- Lead precision. Lead precision of ball screw of CIE Auto Source Industry Co.,Ltd takes ISO 3408-4 as base, and according to using range and requirements, it is divided into orientation ball screw assembly (P) and transmission ball screw assembly (T), and the precision is divided into seven grades, they are 1,2,3,4,5,7 and 10, grade 1 is the highest.
- Change volumes within random 300mm journey and 2 π radian journey are as follows:
Symbol |
Inspection content |
Symbol |
Precision grade |
|
1 |
2 |
3 |
4 |
5 |
7 |
10 |
|
1 |
Change volume within random 300mm journey |
V300p |
6 |
8 |
12 |
16 |
23 |
52 |
210 |
|
2 |
Change volume within random 2π radian journey (this item is only suitable for P type ball screw assembly) |
V2πp |
4 |
5 |
6 |
7 |
8 |
|
|
- Clearance at axial direction. Preloading grade of axial clearance of COMTOP precise ball screw is as follows:
Grade |
P0 |
P1 |
P2 |
P3 |
P4 |
|
Clearance |
With |
Without |
Without |
Without |
Without |
|
Pre-pressure |
Without |
Without |
Light |
Middle |
Heavy |
- Reference values of selected precision, clearance, preloading grade and screw cap
| Precision |
Preloading and clearance |
Screw cap |
Screw |
|
C10 |
(P0) with clearance |
Single screw cap |
Cold rolled and Milling |
|
C7 |
P1 or P0 (Standard) |
According to COMTOP catalog |
Cold rolleed and milling grade |
|
C5 |
P1 or P2 (Standard) |
According to COMTOP catalog |
Milling grade |
|
C3 |
P1 or P2 (Standard) or P3 |
According to COMTOP catalog |
Milling grade |
Clearance (P0)
Cold rolled and milling grade ball screw (P0) max axial clearance Unit: mm
Dimension of outer diameter of screw |
Max axial clearance of cold rolled ball screw |
Max axial clearance of milling grade ball screw |
|
Miniature ball screw with diameter of 04-14 |
0.05 |
0.015 |
|
Middle dimension of ball screw with diameter of 15-40 |
0.08 |
0.025 |
|
Large dimension of ball screw with diameter of 50-100 |
0.12 |
0.05 |
- Reference value of preloading (P2) in common use
Specification |
Spring force of single screw cap (KG) |
Spring force of double screw cap (KG) |
|
1605 |
0.1-0.3 |
0.3-0.6 |
|
2005 |
0.1-0.3 |
0.3-0.6 |
|
2505 |
0.2-0.5 |
0.3-0.6 |
|
3205 |
0.2-0.5 |
0.5-0.8 |
|
4005 |
0.2-0.5 |
0.5-0.8 |
|
2510 |
0.2-0.5 |
0.5-0.8 |
|
3210 |
0.3-0.6 |
0.5-0.8 |
|
1040 |
0.3-0.6 |
0.5-0.8 |
|
5010 |
0.3-0.6 |
0.8-1.2 |
|
6310 |
0.6-1.0 |
0.8-1.2 |
- Precision of axis
Model Grade of outer diameter of guide screw |
C7 |
C10 |
|
1605 1610 2005 2505 |
0.04mm |
0.10mm |
|
2510 3205 3210 |
0.07mm |
0.17 |
|
4005 4010 5010 |
0.10 |
0.20 |
- Precision and testing method of precision of ball screw’s installation position:
- Take axes A of screw groove face as frame of reference to test run-out value of circumference at radial direction.
- Take axes F, which lies in the supporting part of screw, as frame of reference to measure coaxial degree of accessories’ installation position.
- Take axes E, which lies in the supporting part of screw shaft, as frame of reference to measure right angle degree of the surface of supporting part.
- Take axes G of screw as frame of reference to measure right angle degree of screw cap’s datum plane or the installation surface of flange.
- Take axes A of screw as frame of reference to measure coaxial degree of circle (cylinder type) of screw cap’s peripheral.
- Take axes C of screw as frame of reference to measure parallelism of peripheral of screw cap (flat type installation surface)
- General run-out valve of screw axes at radial direction.
- The precisions here take JIS B 1191、1192 as standard.
- B: Testing method of precision of installation position:
Put the ball screw on V-shaped cushion iron of AA at the time of testing, meanwhile, let testing head of the two dial indicators vertically touch surface of axial column respectively, slowly turn guide screw and write down change range of reading of the two dial indicators, calculate max tolerance of the reading, that is required warp, then check the guide screw with checkout apparatus, control this warp within allowed range through the control to guide screw.
Note: allowed error
- When l6>l, the allowed error is t7a<=t7p(l7/l)
When testing, put the ball screw in V-shaped cushion iron terrine of AA, let the gauge head vertically touch column surface of guide screw at the distance of 15, turn guide screw slowly, write down max tolerance value of the reading, test within fixed measuring interval over and over again to receive max value.
Note: when l1<2l5, can be measure at l1/2
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