Lovejoy 1060 Grid Coupling, Horizontal Split Cover

Lovejoy 1060 is the size 1060 grid coupling in the Lovejoy tapered-grid range, rated 6,050 in-lb (683 Nm) nominal and bored up to 2.125 in (54 mm). A steel grid spring sits in curved grooves in two hubs under a split cover; the spring absorbs shock and vibration, and a worn grid can be replaced at a fraction of the cost and time of a complete coupling.

Torsional damping from a grid spring

Lovejoy describes the tapered grid as spreading impact energy along the full spring length, which lowers torque spikes, and says its grid couplings have demonstrated vibration damping of as much as 30 percent. The hub tooth profile is curved so contact with the grid becomes progressive as torque rises. Grid sizes cover 1020 to 1200, in horizontal and vertical cover styles and in full-spacer and half-spacer versions with horizontal covers.

Features listed in the catalogue are high tensile, shot-peened alloy steel grid springs, precision-machined hubs, cover fasteners in inch or metric sizes, and easy installation. The horizontal cover is die-cast aluminium and is described as ideal for limited space, easy access to the grid and well suited to reversing applications.

Technical specifications

Grid sizes 1020 to 1140

Nominal torque, maximum horizontal-cover speed and maximum bore for the larger-volume sizes, as printed in the catalogue:

Selecting and ordering the 1060

Application torque is HP x 63,025 / RPM in in-lb. Multiply by the service factor from the catalogue application charts to get the selection torque, then choose the first size whose nominal rating covers it. Where high peak loads or brake torque are present, double the application torque before applying the service factor. The catalogue worked example selects a 1060 for a 60 HP motor at 1,760 RPM driving a rotary lobe compressor: 2,149 in-lb application torque, 2,687 in-lb with the service factor, against 6,050 in-lb rating.

Component numbers carry the 697904 prefix. For size 1060 they include grid spring 05248, horizontal cover and grid assembly 05353 (inch hardware) or 05370 (metric), horizontal cover set 05277 or 05294, seal kit 05180, and cover hardware 05434 (inch) or 05211 (metric). The selection example in the catalogue uses hub 05491 for a 2-1/8 in bore and 05815 for 48 mm. Grease packets are included with cover sets through size 1090.

Installation and operation notes

Install within the allowances above, ideally well inside them, and set the hub gap to the 0.118 in value in the table above, within the catalogue gap tolerance. Parallel offset is accommodated by movement of the grid in the hub grooves, angular misalignment by a rocking and sliding action, and end float because the grid slides freely in the grooves. Follow the catalogue warnings: do not exceed ratings, avoid shock loads at start-up, and recheck alignment if the coupling vibrates or beats.

Where it is used

The catalogue example is a rotary lobe compressor; grid couplings also serve conveyors, crushers, mixers and pump drives where shock cushioning is wanted. For spacer duty on pumps, stock spacer sizes run from 1020 to 1090 with horizontal covers. Compare gear-type alternatives such as the Flender ZAPEX gear coupling.

Operating notes for Oman and the GCC

Grid couplings are common on pumps, fans, conveyors and mixers in water, cement and mining plants in the region. In dusty or sandy areas the seals and cover gaskets keep the grease in and the sand out, so inspect them at each lubrication interval and replace damaged seals at once. Use the grease grade and interval in the Lovejoy installation instructions, and shorten the interval for very hot or dusty duty.

Frequently asked questions

What does the 1060 grid coupling consist of?

Two grid hubs, one tapered steel grid spring and a split cover assembly; spacer versions add two spacer hubs.

Horizontal or vertical cover for the 1060?

The horizontal split cover suits limited space and reversing duty; the vertical cover is recommended where higher speed matters, 6,000 RPM against 4,350 RPM on this size.

How much torsional damping does the grid give?

The catalogue says the tapered grid design has shown vibration damping by as much as 30 percent and cushions shock loads.

Is the 1060 interchangeable with other grid couplings?

Lovejoy states that its hubs and tapered grid springs are designed to interchange with industry standard grid couplings, with an interchange chart on page GD-15.

How is the bore fit supplied?

Sizes 1020 to 1090 are bored for a clearance fit with two set screws at 90 degrees; sizes 1100 and larger are interference fit with no set screw.

Documents and quotation

The Lovejoy grid coupling catalogue section is hosted on this page. See Couplings and Shaft Locking Devices. Seven Star LLC is an independent supplier in Muscat; send size, both bores and keyways, cover style and quantity for a quotation.