gearbox.standards.iso6336.bending

Tooth root strength of cylindrical gears according to ISO 6336-3.

class BendingResult

Bases: object

Result of an ISO 6336-3 tooth root stress calculation. Stresses are in MPa.

tooth_root_stress_pinion: float

sigma_F1.

tooth_root_stress_wheel: float

sigma_F2.

permissible_tooth_root_stress_pinion: float

sigma_FP1 (includes S_Fmin).

permissible_tooth_root_stress_wheel: float

sigma_FP2.

safety_factor_pinion: float

S_F1 = sigma_FP1 * S_Fmin / sigma_F1.

safety_factor_wheel: float

S_F2.

stress_correction_factor_reference: float

Y_ST, stress correction factor of the reference test gear.

size_factor_pinion: float

Y_X.

form_factor_pinion: float

Y_F.

stress_correction_factor_pinion: float

Y_S.

helix_angle_factor: float

Y_beta.

rim_thickness_factor_pinion: float

Y_B.

relative_notch_sensitivity_pinion: float

Y_delta_relT.

deep_tooth_factor: float

Y_DT.

life_factor_pinion: float

Y_NT.

relative_surface_factor_pinion: float

Y_R_relT.

dynamic_factor: float

K_v.

transverse_load_factor: float

K_F_alpha.

face_load_factor: float

K_F_beta.

__init__(tooth_root_stress_pinion, tooth_root_stress_wheel, permissible_tooth_root_stress_pinion, permissible_tooth_root_stress_wheel, safety_factor_pinion, safety_factor_wheel, stress_correction_factor_reference, size_factor_pinion, size_factor_wheel, form_factor_pinion, form_factor_wheel, stress_correction_factor_pinion, stress_correction_factor_wheel, helix_angle_factor, rim_thickness_factor_pinion, rim_thickness_factor_wheel, relative_notch_sensitivity_pinion, relative_notch_sensitivity_wheel, deep_tooth_factor, life_factor_pinion, life_factor_wheel, relative_surface_factor_pinion, relative_surface_factor_wheel, dynamic_factor, transverse_load_factor, face_load_factor)

class ToothRootGeometry

Bases: object

Critical-section geometry of the tooth root (ISO 6336-3, Method B), per gear.

__init__(load_angle_at_load_point, tooth_root_chord, root_fillet_radius, bending_lever_arm)

load_angle_at_load_point: float

alpha_Fen - gamma_e [rad].

tooth_root_chord: float

s_Fn [mm].

root_fillet_radius: float

rho_F at the critical section [mm].

bending_lever_arm: float

h_Fe [mm].

calculate_bending(transmission, *, static=False)

Compute the tooth root stress and permissible stress of both gears.

Parameters:

• transmission (Transmission) – The gear pair and its operating conditions.

• static (bool) – Evaluate the permissible stress for a static load: Y_NT is the value of the horizontal branch (table 3), Y_R_relT = Y_X = 1 and Y_delta_relT follows formulae (78) to (83), which need Material.yield_strength for St, V and GGG(perl.). The design life is ignored.

Returns:

A BendingResult with the stresses and every intermediate factor.

Raises:

ValueError – If a gear’s rim is too thin (s_R / h <= 0.5).

Return type:

BendingResult