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CUSTOMER RFQ TECHNICAL DATA SHEET:
Customer RFQ technical data sheet
Terminology & definitions
Dimension & section of ball screw
Permissible travel deviation and variation

 

Note: Please complete one data sheet for each screw size

 

 
Customer RFQ technical data sheet Back to top

 

Dear Customer,

Please fill-in the blanks the data You consider to be appropriate for your application and let us know as soon as possible by returning to: 

Fax: 40 21-255.78.27 or E-Mail: wpc@fx.ro 

 

Date:                   / / (dd/mm/yy)

 

Contact person:

Company Name:

& Address:         

E-mail:               

Phone:               

Fax:                    

 

 

Our identification:

Contact person ......... Marcel Dascaliuc

Position .................... Chief of Engineering

E-mail ....................... wpc@fx.ro 

Phone ....................... +40 21 255.00.19

Fax ........................... +40 21 255.78.27

Mobile ...................... +40 732 376.991

 

 

Swift Identification Data

Screw Size:

Nominal Diameter (see Glossary)............................... mm [See Note#1]

Nominal Lead........................................................... mm

Total Length (end to end)............................................ mm

Indicate part number if available..............................#

Engineering drawing available:

                     YES    Please attach and indicate Drawing

                                            Ref. No. :

                     NO

 

General data

1. Specifications (for more reference please ask for "WPC" catalog)

Screw shaft....................Nominal diameter: mm

Thread direction............Right                  Left

Nominal lead................. mm     Please include number of starts

Threaded length............ mm

Ball screw type..............Positioning    Transport

Nut type.......................Single           Double           Flanged

                                Yes                                         

                                 No                                         

             ........................Other (specify):    

Seal...............................Yes     If yes, check type: PTFE (Teflon) or Felt

       ...............................No

Indicate (in special cases) if nut is supported by:

                                       Ball bearing

                                       Roller bearing

 

2. Load conditions

Working axial load

     Maximum daN at rpm for % of operation time

     Medium    daN at rpm for % of operation time 

     Minimum  daN at rpm for % of operation time

 

Basic dynamic axial load rating [Ca]................daN

Basic static axial load rating [Coa] ..................daN

Ball screw assembly axial rigidity [Ru]..............daN/mm

Preload [Fpr] ................................................... daN

Equivalent load [Fm] ....................................... daN

Drag torque:

a) Total dynamic drag torque [Tt] - (with wipers)daNcm

b) Dynamic drag torque [Tp] - (without wipers)    daNcm

 

3. Operating conditions

Useful travel [Iu] ..............................................mm

Motor power used.............................................kW

Product Life Expectancy [L10]............................x106rev, km, hr

(see Glossary)

Rotating element .............................................Shaft            Nut  

Working position ..............................................Horizontal     Vertical

Shock/vibration conditions................................Smooth         Normal      High

Screw end fixity types (check one):

               Fixed-fixed      Floating-fixed     Floating-free  Floating-floating

4. Lead accuracy

Standard ISO tolerance grades (check box)     1    3    5    7    10

                                             Other (specify)     

Travel variation (complete all three a, b & c):

a) For one screw rotation [V2p] ....................... mm

b) For 300 mm displacement [V300] ................. mm

c) For useful travel [Vu] .................................... mm

Travel compensation [C] .................................. mm

Maximum axial play [backlash] [Sa] .................. mm

 

5. Miscellanous 

Lubrication type ...............................................Grease           Oil

Operating Temperature ....................................oC

 

Other specifications required as following

Type of oil hole ..........................            Special climatic protection .....................
Lubricant type/viscosity .............            Coating .................................................
Preloading type .........................            Special packing boxes ...........................
Ball diameter .............................            Special checking tests ...........................
Noise .........................................            Acceleration/ Deceleration ....................
Quantity ....................................            Other catalogues references ................
Housing/case ............................             Drive characteristics ..............................
Hollow ball screws .....................

 

6. Shipping & Delivery

Customer suggested delivery date  / / (dd/mm/yy)

Delivery conditions (please check one box)

         EXW        FCA        FOB        CFR        CIF        CPT        CIP        DDU

                                                                        

       

Note: if the Customer do not indicate otherwise, the delivery terms are to be understood Ex Works WPC, Romania.

Standard Packing boxes (according the quantity length and delivery type): wood boxes/crane or cardboard at request only.

    

NOTE #1: Technical references and definitions are according to ISO 3408-1 to 3/1991

NOTE #2: WPC produces screws with a "gothic (ogival) groove" profile [See ISO 3408-1 1991 E/F]

 

 

 

 
TERMINOLOGY & DEFINITIONS: (according ISO 3408-1 : 1991) Back to top
Positioning ball screw (type P) - Ball screw use for precision positioning which enables the indirect measurement axial travel from the angle of rotation and the lead, without backlash (preload).
Transport ball screw (type T) - Ball screw the travel of which is measured directly by a separate measuring system independent of the angle of rotation and lead of the ball screw.
Pitch circle diameter (Dpw) - The diameter of the cylinder containing the centers of the balls screw which are in contact with the screw shaft and the ball nut body at the theoretical contact points.
Nominal diameter (do) - The value used for shaft diameter designation (without tolerance).
Conformity (frs) (frn) - Ratio of the ball track radius of the ball screw shaft, ( rs ), or of the ball nut body,  ( rn ), to the ball diameter, ( Dw ).
Nominal contact angle (a) - The angle between a plane perpendicular to the ball screw shaft axis and the resultant of the forces transmitted by a ball track to a rolling element.
Backlash (axial play) (sa) - Total free axial displacement between the ball nut body and the ball screw shaft when there is no rotation between the two components.
Nominal lead (Ph0) - Lead value used for general identification of size (without tolerance).
Lead (Ph) - Product of the number of starts and nominal lead.
Starts number (i) - The number of starts of the thread.
Useful travel (lu) - The portion of the travel to which the specified accuracy is not applicable.
Nominal travel (lo) - The product of the nominal lead times the number of revolutions.
Specified travel (ls) - The product of the specified lead times the number of revolutions. In some cases, the specified travel is represented by a nominal travel and a travel compensation value. 
Travel compensation (c) - The difference between the specified travel and the nominal travel within the useful travel.
Travel variation:

~within useful travel

~within 300 mm travel

~within 2p rad 

  - The corresponding band width parallel to the actual mean travel.
(Vup) - Travel variation corresponding with band width of (Vup)
(V300p) - Travel variation corresponding with band width of (V300p)
(V2pp) - Travel variation corresponding with band width of (V2pp)
Tolerance on specified travel (ep) - Half the difference between the maximum and minimum values of the permissible actual mean travel, 2ep.
Life (L) - For an individual ball screw, the number of revolutions that the ball screw shaft makes in relation to the ball nut body before the first evidence of fatigue develops in the material of one of them or in the rolling elements.
Basic rating life (L10) - For an individual ball screw, or groove of apparently identical ball screws operating under the same conditions, the life associated with a 90% of achieving the stated life.
Basic dynamic axial load rating (Coa) - The static centric axial load that corresponds to a total permanent deformation of ball and track at the most heavily stressed point of contact between the ball and the ball track of 0,0001 times the ball diameter.
Basic static axial load rating (Ca) - The constant centric axial load that a ball screw can theoretically endure for a basic rating life of one million revolutions.
Equivalent load rating (Fm) - The mean load that will result in the same life as a combination of various loads.
Preload (Fpr) - Force applied on a group of balls and ball tracks, for example by their axial displacement relative to another group, to eliminate backlash and to increase rigidity.
Dynamic drag torque (Tp) - Torque required to rotate the preloaded ball nut relative to the ball screw shaft, or vice versa, in the absence of an internal load and any friction torque of the end seals.
Total dynamic drag torque (Tt) - Torque required to rotate the preloaded ball nut relative to the ball screw shaft, or vice versa, in the absence of an external load but including the friction torque of the end seals.
Column strength (Fc) - Maximum compressive axial load that can be applied to the ball screw without resulting in permanent structural deformation to it.
Axial rigidity; stiffness; spring rate

~stiffness

~spring rate

(R) - A measure of the resistance of the ball screw to axial deflection (load per unit of deflection).
- - The resistance to deflection (is expressed by spring rate).
- - The amount of elastic deformation under a certain load.
Critical speed (ncr) - Rotational speed of the bal nut or ball screw shaft that produces resonant vibrations of the ball screw.
DN rating value (DN) - The product of the Pitch Circle Diameter and the rotational speed of the ball screw (for WPC ball screws is less equal to 70000).
Spacer balls - - Balls smaller than load balls used when intend to reduce the contact friction.
Index « p » - Index for permissible values.
« a » - Index for actual values.

 

 

 

Dimensions & Section of ball screw and nut assembly Back to top

 

do       nominal diameter
d1       ball screw shaft outer diameter
d2       ball screw shaft root diameter
d3       journal diameter
D1       ball nut body outer diameter
D2       ball nut body root diameter
D3       ball nut body internal diameter
Dpw     pitch circle diameter
Dw       ball diameter
l        thread length
Ph        lead
a          nominal contact angle
φ           lead angle

 

 

Permissible travel deviation and travel variation in relation to the nominal travel Back to top

 

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