鲁达
参数说明 P：节距，R：滚子直径 ，N：链轮的齿数
◎节距直径PCD = P/(sin180°/N)
◎外径OD = P°/N)
下表给出一种标准节距链轮的节距直径和外径(节距1)。
例：
为了得到120号NT(齿数)25链轮的节径和外径从表中可得到节距为7.9789。因此PCD=38.1×7.9789=303.98847，或者取小数点后1位并四舍五入303.99。
外径可从表中查得为8.516。因此OD=38.10×8.516=324.4596，或取小数点后1位并四舍五入324。
齿根圆直径BD=PCD—R
最大齿根距离(卡钳测量)：CD
对于奇数齿：CD=PCDcos90/N—R
对于偶数齿：CD=BD
●节距直径系数和外径系数清单 (mm)
齿数 | 系数 1/[sin(180/N)] | 系数 0.6+cot(180/N) | 齿数 | 系数 1/[sin(180/N)] | 系数 016+cot(180/N) | 齿数 | 系数 1/[sin(180/N)] | 系数 0.6+cot(180/N) |
11 12 13 14 15 16 17 18 19 20 2l 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | 3.5495 3.8637 4.1786 4.4940 4.8097 5.1258 5.4422 5.7588 6.0755 6.3925 6.7095 7.0267 7.3439 7.6613 7.9787 8.2962 8.6138 8.9314 9.2491 9.5668 9.8845 10.2023 10.5201 10.8380 11.1558 11.4737 11.7916 12.1096 12.4275 12.7455 13.0635 13.3815 13.6995 14.0175 14.3356 14.6536 14.9717 15.2898 15.6079 15.9260 | 4.006 4.332 4.657 4.981 5.305 5.627 5 950 6.271 6 593 6 914 7.235 7.555 7 876 8 196 8.516 8.836 9.156 9.475 9.795 10.114 10.434 10.753 11.072 11.392 11.711 12.030 12.349 12.668 12.987 13.306 13.625 13.944 14.363 14.582 14 901 15.219 15.538 15.857 16.176 16.495 | 52 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 | 16.2441 16.5622 16.8803 17.1984 17.5166 17.8347 18.1529 18.4710 18.7892 19.1073 19.4255 19.7437 20.0618 20.3800 20.6982 21.0164 21.2349 21.6528 21.9710 22.2892 22.6074 22.9256 23.2438 23.5620 23.8802 24.1984 24.5167 24.8349 25.1531 25.4713 25.7896 26.1078 26.4261 26.7443 27.0625 27.3807 27.6990 28.0172 28.3355 28.6537 | 16.813 17.132 17.451 17.769 18.088 18.407 18.725 19.044 19.363 19.681 20.000 20.318 20.637 20.955 21.274 21.593 21.911 22.230 22.548 22.867 23.185 23.504 23.822 24.141 24.459 24 778 25.096 25.415 25.733 26.052 26.370 26.689 27.007 27.326 27.644 27.962 28.281 28.599 28.918 29.236 | 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 | 28.9720 29.2902 29.6085 29.9267 30.2449 30.5632 30.8815 31.1997 31.5180 31.8362 32.1545 32.4727 32.7910 33.1093 33.4275 33.7458 34.0641 34.3823 34.7006 35.0189 35.3371 35.6554 35.9737 36.2919 36.6102 36.9285 37.2467 37.5650 37.8833 38.2016 | 29.290 29.873 30.192 30.510 30.828 31.147 31.465 31.784 32.102 32.421 32.739 33.057 33.376 33.694 34.013 34.331 34.694 34.968 35.286 35.605 35.923 36.241 36.560 36.878 37.197 37.515 37.833 38.152 38.470 38.788 |