1、BSI BS*1(5 colour printing machinery; control systems (when multiple trains of gears are involved this grade would generally be used for low speed components where the effect of positional accuracy is important). Class B. Navigational instruments ; high speed compo- nents of control systems where qu
2、ietness and smooth running are essential; machine tool speed control; photo- graphic instruments. Class C. General purpose instruments; accounting and calculating machinery; counters; clockwork mechanisms. Class D. Textile machinery; switch operating gear; clockwork mechanisms where accuracy is not
3、the primary consideration. It is recommended that all spur, helical and crossed helical gears for use in horology should be produced to this British Standard, with the possible exception of gears for weight or spring-driven mechanisms in which the pinion is the driven member and has 12 or fewer teet
4、h. In such cases it may be preferable to use cycloidal type spur gears, conforming to BS 978, Part 2t. Examples of calculation are given in Appendix B. 1.2 TERMIN OLOGY AND NOTATION As the first step towards achieving international under- standing of gears terminology, the terms and definitions of D
5、raft IS0 Recommendation No. 888$, International vocabulary of gears , have been applied, together with corresponding notation derived from IS0 Recommenda- tion No. 701, International gear notation, symbols for geometrical data 3. * BS 978, Fine pitch gears , Part I, Involute spur and helical gears .
6、 t BS 978, Fine pitch gears , Part 2, Cycloidal type gears . $ To be incorporated in BS 2519, Glossary of terms for toothed gearing . The notation used is as follows: a centre distance n, virtual centre distance d reference circle diameter dl reference circle diameter : pinion d2 reference circle di
7、ameter: wheel da tip diameter da, tip diameter: pinion da, tip diameter : wheel 0.16 0,095 0.17 mm 0.18 0.19 0.20 0.21 0.22 0.24 0.25 0.26 0.28 0.30 mm 0.32 0.35 0.38 0.40 0.42 0.45 0.48 0.50 0.52 0.55 mm 0.58 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 NOTE. For comparable metric modules and diame
8、tral pitches, see Appendix C. 1.4 BASIC RACE TOOTH PROFILE Fig. 1 shows the basic rack usually employed where it is desired to have minimum backlash, as inservo-mechanisms. That shown in Fig. 2 is used where it is desired to have backlash to avoid any risk of jamming and where the load is usually un
9、i-directional, for example, in clockwork mechanisms. When non-topping hobs are used it is permissible to use a hob conformmg to Fig. 1 basic rack and to cut at greater depth than normal to obtain the required tooth thickness. For internal gears (Fig. 1 and Fig. 2 basic racks) the basic rack referenc
10、e addendum shall normally be 0.850 instead of 1.OOO. In cases when the tips of the teeth have a radius of 0.25 or greater (up to 0.3 maximum as shown) the 1.O addendum may be applied. Fig. 1. Basic rack tooth profile for unit normal module 2. DESIGN DETAILS (For spur gears, sec = 1.) Fig. 2. Basic r
11、ack tooth prole for unit normal module with backlash allowance 2.1 OUTSIDE DIAMETER AND CENTRE DISTANCE For the normal case when both z1 sec3 and z2 sec9 are greater than 17 the dimensions are as follows: ti, = m.z, sec (1) d2 = m.z, sec (2) (3) (4) (5) da, = m.(zl sec + 2) da2 = m.(zz sec + 2) m.(z
12、, + Zq) sec 2 a= 2.2 MODIFICATION OF ADDENDUM AND CENTRE DISTANCE 2.2.1 For an explanation of the principles followed in connection with addendum modification see Appendix A. 2.2.2 Where no limitations are imposed, the value of x for any gear whose virtual number of teeth z, is less than 17 is given
13、 by the formulae: x=l- v where z, = z sec seca, m z sec3. z sinla, (see Table 2 and Figs. 3 (6) (7) 2 and 4)s This gives values in accordance with the lower limiting line XX in Fig. 3 and a small and normally negligible amount of undercutting is thereby permitted. The addendum modification coefficie
14、nt for helical pinions from 6 to 16 teeth and helix angles up to 45“ is shown in Fig. 4. 2.2.3 When the pinion is modified as above and there are no other limitations,. the wheel is unmodified and its dimensions are obtained from the formulae in 2.1 ; but the dimensions of the pinion and centre dist
15、ance are as follows: s, = m(1.5708 + 0.72793 (Fig. 1 type gears) (9) s1 = m(1.4136 + Oa7279xl) (Fig. 2 type gears) (10) d(z1 + zd sec + h,. 2 a= Parallel axis external gear pairs designed as above have backlash at this centre distance. (See Appendix A.) 5 BS 4582 : Part 1 : 1970 BSI BS*q582 PART*L 7
16、0 Lb2YbbS 0038877 b TABLE 2. DATA FOR SPUR- PINIONS OF UNIT MODULE HAVING FEWER THAN 17 TEETH NO. of teeth Zl - 8* 9* 10 11 12 13 14 15 16 - Addendum nodification coefficient Xi 0,5321 0,4736 0.4151 0.3566 0,2982 0.2397 0.1812 0.1227 0-0642 Tip iiameter dai 11.0642 11.9472 12.8302 13.7132 14.5963 15
17、,4793 16.3623 17.2453 18.1284 - ncrease in circu- Recommended ir tooth thickness minimum number af standard of teeth in pitch diameter mating wheel 22 - 0.3874 0.3448 0.3022 0,2596 0.2170 0.1744 0,1319 Os0467 0.0893 26 25 24 23 22 21 20 19 ia * Pinions havin 8 or 9 teeth generated from basic rack Fi
18、g. 1 have narrow crest wifith, as also have pinions of 10 and 11 teeth generated from basic rack Fig. 2.10 is the smallest number of teeth that can be generated at full depth from basic rack Fig. 2. 2.3 ENLARGED SPUR PINIONS WITH MIKIMCAI BACI(LASH Spur pinions enlarged according to Table 2 may be e
19、ngaged with wheels in which Xa is zero, at centre distance derived from Table 3. Gears derived from Fig. 1 basic rack will have no backlash at this centre distance. A small and negligible reduction of tip-to-root clearance is obtained at this centre distance. Table 2 is not applicable to helical gea
20、rs, for which the formulae in Appendix A are required. Alternatively, spur pinions enlarged according to Table 2 or helical pinions enlarged according to Fig. 4 may be engaged with wheels in which Xa = - xl, in which case the centre distance is as obtained in 2.1, and (12) (13) s2 = m(1.5708 - 0.727
21、93 (Fig. 1 type gears) sa = in(l.4136 - 0.7279) (Fig. 2 type gears) Such gears derived from Fig. 1 basic rack will have zero backlash at nominal dimensions. 6 F BSI BS*4582 PART*1 70 U 1624669 0038878 8 U BS 4582 : Part 1 : i970 e O ._ s IE E o Ii, O E P cl 7 BSI BS*4582 ES 4582 : Part 1 : 1970 n aJ
22、 aJ aJ v) L m 3 Q aJ m f - m X 0 z .- I 8 Y BSI BS*k4582 PART*L 70 m Lb24bb 0038880 b I BS 4582 : Part 1 : 1970 TABLE 3. CENTRE DlSTANCES FOR SPUR GEAR PAIRS OF UNIT MODULE FOR THE CONDITIONS GIVEN IN 2.3, PARA. 1 1 10; xi = 0.4151 I ZS 10 20 30 I 40 50 , 60 70 1 80 I 90 100 t ! i 404004 1 45,4019 5
23、0.4032 55.4043 ! O 10,6845 15.3814 i 20.3887 25.3934 25.8938 26.3941 26.8944 27.3947 27.8950 28.3853 28.8956 29.3958 29.8961 -_ -. _- 30,3963 30.8966 31.3968 31.8971 32.3974 32.8976 33.3978 33.8981 34.3982 34,8985 35.3987 35.8980 36.3991 36,8993 37.3994 37,8996 38.3998 38.9000 39*4000 39.9002 1 11.1
24、460 2 . 11.6060 3 , 12.0644 4 i 12-5213 5 12.9767 6 13,4307 7 13*8833 8 14.3795 9 I 14,8804 15,8822 I 20.8893 16.3831 i 21-3898 16.8839 i 21.8904 17.3846 -1 22.3909 17.8854 i 22.8913 18.3861 23.3918 18.8868 i 23.8922 19.3875 24.3927 19,8881 24.8931 I _- _ .- - 409005 I 41.4007 i 414008 I 42,4010 i 4
25、2.9012 1 43.4013 43.9014 ! 44.4016 i 44.9017 ; 45.9020 46.4022 46.9022 47,4024 47.9026 48.4027 48.9028 494029 49,9031 i 50.9033 ! 51.4034 I 51.9035 i 52,4036 i : 52.9038 53.4039 53.9040 54.4041 , 54.9042 5 5.9 O 4 4 56.4045 56.9046 57,4046 57.9047 584048 589049 59.4050 59.9051 140 I 150 120 130 160
26、170 i 180 190 ! 200 f- O 60.4052 1 60.9052 2 61.4053 3 61.9054 4 ; 62.4055 5 62.9056 6 : 63.4056 7 63.9057 I 90.4083 i 90.9084 91.9084 92.4085 : 92.9085 i 93.4085 93.9086 i 94.4086 94-9086 914084 : f 75.4071 75.9071 76.4072 76.9072 77.4073 80.4076 80,9076 81.4076 81.9077 82.4077 85.4080 864080 86,90
27、81 87.4081 a5.9080 100.4089 1009090 101*4090 101*9090 . 1024091 65.4059 65.9060 66.4060 669062 67.4062 67.9062 68.4064 689063 70.4066 70.9066 71.4067 71.9067 72.4068 72.9068 73.4069 73.9069 95.4086 95.9087 96.4087 96.9087 97.4088 1054092 105.9092 106.4092 106.9093 107.4093 77.9073 i 82.9078 78.4074
28、. 83.4078 78.9074 i 83.9078 87.9082 88.4082 88,9082 89,4083 89-9083 102.9091 103-4091 103.9091 104.4092 1049092 107.9693 108.4093 108.9093 109.4094 1099094 97.9088 984088 98,9088 994089 99.9089 8 64.4058 f 69.4064 9 64,9058 i 699065 74,4070 79.4075 : 84.4079 74.9070 79.9075 84.9079 9 - 1b2 4bb 00388
29、81 BSI BSmY582 PARTm1 70 ES 4582 : Part 1 : 1970 TABLE 3 (continued) 21 = 11; XI = 0,3566 10 20 30 40 50 70 80 t 90 j 100 j 1 50.8480 55,8488 60 11,1461 1106060 12.0644 12.5213 12,9767 13,4307 13.8833 14.3344 14.8302 15.3309 15.8315 16.3321 16,8327 17,3333 17.8338 18,3343 18.8348 19.3353 19.8358 20,
30、3362 25.8402 26.3405 26,8408 27.3410 27,8413 28,3416 28,8418 294421 29,8423 30.3425 30,8427 31.3429 31.8431 32.3433 32.8435 33.3437 33,8438 34.3440 34.8442 35,3444 O 1 2 3 4 5 6 7 8 9 35.8445 36.3447 36.8448 37,3450 37,8451 38.3453 38.8454 39.3456 39.8457 40.3458 40.8460 41.3461 41,8462 42,3463 42.8
31、464 43.3465 43,8466 44.3468 44,8469 45.3470 20.8366 21.3370 21.8374 22,3378 2208382 23.3385 23.8389 24.3392 24,8395 25.3399 _._ 130 70.8504 71.3505 71.8505 72,3506 72.8506 73.3506 73.8507 74:3507 74.8508 75.3508 45,8471 46.3472 46,8473 47.3474 47.8474 48.3475 48,8476 49,3477 49.8478 50.3479 _ - - 18
32、0 95.8520 96,3520 96.8520 97,3520 97,8520 98.3520 98.8521 99.3521 99,8521 100.3521 56.3488 56,8489 57.3490 57.8490 58.3491 58,8492 59.3492 59.8493 60,3493 51.3481 52.3483 52.8483 53.3484 53.8485 54,3486 54,8486 55.3487 51.8482 I_ 190 100.8522 101.3522 101-8522 102,3522 102.8522 103.3522 103.8523 104
33、.3523 104-8523 105.3523 150 . , 160 _- 170 90.8518 91.3518 91.8518 92,3518 92.8518 93,3518 93.8519 94.3519 94,8519. 95.3519 120 65.8500 66,3500 66,8500 67.3501 67,8502 ss.3502 68,8502 69.3503 69,8504 70.3504 140 75,8508 76.3509 76,8509 77.3510 7 7 * 8 5 1 O 78.3510 78.8511 79.3511 79.8512 80.3512 11
34、0 60,8494 61.3495 61.8495 62.3496 62.8496 63.3497 63,8498 64.3498 64.8498 65,3499 200 105,8523 106-3523 106.8523 107.3523 107-8524 108.3524 108.8524 109.3524 109,8524 110.3524 ! 80,8512 i 85,8515 .o 1 2 3 4 5 6 7 8 9 81.3512 81,8513 82.3513 82.8513 83.3514 83.8514 84,3514 84.8514 85.3515 - 86.3515 8
35、6,8516 87,3516 87,8516 8 8 3 5 16 88.8517 89,3517 90.3518 89.8517 10 BSI BS*4582 PART*L 70 H 3b24bb7 0038882 T BS 4582 : Part 1 : 1970 TABLE 3 (continued) ZI = 12; XI = 0.2982 ZP 10 20 30 40 50 60 70 80 90 100 O 11.6060 16.2806 21.2844 26.2868 31.2884 36.2896 41.2905 46.2913 51.2919 56.2925 1 12.064
36、4 16.7811 21.7847 26.7870 31.7885 36,7897 41.7906 467914 51.7920 56.7925 2 12.5213 17.2815 22.2850 27.2872 32.2886 37.2898 42,2907 47.2914 52.2921 57.2926 3 12.9767 17.7826 22.7852 27.7874 32.7888 , 377899 42.7908 47.7915 52.7921 57.7926 4 13.4307 18.2827 23,2855 28,2876 33.2889 38.2900 43.2909 48.2
37、916 53.2922 58.2927 5 13.8833 18,7828 23.7858 28.7877 33.7890 38.7901 43.7909 48.7916 53.7922 58.7927 6 14,3344 19.2831 24.2860 29.2879 34.2891 39.2902 : 44.2910 49.2917 54.2923 59.2928 7 14.7841 19.7835 24.7862 29.7880 34.7892 39.7903 44.7911 49.7918 54.7923 59.7928 8 15.2976 20.2838 252864 30.2882
38、 35.2893 40.2904 45.2912 50.2918 55.2924 60.2928 9 15.7801 20,7841 25.7866 30.7883 35.7894 40.7905 45.7912 50.7919 55,7924 60.7929 2s I 110 , 120 130 140 150 160 170 180 190 200 I - I I O 61.2929 66.2933 71.2936 76.2939 81.2942 86.2944 91.2946 96.2948 101.2919 106.2950 1 61.7930 66.7934 71.7937 76.7
39、940 , 81.7942, 86.7944 91.7946 96.7948 101.7949 106.7950 2 62.2930 67.2934 72.2937 77,2940 82.2942 87.2944 92,2946 97.2948 102.2949 107-2950 3 62.7930 67.7934 72.7937 77.7940 82.7942 87.7944 92.7946 97.7948 102.7949 107.7950 4 63.2931 68.2934 73.2938 78.2940 83.2942 88.2944 . 93.2946 , 98.2948 103.2
40、950 108.2950 5 63.7931 68.7935 73.7938 78.7941 83.7913 88,7945 93.7947 98.7949 103.7950 108.7951 6 64.2932 69.2935 74.2938 79.2941 84.2943 89.2945 94.2947 99.2949 104.2950 109.2951 7 64.7932 69,7935 74.7938 79.7941 84.7943 89.7945 94.7947 99.7949 104.7950 109.7951 8 65.2932 70.2936 75.2939 80.2941 8
41、5.2943 90.2945 95.2947 100.2919 105.2950 110.2951 9 65.7933 70.7936 75,7939 90.7942 85.7944 90.7946 95.7948 100.7949 105.7950 110.7951 11 BSI BSm11582 PART* XI = 0.2397 io 20 30 40 50 60 70 80 90 100 O 1 2 3 4 5 6 7 8 9 12.0644 12,5213 12-9767 13,4307 13.8833 14,3344 14.7841 15,2324 15.7276 16.2280
42、16,7282 17.2285 17.7288 18.2291 18,7293 19,2296 19,7298 20.2300 20.7302 21,2304 21.7306 22.2308 22-7310 23.2312 23.7314 24.2316 24.7317 25,2318 25.7320 26,2321 26,7322 27.2323 27.7325 28.2326 28.7327 29.2328 29.7329 30.2330 30.7331 31.2332 31.7333 32,2334 32.7335 33.2336 33.7337 34.2338 34.7338 35,2
43、339 35,7340 36,2340 364341 37.2342 37.7343 38.2344 38.7344 39.2344 39.7345 40.2346 40.7346 414347 41.7347 42.2348 42,7348 43.2349 4377349 44.2350 44.7350 45.2351 45.7351 46,2352 46,7352 47.2353 47,7353 48,2353 48.7354 49.2354 49.7355 50,2355 50,7355 51.2356 51.7356 52,2357 52-7357 53.2357 53.7358 54
44、.2358 54.7358 55,2358 55.7359 56.2359 56.7359 574360 57.7360 58,2360 58.7361 59.2361 59.7361 60,2362 60.7362 61,2362 110 120 130 140 150 160 180 190 200 170 101.7375 102,2375 102,7375 103-2375 103.7376 104.2376 104.7376 105.2376 105.7376 106,2376 61.7362 62.2363 62.7363 63,2363 63,7364 64.2364 64.73
45、64 65.2364 65,7365 66,2365 664365 67,2366 67.7366 68.2366 68.7366 69,2366 69.7366 70,2367 70.7367 71.2367 714367 72.2368 72.7368 73.2368 73.7368 74,2368 74.7368 75,2369 75,7369 76,2369 764369 77.2370 77.7370 78.2370 78.7370 79,2370 79.7370 80.2371 80.7371 81.2371 81.7371 82.2371 82.7371 83.2371 83.7
46、372 84.2372 84.7372 85.2372 85,7372 86.2372 86.7372 87.2372 87.7372 88.2372 88.7372 89,2373 89.7373 90.2373 90.7373 91.2373 96.7374 97.2374 97.7374 98.2374 98.7371 994375 99.7375 100.2375 106.7375 101.2375 106.7376 107.2376 4.07.7376 108.2376 108.7376 109-2376 109.7376 110-2376 110-7377 111.2377 O 1
47、 2 3 4 5 6 7 8 9 91.7373 92.2373 92.7373 93.2373 93.9374 94.2374 94.7374 95,2374 95.7374 96.2374 12 BSI BS*ll582 PART* XI = 0,1812 i 80 90 100 Za 10 30 40 50 I 60 ! 70 20 17.1746 17.6748 ia.1749 18.6751 19.1752 19,6754 20.1755 20,6756 21.1758 21.6759 O 1 2 3 4 5 6 7 8 9 12.5213 12-9767 13.4307 13.88
48、33 14.3344 14.7841 15.2324 15.6793 16.1740 16.6744 22.1760 22.6761 23.1762 23,6763 24.1764 24.6765 25.1766 25.6766 26.1767 26.6768 27.1769 27.6770 28.1770 28.6771 29.1772 29.6773 30-1773 30.6774 32.1775 32.6776 33.1776 33.6777 34-1777 34.6778 35.1778 35,6779 49.6788 54.6790 59.6792 50.1788 50.6788 5
49、5.1790 60.1792 55,6790 60.6792 56.1791 , 61.2792 56,6791 j 61.6792 31.1774 i 36.1779 31.6775 i 36.6780 .- - . . - . 150 I 160 ! 190 200 ! 67.1794 1 72.1794 67.6794 72.6795 68.1794 I 73.1795 68.6794 I 73.6795 69.1794 i 74.1795 O 1 2 3 4 5 6 L 8 9 62.1792 62.6793 63.1793 63.6793 64.1793 64.6793 65.1793 65.6793 66.1793 66.6793 77.1796 77.6796 78.1796 78.6796 79,1796 13 ES I O 12,9767 17,6195 : 22,6202 1 2 3 4 5 6 7 8 9 ._ 13.4307 18.1196 13,8833 18.6197 14.3344 19.1198 14.7841 19,61
