Change Nut

The Change Nut Models DCMA and DCMB have a lead angle of 45°, which is difficult to achieve through machining. Each model is capable of converting linear motion into rotary motion, or vice-versa, at high efficiency. Because of the large leads, they are optimal for providing a fast-feed mechanism at low-speed rotation. The multi-thread screw shafts to be combined with these change nuts are formed through cold gear rolling. The surface of the teeth is hardened to over 250 HV and mirror-finished. As a result, the shafts are highly wear-resistant and achieve significantly smooth motion when used in combination with these change nuts. Models DCMA40, DCMB40, or higher are designed for use in combination with cut screw shafts.
Miniature change nuts are made of an oil-impregnated plastic,
enabling them to have wear resistance and excel in lubrication especially in an oil-less operation. In addition, since the high level of their performance can be maintained for a long period, they enable long-term maintenance-free operation.

Types

Highlight feature tags

  • Miniature
  • Wear resistance
  • Long nut
Model DCMA
  • Wear resistance
Model DCMB
  • Miniature
  • Long nut
  • Wear resistance

Features

Structure and Features

The Change Nut models DCMA and DCMB have a lead angle of 45°, which is diffi cult to achieve through machining. Each model is capable of converting a straight motion to a rotary motion, or a vise versa, at high efficiency. Because of the large leads, they are optimal for providing a fast feed mechanism at a lowspeed rotation. The multi-thread screw shafts to be combined with these change nuts are formed through cold gear rolling. The surface of the teeth is hardened to over 250 HV and mirror-finished. As a result, the shafts are highly wear resistant and achieve significantly smooth motion when used in combination with these change nuts. Models DCMA40, DCMB40 or higher are designed for use in combination with the cut screw shafts. The Miniature Change Nuts are made of an oil-impregnated plastic, and have a wear resistance and excel in lubrication especially in an oil-less operation. In addition, since the high level of their performances can be maintained for a long period, they allow long-term maintenance-free operation.

Features of the Special Rolled Shafts

Dedicated rolled shafts with the standardized lengths are available for the Change Nut.

Increased Wear Resistance

The shaft teeth are formed by cold gear rolling, and the tooth surface is hardened to over 250 HV and mirror-finished. As a result, the shafts are highly wear resistant and achieve significantly smooth motion when used in combination with the nuts.

Improved Mechanical Properties

Inside the teeth of the rolled shaft, a fi ber fl ow occurs along the contour of the tooth surface of the shaft, making the structure around the teeth roots dense. As a result, the fatigue strength is increased.

Additional Machining of the Shaft End Support

Since each shaft is rolled, additional machining of the support bearing of the shaft end can easily be performed by lathing or milling.

High Strength Zinc Alloy

The high strength zinc alloy used in the change nuts is a material that is highly resistant to seizure and the wear and has a high load carrying capacity. Information on mechanical properties, physical properties, and wear resistance is presented below.

*The figures shown are target values—these figures are not guaranteed.

Mechanical Properties

Table1
Item Description
Tensile strength 275 to 314 N/mm2
Tensile yield strength (0.2%) 216 to 245 N/mm2
Compressive strength 539 to 686 N/mm2
Compressive yield strength (0.2%) 294 to 343 N/mm2
Fatigue strength 132 N/mm2×107 (Schenk bending test)
Charpy impact 0.098 to 0.49 N・m/mm2
Elongation 1 to 5 %
Hardness 120 to 145 HV

Physical Properties

Table2
Item Description
Specifi c gravity 6.8
Specifi c heat 460 J/(kg・K)
Melting point 390 ℃
Thermal expansion coeffi cient 24×10-6

Wear Resistance

Table3 [Test conditions: Amsler wear-tester]
Item Description
Test piece rotational
speed
185 min-1
Load 392 N
Lubricant Dynamo oil