# SphericalRollerBearing

Model ElementSpecifies an analytical bearing that overtakes the radial and axial loads in both directions. This bearing cannot overtake any tilting moments.

## Class Name

SphericalRollerBearing

## Description

The bearing is defined by the following dimensions:

## Attributes

The table below summarizes the attributes of the SphericalRollerBearing classes.

Variable  Type  Notes  Symbol
id Int() Unique identification number.
label Str() Descriptor of the bearing element.
rm Reference("Marker", required=True) The reference marker of the bearing element.

This marker points to the center of the bearing.

Defines the orientation of the bearing (z axis of reference marker is the bearing axial axis).

The rm part must always be on the housing of the system.

number_of_rollers Int(required=True) The number of rolling elements at the bearing in a single row.
pitch_diameter Double(required=True) The pitch diameter of the bearing. dp
width Double(required=True) The width of the bearing. b
contact_angle Double(required=True) The contact angle of the bearing. Defined in degrees [deg]. a0
inner_diameter Double(required=True) The inner diameter of the bearing. d
inner_shoulder_diameter Double() The inner ring shoulder diameter. The default value is calculated internally as a function of the pitch diameter and other input parameters. d1
outer_diameter Double(required=True) The outer diameter of the bearing. D
outer_shoulder_diameter Double() The outer ring shoulder diameter. The default value is calculated internally as a function of the pitch and outer diameters. D1
roller_diameter Double(required=True) The rolling element diameter. dr
roller_length Double(required=True) The rolling element length.
bearing_clearance Double(0.0) The bearing clearance. Apply the correct clearance for each bearing.
inner_race_conformity Double(0.52) This value expresses the relation or rolling element contour radius (rs) to the inner raceway groove radius (ri):

(fi: inner race conformity fi = ri / 2*rs, 0.51 < fi < 0.54)

outer_race_conformity Double(0.53) This value expresses the relation or rolling element contour radius (rs) to the outer raceway groove radius (ro):

(fo: outer race conformity fo= ro / 2*rs, 0.51 < fo < 0.54)

angular_offset Double(0.0) This parameter specifies the angular offset between the two rows of the rolling elements. It is the measure of asymmetry in SRBs.

Defined in degrees [deg].

young_modulus Double() The young modulus of the bearing components. See Comment 2.
poisson_ratio Double() The Poisson ratio of the bearing components. See Comment 2.
bearing_density Double() The density of the bearing parts. See Comment 2.
roller_pass_frequency Bool (True) Defines if the bearing rotates with the inner and outer shaft. Default is set to True. Deactivating the rotation improves the computational performance, but neglects excitations caused by rollers passing through the loading zone.
friction_torque Bool (False) Activates the friction torque in the bearing.
simplified_graphics Bool (False) Creates simplified graphics for bearing rings and avoids graphics for rollers.

This can reduce the H3D file size for large models.

rollers_force_graphics Bool (False)  Activates force vector graphics in the rolling elements.
vec_gra_scale Double(1.0) Scales the rollers force vector graphics.
damping_force Bool (True) Activates the damping force in the bearing.
output_rm Reference("Marker")        Defines the reference marker where output results are written.

The default value is the defined bearing reference marker (rm).

damping_ratio Double(0.1) The damping ratio of the bearings. This value must be between 0.0-1.0.
lubricant_viscosity Double(0.0) The lubricant viscosity of the bearing in [cSt]. It is used in the friction torque calculation.
lubrication_method Enum("grease

oil_mist

oil_bath

oil_jet",

default="grease")

The lubrication method of the bearing. It is used in the friction torque calculation.
calculation_factor_y0 Double(0.0) Defines the calculation factor Y0 for the SRB, where: P0 = Fr + Y0 · Fa is the basic static equivalent radial load. It is used in the friction torque calculation.
transition_velocity Double(0.1) The angular velocity at which the friction torque takes full effect [rad/sec]. Friction is ramped up smoothly from 0 until the transition velocity for solver stability.
inner_connection_part Reference("Part", required=True) The part/shaft that connects to the inner ring. See Comment 1.
outer_connection_part Reference("Part", required=True) The part/shaft that connects to the outer ring. See Comment 1.
na Int(60) Defines the number of nodes in the perimeter of the ring graphics.
nc Int(6) Defines the number of nodes in the raceway of the ring graphics.
no Int(2) Defines the number of nodes in the width of the ring graphics.

## Example

b = SphericalRollerBearing(
id=1,
label='bearing',
rm=Marker(part=ground),

number_of_rollers=15,
pitch_diameter=39.5,
width=18.0,

roller_diameter=7.13,

roller_length=6.0,

inner_diameter=25.0,
inner_shoulder_diameter=31.3,

outer_diameter=52.0,
outer_shoulder_diameter=44.2,

bearing_clearance=0.024,
contact_angle=13.2,

inner_race_conformity=0.52,
outer_race_conformity=0.53,

young_modulus=210000,
poisson_ratio=0.3,
bearing_density=7.85e-06,

roller_pass_frequency=True,
friction_torque=True,
damping_force=True,

damping_ratio=0.1,

lubricant_viscosity=80,
lubrication_method='grease',
calculation_factor_y0=1.8,

inner_connection_part=b_shaft,
outer_connection_part=B_Ground,

)