The Nord-Lock bolt securing system uses tension instead of friction to ensure that joints holding sub-assemblies together remain secure. Bolts on pumps need to be easily removable during maintenance procedures, but must resist the loosening effects of vibrations and dynamic loads. Bolts that are locked conventionally by friction in the thread tend to lose most of their preload through vibrations, while those locked by the tension of this system present a minor loss of preload which is caused mainly by settlement in the thread. Even after moderate tightening, the bolt is safely locked when using Nord-Lock.
It has become increasingly important to have good control of the torque-clamp load relationship when tightening a joint. To optimise the design of the joint and utilise as much of the capacity of each dimension as possible, it is important to know the required tightening torque. Nord-Lock washers, which are installed in pairs, cam face to cam face, have cams on one side, with a greater rise than the pitch of the bolt. When the bolt and/or nut is tightened, the radial teeth on the opposite side grip and seat the mating surfaces. The teeth also lock the washers in place, allowing movement only across the face of the cams. The resulting tension makes the bolt self-locking.
These washers can be used on standard grade, as well as high grade bolts and there is no need for adhesives to lock the stud bolt. This system is designed for use in tapped and counter-bored holes and for larger holes or on soft materials, a flange nut or bolt should be used in combination with Nord-lock washers with a larger outer diameter.
Advantages of this reusable system include maximum safety when locking fasteners, easy assembly and disassembly, positive locking at low or high preload levels and minimum surface marring or scratching. This system, which has the same temperature characteristics as a standard bolt or nut, resists loosening caused by vibration and dynamic loads. The locking function is not lost by lubrication.
A method for testing the security of a bolted joint is the Junker-vibration test where the preload (bolt tension) is measured by a load cell and vibrating motions are generated radically through the bolt.
Innovative sealing and bearing solution for pulp machine SKF South Africa
Shaft power components
A leading South African manufacturer of paper-making equipment sought to modify an existing pulp machine and turned to trusted partner SKF to assist with the redesign of a critical sealing arrangement.
Read more...Polymer bearings for maintenance-free bottling system igus
Shaft power components
A favourite South African beer which is to be found on many a beer connoisseur’s table is being brewed in Belgium with the assistance of lubricant-free polymer bearings that will not contaminate the beer.
Read more...Industrial valve solutions Bearing Man Group T/A BMG
Shaft power components
BMG’s Fluid Technology division supplies and supports an extensive range of components for fluid technology systems. These include valves, hydraulic hoses and fittings, accumulators, cylinders, heat exchangers, hydraulic motors and hydraulic plumbing, as well as pumps and reservoir accessories.
Read more...Direct-controlled seat valve
Shaft power components
A new direct-controlled seat valve enables storage-free, load-tight holding functions in dynamic linear units without an additional control pressure supply, and offers significant advantages over classic, pilot-controlled solutions, particularly in stationary and servo hydraulics.
Read more...Wind energy in the Black Forest
Shaft power components
For more than 20 years, numerous wind turbines have stood in the Black Forest and are now receiving a performance boost through repowering projects.
Read more...The advantages of using an adjustable cable gland
Shaft power components
Pratley continues to demonstrate its engineering leadership with its innovative adjustable cable gland, designed to significantly reduce maintenance and labour costs across a wide range of industrial applications.
Read more...Single DDI cable solution simplifies connectivity SEW-EURODRIVE
Shaft power components
Cabling can be one of the most challenging aspects of automation and drive system installations, often leading to delays, faults and inefficiencies. SEW-EURODRIVE offers a solution that simplifies connectivity, its innovative Digital Data Interface technology combined with a single cable system.
While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.
printer friendly version