7500 Series Rotary Shaft Seals

Our 7500 Series CinchSeals are designed for zero maintenance due to the unique self adjusting design. These are ideal for screw conveyors, bucket elevators, and similar bulk solid applications.

The 7500 Series consumes 30% less power than packing seals and will not undercut shafts. Fully assembled and possessing a rugged modular design, our 7500 Series will not leak to foul bearings or contaminate processing areas.

How the 7500 Series Works

The heart of our seal is our elastomer boot made out of silicone and can handle temperatures up to 500 degrees. The boot is molded slightly smaller than the shaft size so that an interference fit is produced. This snug fit seals the shaft and stops material from migrating down the shaft and leaking out of the equipment. Unlike mechanical packing, our boot spins with the shaft and drives the rotor cups against the stator plates, thus creating a seal that material can’t get past.

Because rope packing is stationary and the shaft is turning through it, it scores and damages the shaft; which can lead to a big expense when you have to replace the shaft. Also, as packing wears it allows product to escape, which can ruin bearings and gearboxes; another expense. With our CinchSeal, the elastomer boot hugs and seals the shaft, but doesn’t damage it. The elastomer silicone boot also drives the rotor cups, which spin as well and create a seal.

The rotor cups are made out of aluminum that we hard coat with a special process that give them a hardness of a 62 on the Rockwell scale. This is the same hardness of Tungsten carbide. The hard coat aluminum rotor cups run against an inner stator, which is made out of a special mineral filled Teflon® with a proprietary durable material, which improves friction stability.

This is the wearable surface and sacrificial part of the seal. When you buy a repair kit, it would consist of a new boot and new Teflon® stator plates. All these pieces compress into the seal, and you will feel the spring tension as you push down and tighten the screws. As the Aluminum rotor cups wear into the stator plates, the spring keeps constant pressure on the two faces. The mechanic bolts it up in place of the packing gland, and the seal will run for 1,000’s of hours before a repair kit will be needed.

The 7500 Series is offered in both the 7520 version for wet / slurry applications, and the 7550 which is a powder seal used on conveying equipment and bucket elevators.

7520 Assembly	7550 Assembly

Materials of construction: Anodized aluminum housing with o-ring at inboard and outboard plate. PTFE inboard and outboard stators. Aluminum hard coat rotor cups, elastomer and springs.	Materials of construction: Anodized aluminum housing with o-ring at inboard. Anodized aluminum inboard stator and outboard plate. PTFE rotor cups, elastomer and springs.

Standard Features

Designed for C.E.M.A. screw conveyor and bulk handling equipment, the 7500 series is a self-adjusting seal.
Temperature ranges -50F/44.55C to 500F/260C
Bolting pattern will accommodate flange mounted bearings
Materials available anodized aluminum and 316 Stainless Steel
Designed to handle linear shaft growth, and axial runout
Purge with air, 5 to 8 psig above vessel pressure, or silicone grease

Available Accessories

Self Adjustment and Aligning

The CinchSeal module readily accommodates a reasonable amount of shaft vibration, misalignment or wobble. The rotor cup "floats" against the face of the stator plate so any lateral shaft movement produces nothing more than a slight orbital eccentricity. View Our Installation Guides

7500 Series Dimensional Information

A	B	C	D (min)	D (max)	E (min)	E (max)	F
1.5	.625	5.375	3.3	4.357	4.709	6.162	1.75
2.0	.750	6.50	4.0	5.386	5.657	7.618	1.75
2.437	.750	7.375	4.5	6.260	6.364	8.856	1.75
3.0	.880	7.875	5.5	6.677	7.778	9.443	1.75
3.437	.880	9.25	6.76	8.052	9.560	11.387	1.75