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:
Figure 1.
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. | |
| roller_contour_radius | Double(required=True) | The rolling element contour radius. | rs |
| 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,
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,
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,
)