BS ISO 6336-6 pdf free download
BS ISO 6336-6-2019 pdf free download.Calculation of load capacity of spur and helical gears Part 6: Calculation of service life under variable load.
This document specifies the information and standardized conditions necessary for the calculation of the service life (or safety factors for a required life) of gears subject to variable loading for only pitting and tooth root bending strength.
If this scope does not apply, refer ISO 6336-1:2019, Clause 4.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1122-1:1998, Vocabulary of gear terms — Part 1: Definitions related to geometry
ISO 6336-1, Calculation of load capacity of spur and helical gears —Part 1: Basic principles, introduction and general influence factors
ISO 6336-2, Calculation of load capacity of spur and helical gears — Part 2: Calculation of surface durability (pitting)
ISO 6336-3, Calculation of load capacity of spur and helical gears — Part 3: Calculation of tooth bending strength
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6336-1 and ISO 1122-1:1998 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.2 Symbols and abbreviated terms
For the purposes of this document, the symbols and abbreviated terms given in ISO 6336-1,ISO 1122-1:1998 and Table 2 apply.
4 General 4.1 Determination of load and stress spectra Variable loads resulting from a working process, starting process or from operation at or near a critical speed will cause varying stresses at the gear teeth of a drive system. The magnitude and frequency of these loads depend upon the driven machine(s), the driver(s) or motor(s) and the dynamic mass elastic properties of the system.
These variable loads (stresses) may be determined by such procedures as
— experimental measurement of the operating loads at the machine in question,
— estimation of the spectrum, if this is known, for a similar machine with a similar operating mode, and
— calculation, using known external excitation and a mass elastic simulation of the drive system, preferably followed by experimental testing to validate the calculation.
o obtain the load spectra for fatigue damage calculation, the range of the measured (or calculated) loads is divided into bins or classes. Each bin contains the number of load occurrences recorded in its load range. A widely-used number of bins is 64. These bins can be of an equal size, but it is usually better to use larger bin sizes at the lower loads and smaller bin sizes at the upper loads in the range. In this way, the most damaging loads may be limited to fewer calculated stress cycles and the resulting design is more accurate regarding the effective load. It is recommended that a zero-load bin be included so that the total time used to rate the gears matches the design operating life. For consistency, the usual presentation method is to have the highest torque associated with the lowest numbered bins, such that the most damaging conditions appear towards the top of any table. The cycle count for the load class corresponding to the load value for the highest loaded tooth is incremented at every load repetition. Table 3 shows as an example of how the torque classes defined in Table 4 can be applied to specific torque levels and correlated numbers of cycles.BS ISO 6336-6 pdf download.
