Change nut
Caution
- Some of the items are scheduled to be discontinued as of end of March in 2023. The manufacturer keep the items produced but they are not available with Misumi.
There are not the replacement items and the plan to resumption of sale. Please check the quotation and order screen for details.
Product Description
The nut and shaft are sold separately. Use together with THK nuts and shafts (DCMA, DCMB, CT). The shaft is cut with no surface treatment.
[Features]
· Change nut DCMA shape and DCMB shape are 45° lead angle change nuts that are difficult to produce with machining machinery.
· Can be used for simple conversion of straight line movement into rotation and rotation into straight line movement at 70% efficiency. Features a large lead, making it optimal for creating speeding up mechanisms for slow rotation.
· The multi-axis screws used in combination with change nuts are molded with cold forging.
· The exterior surface of the dental mold is machined to a hardness of 250HV or more and treated with mirror surface finishing, providing extremely smooth operation and high abrasion resistance in combination with change nuts.
Drawing
Specifications Table
| Change nut part numberNote 1) | External dimensions | Change nut dimensions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Outer diameter | Length L | Flange diameter D1 | H | B | PCD | r | F | d | ||
| D | Tolerance h9 | |||||||||
| DCMB 8TNote 2) | 15 | 0 -0.1 | 16 | 28 | 4 | 3.4 | 21 | 0.8 | - | - |
| DCMB 12TNote 2) | 20 | 25 | 36 | 5 | 4.5 | 27 | 1 | - | - | |
| DCMA 15T DCMB 15T | 22 | 0 -0.052 | 15 | 44 | 6 | 5.4 | 31 | 1.5 | 4.5 | 1.5 |
| 30 | ||||||||||
| DCMA 17T DCMB 17T | 28 | 15 | 51 | 7 | 6.6 | 38 | 1.5 | 4.5 | 1.5 | |
| 35 | ||||||||||
| DCMA 20T DCMB 20T | 32 | 0 -0.062 | 20 | 56 | 7 | 6.6 | 42 | 1.5 | 6.5 | 2 |
| 40 | ||||||||||
| DCMA 25T DCMB 25T | 36 | 25 | 61 | 8 | 6.6 | 47 | 2 | 8.5 | 2 | |
| 50 | ||||||||||
| DCMA 30T DCMB 30T | 44 | 28 | 76 | 10 | 9 | 58 | 2 | 9 | 2 | |
| 56 | ||||||||||
| DCMA 35T DCMB 35T | 52 | 0 -0.074 | 30 | 84 | 10 | 9 | 66 | 2.5 | 10 | 3 |
| 60 | ||||||||||
| Change nut part numberNote 1) | Screw Shaft Part NumberNote 1) | Multi-Start Screw Shaft Detail | Standard Shaft Length | Maximum Shaft Length | Dynamic Allowable Torque TNote 3) N⋅m | Allowable Dynamic Thrust F Note 3) N | Flange Static Allowable Load PNote 4) N | Weight | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Outer diameter Dk | Effective diameter D0 | Root diameter Dr | Lead R | Lead angle α° | Number of teeth Z | Change nut g | Screw shaft kg/m | |||||||
| DCMB 8TNote 2) | CT 8T | 9 | 7.6 | 6.2 | 24 | (45) | 6 | 500 | 1,000 | 3.24 | 863 | 1,800 | 5 | 0.36 |
| DCMB 12TNote 2) | CT 12T | 13.3 | 11.5 | 9.7 | 36 | (45) | 7 | 500, 1,000 | 1,500 | 12.7 | 1,370 | 2,800 | 10 | 0.82 |
| DCMA 15T DCMB 15T | CT 15T | 15.8 | 13.7 | 11.6 | 44.4 | (45) | 8 | 500, 1,000 | 1,500 | 16.7 | 2,300 | 13,800 | 60 | 1.2 |
| 32.4 | 4,610 | 85 | ||||||||||||
| DCMA 17T DCMB 17T | CT 17T | 17.8 | 15.7 | 13.6 | 50 | (45) | 9 | 500, 1,000 | 1,500 | 20.6 | 2,600 | 28,100 | 95 | 1.5 |
| 48 | 6,080 | 140 | ||||||||||||
| DCMA 20T DCMB 20T | CT 20T | 21.2 | 18.7 | 16.2 | 60 | (45) | 9 | 500, 1,000, 1,500 | 3,000 | 40.2 | 4,170 | 34,600 | 135 | 2.6 |
| 79.4 | 8,330 | 210 | ||||||||||||
| DCMA 25T DCMB 25T | CT 25T | 25.6 | 23.1 | 20.6 | 73.3 | (45) | 11 | 500, 1,000, 1,500 | 3,000 | 74.5 | 6,370 | 38,500 | 175 | 3.3 |
| 148 | 12,700 | 280 | ||||||||||||
| DCMA 30T DCMB 30T | CT 30T | 31.9 | 29.4 | 26.9 | 93.3 | (45) | 14 | 500, 1,000, 2,000 | 4,000 | 130 | 8,090 | 55,400 | 290 | 5.3 |
| 269 | 16,200 | 465 | ||||||||||||
| DCMA 35T DCMB 35T | CT 35T | 34.1 | 31.1 | 28.1 | 97.7 | (45) | 11 | 500, 1,000, 2,000 | 4,000 | 144 | 9,260 | 84,500 | 425 | 5.8 |
| 287 | 18,500 | 670 | ||||||||||||
Note 1) The T symbol attached to the nominal model number of the change nut (excluding DCMB8T and DCMB12T types) and screw shaft indicates rolling.
Each item can be purchased separately; in that case, please refer to the example of nominal model number configuration in the digital catalog. When ordering the change nut and screw shaft as a set, please specify the T symbol only at the end of the model number configuration (→ see the example of nominal model number configuration below).
Note 2) The materials for the miniature change nut DCMB8T and DCMB12T types use oil-impregnated plastic. (The dimensional tolerance for the outer diameter is special.)
Note 3) The allowable dynamic torque (T) and allowable dynamic thrust (F) indicate the values when the contact area of the screw tooth surface reaches 9.8 N/mm2.
The maximum axial load (regardless of whether the system is stopped or in operation) must not exceed the allowable dynamic thrust, and selection should be made with consideration of the safety factor in Table 1 of the digital catalog.
Note 4) The static allowable load (P) of the flange indicates the strength of the flange against the type of load shown in the figure below.
Product Feature Details
Features of the Dedicated Rolling Shaft
For the change nut, dedicated rolling shafts with standardized lengths are available.
Improved Abrasion Resistance
Because the tooth profile of the shaft is formed by cold rolling, the surface of the tooth surface is work-hardened to 250HV or higher, and also finished with a smooth mirror finish, providing excellent abrasion resistance. · Movement in combination with the change nut is also extremely smooth.
Improved Mechanical Property
In the tooth surface of the rolled shaft, the internal structure exhibits fiber flow along the contour of the tooth profile, resulting in an extremely dense structure at the tooth root and increased fatigue strength.
Alteration of Shaft End Support Section
Because the shaft is rolled, alterations such as to the shaft end support bearing section can be easily performed by turning or milling.
Selection Support Information
Example of Part Number Structure
Performance / Test Information
High-strength zinc alloy
The high-strength zinc alloy used in change nuts is a material with excellent seizure resistance, abrasion resistance, and load capacity. Its mechanical properties, physical properties, and abrasion resistance are as follows.
*The values below are reference values and are not guaranteed values.
Mechanical Properties
| Tensile strength | 275–314 N/mm2 |
|---|---|
| Tensile Proof Strength (0.2%) | 216–245 N/mm2 |
| Compressive Strength | 539–686 N/mm2 |
| Compressive Proof Strength (0.2%) | 294–343 N/mm2 |
| Fatigue Strength | 132 N/mm2 × 107 (Schenck-type bending test) |
| Charpy impact value | 0.098–0.49 N⋅m/mm2 |
| Elongation | 1 to 5% |
| Hardness | 120 to 145HV |
Physical Properties
| Specific gravity | 6.8 |
|---|---|
| Specific Heat | 460 J/(kg·K) |
| Melting point | 390°C |
| Linear expansion coefficient | 24 x 10-6 |
Abrasion resistance
| Number of Test Piece Rotating Speed | 185 min-1 |
|---|---|
| Load | 392N |
| Lubricant | Dynamo oil |