<p>This International Standard specifies the minimum requirements for enclosed, precision, single and double helical,</p>
<p>one- and two-stage speed increasers and reducers of parallel shaft design with pinion speeds of 3000 min−1 or</p>
<p>greater, or pitch line velocities of 25 m/s or greater, for special purpose applications. Such applications will typically</p>
<p>be required to operate continuously for extended periods, without installed spare equipment and are critical to the</p>
<p>continued operation of the installation. By agreement this International Standard may be used for other services.</p>
<p>This International Standard also specifies a method of rating gears which meet the following criteria:</p>
<p>a) gear accuracy</p>
<p> teeth accuracy: accuracy grade 4 or better as given in ISO 1328-1:1995, for both single pitch deviation, <i>f</i>pt,</p>
<p>and total cumulative pitch deviation, <i>F</i>p,</p>
<p> total helix deviation <i>F</i>β between the helices of the pinion and wheel: accuracy grade 4 or better as given in</p>
<p>ISO 1328-1:1995;</p>
<p>b) range of the transverse contact ratios: 1,2 < εα < 2,0;</p>
<p>c) overlap ratio εβ W 1,0;</p>
<p>d) helix angle: 5 u β u 35°;</p>
<p>e) working flanks of the pinion or gear: provided with profile modifications to obtain a good conjugate tooth load</p>
<p>distribution along the path of contact;</p>
<p>f) working flanks of pinion or gear: modified as necessary to compensate for both torsional and bending</p>
<p>deflections and, when necessary for gears with pitch line velocities in excess of 100 m/s, also for thermal</p>
<p>distortions;</p>
<p>g) gear lubrication: straight mineral oil, viscosity grade VG-32 or VG-46 (see ISO 3448);</p>
<p>h) material of the gear teeth: quality MQ or better, in accordance with ISO 6336-5:1996.</p>
Registration number (WIID)
22638
Scope
<p>This International Standard specifies the minimum requirements for enclosed, precision, single and double helical,</p>
<p>one- and two-stage speed increasers and reducers of parallel shaft design with pinion speeds of 3000 min−1 or</p>
<p>greater, or pitch line velocities of 25 m/s or greater, for special purpose applications. Such applications will typically</p>
<p>be required to operate continuously for extended periods, without installed spare equipment and are critical to the</p>
<p>continued operation of the installation. By agreement this International Standard may be used for other services.</p>
<p>This International Standard also specifies a method of rating gears which meet the following criteria:</p>
<p>a) gear accuracy</p>
<p> teeth accuracy: accuracy grade 4 or better as given in ISO 1328-1:1995, for both single pitch deviation, <i>f</i>pt,</p>
<p>and total cumulative pitch deviation, <i>F</i>p,</p>
<p> total helix deviation <i>F</i>β between the helices of the pinion and wheel: accuracy grade 4 or better as given in</p>
<p>ISO 1328-1:1995;</p>
<p>b) range of the transverse contact ratios: 1,2 < εα < 2,0;</p>
<p>c) overlap ratio εβ W 1,0;</p>
<p>d) helix angle: 5 u β u 35°;</p>
<p>e) working flanks of the pinion or gear: provided with profile modifications to obtain a good conjugate tooth load</p>
<p>distribution along the path of contact;</p>
<p>f) working flanks of pinion or gear: modified as necessary to compensate for both torsional and bending</p>
<p>deflections and, when necessary for gears with pitch line velocities in excess of 100 m/s, also for thermal</p>
<p>distortions;</p>
<p>g) gear lubrication: straight mineral oil, viscosity grade VG-32 or VG-46 (see ISO 3448);</p>
<p>h) material of the gear teeth: quality MQ or better, in accordance with ISO 6336-5:1996.</p>
