ISO/TC 60/SC 2/WG 13 - Bevel gears

This document specifies the methods of calculation of the load capacity of bevel gears, the formulae and symbols used for calculation, and the general factors influencing load conditions. The formulae in this document are intended to establish uniformly acceptable methods for calculating the load-carrying capacity of straight, helical (skew), spiral bevel, Zerol and hypoid gears. They are applicable equally to tapered depth and uniform depth teeth. Hereinafter, the term “bevel gear” refers to all of the gear types; if not, the specific forms are identified. The formulae in this document take into account the known major factors influencing load-carrying capacity. The rating formulae are only applicable to types of gear tooth deterioration, that are specifically addressed in the individual parts of the ISO 10300 series. Rating systems for a particular type of bevel gears can be established by selecting proper values for the factors used in the general formulae. NOTE This document is not applicable to bevel gears which have an inadequate contact pattern under load (see Annex D). The rating system of this document is based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα The user is cautioned that when the formulae are used for large average mean spiral angles (βm1 + βm2)/2 > 45°, for effective pressure angles αe > 30° and/or for large facewidths b > 13 mmn, the calculated results of this document should be confirmed by experience.

This document specifies the fundamental formulae for use in the tooth root stress calculation of straight and helical (skew), Zerol and spiral bevel gears including hypoid gears, with a minimum rim thickness under the root of 3,5 mmn. All load influences on tooth root stress are included, insofar as they are the result of load transmitted by the gearing and able to be evaluated quantitatively. Stresses, such as those caused by the shrink fitting of gear rims, which are superposed on stresses due to tooth loading, are intended to be considered in the calculation of the tooth root stress, σF, or the permissible tooth root stress σFP. This document is not applicable in the assessment of tooth flank fracture. The formulae in this document are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα This document does not apply to stress levels above those permitted for 103 cycles, as stresses in that range can exceed the elastic limit of the gear tooth. NOTE This document is not applicable to bevel gears which have an inadequate contact pattern under load. The user is cautioned that when the formulae are used for large average mean spiral angles (βm1 + βm2)/2 > 45°, for effective pressure angles αe > 30° and/or for large facewidths b > 13 mmn, the calculated results of this document should be confirmed by experience.

This document specifies the methods of calculation of the load capacity of bevel gears, the formulae and symbols used for calculation, and the general factors influencing load conditions. The formulae in this document are intended to establish uniformly acceptable methods for calculating the load-carrying capacity of straight, helical (skew), spiral bevel, Zerol and hypoid gears. They are applicable equally to tapered depth and uniform depth teeth. Hereinafter, the term “bevel gear” refers to all of the gear types; if not, the specific forms are identified. The formulae in this document take into account the known major factors influencing load-carrying capacity. The rating formulae are only applicable to types of gear tooth deterioration, that are specifically addressed in the individual parts of the ISO 10300 series. Rating systems for a particular type of bevel gears can be established by selecting proper values for the factors used in the general formulae. NOTE This document is not applicable to bevel gears which have an inadequate contact pattern under load (see Annex D). The rating system of this document is based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα The user is cautioned that when the formulae are used for large average mean spiral angles (βm1 + βm2)/2 > 45°, for effective pressure angles αe > 30° and/or for large facewidths b > 13 mmn, the calculated results of this document should be confirmed by experience.

This document provides calculation examples for different bevel gear designs regarding the scuffing load capacity according to ISO/TS 10300-20. The initial geometry data of the gear necessary for these calculations are in accordance with ISO 23509. The term "bevel gear" is used to mean straight, helical (skew), spiral bevel, zerol and hypoid gear designs. Where this document pertains to one or more, but not all, the specific forms are identified. The formulae in this document are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα

This document provides a calculation method for bevel and hypoid gears regarding scuffing based on experimental and theoretical investigation[7]. This calculation method is a flash temperature method. The formulae in this document are intended to establish uniformly acceptable methods for calculating scuffing resistance of straight, helical (skew), spiral bevel, Zerol and hypoid gears made of steel. They are applicable equally to tapered depth and uniform depth teeth. Hereinafter, the term “bevel gear” refers to all of these gear types; if not the case, the specific forms are identified. A calculation method of the scuffing load capacity of bevel and hypoid gears based on an integral temperature method is not available when this document is published. The formulae in this document are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα

ISO/TR 10300-30:2017 provides sample calculations for different bevel gear designs, how the load capacity is numerically determined according to the methods and formulae of the ISO 10300 series. The initial geometric gear data necessary for these calculations in accordance with ISO 23509. The term "bevel gear" is used to mean straight, helical (skew), spiral bevel, zerol and hypoid gear designs. Where this document pertains to one or more, but not all, the specific forms are identified. The manufacturing process of forming the desired tooth form is not intended to imply any specific process, but rather to be general in nature and applicable to all calculation methods of the ISO 10300 series. The fact that there are bevel gear designs with tapered teeth and others where the tooth depth remains constant along the face width (uniform depth) does not demand to apply Method B2 for the first and Method B1 for the second tooth configuration. The rating system of the ISO 10300 series is based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα

ISO 23509:2016 specifies the geometry of bevel gears. The term bevel gears is used to mean straight, spiral, zerol bevel and hypoid gear designs. If the text pertains to one or more, but not all, of these, the specific forms are identified. The manufacturing process of forming the desired tooth form is not intended to imply any specific process, but rather to be general in nature and applicable to all methods of manufacture. The geometry for the calculation of factors used in bevel gear rating, such as ISO 10300 (all parts), is also included. ISO 23509:2016 is intended for use by an experienced gear designer capable of selecting reasonable values for the factors based on his/her knowledge and background. It is not intended for use by the engineering public at large. Annex A provides a structure for the calculation of the methods provided in this document.

ISO/TR 22849:2011 provides information for the application of bevel and hypoid gears using the geometry in ISO 23509, the capacity as determined by ISO 10300 (all parts) and the tolerances in ISO 17485. ISO/TR 22849:2011 provides additional information on the application, manufacturing, strength and efficiency of bevel gears for consideration in the design stage of a new bevel gear set.

ISO 10300-2:2014 specifies the basic formulae for use in the determination of the surface load capacity of straight and helical (skew), Zerol and spiral bevel gears including hypoid gears, and comprises all the influences on surface durability for which quantitative assessments can be made. ISO 10300-2:2014 is applicable to oil lubricated bevel gears, as long as sufficient lubricant is present in the mesh at all times. The formulae in ISO 10300-2:2014 are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of Ɛvα

ISO 10300-3:2014 specifies the fundamental formulae for use in the tooth root stress calculation of straight and helical (skew), Zerol and spiral bevel gears including hypoid gears, with a minimum rim thickness under the root of 3,5 mmn. All load influences on tooth root stress are included, insofar as they are the result of load transmitted by the gearing and able to be evaluated quantitatively. Stresses, such as those caused by the shrink fitting of gear rims, which are superposed on stresses due to tooth loading, are intended to be considered in the calculation of the tooth root stress, σF, or the permissible tooth root stress σFP. ISO 10300-3:2014 is not applicable in the assessment of the so-called flank breakage, a tooth internal fatigue fracture (TIFF). The formulae in ISO 10300-3:2014 are based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of Ɛvα

ISO 10300-1:2014 specifies the methods of calculation of the load capacity of bevel gears, the formulae and symbols used for calculation, and the general factors influencing load conditions. The formulae are intended to establish uniformly acceptable methods for calculating the pitting resistance and bending strength of straight, helical (skew), spiral bevel, Zerol and hypoid gears. They are applicable equally to tapered depth and uniform depth teeth. The term "bevel gear" refers to all of these gear types; if not the case, the specific forms are identified. The formulae take into account the known major factors influencing pitting on the tooth flank and fractures in the tooth root. The rating formulae are not applicable to other types of gear tooth deterioration such as plastic yielding, micropitting, case crushing, welding, and wear. The bending strength formulae are applicable to fractures at the tooth fillet, but not to those on the active flank surfaces, to failures of the gear rim or of the gear blank through the web and hub. Pitting resistance and bending strength rating systems for a particular type of bevel gears can be established by selecting proper values for the factors used in the general formulae. If necessary, the formulae allow for the inclusion of new factors at a later date. The rating system of ISO 10300 (all parts) is based on virtual cylindrical gears and restricted to bevel gears whose virtual cylindrical gears have transverse contact ratios of εvα

ISO 23509:2006 specifies the geometry of bevel gears. The term bevel gears is used to mean straight, spiral, zerol bevel and hypoid gear designs. If the text pertains to one or more, but not all, of these, the specific forms are identified. ISO 23509:2006 is intended for use by an experienced gear designer capable of selecting reasonable values for the factors based on his knowledge and background. It is not intended for use by the engineering public at large.

Specifies the fundamental formulae for use in the tooth-bending stress calculation of straight and helical (skew), zerol- and spiral-bevel gears with a minimum rim thickness under the root 3,5 mmm. All load influences on tooth stress are included, insofar as they are the result of load transmitted by the gearing and able to be evaluiated quantitatively. (Stresses such as those caused by the shrink-fitting of gear rims, which are superposed on stresses due to tooth loading, are to be taken into consideration in the calculation of the tooth root stress ofp or the permissible tooth root stress ofp.)