TAS Schäfer RB Locking Assemblies — Models, Torque Ratings and Installation Data

The RB series combines a sleeve with two pressure rings. Its table gives relatively low surface-pressure figures for large shaft connections, making the pressure values as important as the nominal torque during hub design.

TAS Schäfer RB locking assembly — series schematic

Operating principle and connection design

Conical contact surfaces convert an axial clamping action into radial pressure. The inner contact grips the shaft while the outer contact expands against the hub bore. Torque is transmitted through friction over the contact surfaces, producing a backlash-free connection without requiring a keyway for torque transmission. The assembly is placed internally between the shaft and the hub; both mating components therefore form part of the load-carrying system.

Series characteristics and mating surfaces

Characteristic	Series detail
Assembly positioning	Low axial displacement
Self-centering	Good
Self-locking	Low
Recommended shaft tolerance / surface	h8 / Rz10
Recommended hub tolerance / surface	H8 / Rz10
Bending-moment share limit	MB,max = 0.4 × Mt
Maximum bending angle	5 arcminutes

Axial movement in this table describes behavior during installation. Self-centering describes the assembly’s locating action; it does not eliminate the need to check the shaft and hub geometry, runout requirements and bearing arrangement. Self-locking describes the cone behavior and determines the release procedure, rather than the operating torque rating.

Size and capacity table

The table covers 32 catalog size rows, from d = 100 mm to d = 620 mm. Select by the complete d/D combination. Dimensions and ratings are specific to each row; larger nominal diameters do not necessarily mean every rating increases. Decimal points are used throughout.

Ordering designation	d — shaft (mm)	D — hub bore (mm)	Mt — torque (Nm)	Fax — axial force (kN)	pW — shaft pressure (N/mm²)	pN — hub pressure (N/mm²)	Z — screws (pcs)	S — screw size	MA — tightening torque (Nm)	L (mm)	L1 (mm)	L2 (mm)	Weight (kg)
TAS RB/100/145	100	145	7800	157	80	46	7	M10x060	83	62	74	84	4.2
TAS RB/110/155	110	155	9800	180	83	50	8	M10x060	83	62	74	84	4.6
TAS RB/120/165	120	165	12100	202	83	51	9	M10x060	83	64	76	86	5.1
TAS RB/130/180	130	180	14600	225	85	52	10	M10x060	83	64	76	86	6.1
TAS RB/140/190	140	190	17300	247	84	52	11	M10x060	83	66	78	88	6.7
TAS RB/150/200	150	200	18500	247	73	53	11	M10x070	83	62	84	94	6.7
TAS RB/160/210	160	210	23900	299	75	48	9	M12x075	145	78	92	104	8.9
TAS RB/170/225	170	225	28200	332	79	50	10	M12x075	145	78	92	104	10.4
TAS RB/180/235	180	235	29800	332	79	50	10	M12x070	145	75	86	100	10.6
TAS RB/190/250	190	250	38100	401	67	50	9	M14x080	230	85	112	126	13.8
TAS RB/200/260	200	260	44500	446	70	54	10	M14x090	230	85	112	126	14.5
TAS RB/220/285	220	285	53900	490	74	54	11	M14x090	230	85	112	126	17.2
TAS RB/240/305	240	305	66000	551	76	56	9	M16x090	355	85	112	128	18.6
TAS RB/260/325	260	325	87400	673	75	57	11	M16x100	355	97	124	140	22.7
TAS RB/280/355	280	355	111000	795	72	55	13	M16x090	355	108	136	152	31.7
TAS RB/300/375	300	375	119000	795	73	52	13	M16x090	355	108	127	143	33.7
TAS RB/320/405	320	405	138000	865	65	47	15	M16x090	355	120	142	142	45.6
TAS RB/340/425	340	425	142000	841	60	44	15	M16x090	355	120	142	158	48.1
TAS RB/360/455	360	455	195000	1088	67	49	16	M18x130	485	130	160	178	62.1
TAS RB/380/475	380	475	235000	1240	67	48	13	M20x130	690	145	172	192	72.6
TAS RB/400/495	400	495	305000	1526	78	56	16	M20x130	690	145	172	192	76.0
TAS RB/420/515	420	515	320000	1526	69	54	16	M20x130	690	145	180	190	79.4
TAS RB/440/545	440	545	377000	1717	74	52	18	M20x130	690	160	180	200	102.0
TAS RB/460/565	460	565	394000	1717	71	56	18	M20x130	690	145	180	200	96.2
TAS RB/480/585	480	585	457000	1907	75	54	20	M20x130	690	160	180	200	110.3
TAS RB/500/605	500	605	476000	1907	72	60	20	M20x130	690	140	180	200	100.1
TAS RB/520/630	520	630	556000	2141	73	50	18	M22x140	930	180	202	224	140.4
TAS RB/540/650	540	650	610000	2260	74	51	19	M22x140	930	180	202	224	145.3
TAS RB/560/670	560	670	666000	2379	75	52	20	M22x140	930	180	202	224	150.2
TAS RB/580/690	580	690	632000	2180	66	47	20	M22x140	930	180	208	208	155.0
TAS RB/600/710	600	710	653000	2180	64	45	20	M22x140	930	180	208	230	159.9
TAS RB/620/730	620	730	585000	1888	78	62	21	M20x090	930	110	140	140	100.7

Reading torque, force and dimensional values

Mt is the maximum transmitted torque when the external axial force is zero. Fax is the maximum transmitted axial force when the working torque is zero. They are separate limiting cases, so a connection carrying both torque and axial force needs a combined-load assessment. pW and pN are the average contact pressures on the shaft and hub. Z is the clamping-screw quantity, S identifies the screw size and length, and MA is the installation tightening torque for each clamping screw. MA must not be confused with the much larger torque transmitted by the shaft connection.

L is the sleeve length, L1 the width without screws and L2 the width with screws. Check both the contact length and the assembled envelope. A matching shaft diameter alone is insufficient if the hub bore, available axial width or required screw access differs.

Load selection and hub strength

Determine the peak operating torque, reversals, starting events, axial loads, radial loads and any bending moment before selecting a size. The bending share listed for this series is an application limit requiring a combined-load check, not an additional independent load allowance. Shaft and hub material strength, hub outside diameter, hollow-shaft wall thickness and local geometry must support the listed contact pressure. Radial force and bending can increase pressure on one side of the contact and reduce it on the other. The pressure and stiffness assessment therefore remains necessary even when the nominal torque is within the table value.

Installation and removal

Clean the shaft and hub contact surfaces and apply the specified film of oil so the friction condition is controlled. Position the supplied assembly and align the hub before tightening. Use the series-specific screw sequence and bring all screws to the stated MA value with a suitable torque wrench. Retain the specified screw condition and lubrication requirements. Where the design permits axial movement, allow for it while setting the final hub position. For dismantling, follow the prescribed release sequence and any press-off provision for the self-locking cone.

Application and ordering information

Typical internal-clamping applications include gears, sprockets, pulleys and conveyor drums. Match the required torque and positioning behavior to the actual machine duty rather than choosing by diameter alone. State the series, shaft diameter d, hub bore D, load case, shaft and hub materials, available installation space and environmental conditions when ordering. Stainless versions are offered within the wider product group, but their material, size availability and ratings must be confirmed for the requested version. Do not apply standard-version capacity values automatically to a different material or special design.