System for the Contactless Sealing of a Rotatably Mounted Shaft with Respect to a Housing, and Gear Unit

Abstract

A system for the contactless sealing of a rotatably mounted shaft with respect to a housing, and a gear unit, oil being provided in the interior of the housing, in particular, the rotating shaft protruding from the interior into the outer area; a centrifugal disk, joined in rotatably fixed manner to the shaft, having at least partially radially extending bores that connect oil from a centrifugal chamber to a collection chamber surrounding the centrifugal disk.

Claims

1-14. (canceled)

15. A system for contactless sealing of a rotatably mounted shaft with respect to a housing, comprising: housing flange part including a collection chamber, a centrifugal chamber, and a bore connecting the centrifugal chamber and the collection chamber, a first end area of the bore opening into the centrifugal chamber and a second end area of the bore opening into the collection chamber; and a gap region formed between a centrifugal disk, joined in rotatably fixed manner to the shaft, and the housing flange part, the gap region connecting the centrifugal chamber to the collection chamber, so that lubricating oil centrifuged off of the shaft into the centrifugal chamber is collectable and feedable through the bore into the gap region due to rotational movement of the shaft relative to the housing.

16. The system according to claim 15, wherein the second end area of the bore is located radially inward of a radially outside end area of the gap region.

17. The system according to claim 15, wherein the rotational movement of the shaft relative to the housing generates an underpressure to cause pumping out of lubricating oil located in the centrifugal chamber.

18. The system according to claim 15, wherein the centrifugal disk is secured on a centrifugal sleeve that is provided on the shaft and includes centrifugal grooves.

19. The system according to claim 18, wherein at least in one axial partial area, an outside diameter of the centrifugal sleeve increases toward the centrifugal disk with the aid of a chamfer provided on the centrifugal sleeve, so that oil is conveyable in at least one of (a) a direction of the centrifugal disk and (b) a direction of a channel of the centrifugal disk.

20. The system according to claim 18, wherein a gap is provided between the centrifugal sleeve and a further housing flange part joined to the housing flange part, the gap extending radially in a first partial area and axially in a further partial area.

21. The system according to claim 20, wherein the gap opens through into at least one collection groove provided in the further housing flange part and is connected to the collection chamber via a further gap disposed between the further housing flange part and the centrifugal sleeve.

22. The system according to claim 15, wherein the collection chamber is connected in a lower area via a bore to at least one of (a) the interior of the housing and (b) an oil-pan area.

23. The system according to claim 15, wherein the housing flange part and a further housing flange part are screw-connected, and a seal is disposed between the housing flange part and the further housing flange part.

24. The system according to claim 23, wherein a first baffle area, having first drainage channel, is situated on the further housing flange part, a second baffle area having second drainage channel being disposed on the further housing flange part, the baffle areas and the drainage channels being axially symmetric.

25. The system according to claim 15, wherein the gap region is arranged as a capillary gap region.

26. The system according to claim 15, further comprising a dust protector in contact with the housing flange part disposed on the shaft.

27. The system according to claim 15, wherein the gap region is arranged as a capillary gap, and wherein at one axial end area of the gap region, a widening is provided which is arranged such that a capillary effect is interrupted in an area of the widening.

28. A gear unit, comprising: a system according to claim 15; wherein, when the gear unit is at rest, an oil level lies below in a gravitational direction the system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] FIG. 1 illustrates a system according to an example embodiment of the present invention.

[0079] FIG. 2 is an enlarged cross-sectional view of the system illustrated in FIG. 1.

DETAILED DESCRIPTION

[0080] A system according to an example embodiment of the present invention is shown schematically in FIG. 1. An enlarged section is shown in FIG. 2.

[0081] According to example embodiments of the present invention, a contactless sealing is attained between a rotating shaft 1 and a housing.

[0082] In this context, disposed on shaft 1 is a centrifugal sleeve 25 on which, in addition, a centrifugal disk 22 is situated, in particular, joined with material locking or as a press-fitted connection.

[0083] An outer sealing flange 19 and an inner sealing flange 23 are provided on the housing, the centrifugal disk being set apart from outer sealing flange 19 by a gap 12, and centrifugal sleeve 25 being set apart from inner sealing flange 23 by a gap, including entry labyrinth 3 and axial gap 2.

[0084] The sealing system is set up in multiple stages, and in this manner, the oil passing through each obstacle is in each instance met with a further obstacle.

[0085] The entire sealing system is disposed above the oil level which sets in when shaft 1 is at rest. During operation of shaft 1, oil foam or spraying oil may be produced, for example, by gear wheels connected directly or indirectly with the shaft. Preferably, this oil level is below return bore 21.

[0086] The oil striking against baffle surface 9 is drained off via an annularly formed drainage channel 8, and downward toward the oil pan.

[0087] Provided axially somewhat further inside, but radially deeper, is baffle surface 6, which is bounded radially to the inside by an annular calming space 5 that has a drainage channel 4 situated radially inside. Entry labyrinth 3, which is provided between centrifugal sleeve 25 and inner sealing flange 23, begins directed inwards in the axial direction, then goes over into a radially running section and ends as axial gap 2 situated radially further inside, which then runs directed outwards in the axial direction, and at its end area, widens in the direction of collection groove 7. The flaring, thus the widening denoted by reference numeral 29, is realized by a suitable chamfer, so that the capillary effect is interrupted in this area. A centrifugal groove 16 is disposed on centrifugal sleeve 25, opposite collection groove 7, and is provided to spin oil off in the direction of collection groove 7. At the lower area of collection groove 7, a drain bore is provided that is aligned in the axial direction and leads into a collection chamber 10, which in turn returns oil via a bore, namely, outer return bore 21 in inner sealing flange 23, back into the oil pan.

[0088] Between centrifugal sleeve 25 and inner sealing flange 23, a gap is provided that connects collection groove 7 to collection chamber 10.

[0089] A centrifugal groove 15 is again disposed in the axial region of collection chamber 10, so that oil which penetrates via the indicated gap is centrifuged off.

[0090] In addition, provided axially following is centrifugal disk 22 that likewise centrifuges oil off into collection chamber 10.

[0091] Axially following centrifugal disk 22, a further centrifugal groove 14 is again provided, opposite which a collection groove 13 is located on flange part 19. Thus, oil is spun off from the edges of centrifugal groove 14 into collection groove 13.

[0092] Centrifugal sleeve 25 is implemented with a chamfer 28 such that its outside diameter increases in an axial area which is located between centrifugal groove 14 and centrifugal disk 22, and specifically, increases with decreasing distance to centrifugal disk 22, so that oil possibly appearing is conveyed in this direction, thus, toward centrifugal disk 22. Therefore, chamfer 28 contributes in connection with the return flow. The oil is then conveyed into centrifugal chamber 27, which is emptied into collection chamber 10 with the aid of centrifugal bores 11 that are introduced into centrifugal disk 22 in the radial direction. A plurality of such centrifugal bores 11, especially between four and twenty, are provided at the periphery of the centrifugal disk.

[0093] Collection groove 13, situated axially further to the outside, has at its lower region, especially including the deepest point, a bore 18 directed axially toward the gap region, thus, gap 12, which is provided between centrifugal disk 22 and outer flange 19. Collection groove 13 is assigned a centrifugal groove 14, which is provided on centrifugal sleeve 25.

[0094] This gap region of gap 12 is open toward collection chamber 10. Since bore 18 discharges into gap region 12 at a radial distance that is smaller than the radial distance of radially outside end area of gap region 12, where gap region 12 discharges into collection chamber 10, a conveying effect is provided. The reason is that due to the rotational movement, an underpressure is generated, which causes bore 18, and therefore collection groove 13, to be pumped out.

[0095] Thus, not only is the well-known centrifuging provided for the discharge, but also the pumping effect of a gap region 12.

[0096] Collection grooves 7 and 13 are therefore emptied into collection chamber 10, and not directly into the interior and/or the oil-pan area. To that end, bore 24 connects collection groove 7 to collection chamber 10.

[0097] Inner sealing flange 23 and outer sealing flange 19 are joined to each other, sealed off by an O-ring seal 26, a plurality of successive retaining screws 20 in the circumferential direction joining the two sealing flanges. Thus, a one-piece construction of the two sealing flanges 19 and 23 is also possible. A dust protector 17 is just provided externally.

[0098] A further collection-chamber area is formed by collection groove 13, that is situated separate from collection chamber 10 and is provided further axially outwards.