Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B61—RAILWAYS
  • B61F—RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES
  • B61F15/00—Axle-boxes
  • B61F15/20—Details
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/134—Plasma spraying

Definitions

• DE-OS 23 46 144 a light metal disc with a steel bandage is connected by a conical seat with two-component adhesive.
• a socket is used which is softer than the shaft and into which Wheel hub is shrunk. This combination is in turn shrunk onto the shaft.
• DE-OS 23 54 206 an adhesive shrink connection is presented.
• the full wheels have a special shape, so that in the case of a press fit or shrink fit, heat input by the block brake up to over 300 ° C. does not cause any changes in track dimensions or loosening of the disks.
• EP 223759 A1 explains a method for producing surfaces for reusable longitudinal seat connections.
• the hardenable steel shafts are parallel in the axial direction, i. H. Traces of hardness running in the direction of the pressing force, in particular laser hardness traces of the solid phase with a martensite structure.
• the hardened surfaces are intended to reduce the friction in the axial direction in order to facilitate the pressing process, while the friction in the radial direction is to be increased by slightly penetrating the hardness traces into the hub surface.
• non-metallic-organic layers are not designed to reduce friction when joining and releasing longitudinal press connections several times. It continues to take place, even if e.g. T. with hardened surfaces, a friction of steel on steel or on cast steel instead, without introducing a sliding layer and effectively countering the fretting corrosion.
• the invention is based on the object of developing a method which protects the wheel seats from pressing damage in a manner which is workplace-friendly and environmentally friendly, and is energy-efficient and cost-effective.
• This procedure should fit into the existing maintenance technology and should do without constructive changes to the types of wheelsets (oversize) and the joining procedure according to UIC 813.
• the method is intended to offer a level of security against long-term breaks that is comparable with the currently used manufacturing and joining methods, and a comparable level of transmission capability for forces and moments.
• the wheelset shaft is rotated or ground longitudinally in its cylindrical and conical end region and the transition that is created is smoothed and / or rounded off, so that the surface of the wheelset shaft is treated in such a way by means of a plasma ion implantation method is carried out that a finely divided powder, in particular a sulfide-containing powder, is applied to the rotating wheel set shaft under atmospheric pressure by a reactive gas as the carrier gas, so that a very hard metallic sliding layer with a low tendency to adhesion is formed in the nano- / micrometer range, whereby at the highest contact pressures between the wheelset shaft and the wheel, solid lubrication that prevents press damage is generated, especially after a lubricant film has been torn off.
• a finely divided powder in particular a sulfide-containing powder
• the wheelset is joined using the longitudinal press process.
• the powder, in particular sulfide-containing powder, applied to the surface of the wheel set shaft by means of a plasma ion implantation process is applied in a sliding layer thickness in the single-digit micrometer range, preferably from 50 nm to> 2 ⁇ m.
• the plasma surface treatment can be carried out several times in the maintenance process.
• the solid lubricant is applied to the rotating wheelset shaft at a feed rate of 5 - 50 mm / min., Preferably 10 mm / min. applied.
• the cylindrical end area of the wheel seat is longitudinally turned or ground with an optimized feed from the outside inwards.
• the conical end area of the wheel seat is turned or ground lengthways from the inside to the outside.
• An emerging transition area is smoothed and / or rounded off.
• the device for carrying out the method is characterized in that the device is preferably a lathe and the longitudinally rotated or ground wheel set shaft is also integrated in a plasma ion implantation system, the plasma discharge of which is fed with reactive gas as a carrier gas and is a finely divided solid lubricant powder under atmospheric pressure applies to the shaft, wherein the plasma discharge is preferably directed at an angle of 90 ° to the rotating shaft.
• the plasma discharge is arranged at a distance of 20-80 mm, preferably 30 mm, from the wheelset shaft and is provided with a feed to the surface of the wheelset shaft, so that the plasma jet can cover a larger area.
• the device for plasma discharge is preferably attached to a support of a lathe or similar device. Through the plasma treatment, the solid lubricant particles are implanted in the surface and cause solid lubrication precisely where the lubricant film of the pressing aid breaks off. With the reaction gas used as the carrier gas, this or its inhibitors diffuse into the surface of the wheel seat and, due to the increase in hardness, additionally increase the material resistance to the occurrence of press marks.
• the wheel set is joined in the longitudinal pressing process, preferably using a molybdenum disulp paste as a pressing aid.
• the pre-treatment results in an adhesion coefficient against loosening in the longitudinal direction vn of max. 0.15 and an adhesion coefficient against slipping v r] of max. Achieved 0.12.
• the ion implantation system can be integrated into the manufacturing process due to the short treatment times (minute range) and the small space and energy requirements. It is possible to repeat the plasma ion implantation if, for example, in the maintenance process. B. a diameter adjustment of the wheel seat is necessary. The process can also be used in both new production and maintenance.
• the wheel seats of a wheel set shaft were treated by means of plasma ion implantation, the plasma implantation system being fastened to the support of a lathe.
• the press fit oversizes were chosen so that a wheel seat embodied the lower limit and a wheel seat the upper limit of the permissible press fit oversizes according to UIC 813.
• the carrier gas is mixed with the solid lubricant particles (3) by a high frequency and converted into an ionized cold plasma state.
• the ionized reaction gas plasma (5) is directed onto the wheel seat (6) of the rotating wheel set shaft (7).
• the entire surface of the wheel seat is treated by the translational movement of the plasma discharge.
• the wheels were pressed onto a wheelset press under production conditions and pressed after 48 hours without an oil expansion process. All in all, the wheel seats were joined and loosened eight times without any pressing calls.
• the wheel set was subjected to 10 million roll-overs with a wheel contact force of 170 kN and lateral force of 60 kN on a rolling test bench. No cracks and no permanent displacement of the wheel occurred during the test.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Plasma & Fusion (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Rolling Contact Bearings (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Coating By Spraying Or Casting (AREA)
• Lubricants (AREA)
• Platform Screen Doors And Railroad Systems (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7682044

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (2)

Citations (13)

Family Cites Families (9)

• 2001
  • 2001-04-19 DE DE10119309A patent/DE10119309C1/de not_active Expired - Fee Related
• 2002
  • 2002-03-14 CZ CZ2003-2851A patent/CZ305025B6/cs not_active IP Right Cessation
  • 2002-03-14 EP EP02704757A patent/EP1379709B1/de not_active Expired - Lifetime
  • 2002-03-14 AT AT02704757T patent/ATE296906T1/de not_active IP Right Cessation
  • 2002-03-14 DE DE50203281T patent/DE50203281D1/de not_active Expired - Lifetime
  • 2002-03-14 ES ES02704757T patent/ES2240699T3/es not_active Expired - Lifetime
  • 2002-03-14 WO PCT/EP2002/002837 patent/WO2002086182A1/de not_active Application Discontinuation

Patent Citations (13)

Non-Patent Citations (5)

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