This invention relates to the support for a bearing arrangement in a housing formed by a casting, pressure casting, extrusion or injection moulding or like processes. Particularly but not exclusively the invention relates to the provision of supports for bearings for bevel or helical pinion shafts in a cast gear box housing in a so called flying gear design.
For the provision of gear pinion shaft bearing support two possibilities are known. The first design is to cast the support directly in the housing whilst the other is to provide an extra bush or bearing housing which is connected to the main housing. These designs are shown respectively in
It is often required to provide bearings on a gear shaft in an angle design with lubrication. Lubrication may be achieved by various methods including directly by providing a bath of lubricant in which the gears run totally or partially immersed or indirectly by splashing lubricant within the gear housing. With direct immersion in a lubricant bath channels and holes are required in the bearings support or bush to permit necessary lubricant circulation whilst indirect lubrication requires collectors and supply channels or bores to be formed to return the lubricant.
One such prior bush support providing lubrication is shown in
Regardless of the method of lubrication the formation of the necessary collectors, channels, holes and bores in a cast product complicates the design and increases the expense of manufacture. Formation of these internal features entirely during the casting process requires the use of extra mould cores making the castings more complicated thus increasing the expense and risk of defect. Where these features are alternatively formed subsequent to the casting operation, the post machining of the product adds to the manufacturing time and expense. Furthermore where the housing is of the unitary or monolithic construction internal machining is frequently not possible.
One object of the present invention is to provide support or bushing for bearing elements unitarily formed within a housing and having means for lubrication which is capable of manufacture by a material forming process such as casting or injection moulding avoiding or at least mitigating the above mentioned problems.
According to one aspect of the present invention a housing for a gear unit comprises housing watts and support for bearing elements of a gear unit pinion shaft, the housing walls and support being formed in a mould wherein the support is connected to a wall of the housing and extends from that wall in the direction in which the housing is demoulded from the forming mould.
Further aspects of the present invention will become apparent from the following description of embodiments of the invention in conjunction with the following figures in which:
Shown in
Each of the halves 42, 43 of the housing unit are cast separately and is a mirror image of the other with their plane of symmetry passing through the rotational axis of the gear shaft Details of their symmetry are shown in
Accordingly the bridge support is formed in two halves 45, 46 whose interior mating surfaces together define a cylindrical hole 44 located at the center of the unit for supporting the gear shaft and bearing assembly. By interior mating surfaces of the bridge halves it will be understood that whilst the physical contact between the surface may be desirable it is not a necessity and that the surfaces may be spaced apart by a small distance consistent with providing the necessary location and support for the shaft bearings.
In each case the half bridge piece projects from and is connected to a wall of the housing which is perpendicular to the direction of demoulding of the casting. By the direction of demoulding is meant the direction in which the principle parts of the mould move apart or the direction of withdrawal of a shape-forming core to facilitate removal of the moulding or casting. This direction is normally perpendicular to the parting line of the mould. Thus bridge half 45 is connected to housing wall 47 and bridge half 46 is connected to housing wall 48 both housing walls being perpendicular to the direction in which the respective half castings were demoulded. Such directions are indicated by arrows D1 and D2 in
The housing shown in
Such dimensional features facilitate demoulding of the half housing or core. According to this configuration the lowest region of the upper surface 49 of the bridge 41 is thus located directly above the rotational axis of the gear shaft along the plane of the mating surfaces of bridge portions 45, 46. At this point is provided a circular hole 50 formed half in each mating surface and extending from the upper surface of 49 of the bridge to and connecting with the cylindrical hole 44 directly below. The formation of semi-cylindrical impressions in each of the mating surfaces of the bridge halves to define the hole 50 may be accomplished by profiling of the mould wall without the necessity of using a separate core.
According to the above described configuration the upper surface 49 of the bridge 41 is formed with a shallow collector for collecting lubricant splashed upward by a rotating gear wheel and permits channeling of this lubricant via hole 50 to the pinion shaft bearings housed within the cylindrical hole 41.
The above described configuration of the gear housing 40 thus provides means for collecting and channeling lubricant to shaft bearings and comprises two halves 42, 43 which may be individually cast or formed without the necessity to use separate cores or post forming machining.
Cavities 51, 52 formed in the housing walls 47 and 48 respectively and each extending inwardly of the bridge portions 45, 46 may be provided to reduce material usage and weight.
Thus in accordance with the present invention the inner shape or profile of the casting and the outer shape or profile, as illustrated in
Further aspects of the invention are shown in
Number | Date | Country | Kind |
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0106002.9 | Mar 2001 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB02/01808 | 3/12/2002 | WO | 00 | 4/16/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO02/073070 | 9/19/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1496866 | Simpson et al. | Jun 1924 | A |
1560827 | Gustav | Nov 1925 | A |
1794432 | Yonkese | Mar 1931 | A |
2600912 | Olson | Jun 1952 | A |
4297906 | Costello | Nov 1981 | A |
4513599 | Harris | Apr 1985 | A |
Number | Date | Country |
---|---|---|
31 47 853 | Jun 1983 | DE |
0 219 240 | Apr 1987 | EP |
0 547 395 | Jun 1993 | EP |
Number | Date | Country | |
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20040159181 A1 | Aug 2004 | US |