Series 249 and 249N Swivels

Transcription

1 Series 249 and 249N Swivels l Features Strong, durable, versatile swivels specifically designed for the rigorous demands of closed-loop servohydraulic testing applications Series 249 swivels are available in force ratings from 5.5 kip (25 kn) to 220 kip (1000 kn) in six different models Design utilizes cast, fatigue resistant, ductile iron for minimum weight and maximum strength Maintenance free, non-metallic swivel bearings reduce swivel friction, eliminate the need for lubrication, and increase swivel life High axial stiffness improves high frequency performance Rotational constraint about the load axis eliminates undesirable rotation that can cause moment loads and force train misalignment Series 249N swivel bases easily interface with MTS linear actuators with force ratings up to 350 kip (1550 kn) N - 77 kip MTS has added a series of base swivels to the 249 product family identified by the series number 249N. This series of products has all the great features of the 249 series with a major exception, no backlash adjustment. While the majority of test applications are optimally run without the presence of backlash, one method of accomplishing this goal is to run the actuator with a loading scheme that does not reverse the load. For these applications where the loading cycles stay in tension or in compression, the 249N series swivel is ideal N Actuator Currently available in six base swivel models, the 249N is also designed to interface directly with the rear end cap of the series 201 actuator. A feature that eliminates components, shortens overall assembly length, and provides lower costs. MTS patented bearing preload adjustment for eliminating backlash is included in series 249 swivels. Series 249N base swivels do no include a preload adjustment feature and are recommended for non-reversing applications such as tension-tension or compression-compression loading cycles. Series 249 Swivels shown attached to a Linear Hydraulic Actuator

2 Description Series 249 Swivels are typically used for testing purposes where swivel movement with minimum backlash is required. Both the 249 and 249N Series Swivels are suited for the rigorous demands of closed-loop servohydraulic testing applications. Series 249N base swivels are used to mount a linear hydraulic actuator, load cell, or mechanical linkage with a reaction mass, bedplate, or structural component. For structural testing applications, a linear actuator equipped with both a swivel base and swivel rod end provides pivotal freedom at both ends of the actuator. Following are renderings of the back and side views of typical Series 249 and 249N Swivels. The component callouts are described in the table on page 3. Clamping Bolt or Torquenut 4 Hardened Washer 5 8 Pin Adjuster Spherical Washers 7 6 Anti-Rotate Tabs 3 1 Swivel Eye Series 249 Swivel Components (Base Type) 2 Swivel Jaw Spherical Bearing 9 Cutaway View Swivel Eye Pin Swivel Eye 1 8 Pin Swivel Jaw 2 Series 249N base swivels feature a cavity for direct mounting with a series 201 actuator. 3 Anti-Rotate Tabs Spherical Bearing 9 Cutaway View Swivel Eye Pin 2

3 Description of Series 249 Swivel Components Item Component Description 1 Swivel eye The swivel eye contains the spherical bearing (item 9). The base type (shown in Figure 1) has a bolt pattern on the to suitable for mounting it to the base of an actuator. The rod end type (not shown) is designed for mounting to a load cell or the piston rod of an actuator. The Model ,.20,.23, and.32 rod end types are internally tapped to accept a threaded stud. The larger Model ,.42, and.51 rod end types are mounted with an adapter plate. 2 Swivel jaw The swivel jaw secures the swivel to the reaction mass. It is comprised of two sides joined by a pin (item 8) passing through the spherical bearing. 3 Anti-rotate tabs Anti-rotate tabs on the swivel eye restrict the twisting motion of the swivel assembly. 4* Clamping bolt or Depending on the size of the swivel, one of two torque nut different types of bolts is used to clamp the swivel eye. Models ,.20,.23, and.32 use a single bolt. The larger ,.42, and.51 models, which require greater clamping forces, use a torque nut. 5* Hardened washer A hardened washer under the clamping bolt or torque nut provides a hardened surface for it to tighten against, and prevents deformation of the swivel eye. 6* Adjuster The adjuster is a threaded sleeve that screws into and out of the swivel eye to act as a variable shim when adjusting the swivel backlash. Setting the adjuster to the proper position ensures no backlash, and allows the clamping bolt or torque nut to be tightened to the required clamping force without causing excessive friction in the spherical bearing. 7* Spherical washers The spherical washers compensate for non-parallel surfaces within the load path of the swivel eye. Different backlash adjustment settings can cause the surfaces of the split in the swivel eye to be non-parallel. The spherical washers ensure that this does not adversely affect the backlash adjustment or damage the clamping bolt. 8 Pin The pin secures the spherical bearing to the swivel jaw. 9 Spherical bearing The spherical bearing allows the swivel eye to tilt and rotate through a wide range of motion. *Components not used on 249N swivels. 3

4 Swivel Rod End The Series 249 swivel head is typically attached to the other components of the force train with an English or metric thread connector stud. Fatigue resistant, preloaded connections between the actuator and swivel can be created by using spiral washers in conjunction with the connector stud N Swivel Base Either the Series 249 or 249N swivel base can be used to attach a linear hydraulic actuator, or other actuating device to a reaction mass for structural testing applications. The mounting holes are designed to provide easy attachment to a wide variety of actuators and associated fixturing. 249 and 249N Force Rating and Weight Specifications The tables below list the swivel base and swivel rod end force ratings, and the weight specifications in U.S. customary and SI metric units. The table on page 5 lists the swivel base and swivel rod end operational specifications. Page 6 and 7 provide the swivel base and swivel rod end dimensions. 249 Swivel Model 249 Force Base Rod End Model Rating Weight Weight kip kn lb kg lb kg * 178* * 213* * 510* 249N Base Swivel Model 249N Force Base Model Rating Weight kip kn lb kg N N N N N N *Swivel rod end weight includes an adapter. 4

5 Operation Specifications α Tilt Angle β Swivel Angle β +β 249 Operation Specifications 249N Operation Specifications 249 Tilt Angle* Swivel Angle Clamping Bolt Model (α) (β) Torque lbf-ft N m ±7 ** -90, ±17-75, ±17-80, ±14-75, ±6-30, ±7 * -30, ±8-30, N Tilt Swivel Model Angle* (α) Angle (β) N ± 1.75 ± N ± 17 ± N ± 14 ± N ± 6 ± N ± 8 ± N ± 8 ± 90 *Tilt angle capability is reduced when swivel angle exceeds ±30. **Optional ±15 tilt angle is available. Models and use SUPERBOLT torque nut. Each jackbolt in the torque nut is torqued to 45 lbf-ft (70 N m). 5

6 249 Fatigue Rated Base Swivel and Rod End Swivel Product Announcement 249.XX Rod End Swivel F B D C E A 249 Base Swivel External Mounting Dimensions Model A B C D E F mm in mm in mm in mm in mm in mm in Rod End Swivel External Mounting Dimensions Model A B C D E F mm in mm in mm in mm in mm in mm in

7 249N Fatigue Rated Base Swivel Product Announcement 249.XX/249N.XX Base End Swivel F B D 249N Base Swivel External Mounting Dimensions C E A Model A B C D E F mm in mm in mm in mm in mm in mm in N N N N N N Installation All models of the Series 249 Swivels are mounted with four socket head bolts. The mounting bolt size is determined by the model number. Refer to the table to the right for the recommended mounting bolt size, torque, and grade. Special Mounting for Angularly Applied Loads If the swivel mounting surface is not perpendicular to the direction of applied force, it may be necessary to install retaining stops to prevent the swivel from slipping. Slippage between the swivel and mounting surface can be expected if the operating forces for the angle of load application shown in the top graph on the next page are exceeded. Retaining stops must be installed if this is the case. The figure below shows the proper position of the retaining stops and how to determine the angle of load application. Mounting Bolt Size, Torque and Grade Requirements Recommended Mounting Mounting Recommended Model* Bolt Size Bolt Torque Bolt Grade U.S. Customary SI Metric lbf-ft N m SAE IS /8-16 M10 x /8-11 M16 x /8-11 M16 x M24 x /4-7 M30 x /4-7 M30 x /2-6 M42 x *Series 249N swivels use the same bolts as their 249 counterparts. F β Retaining Stops Position of Retaining Stops and Angle of Load Application F β Retaining Stops 7

8 kip (24.5 kn) 15 kip (67 kn) 35 kip (156 kn) 77 kip (343 kn) 110 kip (500 kn) 220 kip (979 kn) Ordering Information β (degrees of rotation from the vertical) lbf kn F (force to produce slippage) Angle of Load Application vs Maximum Load at Slip Point Different system configurations will require the use of different types of retaining stops. In all cases, the retaining stops must withstand a shear force equal to or greater than the forces specified in the graph below kip (67 kn) 5.5 kip (24.5 kn) kip (156 kn) 10, , kip (343 kn) 40, , kip (500 kn) 100, , ,000 1, kip (979 kn) When ordering Series 249 Swivels, ensure that the selected swivel force rating exceeds the maximum tension force rating of its associated actuator. Series 249 Swivels are available in both base and rod end types for the following force ratings: Model* Force Rating kip kn *Series 249 base swivels are rated the same as their 249 counterparts. Please specify metric or English threading for rod end type swivels. (degrees of rotation from the vertical) β lbf kn , , , , , , , , , Minimum Shear Rating of Retaining Stops Shear strength of retaining stops MTS Systems Corporation 14000Technology Drive Eden Prairie, MN USA Toll Free: Fax: info@mts.com Specifications subject to change without notice. MTS is a registered trademark of MTS Systems Corporation. RTM No MTS Systems Corporation a Swivels249/249N Printed in U.S.A. 1/06 ISO 9001 CERTIFIED