Method for installing a transmission and shaftseat applied thereby

Abstract

Method for installing a transmission between a drive with a driveshaft and a load with a driven shaft, where this transmission includes a housing and at least a drive gear and a driven gear, where the method includes first affixing the transmission over the driveshaft and fastening the housing of the transmission to the housing of the drive and then affixing a shaft seal over the driveshaft.

Claims

1. A method for installing a transmission between a drive with a driveshaft and a load with a driven shaft, wherein the method comprises the following steps: first affixing the transmission over the driveshaft, wherein the transmission comprises a housing of the transmission and at least a drive gear to be mounted on the driveshaft and a driven gear mounted on the driven shaft, wherein the housing of the transmission comprises a cavity for fixing a shaft seal around the driveshaft, and wherein a depth of the cavity in an axial direction is smaller than an axial length of the shaft seal; fastening the housing of the transmission to a housing of the drive; and then axially affixing the shaft seal over the driveshaft and in the cavity.

2. The method according to claim 1, wherein after affixing the shaft seal over the driveshaft, the method further comprises a step of the axial clamping of the shaft seal.

3. The method according to claim 2, wherein for the axial clamping of the shaft seal use is made of at least one clamping plate that is fastened in an axial direction against the shaft seal and the transmission or the housing of the transmission.

4. The method according to claim 1, where after a positioning of the shaft seal, the drive gear is affixed on the driveshaft.

5. The method according to claim 1, wherein, before the shaft seal is affixed over the driveshaft, a bush is affixed over the driveshaft, such that the bush and shaft seal are immediately adjacent to one another after the shaft seal is affixed over the driveshaft.

6. The method according to claim 1, wherein an at least one extra seal is provided in the form of a sealing ring to seal or interrupt an oil leakage path, wherein the sealing ring is placed in a groove provided to an end that is integrated in a side of the shaft seal that extends in a radial direction or approximately radial direction, wherein a side is intended to be affixed against the transmission or the housing thereof when the shaft seal is mounted.

7. The method according to claim 1, wherein an at least one extra seal is provided in the form of a sealing ring to seal or interrupt an oil leakage path, wherein the at least one extra sealing ring is placed in a groove provided to an end that is integrated in the housing of the transmission at a location against which a side of the shaft seal that extends in a radial direction or approximately radial direction will go.

8. The method according to claim 4, wherein an at least one extra seal is provided in the form of two sealing rings to seal or interrupt an oil leakage path, wherein the sealing rings are O-rings that are placed in grooves provided to an end surface of a clamping plate.

9. The method according to claim 6, wherein the at least one or more sealing rings are of the O-ring type.

10. The method according to claim 1, wherein the shaft seal is of a lip seal type.

11. The method according to claim 1, wherein the drive is a combustion engine and the driven shaft is a shaft of a rotor of a compressor element or similar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) With the intention of better showing the characteristics of the invention, a few preferred variants of a method according to the invention and a lip seal thereby applied are described hereinafter, by way of an example without any limiting nature, with reference to the accompanying drawings, wherein:

(2) FIG. 1 schematically shows a compressor element with a drive that is provided with a transmission with a lip seal according to the invention;

(3) FIG. 2 shows the section that is shown by F2 in FIG. 1 on a larger scale;

(4) FIG. 3 shows a variant of FIG. 2 according to the known state of the art;

(5) FIG. 4 shows a variant of FIG. 2 whereby the O-ring is affixed in the housing of the transmission;

(6) FIG. 5 shows a variant of FIG. 2 whereby two O-rings are placed in the clamping plate.

DETAILED DESCRIPTION OF THE INVENTION

(7) The compressor element 1 schematically shown in FIG. 1 essentially comprises a housing 2 with two meshed rotors 3 therein, in this case screw rotors.

(8) The compressor element 1 is coupled to a transmission 4, which in turn is coupled to a drive 5, in this case an engine.

(9) It is clear that the invention is not limited to compressor elements 1 or an engine, but any type of machine that must be driven by a drive 5 using a transmission 4 belongs to the scope of the invention.

(10) The aforementioned rotors 3 are provided with a shaft 6, whereby these shafts 6 are mounted on bearings 7 in the housing 2.

(11) One of these shafts 6 extends along one end 8 through the housing 2 into the transmission 4.

(12) The transmission 4 comprises a housing 9 in which the aforementioned end 8 of this one shaft 6 is affixed, that will act as the driven shaft 10.

(13) The drive 5 is further provided with a driveshaft 11. This driveshaft 11 extends from the aforementioned drive 5 into the housing 9 of the transmission 4 via a borehole 12 provided in the housing 9 to this end.

(14) The driveshaft 11 is provided with a drive gear 14 that can mesh with a driven gear 13 that is provided on the driven shaft 10.

(15) In order to ensure that the aforementioned borehole 12 is sufficiently closed, a lip seal 15 is placed in the transmission 4 around the driveshaft 11 at the location of the borehole 12.

(16) According to the invention it is not excluded that instead of a lip seal 15, another type of shaft seal is used. Everything that follows is in principle applicable to shaft seals of a different type to a lip seal 15.

(17) To this end a method for installing a transmission according to the invention is applied, that will be described below on the basis of FIG. 1 and FIG. 2, which shows a detail of FIG. 1.

(18) In a first optional step, a bush 16 is affixed around the driveshaft of the engine.

(19) Bush 16 here means a sleeve-shaped lining that is affixed over the free end 17 of the driveshaft 11.

(20) This bush 16 is affixed at the location where the lip seal goes in one of the following steps of the method according to the invention, as described below.

(21) Then if need be it is ensured that the driveshaft 11 is coupled to the drive 5 or a flywheel of the drive 5, as is well known.

(22) However, it is not excluded that this is done before affixing the aforementioned bush 16.

(23) In a next step, according to the invention, the transmission 4 is affixed over the driveshaft 11 and the housing 9 of the transmission 4 is fastened to the housing of the drive 5.

(24) Then, according to the invention, the lip seal 15 is affixed over the driveshaft 11.

(25) As can be seen in the drawings, to this end a borehole 18 is provided in the housing 9 of the transmission 4 that creates a space or cavity to be able to affix the lip seal 15, whereby this borehole 18 is larger in the radial direction X-X′ than the dimensions of the lip seal 15. As a result of this, a radial clearance 19 occurs around the lip seal 15.

(26) Furthermore, it can be seen in the drawings that the lip seal 15 is affixed over the bush 16, and that the lip seal 15 according to the invention centres itself around this bush 16 and thus around the driveshaft 11.

(27) Then the lip seal 15 can be fastened. Preferably the lip seal 15 is clamped axially, i.e. the clamping force is oriented in the axial direction Y-Y′.

(28) In order to be able to realise this, the axial dimension of the borehole 18, i.e. the depth of the borehole 18 in the axial direction Y-Y′, is taken to be somewhat smaller than the axial dimension of the lip seal 15, i.e. the thickness of the lip seal 15 in the axial direction Y-Y′.

(29) The lip seal 15 thus protrudes somewhat out of the housing 9 of the transmission 4 in the axial direction Y-Y′. This ensures that a clamping force is exerted on the lip seal 15 and not on the housing 9 of the transmission 4.

(30) In the example shown, this axial clamping of the lip seal 15 is realised by making use of a clamping plate 20 that is fastened in the axial direction Y-Y′ against the lip seal 15 and the transmission 4, in particular the housing 9 of the transmission 4, as shown in FIG. 2.

(31) In this case the clamping plate 20 is constructed as a clamping ring that is fastened with a number of screws 21 that are distributed along the periphery of the clamping ring.

(32) It is clear that this clamping plate 20 does not have to be a ring, but for example can also comprise one or more clamping plates 20 that are fastened at certain locations against the transmission 4 to clamp the lip seal 15 at these locations.

(33) The axial clamping can be easily realised, in contrast to radial clamping, which in a method according to the invention is difficult to apply or even not applicable.

(34) It is clear that any other clamping mechanism can be used for the axial clamping of the shaft seal 15, without departing from the scope of the invention.

(35) After the lip seal 15 has been affixed, preferably the drive gear 14 is affixed on the driveshaft 11.

(36) FIG. 3 shows a lip seal 15 that is affixed according to a known method.

(37) In a known method the lip seal 15 is clamped radially in the transmission 4, more specifically in the housing 9 of the transmission 4, in a borehole 18 provided to this end, whereby this borehole 18 is somewhat smaller than the dimensions of the lip seal 15 so that a radial clamping force is realised, i.e. that the clamping force is oriented in a radial direction X-X′.

(38) By applying a method according to the invention it is very difficult, if not impossible, to be able to properly clamp the lip seal 15 into a borehole 18 radially, after the transmission 4 has already been affixed over the driveshaft 11. Even if the lip seal 15 is clamped in the borehole 18, the lip seal 15 is indeed centric in the borehole 18 of the housing 9 of the transmission, but eccentric with respect to the driveshaft 11, which is not the intention.

(39) As already mentioned, a radial clearance 19 occurs around the lip seal 15 because the lip seal 15 is not clamped in radially.

(40) As a result two leakage paths are created along which oil can leak from the transmission 4 to the drive 5. It is important to close off these leakage paths to prevent this.

(41) These two leakage paths are indicated in FIG. 2 by arrows A. These leakage paths go along via the clamping plate 20.

(42) As can be seen in FIG. 2, these leakage paths merge in a radial clearance 19 and then continue to run together to the back 22 of the lip seal 15, i.e. to the side 22 of the lip seal 15 that extends in a radial direction or approximately in a radial direction and which is affixed against the transmission 4 or the housing 9 of the transmission 4.

(43) In other words it is possible to provide one single sealing ring 23, such as, for example but not necessarily, an O-ring 23, on this aforementioned back 22 of the lip seal 15 to close off both leakage paths.

(44) It is sufficient to provide a seal in the form of such an O-ring 23 to seal or interrupt the oil leakage path, whereby this O-ring 23 is placed in a groove 24 that is integrated in a side 22 of the lip seal 15 that extends in a radial direction or approximately in a radial direction, whereby this side 22 is intended to be affixed against the transmission 4 or the housing 9 thereof when mounting the lip seal 15.

(45) To this end, a shaft seal 15 according to the invention is preferably used as shown in FIG. 2. The shaft seal 15 consists of a ring-shaped housing 25. As already mentioned, in this case but not necessarily, the shaft seal 15 is of the lip seal 15 type, whereby the ring-shaped housing 25 is provided with three lips 26 that are provided on the side 27 of the ring-shaped housing 25 that is oriented towards the centre of the ring shape, and which extend over the periphery of the ring-shaped housing 25, whereby the lip seal is provided with an O-ring 23, whereby the O-ring 23 is placed in a groove 24 provided to this end that is integrated in a side 22 of the ring-shaped housing 25 that extends in a radial direction or approximately radial direction.

(46) Due to the axial clamping with the aid of the clamping plates 20, the O-ring 23 will be pressed between the transmission 4 and the lip seal 15 so that a seal is realised that will ensure that no further oil can leak.

(47) As an alternative to the solution of FIG. 2, it is also possible to close off the leakage paths by providing a groove 24 with a single O-ring 23 in the housing 9 of the transmission 4 at a location against which a side 22 of the shaft seal 15, that extends in the radial direction X-X′ or approximately the radial direction X-X′, will go. This is shown in FIG. 4. This solution can be applied with a standard lip seal 15. However, a disadvantage is that the making of the groove 24 in the housing 9 is technically more difficult. The affixing of the O-ring 23 in this groove 24 at this location will also be more difficult to implement on account of the limited space.

(48) Another alternative consists of closing off the leakage paths before they merge, by providing two grooves 24 each with an O-ring 23 in the clamping plate, as shown in FIG. 5. Hereby one groove 24 with an O-ring 23 will be situated at the location of the lip seal 15 and one groove 24 with O-ring 23 at the location of the housing 9 of the transmission 4. Although the solution of FIG. 5 is relatively easy to implement, whereby a standard lip seal 15 can be used, two O-rings 23 do indeed have to be provided.

(49) Note that in principle it is also possible to seal off the leakage paths in the radial clearance 19. However, affixing an O-ring 23 there is not a good solution because the lip seal is eccentric with respect to the borehole 18 in the housing 9 of the transmission 4. As a result of this eccentricity it will be difficult to clamp in the O-ring properly to obtain a good seal.

(50) The present invention is by no means limited to the embodiments described as an example and shown in the drawings, but such a method and a lip seal can be realised according to different variants without departing from the scope of the invention.