CHARGING DEVICE FOR THE HEAT TREATMENT OF WORKPIECES HAVING A HUB

Abstract

The invention relates to a charging device for the heat treatment of workpieces being provided with a hub (3), comprising a charging support (8), a shaft (7) and at least one auxiliary hub (6), wherein the workpiece (1) can be vertically supported on the shaft (7) by means of auxiliary hub(s) (6) precisely fitted into the hub (3), and the shaft being supported by means of the charging support (8) as well as use of auxiliary hubs (6) for the dimensionally stable hardening of gear-wheels (1) in vertical position.

Claims

1. Charging device for the heat treatment of workpieces being provided with a hub (3), comprising a charging support (8), a shaft (7) and at least one auxiliary hub (6), wherein the workpiece (1) can be vertically supported on the shaft (7) by means of auxiliary hub(s) (6) precisely fitted into the hub (3), and shaft (7) being supported by means of the charging support (8).

2. Charging device according to claim 1, characterized in that the workpiece (1) is a gearwheel.

3. Charging device according to claim 1, characterized in that the device is provided with two auxiliary hubs (6).

4. Charging device according to claim 1, characterized in that the auxiliary hub(s) (6) are of disk shape and are fitted to suit hub (3) or are adjustable by means of peripherally arranged adjusting elements.

5. Charging device according to claim 3, characterized in that the auxiliary hubs (6) have a conical/tapered shape.

6. Charging device according to claim 1, characterized in that the workpiece (1) has a hub diameter of more than 20% to of the workpiece diameter.

7. Charging device according to claim 1 made of heat resistant steel.

8. Charging device according to claim 1, characterized in that the shaft (7) is driven.

9. Charging device according to claim 1, characterized in that the charging support (8) is provided with two abutment structures.

10. Method for the heat treatment of workpieces (1) having a hub (3) in a way that they remain dimensionally stable, in particular of gearwheels, comprising the steps Fitting of at least one auxiliary hub (6) into the hub (3) of the workpiece, suspension of the workpiece (1) on a shaft (7) in a charging support (8), with the workpiece (1) being positioned vertically, applying heat to the workpiece (1) over a desired period of time, quenching the workpiece (1) in a customary cooling medium and if required or expedient, tempering the workpiece (1).

11. Method in accordance with claim 10, characterized in that the shaft (7) is driven.

12. Use of one or several auxiliary hubs (6) for the dimensionally stable hardening of gearwheels (1) in vertical position.

Description

[0028] The invention is explained in more detail by way of the enclosed figures, where

[0029] FIG. 1 is a top view as well as cross-sectional view of a gear-wheel to be hardened in the way proposed by the invention:

[0030] FIG. 2 illustrates a view of an inventive charging device with suspended shaft and mounted gearwheel;

[0031] FIG. 3 depicts the charging device shown in FIG. 2 with attached spreader used for handling the gearwheel, and

[0032] FIG. 4 shows an example of an adjustable auxiliary hub.

[0033] FIG. 1 illustrates a gearwheel that can be hardened as proposed by the invention, said gearwheel having a diameter of 2900 mm and a hub opening of 1080 mm. The gearwheel is provided with customary toothed rim 2 and a hub 3 as well as boreholes 4 equally distributed over the circumference. With a view to reducing the weight of the gear, boreholes 4 are located in an area of the gearwheel that is arranged deeper with respect to the toothed rim and the inner ring.

[0034] As can be seen from sectional view A-A (with auxiliary hubs and shaft), hub 3 has a central section 31 and two peripheral sections 32 that are slightly recessed with respect to the central section. These recesses serve to facilitate fitting of auxiliary hubs 6. The arrangement of recesses in this respect is helpful and improves the seat of auxiliary hubs 6, however the recesses are not essentially needed for the inventive method and the device proposed by the invention. Auxiliary hubs 6 are fitted into both peripheral sections 32 and may be connected with each other by means of struts or by means of tensioning elements fixed in position on shaft 7 of the device.

[0035] FIG. 2 shows an inventive charging device with suspended gearwheel 1 as a front and side view. Gearwheel 1 is mounted on shaft 7 by means of two auxiliary hubs 6 that are fitted on both sides into the outer sections 32 (see FIG. 1) of hub 3. The auxiliary hub disks 6 are precisely fit into the gearwheel hub 3, the shaft 7 is mounted into auxiliary hubs 6 with a precise fit.

[0036] Adjacent to auxiliary hub disks 6 shaft 7 is provided with tensioning elements 9 which on the one hand are fixed on shaft 7 and on the other keep auxiliary hubs 6 in their correct position.

[0037] Charging support 8 comprises on each side three adjacently arranged linear tubes the middle one of which is slightly shorter than the two outer tubes. Expediently, the middle tube is suitably rounded concavely at the top to enable shaft 7 to be accommodated. The tubes are securely interconnected by means of inserted connectors 11a. A baseplate 10 serves as stand and may be designed as a grid in the central portion between the tubes to enable the gearwheel to be treated with hot air.

[0038] Basically, any form of charging support may be employed that has two pedestals/supports to carry the shaft.

[0039] FIG. 3 shows the charging device illustrated in FIG. 2 with gearwheel 1, shaft 7, support 8, baseplate 10 as well as a spreader 12 that serves to handle and transport the gearwheel 1 mounted on shaft 7. By means of spreader 12 the gear-wheel is mounted on the charging support, removed from it and inserted into the quenching bath. Spreader elements of this kind are customary lifting equipment.

[0040] Shaft 7 depicted in FIG. 2 and FIG. 3 may be designed in the form of a tensioning axle capable of fixing and preventing detachment of the auxiliary hubs arranged and fitted into the recessed sections 31 and 32 of gearwheel 1. For this purpose, the circumferential area of shaft 7 is made wider in the area adjacent to gear-wheel 1, said circumference being clamped against auxiliary hubs 6 and suitably secured to prevent slipping. It is to be understood that the auxiliary hubs may be of tapered/conical shape, wherein such cones/tapers on the shaft 7 are pushed against the hub 3 of gearwheel 1 thus causing the gearwheel to assume a centered position between them and are secured in this position on shaft 7.

[0041] FIG. 4 shows an auxiliary hub 6 that can be adjusted to suit the diameter of a gearwheel hub, said auxiliary hub having six peripheral tapped holes 14 into which bolts 15 are inserted so as to be adjustable in height. In the area of the gearwheel hub, auxiliary hub 6 via the heads of bolts 15 braces and supports itself against the gearwheel.