1、BRITISH STANDARD BS 4878:1973 Specification for Large (vee-throated) haulage rope pulleys for mines and quarries UDC 622.625.5:625.52-235.15BS4878:1973 This British Standard havingbeenapproved by theMining andQuarrying Requisites Industry Standards Committee,was published underthe authorityof the Ex
2、ecutive Boardon 5 October 1973 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference MQE/18 Draft for comment 70/19950 ISBN 0 580 07377 7 Co-operating organizations The Mining and Quarrying Requisites Industry Standards Committee, under whose supervision t
3、his British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: Association of Mining Electrical and Mechanical Engineers British Electrical and Allied Manufacturers Association British Steel Industry Council of Und
4、erground Machinery Manufacturers Department of Trade and Industry* Engineering Equipment Users Association Federation of Manufacturers of Construction Equipment and Cranes Institute of Quarrying Institution of Mechanical Engineers Institution of Mining Engineers National Coal Board* The Government d
5、epartment and industrial organization marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Council of Ironfoundry Associations Federation of Wire Rope Manufacturers of Great Britain
6、 Amendments issued since publication Amd. No. Date of issue CommentsBS4878:1973 BSI 12-1999 i Contents Page Co-operating organizations Inside front cover Foreword iii 1 General 1.1 Scope 1 1.2 Definitions 1 2 Pulleys 2.1 General 1 2.2 Materials 2 2.3 Rim section 2 2.4 Hubs 2 2.5 Machining 2 2.6 Keyw
7、ays 2 2.7 Spokes 3 3 Shafts 3.1 Material 3 3.2 Machining 3 3.3 Dimensions and tolerances 3 3.4 Bearing pedestal centres 4 4 Bearing pedestals 4.1 General 4 4.2 Material 4 4.3 Machining 4 4.4 Dimensions and tolerances 4 5 Bearing bushes 5.1 Material 5 5.2 Machining 5 5.3 Dimensions and tolerances 5 6
8、 Rolling bearings 6.1 Bearings 5 6.2 Seals 5 6.3 Bearing lubrication 5 7 Keys 7.1 Details 5 8 Bolts for split pulleys 8.1 Bolts 5 8.2 Nuts 6 8.3 Washers 6 9 Workmanship 9.1 Details 6 10 Inspection 10.1 Purchasers rights 6 11 Protective coating 11.1 Details 6 12 Marking 12.1 Details 6 13 Information
9、to be provided with order 13.1 Details 6BS4878:1973 ii BSI 12-1999 Page Appendix A Notes on the determination of minimum pulley diameters 8 Figure 1 Rim section (one-piece solid type pulley) for topes of 19 mm diameter and under 10 Figure 2 Rim section (spoked type pulley) for ropes of 22 mm and und
10、er 11 Figure 3 Rim section for ropes of 14 mm to 38 mm diameter (inc.) 12 Figure 4 Pulleys 600 mm (2 ft) and 750 mm (2 ft 6 in) diameter 13 Figure 5 Pulley 900 mm (3 ft) diameter (internalrolling bearings) 14 Figure 6 Solid hub and shaft arrangement (internalrolling bearings) 15 Figure 7 Split hub a
11、nd shaft arrangement (internalrolling bearings) 16 Figure 8 Pulleys 600 mm (2 ft) diameter and 750 mm (2 ft 6 in) diameter(external plain bearings) 17 Figure 9 Pulley 900 mm (3 ft) diameter (external plain bearings) 18 Figure 10 Solid hub and shaft arrangement(external plain bearings) 19 Figure 11 S
12、plit hub and shaft arrangement (external plain bearings) 20 Figure 12 Pedestal 21 Figure 13 Bearing housing 22 Figure 14 Bush and thrust washer 23 Figure 15 Pulley/rope diameters (6 7 (6/1) round and 6 8 (7/%) triangularstrand) 24 Figure 16 Pulley/rope diameters (6 19 (9/9/1) round strand) 25 Figure
13、 17 Pulley/rope diameters (6 22 (9/12/%) triangularstrand) 26 Figure 18 Pulley/rope diameters (6 25 (12/12/%) triangularstrand) 27 Table 1 Pulley classification 1 Table 2 Details of spokes 3 Publications referred to Inside back coverBS4878:1973 BSI 12-1999 iii Foreword This British Standard has been
14、 prepared under the authority of the Mining andQuarrying Requisites Industry Standards Committee to cover a range of large diameter pulleys designed primarily for haulage purposes at mines and quarries, and intended for use with steel wire ropes complying with the requirements of BS330. The pulleys
15、covered by this British Standard have been specifically designed for return wheel duty, i.e. where the lap of the rope on the pulley is 180 . However, the pulleys are suitable for other conditions, where the rope lap is less than 180 . Pulleys and shafts embodying rolling bearings are regarded as a
16、composite unit. However, in the case of pulleys having bronze bushed bearings, all components are intended to be interchangeable for a given pulley diameter. It is also intended that, for a given pulley diameter, a rolling bearing pulley assembly and a bronze bushed bearing pulley assembly will be i
17、nterchangeable. Rolling bearings in the pulley boss are specified throughout a full range of pulley diameters and it is recommended that, wherever possible, rolling bearings should be used to reduce to a minimum the necessity for service and maintenance. Phosphor bronze bearing bushes in pedestals a
18、re specified up to a maximum pulley diameter of 1350 mm and are not intended to be used with the shaft in a vertical position. The pulleys covered by this standard are not designed to be hoisted in the horizontal position by means of attachments to the rim or spokes, nor for multiple stacking, stora
19、ge or lifting one on top of the other. It is not intended to cover U-shaped groove pulleys, or multiple pulley arrangements, although certain parts of the specification are pertinent to such designs and should be used where possible. A method of determining minimum pulley diameters is given in Appen
20、dix A, taking into account the normal haulage loads in a straight rope and the induced loads when it is bent around a pulley. NOTEWhile this is a metric standard, certain principal dimensions are stated in (approximate) imperial units for convenience at this stage; reference may be made to BS 350, “
21、Conversion factors and tables”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary o
22、f pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to 28, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cov
23、er.iv blankBS4878:1973 BSI 12-1999 1 1 General 1.1 Scope This British Standard specifies requirements for a range of haulage pulleys (with shafts) and pedestals designed to incorporate, appropriately, either rolling bearings or plain bearings. NOTEThe titles of the British Standards referred to in t
24、his standard are listed on the inside back cover. 1.2 Definitions For the purposes of this British Standard, the following definitions apply: 1.2.1 rope diameter the value by which the nominal diameter of the wire rope is designated 1.2.2 pedestal a device designed to support the ends of a shaft upo
25、n which a pulley rotates on rolling bearings 1.2.3 bearing housing a device, embodying bronze bushes, designed to support the ends of a rotating shaft 1.2.4 bearing (rolling) a bearing of the ball, roller, or the taper roller type 1.2.5 tread diameter the nominal diameter of the pulley, measured at
26、the root of the rope groove NOTEThe following terminology phrases are provided for information and guidance: One-piece solid casting. A pulley without spokes. Pulley assembly. The designed combination of pulley, shaft, bearings and shaft pedestals. 2 Pulleys 2.1 General The following principal pulle
27、y arrangements are covered by this standard: 1) Pulleys of 600 mm to 2100 mm diameter,incorporating rolling bearings intheboss(seeFigure 4, Figure 5, Figure 6 and Figure 7);and 2) Pulleys of 600 mm and 1350 mm diameter, incorporating phosphor bronze bushes in the associated pedestals (see Figure 8,
28、Figure 9, Figure 10 and Figure 11). 2.1.1 Design criteria. A pulley complying with the requirements of this British Standard shall be capable of withstanding a load equal to twice the minimum breaking load of the largest diameter ofrope nominated for use with that pulley (seeFigure 1, Figure 2 and F
29、igure 3), assuming a rope lap of 180 (i.e. return pulley conditions), without permanent deformation of any part of the pulley assembly. 2.1.2 Classification. Pulleys shall be in accordance with the classification shown in Table 1. Table 1 Pulley classification Description Pulley size Group Construct
30、ion Diameter at rope tread Type reference mm ft in C One-piece solid casting 600 750 900 2 2 3 0 6 0 C.60 C.75 C.90 S Cast rim and hub, with spokes(one-piece) 900 1050 1200 1350 1500 3 3 4 4 5 0 6 0 6 0 S.90 S.105 S.120 S.135 S.150 SH Cast rim and hub, with spokes (two-piece) 1350 1500 1800 2100 4 5
31、 6 7 6 0 0 0 SH.135 SH.150 SH.180 SH.210BS4878:1973 2 BSI 12-1999 2.2 Materials 2.2.1 Pulley rims and hubs. The materials of pulley rims and hubs shall comply with the requirements of one or other of the following British Standards, subject to agreement between the purchaser and the manufacturer: BS
32、 1452, Grade 14 grey cast iron (as minima) BS 2789, Grade SNG37/2 nodular graphite castiron BS 3100, (BS 592, Grade B carbon steel) BS 3100, (BS 1456 Grade A 1% manganese steel) 2.2.2 Spokes. The material of pulley spokes shall be either mild steel complying with the requirements of Grade 43A of BS
33、4360, or wrought iron complying with the requirements of BS 2772, subject to agreement between the purchaser and the manufacturer. 2.3 Rim section The rim section shall conform appropriately to theprincipal dimensions of Figure 1, Figure 2 or Figure 3. The rope groove radius of the pulley shall be a
34、pproximately 10% greater than the nominal radius of the rope to be used with the pulley. NOTEThe rim sections illustrated in Figure 1, Figure 2 and Figure 3 provide a progressive range of nine pulleys for rope diameters complying with the requirements of BS 330. Users are advised to consult Appendix
35、 A, which gives a method of determining minimum pulley diameters and takes account of necessary factors in order to limit to an acceptable maximum the loading of a rope bent around a pulley. 2.4 Hubs 2.4.1 For solid type pulleys. The hubs for one-piece solid cast pulleys shall conform to the general
36、 arrangement of Figure 4, Figure 5, Figure 8 and Figure 9, as appropriate. 2.4.2 For spoked pulleys 2.4.2.2 The hubs for one-piece spoked type pulleysshall conform to the general arrangement ofFigure 6 and Figure 10, as appropriate. 2.4.2.2 The hubs of spoked type split pulleys shall conform to the
37、general arrangement of Figure 7 and Figure 11, as appropriate. 2.5 Machining 2.5.1 Rims. Unless otherwise agreed between the purchaser and the manufacturer, rope grooves shall be “as cast”. Where high spots, or areas of undue roughness occur, these shall be dressed smooth and flush with the general
38、contour of the groove. The tolerance on diameter for “as cast” pulleys shall be mm. The total variation from true running for “as cast” rope grooves shall not exceed3mm in any direction. Where machined rims are required by the purchaser the rope groove radius shall comply with the requirements of 2.
39、3. The machined radius shall blend smoothly into the flanks of the “vee” without step or undercut. The tolerance on diameter for machined rope grooves shall be mm. The total variation from true running of the machined rope groove radius shall not exceed0.5mm in any direction. 2.5.2 Hubs 2.5.2.1 Hubs
40、 for keyed shafts shall be faced on both sides subject to a tolerance on width of mm. The bores shall comply with H8 1)limits for holes. 2.5.2.2 Hubs to accommodate rolling bearings shall be concentric within the tolerance grade IT 4 1)and be subject to a tolerance on width of mm. The tolerances on
41、bores shall comply with the N6 1)limits for holes. 2.5.3 Split pulleys. The mating faces of split pulleys shall be machined flat and square with the plane of the rope tread. The bolt holes in the mating faces of split pulleysshall be accurately drilled, and then countersunk 1.5 mm at 45 on the face.
42、 The nut seatings shall be spotfaced to provide square seating for the nuts. Means, additional to fixing bolts, shall be provided to ensure accurate assembly of the components. 2.6 Keyways Any pulley having a keyed shaft shall have a rectangular keyway, complying appropriately with the requirements
43、of BS 4235, cut in the hub bore (see also Section 7). 1) See BS 4500. 3 0 1.5 0 0.5 0 0.5 0BS4878:1973 BSI 12-1999 3 2.7 Spokes The number of spokes per pulley and their respective diameters shall be as given in Table 2. All spokes shall be set (cranked) at both ends, to enter the rim bosses and the
44、 hub at right angles to the axis of the shaft. The set of a spoke shall be as near as possible to the point where the spoke enters the hub and the rim boss; the set shall in no case be inside the boss or hub. The spoke ends shall be knuckled (as shown in Figure 2 and Figure 3) by swaging or rolling.
45、 Spoke ends shall be cleaned and evenly tinned after knuckling, such tinning to extend clear of the finished casting. The root diameter of each knuckle shall be not less than the nominal diameter of the spoke. The contour of the knuckle shall be fully radiused and have no sharp lines. There shall be
46、 1) a 20 mm minimum parallel portion of the spoke end immediately inside the rim boss and hub, 2) a 58 mm minimum length of spoke inside the rim boss and hub and 3) a 20 mm minimum of material covering the end of each spoke in the rim and hub after any machining. Table 2 Details of spokes 3 Shafts 3
47、.1 Material The material for keyed (rotating) shafts shall comply with the requirements of BS 970-1, grade070M20 (hot rolled, forged, or normalized). The material for fixed shafts shall comply with therequirements of BS 970-1, grade 070M26 (colddrawn from hot rolled condition). In either instance th
48、e material shall be free from seams, laps and other such defects. 3.2 Machining 3.2.1 Shafts for use with phosphor bronze bearings. The surface finish on journals, pulley seatings and radii on shafts in accordance with Figure 8, Figure 9, Figure 10 or Figure 11 shall be of a quality grade complying,
49、 both diametrically and longitudinally, with 63R a 2) . Fillet radii shall blend smoothly, without step or undercut, into the journal. All burrs and sharp edges shall be removed. 3.2.2 Shafts for rolling bearings. The surface finish on all parts of the shaft which come into contact with rolling bearings shall be of a quality grade complying, both diametrically and longitudinally, with 63R a 2) . Fillet radii shall blend smoothly. All burrs and sharp edges shall be removed. Thread holes for lubricators shall be c
