B3007E Installation & Maintenance Rolling Mill Bearings Sealed Type Tapered Roller Bearings
24Pages

Koyo INSTALLATION AND MAINTENANCE MANUAL FOR ROLLING MILL BEARINGS (3) SEALED TYPE FOUR ROW TAPERED ROLLER BEARINGS JTEKT JTEKT CORPORATION

★The contents of this installation and handling manual are subject to change without prior notice. Every possible effort has been made to ensure that the data listed in this catalog is correct. However, we cannot assume responsibility for any errors or omissions. Reproduction of this installation and handling manual without written consent is strictly prohibited.

1. INTRODUCTION We, JTEKT developed the sealed type four row tapered roller bearing for steel mill roll neck application in order to meet the request from the steel makers in Japan. The main purpose of the development was come from the following three items, which are prolongation of the actual life, maintenance interval and saving of the grease consumption. It is very commonly known that the cause of premature life of conventional bearing is almost due to excessive operating condition which is induced by entry of water into the bearing because of poor sealing performance of the chock...

The structural features of the developed bearing are mainly to prevent the entry of water into the bearing and grease leakage from the bearing, that is to say; 1. O rings are applied on bearing outside for preventing the entry of water through the clearance between the chock bore and bearing outside. 2. The grease hole and groove are eliminated from the cup and cone spacers. 3. The grease seals are equipped into the both seal cover. 4. The special spiral groove is prepared on bore wall for retaining the grease between the roll neck and bearing bore. Since the developed bearing is designed...

1) The bearing is prevented from the entry of water and the leakage of grease by the fixed O ring on the outside of seal cover. 2) To prevent the entry of water and the leakage of grease, the oil groove on the cup spacer is eliminated. 3) The bearing has two double lipped oil seal assemblies which are incorporated in the bore of seal cover for preventing the entry of water and the leakage of grease. 4) The special spiral groove is provided on the cone bore for retaining the grease between the roll neck and bearing bore. 5) The special seal is set on the cone spacer for prevention of such...

1) The bearing should never be unpacked prior to installation. 2) Removing the rust preventive oil from the bearing by wiping is ideal. However, the bearing may be used with the rust preventive oil, as it is coated, because it has no influence on the bearing performance when it is combined with the grease. 3) The serial number and the row number are indicated on each bearing component. Example; VG-10 - 1 —*- Row number -► Serial number case of the bottom roll, it is the bottom in the bottom chock), then after a certain period of operation time (at each maintenance time), the zone number at...

1) Unwrap the bearing from the wooden box and take vinyl sheets off, which sheets protect bearing damage during transportation, and collect grease on the sheet and return such grease to the bearing inside, then adjust line which is marked on the bearing outside as sketched below in order to match load zone mark. Seal Cover Single Cup Cup Spacer Double Cup Fig.8 Load zone line 2) Make sure if seals seat proper place. 3) Clamp the bearing unit by the clamp lifting tool as shown Fig. 10. 4) Coat the grease or oil on the chock bore as Fig.11 for easy installation of the bearing assembly.

5) Install the bearing assembly into the chock by using the hoist after indicating the load zone as Fig.12. At this time, pay attention to O ring fixed on seal cover outside to avoid damage. 6) Assemble chock and chock cover in same process as conventional method. 7) Before mounting the chock and bearing assembly on the roll neck, coat the grease on the cone bore and the Molycoat (Molybdenum Dersulfied and grease mixture) on the roll neck. This is very important work in order to prevent trouble such as seizure on roll neck.

5. DISMOUNTING, INSPECTION AND REFRESHMENT 1) In case of dismounting the bearing from the chock, use the tool (Fig.14 ... same tool with Fig.11) and pull the bearing assembly out. 2) After the washing and cleaning the bearing, take a visual inspection to each component and seals. 3) Record the load zone number used in service at every load zone changing as usual. 4) Prepare two timbers and lay the seal cover (row number 4) on the timbers by indicating the load zone number® at a certain location (Fig. 15). 5) Fit the O ring on the outside of the seal cover. 6) Lay the single cup of row...

10) Fill the grease approx, a quarter of specified grease amount per row in space between rollers, cage, cone raceway and cone rib of row number 3 while rotating the case and rollers. 11) Place the cone assembly on the cup (row number 4) by matching the row number i.e.; row number 4 roller side must be bottom. At this time, the placing must be done carefully by aligning the center line to avoid seal lip inversion. 12) Place the cup spacer (row number 4-3) on the single cup (row number 4). 13) Place the double cup (row number 3-2) on the cup spacer with double cup row number 3 side down and...

6. THE RECOMMENDABLE GREASE AND AMOUNT The following characteristics are required as the grease for sealed type four row tapered roller bearing for roll neck application. 1) High water proof and high mechanical stability under condition of water inclusion. 2) High rust resistance. 3) High oxidation stability. 4) High extreme pressure and anti abrasion. 5) Less penetration value change, oil separation and leakage at the high temperature condition Recommendable grease amount: 1.0 kg per bearing for the bearing No. 47TS694625 and 2.3 kg per bearing for the bearing No. 4TRS19. The routine...

1) Please do not mount the bearing part by part as previous method which is applied for the conventional bearing because there is a risk to damage seal lip. Bearing assembly should be installed into chock at once by using the tool. 2) O rings and seals are damaged and should be serapped at several cases, so that for the spare, some quantity of stock shall be recommended. Great advantages and merits depending on the adoption and employment of the various kinds of Koyo four row sealed bearings have been recognized in many customers. 1) Much reduction of grease consumption especially in the...