ZARN2557-TV 25*57*50mm Slewing drive dual axis for solar PV and solar thermal tracker horizontal rotation

Product Details

Product Description

Product Description

Designation	Dimensions																		Mounting dimensions		Basic load ratings				Limiting speeds		Bearing frictional torque MRL Nm	Rigidity axial caL N/µm	Tilting rigidity ckL Nm/ mrad	Mass moment of inertia3) Mm kg · cm2	Axial runout6) µm	Mass m =kg
																					axial		radial
																			Da max.	da min.	dyn.Ca	stat. C0a	dyn.Cr	stat. C0r	nG oil	nG grease
	d	D	H	H1	H2	H3	C	C1	D1	D2	D3	B	B1	B2	r min.	r1 min.	d1	J			N	N	N	N	min–1	min–1
ZARN2557-TV	25	57	50	35	–	–	20		47	–	–	10	–	–	0.3	0.6			48	39	35,500	86,000	22,600	36,000	6,000	1,900	0.55	1,900	350	0.989	1	0.53
ZARN2557-L-TV	25	57	–	–	65	50	20		47	36	45	10	25	11	0.3	0.6			48	34	35,500	86,000	22,600	36,000	6,000	1,900	0.55	1,900	350	1.15	1	0.59

Needle roller/axial cylindrical roller bearings (With fixing holes Without fixing holes)
Features
Needle roller/axial cylindrical roller bearings comprise an outer ring with radial and axial raceways, shaft locating washers, an inner ring, a radial needle roller and cage assembly and axial cylindrical roller
and cage assemblies. The bearings are available in versions with or without fixing holes.
Radial and axial load carrying capacity
In addition to radial forces, the bearings can also support axial forces from both directions and tilting moments.
Preload and internal clearance
The outer ring, inner ring and axial cages are matched to each other such that the bearing is axially clearance-free after preloading by means of an theprecision locknut. The radial internal clearance conforms to Group 2 in accordance with ISO 5753-1 .
Bearings for screw mounting
Needle roller/axial cylindrical roller bearings ZARF(L) have holes in the outer ring. These are used for screw mounting directly on the adjacent construction or in a radial locating bore Figure 1.
Due to screw mounting of the outer ring, the cover that would otherwise be required and the matching work can therefore be dispensed with. The bearings are preloaded against the shaft shoulder by means of a locknut AM or ZM(A).
With seal carrier assembly
In the interests of a simpler design, a seal carrier assembly DRS, Figure 1 is recommended. The seal carrier assembly is centred on the outer ring and seals the bearing against outside influences.
ZARF..-L
Figure 1 Stepped shaft locating washer with sealing ring
1.Seal carrier assembly DRS
2.Locknut AM
3. Stepped shaft locating washer extended on one side
4. Rotary shaft seal DIN 3760-..-NBR
With stepped shaft locating washer
ZARF..-L has a stepped shaft locating washer extended on one side, Figure 1. These series are used in preference where the shaft locating washers are not adequately supported axially by the shaft shoulder or the bearing unit cannot be sealed on the outside surface of the normal shaft locating washer due to space conditions in the adjacent construction.
Heavy series
ZARF(L) is also available in a heavy series. This series has a larger cross-section for the same shaft diameter and therefore higher basic load ratings.
Bearings not for screw mounting
Bearings ZARN(L) are mounted in a housing bore and the outer ring is located using a cover, Figure 2. They are preloaded against the shaft shoulder by means of a locknut AM or ZM(A).
ZARN
Figure 2
Bearing outer ring located using cover
With stepped shaft locating washer
ZARN..-L has a stepped shaft locating washer extended on one side, Figure 3. This series is used in preference where the shaft locating washer is not adequately supported axially by the shaft shoulder or the bearing unit cannot be sealed on the outside surface of the normal shaft locating washer due to space conditions in the adjacent construction.
Figure 3
ZARN..-L
1.Stepped shaft locating washer extended on one side
2.Rotary shaft seal DIN 3760
Stepped shaft locating washer with sealing ring
Heavy series
ZARN(L) is also available in a heavy series. This series has a larger cross-section for the same shaft diameter and therefore higher basic load ratings.
Operating temperature
The bearings are suitable for temperatures from –30 °C to +120 °C.
Suffixes Suffixes for available designs, see table.
Available designs