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MDSDK51-25-20-A

Product Discontinued. Click here to see similar items.

$300.04
Product DiscontinuedPlease inquire for special pricing
Ruland MDSDK51-25-20-A, 25mm x 20mm Double Disc Coupling, Aluminum, Set Screw Style With Keyway, 50.8mm OD, 64.0mm Length

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PRODUCT SPECIFICATIONS

Ruland MDSDK51-25-20-A is a set screw double disc coupling with 25mm x 20mm bores, 50.8mm OD, 64.0mm length, and 8mm x 6mm keyways. It is zero-backlash and has a balanced design for reduced vibration at high speeds. The double disc design is comprised of two anodized aluminum hubs, two sets of thin stainless steel disc springs, and a center spacer allowing each disc to bend individually and accommodate all types of misalignment. MDSDK51-25-20-A is lightweight and has low inertia making it well suited for applications with speeds up to 10,000 RPM. Hardware is metric and tests beyond DIN 912 12.9 standards for maximum torque capabilities. Ruland manufactures MDSDK51-25-20-A to be torisionally rigid and an excellent fit for precise positioning stepper servo applications commonly found in semiconductor, solar, printing, machine tool, and test and measurement systems. It is machined from solid bar stock that is sourced exclusively from North American mills and RoHS3 and REACH compliant. MDSDK51-25-20-A is manufactured in our Marlborough, MA factory under strict controls using proprietary processes.

PRODUCT SPECIFICATIONS

Dimensions

Bore (B1) Larger inner diameter. Should match nominal shaft diameter.

25 mm

Small Bore (B2) Smaller inner diameter. Should match nominal shaft diameter.

20 mm

Keyway (K1)

8 mm

Keyway (K2)

6 mm

B1 Max Shaft Penetration The maximum depth the shaft can penetrate into Bore B1.

30.3 mm

B2 Max Shaft Penetration The maximum depth the shaft can penetrate into Bore B2.

30.3 mm

Bore Tolerance Variance in finished bore range before installation.

+0.03 mm / -0.00 mm

Outer Diameter (OD)

50.8 mm

Length (L)

64.0 mm

Hub Width (LH)

20.55 mm

Recommended Shaft Tolerance Acceptable variance in nominal shaft diameter before performance loss.

+0.000 mm / -0.013 mm

Fastening Hardware

Forged Set Screw Inch or metric socket head set screw size.

M6

Number of Screws

4 ea

Screw Material

Alloy Steel

Screw Finish Surface finish and treatments on supplied hardware.

Black Oxide

Hex Wrench Size Wrench size that fits the screw head to tighten or loosen the screw.

3.0 mm

Seating Torque Torque required to install supplied hardware. Use torque wrench for accurate seating torque.

7.2 Nm

Performance Specifications

Dynamic Torque Reversing Max torque when coupling reverses direction without stopping.

9.90 Nm

Angular Misalignment Max angle of the shaft axes relative to each other.

2.0°

Dynamic Torque Non-Reversing Max torque for the coupling during quick changes in acceleration or deceleration.

19.80 Nm

Parallel Misalignment Shafts are parallel to each other, but not in-line with each other. They are offset.

0.30 mm

Static Torque Unidirectional constant max torque.

39.6 Nm

Axial Motion The amount shafts can move closer to or away from each other. This is meant for thermal expansion of the shafts. No axial force can be placed on the coupling.

0.64 mm

Torsional Stiffness Measures the rigidity of the coupling. The more rigid the coupling, the less windup it will have.

67.2 Nm/Deg

Maximum Speed

10,000 RPM

Full Bearing Support Required? Full bearing support is a bearing in close proximity to both sides of the coupling to prevent axial loads that could result in rapid coupling failure.

Yes

Recommended Installation Tools

Torque Wrench This torque wrench and bit combo is recommended to ensure proper installation. A torque wrench prevents the screw from being over torqued which can lead to product failure.

TW:BT-4C-3/8-64

Recommended Hex Key This hex key set has the appropriate hex key for product installation. Trained and experienced assemblers can use a hex key in place of a torque wrench.

Metric Hex Keys

Additional Information

Material Specification

Hubs and Center Spacer: 2024-T351 Aluminum Bar
Disc Springs: Type 302 Stainless Steel

Temperature Minimum and maximum operating temperature. Operating temperature includes ambient temperature plus or minus factors such as system heat generated during operation, washdown, vacuum, etc...

-40°F to 200°F (-40°C to 93°C)

Finish Specification Surface finish specifications.

Sulfuric Anodized MIL-A-8625 Type II, Class 2 and ASTM B580 Type B Black Anodize

Manufacturer

Ruland Manufacturing

Country of Origin

USA

Weight (lbs)

0.581100

UPC

634529189900

Tariff Code

8483.60.8000

UNSPC Code used to identify products to standardize nomenclature around the world.

31163008

Product Notes

Note 1

This product has been discontinued as a standard item. Please inquire for special pricing.

Note 2

Torque ratings are at maximum misalignment.

Note 3

Performance ratings are for guidance only. The user must determine suitability for a particular application.

Note 4

Torque ratings for the couplings are based on the physical limitations/failure point of the disc springs. Under normal/typical conditions the hubs are capable of holding up to the rated torque of the disc springs. In some cases, especially when the smallest standard bores are used or where shafts are undersized, slippage on the shaft is possible below the rated torque of the disc springs. Keyways are available to provide additional torque capacity in the shaft/hub connection when required. Please consult technical support for more assistance.

Prop 65 Required for the US State of California only.

WARNING This product can expose you to chemicals including Ethylene Thiourea and Nickel (metallic), known to the State of California to cause cancer, and Ethylene Thiourea known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

CERTIFICATIONS/STANDARDS
ISO 9001:2015

Certified

Conflict Minerals

Compliant

RoHS3

Compliant

REACH

Compliant

Installation Instructions

  1. Align the bores of the MDSDK51-25-20-A double disc coupling on the shafts that are to be joined and determine if the misalignment parameters are within the limits of the coupling. (Angular Misialignment: 2.0°, Parallel Misalignment: 0.30 mm, Axial Motion: 0.64 mm)
  2. Fully tighten the M6 screws on the first hub to the recommended seating torque of 7.2 Nm using a 3.0 mm hex torque wrench.
  3. Before tightening the screws on the second hub, rotate the coupling by hand to allow it to reach its free length.
  4. Tighten the screws on the second hub to the recommended seating torque. Make sure the coupling remains axially relaxed and the misalignment angle remains centered along the length of the coupling.
  5. The shafts may extend into the relieved portion of the bore as long as it does not exceed the shaft penetration length of 30.3 mm.

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