Leaf Ends

Use Leaf Ends to specify the type of spring ends that you want. There are three types: Eyes, Slipper-ends, and None.

Eyes
Connects the spring to the frame or shackle using a revolute joint or a bushing.
Slipper-ends
Transmits vertical force to the frame by sliding contact that allows the spring length to change as the spring deflects. A bracket on the frame captures the spring limiting lateral motion and a retaining pin typically prevents the spring from dropping out of the bracket in rebound.
None
Implies that the spring does not connect to the frame using a spring eye or slipper end, but by other means such as an air spring. It is incumbent upon the user to model the connection in MotionView after creating the leaf spring system in the builder.
Use the Leaf End Type drop-down menu to select Spring eye, Slipper end, or None.


Figure 1. Leaf Ends Panel in the Leaf Builder

Spring eyes and Slipper ends are described in greater detail below.

Spring Eye

Type
Defines the type of Spring Eye.


Figure 2. Available selections for spring eye
  • Upturned


    Figure 3.
  • Downturned


    Figure 4.
  • Berliner


    Figure 5.
Inner Radius
Defines the leaf end radius.
Eye Position
Defines either rear or front position of the leaf end.
Bushing
By selecting the bushing option, a new option Eye Bushing is displayed. The Eye Bushing drop-down menu lists all the bushings that are added in the Bushings Component.


Figure 6. Bushing Selection in Leaf Ends
Spring Eye Location
Defines the location of the leaf end. Represents the center of the rear eye hook with respect to either ‘Leaf_Ref_Loc’ or ‘BOLTLOCATION’ depending upon the shape condition.
Note: If the shape Condition is ‘PRE_ASSEMBLY’, the location should be defined with respect to the ‘BOLTLOCATION’ of ‘MASTER’ leaf.


Figure 7. Spring Eye Location in Leaf Ends

Slipper End

Another available option for leaf ends which is a step away from traditional spring eyes is slipper ends, where one end of the leaf spring or both ends comprises the open leaf which slides in a ‘bracket’ or ‘hanger’ which is welded to the chassis of the trailer.

The top surface of the bracket (contact pad) can have many shapes based on the requirement.

Here you can enter data for a primitive shape such as cylinder, for more refined shapes you will have to replace the primitive slipper bracket graphic with a refined one in MotionView.



Figure 8. Leaf Ends - Slipper End Type
Slipper Type (Round Surface)
By default, the round surface type is used. It is a cylindrical pin-based slipper end.
Leaf Contact Len
Defines an approximate length along the leaf surface that will make contact with the slipper end. It is centered about the slipper center location.
Pad Radius
Defines the radius of the cylindrical slipper end.
X
Center X location of the slipper end.
Z
Center Z location of the slipper end.
Retaining Pin Details
Pin Radius
Defines the radius of the cylindrical pin.
X
Center X location of the retaining pin.
Z
Center Z location of the retaining pin.
Side Contact Details
Width
Length of the bracket along Y direction.
Height
Length of the bracket along Z direction.
Depth
Length of the bracket along X direction.

Leaf Ends for Leaf Property File (*lpf)

An example of how a Leaf Ends block is represented in a TiemOrbit file format is shown below:
$------------------------------------------LEAF_ENDS
[LEAF_ENDS]
FRONT = 'FRONT_EYE_HOOK'
REAR = 'REAR_EYE_HOOK'
Block Name = ‘LEAF_ENDS’ (Required)
Attributes Type Valid Value Required
Front String 'Front_Leaf_End’,

‘Front_Eye_Hook’

 Yes
Rear String 'Rear_Leaf_End’,

'Rear_Eye_Hook'

 Yes

Rear Leaf End for Leaf Property File (*lpf)

An example of how a Rear Leaf End block is represented in a TiemOrbit file format is shown below:
$-----------------------------------------REAR_LEAF_END
[REAR_LEAF_END]
ENDTYPE = ‘SPRING EYE’
INNERRADIUS = 20.0
LOCATION – [636.027, 0.0, 140.0]
TYPE = ‘UPTURNED’
Note: A Rear Leaf End block is required only if block name has been defined in the “Leaf_Ends” block.
Block Name = ‘Rear_Leaf_End’ (Required)
Attributes Type Valid Value Required
EndType String 'Spring Eye'

'Slipper End'

 Yes
Type String ‘Berliner’,

‘upturned’,

‘downTurned’

 Yes
innerRadius Real - Yes
Location List [x,y,z] Optional

Front Leaf End for Leaf Property file (*lpf)

An example of how a Front Leaf End block with Slipper End is represented in a TiemOrbit file format is shown below:
$-------------------------------------FRONT_LEAF_END
[FRONT_LEAF_END]
BLOCKNAME = ‘FRONT_LEAF_END’
ENDTYPE = ‘SLIPPER END’
SLIPPERTYPE = ‘ROUND SURFACE’
(PINDATA)
PINCONTACTPROP = ‘METAL_METAL’
PINLOCX = -530.0
PINLOCZ = 110.0
PINRADIUS = 20.0
(SIDECONTACTDATA)
DEPTH = 5.0
HEIGHT = 50.0
SIDECONTACTPROP = ‘METAL_METAL’
WIDTH = 85.0
(SLIPPERDATA)
LEAFCONTACTLEN = 100.0
PADCONTACTPROP = ‘METAL_METAL’
PADLOCX = -530.0
PADLOCZ = 190.0
PADRADIUS = 30.0
Note: A Front Leaf End block is only required if block name has been defined in the “Leaf_Ends” block.
Block Name = ‘Front_Leaf_End’ (Required)
Attributes Type Valid Value Required
EndType String 'Spring Eye'

'Slipper End'

 Yes
Slipper Type String 'Round Surface' Yes

Slipper Data for Leaf Property file (*lpf)

Block Name = ‘Front_Leaf_End’ (Required)
Sub-Block Name = ‘SLIPPERDATA’ (Required)
Attributes Type Valid Value Required
Leaf Contact Length Real - Yes
Pad Contact Property String 'METAL_METAL' Yes
Pad Location X Real - Yes
Pad Location Z Real - Yes
Pad Radius Real - Yes

Retaining Pin Data for Leaf Property file (*lpf)

Block Name = ‘Front_Leaf_End’ (Required)
Sub-Block Name = ‘PINDATA’ (Required)
Attributes Type Valid Value Required
Pin Contact Property String 'METAL_METAL' Yes
Pin Location X Real - Yes
Pin Location Z Real - Yes
Pin Radius Real - Yes

Retaining Side Contact Data for Leaf Property file (*lpf)

Block Name = ‘Front_Leaf_End’ (Required)
Sub-Block Name = ‘SIDECONTACTDATA’ (Required)
Attributes Type Valid Value Required
Side Contact Property String 'METAL_METAL' Yes
Width Real - Yes
Height Real - Yes
Depth Real - Yes