GB2246412A

GB2246412A - Gear case in particular for worm gearing.

Info

Publication number: GB2246412A
Application number: GB9114459A
Authority: GB
Inventors: Friedrich Muller
Original assignee: Stoeber Antriebstechnik GmbH and Co KG
Current assignee: Stoeber Antriebstechnik GmbH and Co KG
Priority date: 1990-07-07
Filing date: 1991-07-04
Publication date: 1992-01-29
Anticipated expiration: 2011-07-04
Also published as: AT402845B; CH684358A5; GB2246412B; ATA134191A; IT1250651B; ITMI911870A0; GB9114459D0; ITMI911870A1; FR2664346A1; FR2664346B1

Abstract

In a gearing casing, particularly for gearing with straight-cut gears/worms or worm gears which exhibit bearing zones for gear pieces and an assembly opening through which the latter may be installed in the casing, one (34, 49) of the bearing zones located at the assembly opening (7) is produced so as to exhibit a passage opening (35) extending in the assembly direction for gearing components, the said bearing zone advantageously constituting a support for a bearing which is interrupted in order to form the passage opening (35). <IMAGE>

Description

GEAR CASE IN PARTICULAR FOR SPUR GEARING/WORM GEARING OR WORM GEARING The invention relates to a gear cas < ; in particular for spur gearing/worm gearing or worm gearing according to the preamble of Claim 1.

In known gear cases, the gear components are introduced into the inside of the case through the assembly opening. The spur gear and worm gear sets have gear components: of different size, so that in the known gear cases, an additional assembly opening is provided for inserting a large gear component, such as a worm gear. For this purpose, for example the gear case is open on one side and after inserting the worm gear must be closed by a cover. Problems occur in this case as regards sealing this cover. In addition it is also used simultaneously as a bearing for the respective shaft.

The cover is consequently subject to transverse forces at the time of operation of the gear case, due to which additional sealing problems occur.

It is the object of the invention to construct the gear case of the aforementioned general type so that even larger gear components can be inserted in the inside of the case through a single assembly opening.

This object is achieved according to the invention in the gear case of the aforementioned general type by the characterising features of Claim 1.

On account of the inlet opening in the region of the support point, a larger gear component, for example a worm gear can be inserted through the single assembly opening of the gear case according to the invention. An additional cover can thus be saved, due to which not solely the manufacture, but also the assembly of the gearing to be installed is simplified. The larger gear component is inserted through the assembly opening so that it projects through the inlet opening partly into the support point in the region of the assembly opening. Since the inlet opening extends in the assembly direction, thus into the inside of the case, in this way the larger gear component can be installed effortlessly.

Since an additional cover is not necessary, the sealing problems connected with such additional covers are avoided. The gear case according to the invention is distinguished by a simple construction and can be assembled easily. A spur gear/worm gear set or a worm gear set can optionally be installed in such a gear case through the assembly opening adjacent to the motor.

Further features of the invention will become apparent from the other Claims, the description and the drawings.

The invention will be described in detail with reference to one embodiment illustrated in the drawings, in which: Figure 1 shows a gear case according to the invention in a section on line C-D of Figure 2, Figure 2 is a view of one side wall of the gear case according to Figure 1 comprising an assembly opening, Figure 3 is a section on line A-B of Figure 1, Figure 4 shows the gear case according to the invention, according to Figures 1 to 3, in an enlarged and perspective illustration, Figure 5 is an illustration corresponding to Figure 3 with the worm gearing installed, Figure 6 is an illustration corresponding to Figure 1 with the worm gearing installed.

As shown in Figure 4, the gear case is constructed in the form of a block and has side walls 1 to 4, which are connected to each other at the lower end by a base 5 and at the upper end by an upper wall 6. Located in the side wall 4 is an assembly opening 7, through which the respective gear components can be inserted in the case.

The side wall 2 lying opposite the side wall 4 comprising the assembly opening 7 as well as the base 5 and the upper wall 6 have a closed construction.

The case has a rectangular cross-section and on the two side walls 1 and 3 adjoining the side wall 4 comprising the assembly opening 7 at right angles respectively comprises a bearing opening 8 and 9, in which a shaft 10 (Figure 5) can be mounted to rotate.

The two bearing openings 8, 9 are located in the half of the case comprising the upper wall 6 and are arranged coaxially (Figure 3). Both bearing openings 8 and 9 are defined by an enlarged rim 11 and 12, which projects inwards and outwards beyond the associated side wall 1, 3. In order to be able to absorb reliably the forces occurring at the time of operation of the gearing located in the case, the side walls 1 and 3 have a construction of increased thickness over the entire periphery of the bearing openings 8 and 9. Preferably at the mid-point of their axial width, the rims 11, 12 comprise an annular groove 13 and 14, in which a retaining ring 15, 16 (Figure 5) respectively for one roller bearing 17, 18 can be inserted. The shaft 10 is supported in a rotary manner in the bearing openings 8, 9 by the roller bearings 17, 18.As shown in Figure 5, the roller bearings 17, 18 are located at the facing ends of the rims 11, 12 within the gear case.

In order to prevent the penetration of dirt and the like through the bearing openings 8, 9, they are sealed with seals 19, 20, which are preferably radial shaft seals, which bear in a sealing manner on the shaft 10 byasealing lip 21, 22 as well as a preceding dust lip 23, 24. The seals 19, 20 are pressed in known manner from the outside of the gear case into the bearing openings 8, 9, so that they are seated with a press fit in the bearing openings.

The side wall 2, which lies opposite the assembly opening 7, comprises internally an inwardly projecting peripheral bearing rim 25 (Figures 1 and 3), which surrounds a bearing opening 26. The inner wall 27 of the bearing rim 25 is provided with a shoulder 28, against which a roller bearing 29 (Figure 6) bears in the installed position. One end of a worm 30 in the bearing opening 26 is supported to rotate by the roller bearing 29. In order to be able to absorb reliably the forces occurring at the time of operation of the gearing located in the case, the bearing rim 25 widens out from its end face in the direction of the side wall 2.

As shown in Figures 1 and 3, the bearing rim 25 is located in the region below the bearing openings 8 and 9, whereof the axes 31, 32 lie perpendicular to the axis 33 of the bearing rim 25.

Located coaxially opposite the bearing rim 25, in the region of the assembly opening 7, is a further bearing rim 34 (Figures 1, 2 and 4), which is located completely inside the case, in the same way as the bearing rim 25. However, in contrast to the bearing rim 25, the bearing rim 34 does not extend completely over 3600, but is interrupted in order to form an inlet opening 35 (Figures 2 and 4). The bearing rim 34 extends over an angular region of approximately 3000. Due to this the roller bearing 36 to be located in the bearing rim 34 (Figure 6) is still reliably supported over a sufficiently large peripheral region, so that loads can be absorbed without difficulty at the time of operation of the gearing located in the case.The edges 37 and 38 (Figure 2) defining the inlet opening 35 preferably lie respectively on one radius of the bearing rim 34, seen in the axial direction of the bearing rim (Figure 2). Due to this the inlet opening 35 may already be provided at the time of manufacture of the case constructed in one piece. The bearing rim 34 is connected by a total of five webs 39 to 43 to the side walls 1 and 3 and to the base 5 (Figures 2 and 4). As is also shown in Figure 2, the bearing rim 34 with the webs 39 to 43 is arranged with mirror symmetry with respect to the longitudinal plane of symmetry 44 of the case. Since the bearing rim 34 is connected solely by the relatively narrow webs 39 to 43 to the side walls 1, 3 and the base 5, a considerable saving of weight is achieved.

Provided in the inner wall 45 (Figures 1 and 4) of the bearing rim 34 is a groove 46 for a retaining ring 47 (Figure 6), by which the position of the roller bearing 36 may be secured in an axial direction.

Figures 1 and 4 show that the bearing rim or bearing ring 34 is connected by a further web 48 to the bearing rim 11. The web 48 is located at the height of the web 39 and extends at a short distance from the inlet opening 35 as far as the adjacent side wall 1 of the case (Figure 4). Furthermore, the web 48 extends in the axial direction of the bearing openings 26 and 49, of which the bearing opening 49 is defined by the bearing rim 34. The web 48 supports the bearing rim 34 with respect to the bearing rim 11 on the output side.

The two bearing rims form force-receiving points at the time of operation of the gearing located in the case. The web 48 in this case prevents undesirable relative movements between the bearing rims 34 and 11. The bearing rims 12 and 25, in the same way as the bearing rim 34, form bearing hubs.

The case serves to receive a spur gear/worm gear set or a worm gear set. The respective gearing components are inserted into the case through the assembly opening 7 and are brought into their installed position. Since the bearing rim 34 is provided with the inlet opening 35, even a gear can be introduced into the case through the assembly opening 7, the diameter of which gear is greater than the distance between the upper webs 49, 43 lying horizontally at the same height and the opposing edge 50 of the assembly opening 7 (Figure 4). At the time of insertion in the case, such a large gear is held so that it projects through the inlet opening 35 into the bearing opening 49. In this way, a large gear can be installed effortlessly in the case, without a second assembly opening being necessary in another side wall of the case.

Figures 5 and 6 show a two-stage worm gear, whereof the gear components have all been inserted in the case through the assembly opening 7. The worm gear 51 is seated on a bush 52, which at its end remote from the roller bearing 17 has a radial flange 53, to which the worm gear 51 is attached preferably in a releasable manner. At its end facing the roller bearing 18, the worm gear 51 has a corresponding recess, in which the radial flange 53 of the bush 52 engages (Figure 5). The bush 52 itself is connected by a spring 54 in a non-rotary manner to the shaft 10. The roller bearing 17 is secured in one axial direction by the retaining ring 15 and in the other axial direction by the bush 52, which bears against the roller bearing. The position of the opposing roller bearing 18 is secured by the retaining ring 16 and by a shoulder 55 in the surface of the shaft 10 in the other direction.

The roller bearing 18 bears on this shoulder 55, as shown in Figure 5.

The worm gear 51 meshes with the worm 30, whereof the axis 56 lies perpendicular to the worm gear axis 57. The worm 30 is mounted to rotate in the bearing hub 25 by means of the roller bearing 29, which bears against the shoulder 28 of the bearing hub and due to this its position is secured in one axial direction. In the other axial direction, the position of the roller bearing 29 is secured by a flange 58 of the worm, against which the roller bearing bears. On the opposite side, the worm 30 has a further flange 59, on which the roller bearing 36 bears, the position of which is secured axially on the opposite side by the retaining ring 47.

The diameter of the worm gear 51 is greater than the distance 60 (Figure 6) between the upper edge 50 of the assembly opening 7 and the upper side of the webs 39, 43. Nevertheless, as a result of the inlet opening 35, this worm gear 51 can be guided through the assembly opening 7 into the case.

The distance 61 between the upper edge 50 of the assembly opening 7 and the lowermost point 62 of the bearing rim 34 is in this case greater than the diameter of the worm gear 51. The shaft 10 is inserted through one of the two bearing openings 8 and 9 into the case, in which the worm gear 51 has been previously inserted in the manner described.

Then the worm 30 with the roller bearings 29 and 36 can be assembled by way of the assembly opening 7.

The end 63 of the worm 30 pointing beyond the roller bearing 36 in the direction of the assembly opening 7 supports a gear 64 in a non-rotary manner, in which a gear 65 of a drive shaft 66 engages.

The two intermeshing gears 64 and 65 lie in the assembly opening 7, whereas the drive shaft 66 projects from the case through the assembly opening 7.

Screwed to the edge 67 surrounding the assembly opening 7 (Fig. 4) is a connecting flange 68 (Figure 6), by which the gear case is flange-mounted on a motor (not shown). The edge 67 is provided over its periphery with corresponding bores 69 (Figure 4) for screws or threaded bolts, by which the connecting flange 68 can be screwed to the edge 67.

In the gear case described, all the bearing points 8, 9, 25, 34 are located within the gear case of block-like construction. This produces very high overall rigidity of the gear case. Since no bearing covers loaded by transverse forces are required, the sealing problems connected with such bearing covers do not occur. Finally, this gear case can be produced very simply and above all economically.

Claims

1. Gear case, in particular for spur gearing/worm gearing or worm gearing, with bearing points for gear components and with an assembly opening, through which gear components can be inserted in the gear case, characterised in that provided in the region of the assembly opening (7) is one of the bearing points (34, 49), which comprises an inlet opening (35) extending in the assembly direction, for gear components.

2. Gear case according to Claim 1, characterised in that the bearing point (34, 49) comprises a bearing hub, which is interrupted to form the inlet opening (35).

3. Gear case according to Claim 1 or 2, characterised in that the distance (60) between the inlet opening (35) and the opposite edge (50) of the assembly opening (7) is smaller than the distance (61) between this edge (50) of the assembly opening (7) and the lowermost point (62) of the bearing point (34, 49) located opposite the inlet opening (35).

4. Gear case according to Claim 2 or 3, characterised in that the bearing hub (34) extends over an angular region of approximately 300 .

5. Gear case according to one of Claims 2 to 4, characterised in that the bearing hub (34) is connected by webs (39 to 43) to side walls (1, 3) and to the base (5) of the gear case.

6. Gear case according to one of Claims 1 to 5, characterised in that the side walls (1, 3), which adjoin the side wall (4) containing the assembly opening (7), comprise bearing points (11, 12) for a shaft (10), which align one with the other.

7. Gear case according to Claim 6, characterised in that the bearing points (11, 12) each comprise a bearing hub (11, 12).

8. Gear case according to Claim 7, characterised in that the bearing. hub (11) on the output side is supported on the bearing hub (34) in the region of the assembly opening (7).

9. Gear case according to Claim 7 or 8, characterised in that the bearing hub (11) on the output side and the bearing hub (34) in the region of the assembly opening (7) are connected to each other by at least one web (48).

10. Gear case according to one of Claims 1 to 9, characterised in that at least the bearing point (34, 49) located in the region of the assembly opening (7), preferably all the bearing points (11, 12; 25, 26; 34, 49), are located within the gear case.

11. Gear case according to one of Claims 1 to 10, characterised in that it is constructed symmetrically with respect to a longitudinal plane of symmetry (44).

12. Gear case according to one of Claims 1 to 11, characterised in that it is constructed in one piece.