1. Sleeve (12) comprising a carrier (9) made out of injection molded thermoplastic material and at least one susceptor (13, 14) being at least partially embedded in the carrier (9).
2. The sleeve (12) according to claim 1, characterized in that at least one susceptor (13, 14) is arranged equidistant to a contact surface (18) of the carrier (9).
3. The sleeve (12) according to one of the previous claims, characterized in that the at least one susceptor (13, 14) is ring-shaped.
4. The sleeve (12) according to one of the previous claims, characterized in that the at least one susceptor (13, 14) consists out of perforated metal sheet with openings (25).
5. The sleeve (12) according to claim 2, characterized in that the ratio between cross-section of the openings (25) of the perforation and the adjacent solid susceptor surface is in the range of 40% to 65%.
6. The sleeve according to one of the claims 2 to 5, characterized that the openings (25) of the perforation are at least partially filled with injection molded plastic material suitable to form bridges (27) in a joint connection (17) across the susceptor (13, 14).
7. The sleeve (12) according to one of the previous claims, characterized in that the at least one susceptor (13, 14) is made out of a non-corrosive material.
8. The sleeve (12) according to claim 7, characterized in that at least one susceptor (13, 14) is made out of stainless steel, or aluminum, or titanium.
9. The sleeve (12) according to one of the previous claims, characterized in that the at least one susceptor (13, 14) is arranged flush to the contact surface (18).
10. The sleeve (12) according to one of the claims 1 to 8, characterized in that the at least one susceptor is arranged at a distance up to 1 mm below the contact surface (18) embedded by injection molded material.
11. The sleeve (12) according to claim 10, characterized in that the at least one susceptor comprises protrusions arranged in the direction of a contact surface (18), said protrusions acting as distance means.
12. The sleeve (12) according to one of the previous claims, characterized in that the sleeve (12) comprises a tag carrying information about the characteristics of the at least one embedded susceptor (13, 14).
13. The sleeve (12) according to claim 12, characterized in that the tag is a one or a two dimensional barcode or a RFI Stag.
14. The sleeve (12) according to one of the previous claims, characterized in that the sleeve (12) comprises means to determine the temperature of the at least one susceptor (13, 14).
15. The sleeve according to claim 12, characterized in that the means to determine the heat is a RFID-tag.
16. Welding device (1) to establish a joint connection by a sleeve (12) according to one of the previous claims, characterized by a coil (3) to generate an electromagnetic field field, a HF-generator to drive the coil (3), a control means interconnected to the HF-generator andor the coil (3) to control a welding process and an input means (22, 23) to provide the control means with information about the characteristics of a susceptor embedded in the sleeve (12).
17. The welding device (1) according to claim 16, characterized in that the input means is a barcode reader andor a keyboard andor a touch screen andor a RFID-reading means.
18. The welding device (1) according to one of the previous claims 16 or 17, characterized in that the welding device comprises or is interconnected to a database means wherein information and characteristics about several sleeves (12) andor susceptors (13, 14) are stored.
19. Method for establishing a joint connection (17) between at least one part (10, 11) and a sleeve (12), comprising at least one susceptor (13, 14) and a carrier (9), according to one of the claims 1 to 15 comprising the following process steps:
a) Positioning the at least one part (10, 11) and the sleeve (12) such that the at least one susceptor (13, 14) is arranged adjacent to a connection surface (26) of the at least one part (10, 11);
b) Arranging the sleeve (12) and the at least one part (10, 11) in the effective range of a coil (3) of a welding device (1);
c) Generating an oscillating electromagnetic field (35) by the coil (3) such that a current (36) is induced in the at least one susceptor (13, 14);
d) Adjusting the level of the electromagnetic field (35) such that the at least one susceptor (13, 14) is heated due to electrical resistance of the material of the at least one susceptor (13, 14);
e) Applying the electromagnetic field (35) for a certain time until the material of the carrier (9) surrounding the at least one susceptor (13, 14) and the material adjacent to the connection surface (26) of the at least one part (10, 11) melt superficially and join each other;
f) Cooling of the melted material until the material of the sleeve and the at least one part cure and form a joint connection.
20. Method according to claim 19 characterized in that the at least one susceptor has a ring-like shape and is arranged in general coaxial to the coil (3).
21. Method according to one of the claims 19 to 20 characterized in that the carrier material surrounding the at least one susceptor is heated to 240\xb0 C. to 300\xb0 C.
22. Method according to one of the claims 19 to 21 characterized in that the temperature of the at least one susceptor is determined in function of the intensity and the time of the electromagnetic field applied and the starting temperature.
23. Method according to claim 22 characterized in that the thermal characteristics of the at least one susceptor is determined by a calorimetric method in that the susceptor is inductively heated in a water quench andor by a sensor interconnected to the susceptor during heating.
24. Method according to one of the claims 22 to 23 characterized in that information about the characteristics of the at least one susceptor is stored in a database means.
25. Method according to one of the claims 22 to 24 characterized in that information about the characteristics of the at least one susceptor is stored in a tag applied to the at least one susceptor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A hydrodynamic bearing apparatus comprising:
at least a pair of hydrodynamic bearing surfaces that face each other in the radial direction being formed with an outer circumferential surface of a shaft unit and an inner circumferential surface of a shaft fitting unit relatively and rotatably attached to said shaft unit;
hydrodynamic pressure generating grooves of a predetermined shape being produced on either one of said hydrodynamic bearing surfaces of said shaft unit and said shaft fitting unit; and
a lubricant coating being formed by electrodeposition on either of the hydrodynamic bearing surfaces of said shaft unit and said shaft fitting unit.
2. The hydrodynamic bearing apparatus as set forth in claim 1 wherein an anodic oxidization coating is formed on the other hydrodynamic bearing surface of said shaft unit or said shaft fitting unit.
3. The hydrodynamic bearing apparatus as set forth in claim 2 wherein said shaft unit or said shaft fitting unit on which said anodic oxidization coating is deposited is formed of aluminum, aluminum alloy, or magnesium alloy.
4. The hydrodynamic bearing apparatus as set forth in claim 2 wherein said anodic oxidization coating is made of a hard alumetized layer.
5. A method for manufacturing a hydrodynamic bearing apparatus comprising the steps of:
forming at least a pair of hydrodynamic bearing surfaces that face each other in the radial direction with an outer circumferential surface of a shaft unit and an inner circumferential surface of a shaft fitting unit relatively and rotatably attached to said shaft unit;
producing hydrodynamic pressure generating grooves of a predetermined shape on either one of said hydrodynamic bearing surfaces of said shaft unit and shaft fitting unit; and
putting either one of the hydrodynamic bearing surfaces of said shaft unit and said shaft fitting in an electrodeposition chamber to form a lubricant coating by electrodeposition.
6. The method for manufacturing a hydrodynamic bearing apparatus as set forth in claim 5 wherein the other hydrodynamic bearing surface of said shaft unit or said shaft fitting unit is put in an anodic oxidization treatment chamber to form an anodic oxidization coating on the surface thereon.
7. The method for manufacturing a hydrodynamic bearing apparatus as set forth in claim 6 wherein said anodic oxidization coating is formed by a hard alumetizing treatment.
8. The hydrodynamic bearing apparatus as set forth in claim 1 wherein said lubricant coating is provided in a predetermined thickness on said hydrodynamic bearing surface of said shaft unit or said shaft fitting unit on which said hydrodynamic pressure generating grooves are produced, and said hydrodynamic pressure generating grooves are produced using a step between the outer surface of said lubricant coating consisting of said electrodeposition coating portion and the outer surface of non-electrodeposition coating portion where the electrodeposition coating is not provided.
9. The hydrodynamic bearing apparatus as set forth in claim 8 wherein said non-electrodeposition coating portion is coated with an insulating coating.
10. The hydrodynamic bearing apparatus as set forth in claim 9 wherein said insulating coating in said non-electrodeposition coating portion is peeled off.
11. A method for manufacturing a hydrodynamic bearing apparatus comprising the steps of:
forming at least a pair of hydrodynamic bearing surfaces that face each other in the radial direction with an outer circumferential surface of a shaft unit and an inner circumferential surface of a shaft fitting unit relatively and rotatably attached to said shaft unit;
producing hydrodynamic pressure generating grooves of a predetermined shape on either one of said hydrodynamic bearing surfaces of said shaft unit and shaft fitting unit;
first coating an insulating coating on the portion in said hydrodynamic bearing surface of said shaft unit or said shaft fitting unit, on which hydrodynamic pressure generating grooves are formed;
providing a coating by electrodeposition to said hydrodynamic bearing surface of said shaft unit or said shaft fitting unit;
forming a lubricant coating consisting of electrodeposition coating portion in a predetermined thickness on the portion other than the portion having said insulating coating thereon; and
forming said hydrodynamic pressure generating grooves utilizing a step between the outer surface of said lubricant coating consisting of said electrodeposition coating portion and the outer surface of non-electrodeposition coating portion on which electrodeposition coating is not provided.
12. The method for manufacturing a hydrodynamic bearing apparatus as set forth in claim 11 wherein said insulating coating in said non-electrodeposition coating portion is peeled off.
13. The method for manufacturing a hydrodynamic bearing apparatus as set forth in claim 11 wherein said insulating coating is coated by a masking printing method.
14. The method for manufacturing a hydrodynamic bearing apparatus as set forth in claim 11 wherein said insulating coating consists of an epoxy type rein coating material.