Installation

A flat mounting surface free of grease and oil is essential for the upper and lower ring to seat firmly. Welding beads, burrs, excessive paint and other irregularities must be removed prior to installation. The bearing rings must be completely supported by the connecting structure.

Rothe Erde recommends conducting a check on the mounting surfaces with a leveling instrument or laser equipment (this service can be provided by Rothe Erde). The flatness values should not exceed the values shown in table 1. To avoid larger deviations and the occurrence of peaks in smaller sectors, any deviation in the range of 0°-180° may only rise evenly once and fall again.

Example of flatness deviation acc. to DIN EN ISO 1101

Table 1:
Permitted flatness deviation acc. to DIN EN ISO 1101 on the support surfaces

Track diameter in mm DL	Flatness acc. to DIN EN ISO 1101 per support surface in mm
	BF 01 Double-row ball bearing slew rings BF 08 Axial ball bearing	BF 06 Single-row ball bearing slewing ring 4-point contact bearing BF 09 Double 4-point contact bearing BF 23, 25, 28 profile bearing*	BF 19 BF 13 Roller slewing bearings BF 12 Combination bearing
to 500 to 1000 to 1500 to 2000 to 2500 to 4000 to 6000 to 8000	0.15 0.20 0.25 0.30 0.35 0.40 0.50 0.60	0.10 0.15 0.19 0.22 0.25 0.30 0.40 0.50	0.07 0.10 0.12 0.15 0.17 0.20 0.30 0.40

BF is the abbreviation for the german term "Bauform" (means design) and refers to the first two digits of the drawing number.
The permitted values in Table 1 are not allowed to be used for special configurations as high-precision bearings with high running accuracy and low bearing play, please contact Rothe Erde.
*) Double these values are permitted for normal bearings BF 25.

Mechanical machining of the bearing connection surfaces on the connecting structure is required if the values are exceeded. The mounting position of slewing bearings must correspond to that shown in the drawing.

The corrosion protection can be removed with an alkaline cleaner. Solvent must be prevented from coming into contact with the seals or the raceway. Remove the protective coating from the upper and the lower mounting surfaces of the slewing bearing as well as from the gear.

Note: The corrosion protection can easily be removed, for example, using a biodegradable alkaline cleaner.

Advantage: Rapid removal of the corrosion protection and low environmental impact.

Hardness gap

The unhardened zone between the beginning and the end of the hardened region of the raceway is marked with an “S” on the inner or outer diameter of each bearing ring. On the gear ring, the hardness gap is marked on the axial surface. Wherever possible, the hardness gap “S” must be positioned outside the main load-carrying areas. If the main working area for the application is known, then the hardness gap of the ring loaded on the circumference must also be positioned outside the main loadcarrying area.

Gearing

The backlash is adjusted relative to the three gear teeth marked in green and should be at least 0.03-0.04 x module. After the final tightening of the bearing, the back lash should be rechecked over the entire circumference. A tip edge radius and a tip relief must be provided on the pinion.

Backlash measurement

Bolting/bolting assembly

Bolt holes on the bearing and connecting structure must match up, otherwise impermissible levels of stress will be established. Through-holes shall be configured acc. to DIN EN220 73, medium series, – see table below.

Thread/bolt diameter	Drilling diameter	Tightening torque Nm with bolts with a strength class μG ≈ μK = 0.14
	mm	for hydr. + electr. Md torque wrench	for Md- key	for hydr. + electr. Md torque wrench	for Md- key
	DIN/ISO 273	8.8	8.8	10.9	10.9
M 12	14	87	78	130	117
M 14	16	140	126	205	184
M 16	17.5	215	193	310	279
M 18	20	300	270	430	387
M 20	22	430	387	620	558
M 24	26	740	666	1,060	954
M 27	30	1,100	990	1,550	1,395
M 30	33	1,500	1,350	2,100	1,890
		Grade 5	Grade 5	Grade 8	Grade 8
UNC 5/8'' -11	18	200	180	286	260
UNC 3/4'' -10	21	352	320	506	460
UNC 7/8'' -9	25	572	520	803	730
UNC 1'' -8	27.5	855	770	1,210	1,100
UNC 11/8'' -7	32	1,068	970	1,716	1,560
UNC 11/4'' -7	35	1,507	1,370	2,410	2,190
		Grade 5	Grade 5	Grade 8	Grade 8
UNF 5/8'' -18	18	230	210	320	290
UNF 3/4'' -16	21	396	360	560	510
UNF 7/8'' -14	25	638	580	902	820
UNF 1'' -12	27.5	946	860	1,330	1,210
UNF 11/8'' -12	32	1,210	1,100	1,936	1,760
UNF 11/4'' -12	35	1,672	1,520	2,685	2,440

 

Fastening bolts

Normal fastening bolts, nuts and washers (without surface treatment) in strength class 10.9 acc. to DIN ISO 267. It is essential to comply with the specified number and diameter. The bolts must be carefully preloaded crosswise to the specified values (the table above gives several recommended values). The surface pressure underneath the bolt head or nut must not exceed the permitted limit values. If the limiting surface pressure is exceeded, washers of the appropriate size and strength must be provided. The minimum length of engagement must be guaranteed in the case of blind hole threads. If a hydraulic tensioning device is used, it is essential to adhere to the required projections for the screw threads or stud bolt threads and to use the appropriate washers

The determination of the tightening torque depends not only on the strength class of the bolt and the tightening process but also on the friction in the thread and the contact surface of the bolt head and nut. The tightening torques given in the table above are recommended values based on lightly oiled threads and contact surfaces.

Dry threads will require higher torques whilst heavily oiled threads will require lower tightening torques. The values may, therefore, vary considerably. This applies in particular to threads larger than M 30 or 1¼". For bolts of this size the use of bolt tensioning is recommended. If the frictional bond is not adequate, it is advisable to use a suitable compound to increase the frictional bond, or else make a form-locking connection. Welding of slewing bearings is not permitted.

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