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:
Figure 1.
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=7.85e-06,
roller_length=6.0,
inner_diameter=25.0,
inner_shoulder_diameter=31.3,
inner_density=7.85e-06,
outer_diameter=52.0,
outer_shoulder_diameter=44.2,
outer_density=7.85e-06,
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,
)