Journal Bearings#

class AlignedJournalBearing(**kwds)#

Creates a journal bearing that can overtake radial loads.

The AlignedJournalBearing is a combination of a force element and optionally, a planar or inplane joint. The force element is a function of bearing dimensions, relative radial displacement, and velocity, as well as rotational velocity between the inner journal and outer bearing. The force can act only radially between the inner journal and outer bearing and does not account for tilting and axial misalignment.

The journal bearing is defined by the following dimensions:

Geometry of an aligned journal bearing. — Aligned Journal Bearing Geometry.#

Example

Connect two parts with an aligned journal bearing.#

from msolve import *
from msolve.machinery.journal_bearings.journal_bearings import AlignedJournalBearing

model = Model(output="aligned_journal_bearing")

ground = Part(ground=True)
global_ref = Marker(body=ground)

Units(mass="KILOGRAM", length="MILLIMETER", time="SECOND", force="NEWTON")
Accgrav(kgrav=-9.81)

marker_0 = Marker(body=ground, qp=[0,0,0], zv=[0,0,1], xv=[1,0,0])

part_0 = Part(ip=[5,5,5,0,0,0], mass=0.001, cm=Marker(qp=[0,0,0], zv=[0,0,1], xv=[1,0,0]))

jt_bearing_rev = Joint(type="REVOLUTE", i=part_0.cm.id, j=global_ref.id)

mot_driver = Motion(joint=jt_bearing_rev.id, dtype="VELOCITY", icdisp=0.0, function="STEP(TIME,0,0,1,1)")

ajb = AlignedJournalBearing(rm=marker_0, bearing=part_0, journal=ground, mu=5e-08,
                            width=40.0, rb=15.015, rj=15.0, method="gumbel_short",
                            internal_connection_type="INPLANE", lubrication_force_graphics=True,
                            contact=True, contact_stiffness=1000.0, contact_exponent=2.1,
                            contact_damping=0.1, contact_dmax=0.1)

Name	Type	Symbol	Required	Default	Modifiable
`active`	Bool			True	\(\checkmark\)
`bearing`	Reference - `Part`		\(\checkmark\)
`contact`	Bool			True
`contact_damping`	Double			0.1
`contact_dmax`	Double			0.1
`contact_exponent`	Double			2.1
`contact_stiffness`	Double			1000
`force_graphics_scale`	Double			1
`id`	Int			Auto
`internal_connection_type`	Str			INPLANE
`journal`	Reference - `Part`		\(\checkmark\)
`label`	Str
`lubrication_force_graphics`	Bool			False
`method`	Enum
`mu`	Double			0.0
`na`	Int			7
`name`	Str
`nr`	Int			20
`output_rm`	Reference - `Marker`
`rb`	Double	\(R_{B}\)		0.0
`rj`	Double	\(R_{J}\)		0.0
`rm`	Reference - `Marker`		\(\checkmark\)
`width`	Double	\(l\)		0.0

active#

Defines the state of the object.

Type=Bool, Default=True, Modifiable

bearing#

The part that acts as the bearing.

Type=Reference (Part), Required

contact#

A flag that initiates Impact contact between journal and bearing graphics.

Type=Bool, Default=True

contact_damping#

Damping property of IMPACT contact element.

Type=Double, Default=0.1

contact_dmax#

dmax property of IMPACT contact element.

Type=Double, Default=0.1

contact_exponent#

Exponent property of IMPACT contact element.

Type=Double, Default=2.1

contact_stiffness#

Stiffness property of IMPACT contact element.

Type=Double, Default=1000

force_graphics_scale#

A scale for the visualization of the lubrication force graphics vector.

Type=Double, Default=1

id#

The id of the object.

Type=Int

internal_connection_type#

The type of joint used to constrain the journal and the bearing together, so the formulation is applied correctly.

Type=Str, Default=INPLANE

journal#

The part that acts as the journal.

Type=Reference (Part), Required

label#

The label of the composite element.

Type=Str

lubrication_force_graphics#

A flag that creates 3D lubrication force vectors at discrete points around the journal circumference.

See Comment 3.

Type=Bool, Default=False

method#

The hydrodynamic lubrication type that defines the expressions for the hydrodynamic forces.

See Comment 2.

Type=Enum

Permitted values are:

dynamic_gumbel_long
dynamic_gumbel_short
gumbel_long
gumbel_short
sommerfeld_long
sommerfeld_short

mu#

The lubricant fluid dynamic viscosity.

Type=Double, Default=0.0

na#

The number of axial segments used for the misaligned journal bearing GFOSUB, force vector graphics and Max pressure/ MOFT REQSUB.

See Comment 5.

Type=Int, Default=7

name#

Defines a nametag for the object.

Type=Str

nr#

The number of radial segments used for the misaligned journal bearing GFOSUB, force vector graphics and Max pressure/ MOFT REQSUB.

See Comment 5.

Type=Int, Default=20

output_rm#

The Marker in which the results are written.

See Comment 4.

Type=Reference (Marker)

rb#

The bearing radius.

Type=Double, Default=0.0

rj#

The journal radius.

Type=Double, Default=0.0

rm#

The reference marker of the composite element.

Type=Reference (Marker), Required

width#

The journal bearing axial width.

Type=Double, Default=0.0

class MisalignedJournalBearing(**kwds)#

Creates a journal bearing that can overtake radial loads and misaligned moments.

The MisalignedJournalBearing is a combination of a force element and optionally, an inplane joint. The force element is a function of bearing dimensions, relative radial, and angular displacement and the velocity between the inner journal and outer bearing. The force element applies radial forces and alignment moments between the inner journal and outer bearing. It does not account for axial misalignment.

The journal bearing is defined by the following dimensions:

Geometry of a misaligned journal bearing. — Misaligned Journal Bearing Geometry.#

Example

Connect two parts with a misaligned journal bearing.#

from msolve import *
from msolve.machinery.journal_bearings.journal_bearings import MisalignedJournalBearing

model = Model(output="misaligned_journal_bearing")

ground = Part(ground=True)
global_ref = Marker(body=ground)

Units(mass="KILOGRAM", length="MILLIMETER", time="SECOND", force="NEWTON")
Accgrav(kgrav=-9.81)

marker_0 = Marker(body=ground, qp=[0,0,0], zv=[0,0,1], xv=[1,0,0])

part_0 = Part(ip=[5,5,5,0,0,0], mass=0.001, cm=Marker(qp=[0,0,0], zv=[0,0,1], xv=[1,0,0]))

jt_bearing_rev = Joint(type="REVOLUTE", i=part_0.cm.id, j=global_ref.id)

mot_driver = Motion(joint=jt_bearing_rev.id, dtype="VELOCITY", icdisp=0.0, function="STEP(TIME,0,0,1,1)")

mjb = MisalignedJournalBearing(rm=marker_0, bearing=part_0, journal=ground, mu=5e-08,
                               width=40.0, rb=15.015, rj=15.0, method="gumbel_short",
                               internal_connection_type="INPLANE", lubrication_force_graphics=True,
                               contact=True, contact_stiffness=1000.0, contact_exponent=2.1,
                               contact_damping=0.1, contact_dmax=0.1)

Name	Type	Symbol	Required	Default	Modifiable
`active`	Bool			True	\(\checkmark\)
`bearing`	Reference - `Part`		\(\checkmark\)
`contact`	Bool			True
`contact_damping`	Double			0.1
`contact_dmax`	Double			0.1
`contact_exponent`	Double			2.1
`contact_stiffness`	Double			1000
`force_graphics_scale`	Double			1
`id`	Int			Auto
`internal_connection_type`	Str			INPLANE
`journal`	Reference - `Part`		\(\checkmark\)
`label`	Str
`lubrication_force_graphics`	Bool			False
`method`	Enum
`mu`	Double			0.0
`na`	Int			7
`name`	Str
`nr`	Int			20
`output_rm`	Reference - `Marker`
`rb`	Double	\(R_{B}\)		0.0
`rj`	Double	\(R_{J}\)		0.0
`rm`	Reference - `Marker`		\(\checkmark\)
`width`	Double	\(l\)		0.0

active#

Defines the state of the object.

Type=Bool, Default=True, Modifiable

bearing#

The part that acts as the bearing.

Type=Reference (Part), Required

contact#

A flag that initiates Impact contact between journal and bearing graphics.

Type=Bool, Default=True

contact_damping#

Damping property of IMPACT contact element.

Type=Double, Default=0.1

contact_dmax#

dmax property of IMPACT contact element.

Type=Double, Default=0.1

contact_exponent#

Exponent property of IMPACT contact element.

Type=Double, Default=2.1

contact_stiffness#

Stiffness property of IMPACT contact element.

Type=Double, Default=1000

force_graphics_scale#

A scale for the visualization of the lubrication force graphics vector.

Type=Double, Default=1

id#

The id of the object.

Type=Int

internal_connection_type#

The type of joint used to constrain the journal and the bearing together, so the formulation is applied correctly.

Type=Str, Default=INPLANE

journal#

The part that acts as the journal.

Type=Reference (Part), Required

label#

The label of the composite element.

Type=Str

lubrication_force_graphics#

A flag that creates 3D lubrication force vectors at discrete points around the journal circumference.

See Comment 3.

Type=Bool, Default=False

method#

The hydrodynamic lubrication type that defines the expressions for the hydrodynamic forces.

See Comment 2.

Type=Enum

Permitted values are:

gumbel_short
sommerfeld_short

mu#

The lubricant fluid dynamic viscosity.

Type=Double, Default=0.0

na#

The number of axial segments used for the misaligned journal bearing GFOSUB, force vector graphics and Max pressure/ MOFT REQSUB.

See Comment 5.

Type=Int, Default=7

name#

Defines a nametag for the object.

Type=Str

nr#

The number of radial segments used for the misaligned journal bearing GFOSUB, force vector graphics and Max pressure/ MOFT REQSUB.

See Comment 5.

Type=Int, Default=20

output_rm#

The Marker in which the results are written.

See Comment 4.

Type=Reference (Marker)

rb#

The bearing radius.

Type=Double, Default=0.0

rj#

The journal radius.

Type=Double, Default=0.0

rm#

The reference marker of the composite element.

Type=Reference (Marker), Required

width#

The journal bearing axial width.

Type=Double, Default=0.0