Locking Elements: Beginners Guide - Design Considerations

Beginners Guide

Design Considerations

The following points are provided to assist the designer in selecting the correct locking element for a particular application.

The items listed are considered important to the selection process.

a) Design data

To commence with the selection of a locking element, details about the particular application are essential.
The following information should be obtained :-

The particular application where the locking element is to be used e.g. on a pulley or on a flanged coupling.

The type of hub or coupling to be used including basic dimensions.

The maximum torque which must be transmitted into the shaft by a flanged coupling via the locking element.

The maximum torque which the locking element must transmit to the pulley hub.

The diameter of the shaft and hub or coupling, etc.

The maximum axial forces which the locking elements should withstand.

The extent of bending in the shaft.

The specification for the shaft and hub materials used, in order to ensure that deformation does not occur.

Details of any physical limitations or constraints which may be imposed on the design or selection of the type of locking elements used.

Details of preferred suppliers products or brand names.

Determine whether standardisation of equipment will affect the selection of components.

b) Mechanical properties of locking elements

The mechanical properties of the locking elements must be considered as this establishes whether or not a particular component can satisfy the performance requirements.

The specific details of different locking elements must be obtained from the suppliers.

Examples of the mechanical properties of RINGFEDER-Type ______ locking elements is provided below :-

Table showing mechanical properties of locking elements

B mm	T kNm	F kN	Ps MPa	PH MPa	M Nm	B Mm	T kNm	F kN	Ps MPa	PH MPa	M Nm
20	0,27	27	210	90	14	140	20	298	165	125	125
22	0,30	27	195	90	14	150	24	324	170	125	125
24	0,36	30	195	90	14	160	28	350	170	130	125
25	0,38	30	190	95	14	170	32	386	160	120	190
28	0,47	33	185	95	14	180	37	420	165	125	190
30	0,50	33	175	95	14	190	46	490	150	115	190
35	0,70	40	180	105	14	200	52	525	150	115	190
40	0,92	46	180	110	14	220	68	620	150	115	295
45	1,61	72	210	125	35	240	85	715	160	125	295
50	1,77	71	190	115	35	260	104	800	165	130	295
55	2,27	83	200	130	35	280	128	915	145	115	405
60	2,47	83	180	120	35	300	153	1020	150	120	405
65	3,04	93	190	130	35	320	210	1310	150	120	580
70	4,60	132	210	130	70	340	224	1310	145	115	580
75	4,90	131	195	125	70	360	294	1630	145	115	780
80	5,20	131	180	120	70	380	308	1620	135	110	780
85	6,30	148	195	130	70	400	322	1610	130	105	780
90	6,60	147	180	125	70	420	374	1780	135	110	780
95	7,90	167	195	135	70	440	455	2060	130	105	1000
100	9,60	192	195	135	125	460	470	2040	125	100	1000
110	10,50	191	180	125	125	480	515	2160	125	100	1000
120	13,10	218	185	135	125	500	560	2240	125	100	1000
130	17,60	272	165	115	125

Where :-

'T' = Transmissible Torque
'F' = Axial Force Absorbed
'Ps' = Pressure Between Locking Assembly And Shaft
'PH' = Pressure Between Locking Assembly And Hub
'M' = Torque Per Locking Screw (Applied By Torque Wrench)

c) Dimensions of locking elements

The physical dimensions of the various locking elements should be considered.

Dimensions for the following locking element are provided in the table below :-

Table showing dimensions of ___ Type locking elements
(Refer to diagram above)

BASIC DIMENSIONS					LOCKING SCREW			MASS kg.
B	D	W	V	L	T	S	No.	MASS kg.
20	47	20	17	27,5	M6	18	8	0,24
22	47	20	17	27,5	M6	18	8	0,23
24	50	20	17	27,5	M6	18	9	0,26
25	50	20	17	27,5	M6	18	9	0,25
28	55	20	17	27,5	M6	18	10	0,3
30	55	20	17	27,5	M6	18	10	0,29
35	60	20	17	27,5	M6	18	12	0,32
40	65	20	17	27,5	M6	18	14	0,34
45	75	24	20	33,5	M8	22	12	0,57
50	80	24	20	33,5	M8	22	12	0,6
55	85	24	20	33,5	M8	22	14	0,63
60	90	24	20	33,5	M8	22	14	0,69
65	95	24	20	33,5	M8	22	16	0,73
70	110	28	24	39,5	M10	25	14	1,26
75	115	28	24	39,5	M10	25	14	1,33
80	120	28	24	39,5	M10	25	14	1,4
85	125	28	24	39,5	M10	25	16	1,49
90	130	28	24	39,5	M10	25	16	1,53
95	135	28	24	39,5	M10	25	18	1,62
100	145	33	26	47,0	M12	30	14	2,01
110	155	33	26	47,0	M12	30	14	2,15
120	165	33	26	47,0	M12	30	16	2,35
130	180	38	34	52	M12	35	20	3,51
140	190	38	34	52	M12	35	22	3,85
150	200	38	34	52	M12	35	24	4,07
160	210	38	34	52	M12	35	26	4,3
170	225	44	38	60	M14	40	22	5,78
180	235	44	38	60	M14	40	24	6,05
290	250	52	46	68	M14	45	28	8,25
200	260	52	46	68	M14	45	30	8,65
220	285	56	50	74	M16	50	26	11,22
240	305	56	50	74	M16	50	30	12,2
260	325	56	50	74	M16	50	34	13,2
280	355	66	60	86,5	M18	60	32	19,2
300	375	66	60	86,5	M18	60	36	20,5
320	405	78	72	100,5	M20	70	36	29,6
340	425	78	72	100,5	M20	70	36	31,1
360	455	90	84	116	M22	80	36	42,2
380	475	90	84	116	M22	80	36	44
400	495	90	84	116	M22	80	36	46
420	515	90	84	116	M22	80	40	50
440	545	102	96	130	M24	90	40	64,6
460	565	102	96	130	M24	90	40	67,4
480	585	102	96	130	M24	90	42	71
500	605	102	96	130	M24	90	44	72,6