Screw Gears Used for Non-Intersecting Shafts

Screw gears, also sometimes called crossed helical gears, are helical gears used in motion transmission between non-intersecting shafts. The helical gears used in parallel shafts have the same helix angle but in the opposite directions. For shaft angles other than parallel, an arbitrary helix angle can be chosen, and, assuming no profile shift, the intersecting angle of the shafts is the sum of the respective helix angles. Helical gears have point contacts and have lower efficiency than parallel or perpendicular shaft gears and cannot transmit heavy loads.
Also, if the same material is used in screw gears, it could lead to friction and galling. Therefore, KHK recommends the use of different materials in a pair. Besides, unlike bevel gears, there are no restrictions on the numbers of teeth combinations and the speed transmission ratio becomes the number of teeth of the driving gear divided by the number of teeth of the driven gear. Please consult the “Gear Applications” pages for the actual working of screw gears.
With this technical data you can view comprehensive information regarding KHK gears such as their features and advice and warnings when selecting and using them.
SN
Steel Screw Gears
Module : 1 – 4
Material : S45C
Hardening : None
Tooth finish : Cut (non-ground)
Grade : JIS N9 (Please see details on PDF)
Many lineups are available at a low price. The teeth can be hardened.
Click Here to Select Screw GearsSUN
Stainless Steel Screw Gears
Module : 1 – 3
Material : SUS303
Hardening : None
Tooth finish : Cut (non-ground)
Grade : JIS N9 (Please see details on PDF)
Stainless steel gears with rust resistance.
Click Here to Select Screw GearsAN
Aluminum Bronze Screw Gears
Module : 1 – 3
Material : CAC702 (AlBC2)
Hardening : None
Tooth finish : Cut (non-ground)
Grade : JIS N9 (Please see details on PDF)
Aluminum bronze made gears with excellent wear resistance.
Click Here to Select Screw GearsPN
Plastic Screw Gears
Module : 1 – 3
Material : MC901
Hardening : None
Tooth finish : Cut (non-ground)
Grade : JIS N10 equivalent
Nylon gears can be used with no lubrication.
Click Here to Select Screw GearsRelated links :
Helical Gears– Main page of helical gears
Equivalent tables of each standard relating to raw materials and precision grades of gears
Plastic Gears– A page of plastic gears
交错轴斜齿轮 (螺旋齿轮) - 中文页