Ringfeder RfN 7013.0 Locking Assembly

Name: Ringfeder RfN 7013.0 Locking Assembly – Datasheet & Quote
Brand: Ringfeder
SKU: RfN 7013.0

Self-centring locking assembly with a reinforced flange

The RfN 7013.0 is a self-centring locking assembly for shafts from 19 to 150 mm. RINGFEDER sums up its character as excellent concentricity with very easy dismantling. A reinforced flange on the inner ring stops the ring bending or lifting while the screws are pulled, which is the usual reason an assembly sticks when it is time to remove it. The series is recommended for higher rotational speeds and radial loads, which suits pump impellers, fan wheels, gear wheels and belt pulleys that must run true.

During mounting the hub moves a short distance toward the screw head. On the smaller sizes only the cone of the inner ring is slotted and the flange stays solid, which prevents crooked pulling; from 55 mm inner diameter both rings are completely unslotted, which gives the stiffest geometry on the larger sizes.

Technical specifications

Parameter	Specification
Manufacturer	RINGFEDER POWER TRANSMISSION GmbH, Groß-Umstadt, Germany
Series	RINGFEDER RfN 7013.0 locking assembly, self-centring, two-piece with reinforced flange
Shaft diameter d	19 to 150 mm
Hub bore diameter D	47 to 200 mm
Overall length L	37 to 77 mm
Transmissible torque T	285 Nm (19 x 47) to 28,500 Nm (150 x 200)
Transmissible axial force Fax	30 kN to 380 kN
Maximum transmissible torque Tmax	320 Nm to 32,770 Nm
Surface pressure on shaft pW / hub pN	180 to 300 N/mm2 / 90 to 150 N/mm2
Locking screws	M6 x 20 to M12 x 40; 4 to 12 screws depending on size
Screw tightening torque TA	17 Nm to 145 Nm
Weight	0.27 kg to 6.7 kg
Surface finish	Shaft and hub bore Ra 1.6 um or better
Tolerances	Shaft h8, hub H8
Ordering example	RfN 7013.0 150 200 (d = 150 mm, D = 200 mm)

Selected sizes from the tech paper

All 30 sizes of the table fall in the 19 to 150 mm range. A cross-section of the table:

d x D (mm)	L (mm)	T (Nm)	Fax (kN)	Screws	TA (Nm)	Weight (kg)
19 x 47	37	285	30	4 x M6 x 20	17	0.29
30 x 55	37	530	40	5 x M6 x 20	17	0.34
45 x 75	46	1,860	80	6 x M8 x 25	41	0.7
60 x 90	46	2,770	90	7 x M8 x 25	41	0.88
80 x 120	60	5,850	140	7 x M10 x 35	83	2.3
100 x 145	68	11,000	220	10 x M10 x 35	83	3.7
120 x 165	68	15,700	260	12 x M10 x 35	83	4.3
150 x 200	77	28,500	380	12 x M12 x 40	145	6.7

Hub dimensioning and a fixed tightening torque

For the RfN 7013.0 the tech paper states that changing the tightening torques TA given in the table is inadmissible, so the torque ratings are tied to the listed screw loads. The minimum hub outside diameter DN depends on the hub yield strength: for the 150 x 200 size it is 357, 288 or 262 mm at Rp0.2 of 200, 300 or 400 N/mm2, and the maximum transmissible torque Tmax is 32,770 Nm against 28,500 Nm rated. DN is calculated with factor C3 = 0.6, so the hub should be at least twice the ring width long and unweakened above the assembly.

Shaft tolerance is h8 and hub H8 with Ra 1.6 um, a tighter band than the RfN 7012 asks for, so the bore has to be prepared to a finer finish. The values apply to assemblies delivered slightly oiled and ready to use. A companion series, RfN 7013.1, and a stainless steel RfN 7013.1 are described in the same product paper.

Confirm before ordering: torque with safety factor, hub material and outside diameter, shaft finish, and operating speed.

Documents and quotation

The PDF is the RINGFEDER tech paper for the RfN 7013.0 (edition 05.2024). For a quotation send shaft diameter, hub bore, torque, speed and the machine concerned. Related drive items are listed under Electric Motors and Gear Units.

Ringfeder is a German manufacturer of shaft-hub connections and couplings for mechanical power transmission, with locking assemblies, shrink discs and locking elements as core product groups. These keyless connections clamp hubs to shafts by friction, so no keyway weakens the shaft and there is no backlash.

Keyless shaft-hub connections

Ringfeder publishes numbered RfN series with tech papers, for example locking assemblies in the RfN 70xx family, shrink discs in the RfN 40xx family and locking elements such as the RfN 8006. Each tech paper lists sizes, transmissible torque and axial force, screws and tolerances.

Typical uses

Ringfeder connections are used where gear wheels, sprockets, pulleys, couplings and brake discs have to be fixed on a shaft: industrial drives, conveyors, wind and mining equipment, and general machine building.

Ordering through Seven Star LLC

Seven Star LLC lists Ringfeder series from the official tech papers and quotes by shaft diameter, hub dimensions and torque. Browse the products below for specifications.

Frequently Asked Questions