1. Shaft material
1.1. Basic requirements
Uhing linear drives must only be used in conjunction with induction-hardened, ground and finished steel shafts.
Minimum requirements:
- Surface hardness: 50 HRC
- Diametral tolerance: h6
- Out-of-roundness: no more than half the diameter variation permitted according to ISO tolerance h6
- Concentricity tolerance (DIN ISO 1101): < 0.1 mm/m
1.2. Uhing precision shafts
Standard shafts:
Material similar to Cf 53, Mat. No.1.1213, surface-hardened by induction, 60-64 HRC
Rust-proof shafts:
Material X 40 Cr 13, Mat. No. 1.4034, surface-hardened by induction, 51-55 HRC
Rust- and acid-proof shafts:
Material X 90 CrMoV 18, Mat. No.1.4112, surface-hardened by induction, 52 -56 HRC
- All ground and superfinished
- Surface roughness: roughness height rating (DIN 4768 T.1) Ra: < 0.35 µm
- Diametral tolerance: h6
- Out-of-roundness: no more than half the diameter variation permitted according to ISO tolerance h6
- Concentricity tolerance (DIN ISO 1101): < 0.1 mm/m
1.3. Uhing precision shafts with special concentricity tolerance
As above but with a concentricity (DIN ISO 1101): =/< 0.03 mm/m
1.4. Leading end chamfer
The leading end of the shaft must be chamfered to avoid damage to the rolling rings when screwing the linear drive onto the shaft.
2. Pitch
The standard pitch is 0.5 x d. The nut can be ordered with a left-handed or a right-handed pitch.
Unless otherwise specified, the nuts will be supplied with a right-handed pitch.
Subsequent alterations to the pitch are possible for drive nuts of design category -4 by replacing the pitch block. Non-standard pitches of 0.1 - 0.2 - 0.3 and 0.4 x d are available. For these versions, the side thrust should be reduced to improve the running behaviour.
3. Payload with separate carriage
If linear drive nuts are used to move payloads with a separate carriage, the coupling must be designed to compensate any misalignment between the drive shaft and the carriage. Otherwise, the available side thrust will be affected.
If the application so permits, we recommend the use of a torque-free coupling.
Torque-free coupling
4. Vertical applications
For vertical applications, we advise the use of a directly braked motor to prevent the shaft from rotating backwards - and thus the linear drive nut from descending - due to the high efficiency of the drive.
Depending on the application (safety, value of the installation), a side thrust reserve (by using a second drive nut) must be included if required.
When using a release lever, make sure that the load cannot drop in an uncontrolled manner before operating the release lever. Danger of injuries!
5. Permissible ambient temperature
Uhing linear drive nuts are suitable for ambient temperatures ranging from -10°C to +70°C.
Higher temperatures on request.
7. Difference in pitch
The maximum difference in pitch for the two directions of travel is 2%. We therefore recommend the use of a length measuring system for positioning applications.
Subject to modifications.
For further information, please refer to Operating Instructions 05e, which are available on request.
9. Maintenance
For the lubrication of the shaft, normal commercially available MoS2-free roller bearing greases can be used (e.g. SKF Alfalub LGMT 2, Shell Alvania R2 or G2, Esso Beacon 2, BP Energrease LS2.
Procedure:
Clean the shaft and spread the grease as thinly as possible using a piece of cloth.
Frequency: Once every four weeks
