TERMS OF LINEAR GUIDE

 

2-12 Model Number Coding

a. Accuracy standard

 

Unit : mm

ITEM GRADE	Normal(N)	High(H)	Precision(P)	Super-Precision(SP)	Ultra-Precision(UP)
Tolerance of height ( H )	±0.1	±0.04	0 -0.04	0 -0.02	0 -0.01
Tolerance of width ( W )	±0.1	±0.04	0 -0.04	0 -0.02	0 -0.01
Difference of heights (△H )	0.03	0.02	0.01	0.005	0.003
Difference of widths (△W )	0.03	0.02	0.01	0.005	0.003
Running parallelism of BR Block surface C with respect to surfaceA	△C Refer to the below Fig. BG rail length and running parallelism
Running parallelism of BR Block surface D with respect to surface B	△D Refer to the below Fig. BG rail length and running parallelism

 

b. Choosing preload
   Replacing larger rolling elements helps strengthening the entire rigidity of the
   carriage while there exists clearance within ball circulation.

Increasing preload would diminish the vibration and reduce the corrosion caused by running back and forth. However, it would also add the workload within those rolling elements. The greater the preload, the greater the inner workload. As a result, choosing preload has to consider both how vibration and preload would affect life and conclude an optimal choice.
Preload grade

 

C: Basic dynamic load rating
GRADE       ITEM	Symbol	Preload force
Clearance	ZF	0
No Preload	Z0	0
Light Preload	Z1	0.02C
Middle Preload	Z2	0.05C
Heavy Preload	Z3	0.07C

Radial clearances

 

Unit: μm
Symbol Type	ZF	Z0	Z1	Z2	Z3
BG 15	5~12	-4~4	-12~-5	-20~-13	-28~-21
BG 20	6~14	-5~5	-14~-6	-23~-15	-32~-24
BG 25	7~16	-6~6	-16~-7	-26~-17	-36~-27
BG 30	8~18	-7~7	-18~-8	-29~-19	-40~-30
BG 35	9~20	-8~8	-20~-9	-32~-21	-44~-33
BG 45	10~22	-9~9	-22~-10	-35~-23	-48~-36

Interchangeability

 

Accuracy	Non - interchangeable					Interchangeable
	UP	SP	P	H	N	H	N
Preload					ZF		ZF
			Z0	Z0	Z0	Z0	Z0
	Z1	Z1	Z1	Z1	Z1	Z1	Z1
	Z2	Z2	Z2	Z2	Z2
	Z3	Z3	Z3

 

 

ITEM	Unit: μm
	e1					e2
	Z3	Z2	Z1	Z0	ZF	Z3	Z2	Z1	Z0	ZF
BG 15			18	25	35			85	130	190
BG 20		18	20	25	35		50	85	130	190
BG 25	15	20	22	30	42	60	70	85	130	195
BG 30	20	27	30	40	55	80	90	110	170	250
BG 35	22	30	35	50	68	100	120	150	210	290
BG 45	25	35	40	60	85	100	140	170	250	350

 

 

 

Cap:
Most chippings are blocked by end seals, but some would stay in the screw
holes. Caps are accessory that can prevent the entry of chippings.
Rail with tapped holes:
Fixing a rail with tapped hole is different from fixing a standard one. A major
strength of it is the shape of the tapped hole (shown as fig.); dust and chippings
would not enter.

 

Size	Screw	Length of thread
BG 15	M5	8mm
BG 20	M6	10 mm
BG 25	M6	12 mm
BG 30	M8	15 mm
BG 35	M8	17 mm
BG 45	M12	24 mm

 

 

d. Accessories of block

Coding of seal end seal side seal inner seal (top seal) double end seal (double front seal) scraper (metal front shield) Not specified ˇ ˇ       UU ˇ         ZZ ˇ ˇ     ˇ DD   ˇ   ˇ   KK   ˇ   ˇ ˇ SS ˇ ˇ ˇ     SD   ˇ ˇ ˇ