Adams Car Package > Adams Driveline > Working with Components > Ravigneaux Gears

Ravigneaux Gears

 
Creating or Modifying Ravigneaux Gears
About Ravigneaux Gears
Example Ravigneaux Gear Property File
This component represents a Ravigneaux planetary gear set using a conceptual model.
Learn about Ravigneaux gears:

Creating or Modifying Ravigneaux Gears

To create or modify Ravigneaux gears:
1. From the Driveline Components menu, point to Ravigneaux Gear, and then select New/Modify.
2. Press F1 and then follow the instructions in the dialog box help for Ravigneaux Gear.
3. Select OK.

About Ravigneaux Gears

The Ravigneaux gear is a conceptual planetary gear set. The planets are not directly modeled. You define the gear set by specifying the suns, ring, carrier, the revolute joints that attach those parts, and a property file. The property file specifies the number of teeth on each of the sun gears and the ring gear.
User define a Ravigneaux planetary gear set by first building the following parts:
■Long pinion sun part (lp sun)
■Short pinion sun part (sp sun)
■Ring part
■Carrier part
User must attach these parts to the powerplant, and specify these joints when building the Ravigneaux gear:
■Long pinion sun joint
■Short pinion sun joint
■Ring joint
■Carrier joint
A construction frame determines the Ravigneaux gear axis.
The Ravigneaux gear connects the two sun parts to the two sun_lash parts (and the ring part to a ring_lash part). The sun_lash part is connected to the sun part through a revolute joint and a torque to model the gear lash and stiffness properties (defined using a property file). The same model technique is used for the ring. The torque expression uses the backlash formulation, as explained for rotational backlash rotational backlash.
The Ravigneaux gear ratio is set between lp sun lash part, sp sun lash part, ring part, and carrier part through two couplers, each enforcing the following constraint:
(r1 * q1) + (r2 * q2) + (r3 * q3) = 0
where r1, r2, and r3 are the scale factors for the three joints, and for each joint, q1, q2, and q3 are rotational displacements of the joint I marker with respect to the joint J marker.
Therefore, using the Willis formula, we can determine that the coupler factors are:
COUPLER 1 (sp_planetary_gear_ratios), acting between sp sun lash joint, carrier joint and ring lash joint:
r1: sp sun number of teeth applied to the sp sun joint
r2: (- sp sun number of teeth + ring number of teeth) applied to the carrier joint
r3: - ring number of teeth applied to the ring joint
COUPLER 2 (lp_planetary_gear_ratios), acting between lp sun lash joint, carrier joint, and ring lash joint:
r1: lp sun number of teeth applied to the lp sun joint
r2: - (lp sun number of teeth + ring number of teeth) applied to the carrier joint
r3: ring number of teeth applied to the ring joint
In the Standard Interface user can vary the property file. The property file specifies the lp sun, sp sun, and ring number of teeth.

Request Definition

 
Component name:
Component units:
Definition:
sp_sun_RPM
angular velocity
Angular velocity of the short pinion sun with respect to the powerplant.
lp_sun_RPM
angular velocity
Angular velocity of the long pinion sun with respect to the powerplant.
ring_RPM
angular velocity
Angular velocity of the ring with respect to the powerplant.
carrier_RPM
angular velocity
Angular velocity of the carrier with respect to the powerplant.
sp_sun_backlash
angle
Angular lash between the short pinion sun and its lash parts.
lp_sun_backlash
angle
Angular lash between the long pinion sun and its lash parts.
ring_backlash
angle
Angular lash between the ring and ring lash parts.
sp_sun_backlash_torque
torque
Torque acting between the short pinion sun and its lash parts.
lp_sun_backlash_torque
torque
Torque acting between the long pinion sun and its lash parts.
ring_backlash_torque
torque
Torque acting between the ring and ring lash parts.

Subsystem Parameters

Property file (<db_name>/gear_elements.tbl)

Example Ravigneaux Gear Property File

$----------------------------------------------------------MDI_HEADER
[MDI_HEADER]
FILE_TYPE = 'rgf'
FILE_VERSION = 1.0
FILE_FORMAT = 'ASCII'
HEADER_SIZE = 6
$---------------------------------------------------------------UNITS
[UNITS]
LENGTH = 'mm'
ANGLE = 'degrees'
FORCE = 'newton'
MASS = 'kg'
TIME = 'second'
$----------------------------------------------------RAVIGNEAUX_MODEL
[RAVIGNEAUX_MODEL]
RAVIGNEAUX_MODEL = 'conceptual'
LASH_MODEL = 'backlash' $allowed options are: 'backlash' , 'bistop'
$----------------------------------------------------SHORT_PINION_SUN
[SHORT_PINION_SUN]
NUMBER_OF_TEETH = 30
BACKLASH = 1
STIFFNESS = 1E+06
DAMPING = 1E+02
$ the following parameter is used if lash_model = 'backlash'
SHARPNESS = 100
$ the following 3 parameters are used if lash_model = 'bistop'
LASH_STIFFNESS_DIVISOR = 10
FORCE_DEFORMATION_EXPONENT = 1.3
FULL_DAMPING_PENETRATION = 1E-02
$-----------------------------------------------------LONG_PINION_SUN
[LONG_PINION_SUN]
NUMBER_OF_TEETH = 35
BACKLASH = 1
STIFFNESS = 1E+06
DAMPING = 1E+02
$ the following parameter is used if lash_model = 'backlash'
SHARPNESS = 100
$ the following 3 parameters are used if lash_model = 'bistop'
LASH_STIFFNESS_DIVISOR = 10
FORCE_DEFORMATION_EXPONENT = 1.3
FULL_DAMPING_PENETRATION = 1E-02
$----------------------------------------------------------------RING
[RING]
NUMBER_OF_TEETH = 80
BACKLASH = 1
STIFFNESS = 1E+06
DAMPING = 1E+02
$ the following parameter is used if lash_model = 'backlash'
SHARPNESS = 100
$ the following 3 parameters are used if lash_model = 'bistop'
LASH_STIFFNESS_DIVISOR = 10
FORCE_DEFORMATION_EXPONENT = 1.3
FULL_DAMPING_PENETRATION = 1E-02