SphericalRollerBearing
Specifies an analytical bearing that overtakes 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:
Attribute Summary
The table below summarizes the attributes of the SphericalRollerBearing classes.
Variable  Type  Notes  Figure Symbol 

id  Int()  The unique identification number of the bearing element.  
label  Str()  The label 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 
inner_density  Double()  The inner ring density. Default value is calculated internally with respect to the units of the system. AISI 52100 steel has been chosen as the default material.  
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 
outer_density  Double()  The outer ring density. Default value is calculated internally with respect to the units of the system. AISI 52100 steel has been chosen as the default material.  
roller_diameter  Double(required=True)  The rolling element diameter.  dr 
roller_length  Double(required=True)  The rolling element length.  
roller_contour_radius  Double(required=True)  The rolling element contour radius.  rs 
roller_density  Double()  The rolling element's density. Cage part mass/inertia properties are calculated from rolling element's properties. Default value is calculated internally with respect to the units of the system. AISI 52100 steel has been chosen as the default material.  
bearing_clearance  Double(0.0)  The bearing clearance. Apply the correct clearance for each bearing.  
inner_race_conformity  Double(0.52)  These values express the relation or rolling element contour
radius (rs) with the inner raceway groove radius (ri): fi:
inner race conformity


outer_race_conformity  Double(0.53)  These values express the relation or rolling element contour
radius (rs) with the outer raceway groove radius (ro): fo:
outer race conformity


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 bearing components. Default value is calculated internally with respect to the units of the system. AISI 52100 steel has been chosen as the default material.  
poisson_ratio  Double()  The Poisson ratio of bearing components. Default value is calculated internally with respect to the units of the system. AISI 52100 steel has been chosen as the default material.  
rotating_bearing  Bool (True)  A flag that defines if the bearing is assumed rotated (useful for identifying generating frequencies).  
friction_torque  Bool (False)  A flag that activates the friction torque in the bearing.  
simplified_graphics  Bool (False)  A flag that creates simplified rings in the bearing (useful for smaller files in design iterations).  
damping_force  Bool (True)  A flag that activates the damping force in the bearing.  
output_rm  Reference("Marker")  Defines the reference marker in which the output results are
written. This does not affect calculation reference marker. The default value is the defined bearing reference marker (rm). 

damping_factor  Double(0.1)  The damping factor of the bearings. This value must be on the
range:


lubricant_viscosity  Double(0.0)  The lubricant viscosity of the bearing in [cSt]. Change the default value for correct calculation of friction torque (used for the friction torque calculation).  
lubrication_method  Enum("grease oil_mist oil_bath oil_jet", default="grease") 
The lubrication method of the bearing (used for the friction torque calculation).  
calculation_factor_y0  Double(0.0)  This parameter defines the calculation factor Y0 for the
SRB where: P0 = Fr + Y0 · Fa is the basic static equivalent radial load. Change the default value for correct calculation of friction torque (used for the friction torque calculation). 

translation_velocity  Double(0.1)  The angular velocity which defines the transition phase of the friction torque [rad/sec].  
inner_connection_part  Reference("Part", required=True)  The part the inner ring is connected to.  
outer_connection_part  Reference("Part", required=True)  The part the outer ring is connected to.  
na  Int(60)  Parameter that defines the number of nodes in the perimeter of the ring's graphics.  
nc  Int(6)  Parameter that defines the number of nodes in the raceway of the ring's graphics.  
no  Int(2)  Parameter that defines the number of nodes in the width of the ring's 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_density=7.85e06,
roller_length=6.0,
inner_diameter=25.0,
inner_shoulder_diameter=31.3,
inner_density=7.85e06,
outer_diameter=52.0,
outer_shoulder_diameter=44.2,
outer_density=7.85e06,
roller_contour_radius=23.295
bearing_clearance=0.024,
contact_angle=13.2,
inner_race_conformity=0.52,
outer_race_conformity=0.53,
angular_offset=math.radians(11.25),
young_modulus=210000,
poisson_ratio=0.3,
rotating_bearing=True,
friction_torque=True,
damping_force=True,
damping_factor=0.1,
lubricant_viscosity=80,
lubrication_method='grease',
calculation_factor_y0=1.8,
inner_connection_part=b_shaft,
outer_connection_part=B_Ground,
)