6902RS Ball Bearing ABEC-3 Blue Rubber Sealed Precision Ball Bearings 6902-2RS 15x28x7mm (Pick of 10pcs)

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Calculation factor Y2:3.9; r1,2 min.:2.1 mm; b:11.1 mm; Basic dynamic load rating C:652 kN; Fatigue load limit Pu:73.5 kN; Calculation factor Y1:2.6; Basic static load rating C0:765 kN; K:6 mm; d3:155 mm; ra max.:2 mm; Size (mm):10 mm x 35 mm x 11 mm ;

D:130.0000 mm; Accessories:One Shield & Snap-Ri; Fillet Radius ra:2.00 mm; Sealed Speed Rating n3:3400 rpm; Oil Speed Rating n2:4500 rpm; Basic Dynamic Radial Load Rating C:134000 N; Basic Static Radial Load Rating Co:143000 N; B:54.00 mm; Grease Speed Rating n1:3400 rpm; d:60.000 mm; Simply replacing the bearings with name brand ones won't help (apart from longevity). The majority of play isn't within the bearings themselves. There is some play within the sprag clutch but nothing can be done about that.If you can remove the play you can go some way towards mitigating the wobble. You could use additional bearings, retaining compound and/or shims. I've been posting about this in the mega thread recently, starting from around here. Chain reaction Cycles and CRC are trading names of Wiggle Ltd (In Administration) registered in the United Kingdom at 1000 Lakeside, Suite 310, Third Floor N E Wing, Portsmouth, Hampshire, PO6 3EN, If your sprag clutch has any play on the torque sensor then you'll need to add shim washer there too, I will likely place them between the torque sensor and sprag clutch to give a bit more wobble room. Earlier motors actually had them there. Registered Australian Company: Small Parts & Bearings Pty Ltd (ABN 79 121 865 414) - Trading as Bearing Shop Online

I read some posts before about replacing the sprag clutch, stating that I need a hydraulic press to remove the big gear, so I didn't expect it can move on the outer race. I replaced the sprag clutch also, and it turned out that I could press the gear in place using the vise - quite easily. It seems like essentially the helical gears want to screw together, pulling the big gear in towards the pinion gear. But not only did they change from straight-cut spur gears to helical, but they introduced more play at the same time. The second 6902RS bearing on the spindle was removed and the sprag clutch fit on the torque sensor was loosened. Previous a puller was required to remove the big gear and sprag clutch, now it slides off easily. Instead of adding a thrust bearing behind the torque sensor, we get two teflon washers. Mrc hybrid bearings run cooler and can operate with thinner lubricant films than conventional bearings. The result? Less aging of the grease, longer relubrication intervals, and increased service life vs. Standard bearings in the same operating conditions.

skf 6902rs bearing Video

According to the available data, this motor can produce somwhere around 90 Nm of torque, so I will use this number for calculation. Radius of the "big gear" is about 58 mm. To produce 90 Nm of torque, motor must provide about 1550 N (it is like weight of 158 kg!). So far, so good. Ceramic balls are only 40% as dense as steel balls, the centrifugal load that they generate is less and the internal bearing friction is lower. The lower density and friction enables cooler running under the same operating conditions, or even higher rotational speeds. Because of the properties of ceramics, a hybrid bearing's service life can be up to 10 times that of a standard steel bearing, reducing the need for maintenance on your machine as well as the costly interruptions in production. Accessories:Snap-Ring; Oil Speed Rating Open/Shielded n2:1700 rpm; Fillet Radius ra:3.00 mm; Basic Dynamic Radial Load Rating C:302000 N; D:420.0000 mm; Grease Speed Rating Open/Shielded n1:1400 rpm; d:280.000 mm; B:65.00 mm; Basic Static Radial Load Rating Co:405000 N; Sealed Speed Rating n3:890 rpm; Size (mm):2.953 Inch | 75 Millimeter x 6.299 Inch | 160 Millimeter x 1.457 Inch | 37 Millimeter ; b:7 mm; Grub (set) screw size:M6; B:15 mm; G:M 65x2; Associated spanner:HN 12-13; h:3 mm; Recommended grub screw tightening torque:8 N·m; d1:77.5 mm; B3:3 mm; d3:85 mm;

I believe that the main issue is the change of design. Initially, Tong Sheng was using straight cut "big gears", and those were probably fine (in that "woblines" parameter), but at some point, somebody decided to use helical gears, to reduce the noise - and here lies the problem. In addition to the shim washer procedure I mentioned in my previous post, on the non-drive side you can add a second bearing as far out as possible. Then remove all play between the inner races and spindle and preferably between the outer races and housing too. Replacing the dust seal in the spider with a 6902 bearing may also help. I have posted about Enduro bearings which are for sealed for external use. cheaper options with no signature required. The no signature required options are at the customer’s risk once the goods leave our store.

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What i didn't realize is that the increased space allowed the big gear to slide invards on the sprag clutch outer surface and start putting pressure on the torque sensor coil, rubbing it against the casing and the static coil, until it broke. Basic Static Radial Load Rating Co:35500 N; Fillet Radius ra:1.00 mm; d:75.000 mm; Accessories:Without Accessories; Oil Speed Rating Open/Shielded n2:6700 rpm; D:115.0000 mm; Grease Speed Rating Open/Shielded n1:5600 rpm; Sealed Speed Rating n3:3400 rpm; Basic Dynamic Radial Load Rating C:42300 N; B:20.00 mm; When electrical current passes across bearings, a washboard pattern appears on the raceways, along with a darkened grey appearance. Typical results include bearing surface damage, premature aging of the lubricant. The natural insulating properties of ceramic material eliminates this type of damage.