

TY — ball-guided cage. The cage rides on the ball complement rather than on a ring land.

DU — universally ground paired unit, matched at manufacture.

L — light preload, 78 N axial for this size and angle.

P4 — ISO Class 4, equivalent to ABEC 7.

What these specs mean in practice:

Dynamic Load Rating: 7,850 N per bearing. Static Load Rating: 5,950 N per bearing. The 19-series section trades capacity for radial envelope, which is the reason to specify one: it fits a 30 mm shaft into a 47 mm housing bore.

Contact Angle: 25°. Steeper than the 15° execution of the same size, so it takes more thrust per bearing and runs a little slower. The 15° 7906C on this envelope carries 8,300 N dynamic against this bearing’s 7,850 N, and takes correspondingly less thrust.

Preload: Light, 78 N, giving 77 N/µm of axial stiffness across the pair. Medium on this size is 150 N and heavy is 290 N.

Cage Type: Ball-guided. The cage is centred by the balls, which keeps cage-to-land friction out of the running torque.

Lubricant: grease or oil.

Mounting data:

Chamfer r min: 0.3 mm. Chamfer r1 min: 0.15 mm. Shaft abutment d1 min: 32.5 mm. Housing abutment D1 max: 44.5 mm, D2 max: 45.8 mm. Effective load centre a: 13.5 mm. Internal volume: 2.3 cm³, which sets the grease charge. Pitch circle diameter for lubrication jets: 36.1 mm.

The high point of radial runout is marked with a burnished spot on the inner ring face and a V line on the outer diameter; the V also indicates the direction of the contact angle.

Grease quantity runs at 30 percent of internal volume at low and medium speeds and 10 to 15 percent above 80 percent of the set’s maximum speed.

Quantity and configuration:

Two bearings, factory matched. Unit Quantity: 2 Pcs. Mounting Arrangement: universally matchable, back-to-back, face-to-face or tandem.

Interchange guidance:

Every cross below sits on the same 30 x 47 x 9 mm envelope in the ISO 719 section. Where a cross runs a 15° contact angle instead of 25°, that is stated: it is a related size, because thrust capacity and speed both move with the angle.

RHP builds this bearing on the same NSK drawing. Fafnir numbers this envelope in the 9300 series, so the cross is a 3MM9306WI and not a 9100-series number.

Searchable forms of the number: 7906A5TYDULP4, 7906-A5-TY-DUL-P4, 7906 A5 TY DUL P4, 7906E, 71906A5, 71906.