Page 16 - Joyce - Jacks, actuators and systems

ENgiNEERiNg iNFORmATiON FAQ

1. What is the difference between upright 3. How is the linear travel speed 6. How is the clevis, T4 end,
and inverted jack configurations? calculated? Each screw jack and actuator positioned on a keyed jack?
The difference between an upright and an has an inherent number of input shaft turns
inverted jack is the location at which the per inch (TPI) of screw travel. TPI is the - Standard clevis mounting position –
lifting screw exits the jack relative to the result of the jack’s gear ratio divided by the the hole in the clevis end is parallel
jack base. For example, an upright jack’s lifting screw lead. The TPI can be found on with the worm input shaft.
lifting screw exits the jack opposite the jack specification pages at the beginning of
base. An inverted jack’s lifting screw exits many product sections. A model WJT242 - Optional mounting position – the hole
the jack on the same side as the base. has a TPI of 96. If 350 RPM is applied to in the clevis end is perpendicular to
The choice between inverted and upright the input shaft, the resultant linear speed of the worm input shaft.
jack is dependent upon the application. travel is 350/96 or 3.65 inches per minute.
What is the difference between upright
Note: An upright jack mounted upside down
and inverted jack conguration?
is still referred to as an upright jack. 4. Are screw jacks lubricated prior
to shipment? All Joyce machine screw
jacks and ComDRIVEs , ball screw jacks
®
and ComDRIVEs , bevel ball actuators,
®
integrated actuators, and electric
cylinders are lubricated with an extreme
pressure NLGI grade #1 grease before Standard Optional
leaving the factory.
Base
Bevel gear jacks are lubricated with NLGI
Upright Inverted grade #1 grease and oil. The upper bearing 7. How is the load pad, T2 end, positioned
Inverted Jack
Upright Jack
and jackscrew are grease lubricated while on keyed jacks?
the remaining internal components are - Standard load pad mounting position –
2. How can I determine worm shaft oil lubricated. They are grease lubricated the holes on the load pad are on the jack
How can I determine
rotation extending the lifting screw? prior to shipment; however oil must be
shaft rotation?
Refer to the views of the standard jack added to the unit prior to operation. centerlines.
with right hand screw threads below: - Optional load pad mounting position –
Screw Linear actuators (LA) are lubricated for life.
Extends Inverted Jack the holes on the load pad end straddle
- For an Upright jack: the jack centerlines.
CCW rotation of right input
shaft extends the lifting screw. 5. What are the standard end conditions
CW rotation of the left for screw jack lifting screws?
shaft extends lifting screw. The following standard end conditions are
Left Right Left Right available on Joyce/Dayton screw jacks:
Side - For an Inverted jack: Side Side
Side
CW rotation of right input - Type 1
shaft extends lifting screw. plain turned end
Upright Jack Screw
CCW rotation of the left
Extends
shaft extends lifting screw. Standard Optional
- Type 2
load pad with
mounting holes
- Type 3
male threaded end

- Type 4
male clevis end

Contact Joyce/Dayton for information

about custom end conditions.

16 joycedayton.com Custom products are available • Contact Joyce/Dayton with your requirements 800-523-5204
sales@joycedayton.com