Roller Bearings
All of the below functions can be found in the roller_bearings
module of the package.
Functions related to roller bearings.
-
fcylrolbear(ang_pos, comb_prof, ax_rol, f_rad, rad_clear=0, max_dif=0.0005)[source]
Calculate the normal force distribution in a cylindrical roller bearing
according to DIN 26281. For the calculation, each roller is modelled as a
set of neighbouring spring slices with known stiffness. Applying an outer
force f_rad leads to an elastic displacement of the spring slices
of each roller. To find the normal force on each roller, the spring slice
displacement is varied systematically until the sum of the inner spring
forces is (approximately) equal to the outer force f_rad.
| Parameters: |
- ang_pos (ndarray) – The angular positions of the rollers in angular coordinates. The length
of the array determines the number of rollers.
- comb_prof (ndarray) – The combined 1D profile of the roller and the bearing inner/outer ring.
- ax_rol (ndarray) – The longitudinal axis of the roller with length
len(comb_prof).
The length of the axis determines the number of roller spring slices.
- f_rad (scalar) – The normal force acting on the inner ring of the bearing. The force acts
from the center of the bearing in the direction of the origin of the
polar axis.
- rad_clear (scalar, optional) – The radial clearance of the bearing. Default is 0.
- max_dif (scalar, optional) – The maximum allowed difference between the outer force
f_rad and
the sum over all roller forces (in percent of f_rad). Default
is 0.05 %.
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| Returns: |
- f_rols (ndarray) – The roller normal forces for each roller position in
ang_pos.
- disp_rols (ndarray) – The elastic normal displacement in the ring-roller contact for each
roller position in
ang_pos.
- delta_f (scalar) – The difference between the outer force
f_rad and the sum over
all roller forces in the direction of applied force, in units of force
(i.e., the difference between user input force and the force used for
the numerical calculation).
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-
kinaxthrustrolbear(rot_vel_1, mean_diam, ax_rol, diam_rol, rot_vel_2=0)[source]
Calculate the kinematics of an axial thrust roller bearing, for example
a bearing of type 81212. This function calculates the effective velocity
along the disc (washer) and roller raceway as well as the slip (in percent)
along the roller’s axis of rotation.
| Parameters: |
- rot_vel_1 (scalar) – The rotational velocity (in rpm) of the shaft washer of the bearing.
- mean_diam (positive scalar) – The mean diameter of the bearing (the diameter of the bearing where
there is zero slip in the contact).
- ax_rol (ndarray) – The axis of rotation of the roller, typically spanning from -length/2
to +`length`/2, where length is the length of the roller (or the
section of the roller length that is of interest for the calculation,
i.e., the points can be asymmetric about the center of the roller).
- diam_rol (positive scalar) – The diameter of the roller.
- rot_vel_2 (scalar) – The rotational velocity (in rpm) of the housing washer of the bearing.
By default, it is assumed that the housing washer is not rotating, so
rot_vel_2 = 0
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| Returns: |
- raceway_vel_eff (ndarray) – The effective velocity of the shaft washer along the roller axis.
- raceway_vel_rol (ndarray) – The raceway velocity of the roller along the roller axis.
- slip_rol (ndarray) – The roller slip (in percent) along the roller axis. This parameter is
calculated by comparing the raceway velocity of the roller (at each
point along its axis) to the ideal rolling velocity in the same point
(the velocity that would lead to zero slip).
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