Textile Machinery Bearing

A textile machinery bearing runs fast, runs for long hours and works in air full of fibre dust, which the trade calls fly. Some of the bearings in spinning frames, looms and winders are special parts that only the machine maker or a specialist supplies. Many others are standard single row deep groove ball bearings from the 6000, 6200 and 6900 series, with bores from 10 to 30 mm, in the drive motors, fans, gear trains, rollers and winding units. Below we cover which bearings are standard and which are special, the sizes, noise and vibration, seals against fly, clearance, lubrication, the usual failure causes and what to send with an inquiry.

Special textile bearings and standard bearings

Before you order, decide which kind of bearing you are replacing. Schaeffler’s publication on rolling bearings for textile machinery describes the special parts used across spinning and weaving [1]:

• Spindle bearings. Spinning and twisting spindles are guided by spindle neck bearings, which are cylindrical roller bearings built for high speed [1].
• Tape tension pulleys. Pulleys that guide and tension the drive belts in spinning, texturing and twisting machines are complete units with their own ball bearings and gap seals [1].
• Opening rollers and rotor bearings. In rotor spinning, the rotor runs at about 150,000 min⁻¹ while the bearings and rolls run at 15,000 to 21,000 min⁻¹. They use double row special ball bearings with restricted internal clearance [1].
• Weaving machine bearings. Weaving machines use drawn cup needle roller bearings with a very small cross section, and lay drives use track rollers on cams [1].
• Flyer bearings. The flyer on a roving frame runs at about 1,800 min⁻¹ on a special ball bearing with restricted operating clearance, lubricated for life and sealed against dust and fly [1].

These parts carry their own part numbers, and a standard bearing is not a substitute. Order them with the machine maker’s number or a drawing.

Standard bearings are everywhere else on the same machines:

Machine area	Typical standard bearing	Notes
Drive motors on spinning, winding and weaving machines	6200 and 6300 series	Same as any motor; see the electric motor bearing page
Blowing room, carding and suction fans	6200 and 6300 series, or inserts in pillow blocks	See the fan and blower bearing page
Gear trains and drafting drives	6000 and 6200 series	Usually open or shielded, inside a lubricated case
Guide, feed and winding rollers	6000, 6200 and 6900 series	Low torque and smooth running matter
Godets on synthetic fibre lines	6000 series, often with C3 or C4	Heated godets need matched clearance and grease [1]
Line shafts and finishing machines	Pillow block and flange units	See pillow block bearings

Schaeffler’s own godet example shows the point. A godet on a spinning and drawing line runs on two deep groove ball bearings, 6013-2ZR-C4-L237, sealed and greased for life with high-temperature grease, because the godet may run hot [1]. The base bearing is a standard 6013; the suffixes carry the seal, the clearance and the special grease.

Textile machinery bearing sizes

The bore equals the shaft diameter at the bearing seat. The 6000 series is the light section, the 6200 series the medium one, and the 6900 series a thin section that saves space in rollers and compact units. These are the common small sizes, with boundary dimensions d × D × B in millimetres:

Shaft (mm)	6000 series	d × D × B	6200 series	d × D × B	6900 series	d × D × B
10	6000	10 × 26 × 8	6200	10 × 30 × 9	6900	10 × 22 × 6
12	6001	12 × 28 × 8	6201	12 × 32 × 10	6901	12 × 24 × 6
15	6002	15 × 32 × 9	6202	15 × 35 × 11	6902	15 × 28 × 7
17	6003	17 × 35 × 10	6203	17 × 40 × 12	6903	17 × 30 × 7
20	6004	20 × 42 × 12	6204	20 × 47 × 14	6904	20 × 37 × 9
25	6005	25 × 47 × 12	6205	25 × 52 × 15	6905	25 × 42 × 9
30	6006	30 × 55 × 13	6206	30 × 62 × 16	6906	30 × 47 × 9

The 6000, 6200 and 6300 series follow the boundary dimensions of the ISO 15 general plan for radial bearings [3], so a 6204 from one maker fits the same seat as a 6204 from another. For tighter spaces there are the thinner 6800 and 6700 series and the 16000 series, for example 16004. The 6000 series and 6200 series pages list every size, and the bearing size finder looks up a bearing from its measured dimensions.

Speed, noise and vibration

In a textile machine the bearing affects the product, not only the machine. Schaeffler states that in rotor spinning machines vibrations impair the quality of the yarn, so the bearings and rollers must run smoothly [1]. The flyer on a roving frame has its operating clearance restricted for the same reason: smooth running gives roving of the quality the ring spinning frame needs [1]. On godets, two preloaded deep groove ball bearings prevent vibration so the drawn yarn reaches the required quality [1].

For standard deep groove ball bearings, the vibration grade is how a buyer specifies quiet running. Our deep groove ball bearings are supplied at vibration grade Z3V3 as standard and checked on vibration and noise test instruments at the factory. Bearings with a special noise or vibration requirement are tested one at a time before packing. If your machine needs a quieter grade than Z3V3, tell us the grade and we will confirm whether we can supply it.

Noise grade and precision class are separate things. A P6 bearing is made to tighter dimensional tolerances, while a vibration grade measures how smoothly it runs. The article on bearing noise grade vs precision class explains the difference. Speed ratings for each size are on the model pages. Check them against the shaft speed, and remember that a contact seal lowers the limit.

Seals against fly and dust

Fibre dust is fine, it travels everywhere in a mill, and once it works into a bearing it mixes with the grease and starves the raceways. Schaeffler’s flyer bearing has highly effective sealing against dust and fly, and its opening roller bearing is protected against fibres by two sheet metal seals [1]. Its tape tension pulleys are sealed by a gap seal on one side and a spring diaphragm on the other [1].

For standard bearings the choice is between open, ZZ and 2RS:

• ZZ (metal shields). A shield is fixed to the outer ring with a small labyrinth gap at the inner ring. NTN’s comparison gives it low torque and the same speed capacity as an open bearing, with dust protection rated good and water protection rated poor [2].
• 2RS (rubber contact seals). The seal lip touches the inner ring. NTN rates its dust protection excellent and water protection very good, with higher torque and a speed limit set by the seal [2].
• Open. Used inside gear cases and housings where oil or grease is supplied from outside.

Where fly is heavy, a contact seal is the usual choice unless the speed is too high for it. Keep the seal of the original bearing unless you know why it was chosen.

Clearance

Radial internal clearance is the free movement between the rings and the balls before mounting. Textile machines use both ends of the range. Positions that need very smooth running, such as flyers and opening rollers, use restricted clearance [1]. Heated positions use more: the godet bearing mentioned above is C4 [1]. Most drives and rollers in between run on normal clearance or C3.

Clearance has to match the job, and a mismatch shows up quickly. A domestic customer in China once ordered 6205 bearings from our factory without agreeing a clearance class, so they were made to the standard C0 range. The customer passed them to a roller drum manufacturer whose drums had to run with very little wobble, which needed C2. The bearings came back, and the factory checked the clearance of every bearing and shipped replacements. The machine was not a textile machine, but the lesson carries over to any roller that must run true: write the clearance class in the order.

If you need a clearance range narrower than a standard class, tell us the range and we will confirm whether we can supply it. The guide to bearing internal clearance explains the classes.

Lubrication

Most standard bearings in textile machines are sealed or shielded and leave the factory greased. For our sealed deep groove ball bearings, the default grease fill is about 30% of the free internal space. The grease machine is set by filling a few bearings to 30%, weighing them before and after, and using that weight for the batch. If your machine maker specifies a different fill or a particular grease, give us the requirement and we will confirm it.

Two points from Schaeffler’s textile publication are useful for maintenance planning:

• Fly shortens relubrication intervals. For its tape tension pulleys, Schaeffler gives a guide relubrication interval of about 30,000 operating hours where little fly is present and about 12,000 hours where there is considerable fly [1].
• Greased bearings have a shelf life. Mineral oil based greases can be stored for up to 3 years in a closed store at 0 to 40 °C, at no more than 65% relative humidity and away from chemical vapours, and after long storage the start-up friction of a greased bearing may be higher than normal [1]. Rotate spare stock rather than keeping it for years.

The bearing lubrication basics article covers fill quantity and relubrication, and the grease fill calculator gives a starting quantity by size.

Why textile machine bearings fail early

Most early failures in textile machines come from a few causes:

1. Fly in the bearing. Lint gets past a shield or a worn seal, packs into the grease and blocks it from the raceways. Look for fibre packed around the seal.
2. Too little grease. The most common grease problem we see is a bearing filled too lightly, with grease visible in the cage pockets on one side only.
3. Wrong grease for the temperature. Heated godets, dryers and stenters need grease rated for the temperature. A general-purpose grease in a hot position dries out quickly.
4. Knocks during fitting. Hitting a bearing onto its shaft dents the raceways, and the bearing is noisy from the first day. Press on the ring with the tight fit.
5. A lower grade than the machine was designed for. A bearing with a noisier grade or wider tolerances in a machine built for a quieter one runs rough from the start. In our experience this is the commonest customer-side cause of noise complaints.
6. Wrong clearance. A normal clearance bearing in a heated position, or a loose one in a position that must run true.

How to write a textile machinery bearing inquiry

An inquiry with these items can usually be priced in one round:

1. The full number with every prefix and suffix, for example 6202-2RS C3 or 6004 ZZ. A missing suffix is one of the most common reasons a wrong bearing is ordered, because the suffix carries the seal, the clearance and often the quality requirement.
2. The quantity for each model.
3. The machine type and position: spinning frame drive, carding fan, godet, winder roller.
4. The noise or vibration grade if the machine maker specifies one.
5. The operating temperature if the position is heated.
6. A photo of the old bearing and its markings. If the marking is a machine maker’s part number rather than a bearing number, say so.
7. Any marking or packaging requirement. Rings can carry your authorized brand, the factory brand, or no brand.

Send your model numbers and quantities to sales@fuli-bearings.com or through the contact page. The quotation request template has a copy-ready format. We check each number against the standard designations, mark any item we cannot meet as an exception on the specification sheet rather than substituting it, and send the quote. Rings and balls are GCr15 chrome bearing steel, and the steel maker’s material certificate is available on request for OEM and industrial orders. An inspection report can cover dimensions, radial clearance, rotation noise, vibration, appearance, material certificate and batch traceability. Export documents are the commercial invoice, packing list and CCPIT certificate of origin, plus an FTA Form COO where the destination country qualifies.

Backed by 20+ years of bearing export experience in Linqing, Shandong. FULI ships to 50+ countries & regions.

Sources

1. https://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/schaeffler_2/publication/downloads_18/tmb_de_en.pdf
2. https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf
3. https://cdn.standards.iteh.ai/samples/69977/9ac39b8b79a94b74b35cba8868eabe4f/ISO-15-2017.pdf