HelicalGearSet

Model ElementSpecifies a helical gear set. Construction of two paired helical gears.

Class Name

HelicalGearSet

Description

The HelicalGearSet is defined by the following dimensions (see comment 10):

Attributes

The table below summarizes the attributes of the HelicalGearSet classes.

Variable	Type	Notes	Symbol
id	Int()	Unique identification number.
label	Str()	Descriptor of the gear set element.
rm	Reference("Marker", required=True)	The reference marker of the gear set element. This marker points to the center of gear 1. Defines the orientation of the gears (z axis of reference marker is the gear’s axial axis).
rm_2	Reference("Marker")	The reference marker of gear 2. This Marker needs to have the same orientation of the z-axis with the rm (axial direction), and its origin should be on the plane that is defined from the z axis of the rm (Inplane to the z axis of rm). The operating center distance is calculated from the two reference markers and is used as an input for the gear set.
module	Double(required=True)	The normal module of the gear.	$m_{n}$
num_of_teeth_1	Int(required=True)	The number of teeth on gear 1 (see comments 5, 7).	$z_{1}$
num_of_teeth_2	Int(required=True)	The number of teeth on gear 2 (see comments 5, 7).	$z_{2}$
gear_ratio	Double(required=True)	The gear ratio (see comments 5, 7).	$u$
pressure_angle	Double(required=True)	The normal pressure angle in degrees.	$a_{n}$
helix_angle	Double(required=True)	The helix angle at the pitch diameter in degrees.	$β$
width_1	Double(required=True)	The width of gear 1.	$b_{1}$
width_2	Double(required=True)	The width of gear 2.	$b_{2}$
addendum_coefficient	Double(1.0)	The basic rack addendum coefficient.	$h_{a}^{*}$
dedendum_coefficient	Double(1.25)	The basic rack dedendum coefficient.	$h_{f}^{*}$
tool_tip_radius_coefficient	Double(0.38)	The basic rack tool tip radius coefficient.	$r_{f}^{*}$
hub_diameter_1	Double(0.0)	The inner/outer diameter of gear 1.	$d_{i / o 1}$
hub_diameter_2	Double(0.0)	The inner/outer diameter of gear 2.	$d_{i / o 2}$
x1	Double(0.0)	The profile shift coefficient of gear 1 (see comment 6).	$x_{1}^{*}$
x2	Double(0.0)	The profile shift coefficient of gear 2 (see comment 6).	$x_{2}^{*}$
j1	Double(0.04)	The circumferential backlash ratio of gear 1. The range should be (0.03 – 0.05) (see comment 2).	$j_{1}^{*}$
j2	Double(0.04)	The circumferential backlash ratio of gear 2. The range should be (0.03 – 0.05) (see comment 2).	$j_{2}^{*}$
g1_connection_part	Reference(“Part", required=True)	The part that is connected to gear 1.
g2_connection_part	Reference(“Part", required=True)	The part that is connected to gear 2.
g1_connection_type	Enum("REVOLUTE FIXED ", default=" FIXED ")	The type of connection between gear 1 and the connected part.
g2_connection_type	Enum("REVOLUTE FIXED ", default=" FIXED ")	The type of connection between gear 2 and the connected part.
num_curve_segments	Int(10)	The number of mesh segments along the involute profile of each gear. When using non-uniform mesh, this parameter is always an even number (the profile is split into two symmetric regions).
num_width_segments	Int(20)	The number of mesh segments along the width of each gear.
non_uniform_factor	Double(1.2)	Defines the factor of the mesh’s non-uniformity. The length of a triamesh element is equal to the previous element length times this factor. Use 1.0 for a uniform mesh.
density	Double()	The density of the gear's material (see comment 4).
contact_creation	Bool(True)	Activates an IMPACT contact between the two gears (see Contact IMPACT).
contact_stiffness	Double(1e5)	Specifies the stiffness parameter of the gear's contact (see Contact IMPACT `stiffness`).
contact_exponent	Double(2.1)	Specifies the exponent of the force deformation characteristic of the gear's contact (see Contact IMPACT `exponent`).
contact_damping	Double(1.0)	Specifies the maximum damping coefficient that is to be used for generating a damping force on the gear's contact (see Contact IMPACT `damping`).
contact_dmax	Double(0.1)	Specifies the penetration at which full damping is applied in the gear's contact (see Contact IMPACT `dmax`).
contact_coulomb_friction	Enum("ON OFF DYNAMICS_ONLY", default="OFF")	Specifies the friction force model that will be used to compute the gear's contact friction force (see Contact IMPACT `coulomb_friction`).
contact_mu_static	Double(0.2)	Defines the coefficient of static friction in gear's contact when the friction is in the static regime (see Contact IMPACT `mu_static`).
contact_mu_dynamic	Double(0.1)	Defines the coefficient of dynamic friction in gear's contact when the friction is in the dynamic regime (see Contact IMPACT `mu_dynamic`).
contact_stiction_transition_velocity	Double(1.0)	Defines the slip velocity at which the static coefficient of friction, mu_static, is applied (see Contact IMPACT `mu_ stiction_transition_velocity`).
contact_friction_transition_velocity	Double(1.5)	Defines the slip velocity at which the dynamic coefficient of friction, mu_dynamic, is applied (see Contact IMPACT `mu_stiction_transition_velocity`).
export_graphic	Bool(False)	Exports the gears' geometries to two *.stl files. These files can be re-meshed in HyperMesh.
export_parameters	Bool(False)	Exports the calculated gear set and gear's parameters in a *.json file.

Example

g = HelicalGearSet (
    id=1,
    label='Helical gear set',
    rm=Marker(part=ground),
    rm_2=Marker(part=B_Ground, qp=[center_distance, 0, 0], rm=rm),
    
    module=1.0,
    num_of_teeth_1=17,
    num_of_teeth_2=35,
    gear_ratio=2.06,
    pressure_angle=20.0,
    helix_angle=15.0,
    width_1=10.0,
    width_2=9.0,

    addendum_coefficient=1.0,
    dedendum_coefficient=1.25,
    tool_tip_radius_coefficient=0.38,

    hub_diameter_1=0.0,
    hub_diameter_2=0.0,

    x1=0.2,
    x2=-0.1,

    j1=0.04,
    j2=0.04,

    g1_connection_part=B_Ground,
    g2_connection_part=B_Ground.

    g1_connection_type='FIXED',
    g2_connection_type='FIXED', 

    num_width_segments=20,
    num_curve_segments=10,
    non_uniform_factor=1.2,

    density=7.85e-06,

)