AU619883B2

AU619883B2 - Gearbox

Info

Publication number: AU619883B2
Application number: AU40148/89A
Authority: AU
Inventors: Godfrey Rolf Blackburn
Original assignee: BROWN DAVID CORP PLC; David Brown Corp PLC
Current assignee: David Brown Corp PLC
Priority date: 1988-09-06
Filing date: 1989-08-22
Publication date: 1992-02-06
Anticipated expiration: 2009-08-22
Also published as: GB8919785D0; GB2224330A; GB8821870D0; DE3928739A1; AU4014889A; GB2224330B

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION 1 9 8 8

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant(s): David Brown Corporation plc Park Gear Works, Huddersfield, HD4 5DD, UNITED KINGDOM Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled:

GEARBOX

Our Ref 144555 S" POF Code: 96821/96821 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 6006 "Gearbox" -I- David Brown Corporation plc Agent's Reference 1740 This invention relates to a gearbox, particularly for high speed applications such as the driving of electric railway locomotives.

The object of the invention is to provide a gear box with lubrication means effective at both high and low operational speeds.

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rft According to the invention, a gearbox including a casing, an input shaft mounted in bearings in'said casing and carrying an Sinput gear, and an output shaft mounted in bearings in said casing and carrying an output gear, is provided with a first lubrication system for low speed operation and a second lubrication system for high speed operation, both of said systems remaining operational at all speeds and both iti o common lubrication spaces for said bearings.

r* A preferred embodiment of the invention will now be described, by

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way of example, with reference to the accompanying drawings of S which:- Fig.l is a vertical section through a gearbox on the centre-line of its input shaft; Fig.2 is a section on the line 2-2 in Figl; Fig.3 is a section on the line 3-3 in Fig.l, with parts omitted for clarity;

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-2- Fig.4 is a part section on the line 4-4 in Fig,l, with parts omitted for clarity; is a section on the line 5-5 in Fig.l; Fig.6 consists of part of Fig.l on a larger scale, showing sealing means for the input shaft; Fig.7 consists of part of Fig.5 on a larger scale, showing sealing means for the output shaft; and Fig.8 is a perspective view of a bogie for an electric railway locomotive incorporating two such gearboxes, on a smaller scale.

1 S, Referring now to the drawings, a gearbox for a high speed electric railway locomotive is of single reduction spiral bevel *type. The gearbox comprises a casing indicated generally at S* *formed of two main parts 11 and 12 and having points 13 for resiliently mounting it in a bogie 14 of the locomotive.

Mounted in the casing 10 are an input shaft 15 inclined at, say, 111 degrees to the horizontal, and a horizontal output shaft 16.

The input shaft 15 has a driving flange 17 secured in engagement with splines 18 on its protruding outer end, and an integral spiral bevel pinion 19 near its inner end. Said shaft 15 is S> mounted between the splines 18 and the pinion 19 in double tapered roller bearings 20 housed in one part 11 of the casing and at its inner end in a parallel roller bearing 21 housed in an inclined web 22 of said one part 11 of the casing 10, said web 22 being perpendicular to the centre-line of the input shaft The output shaft 16 is tubular and protrudes at both of its ends from the casing 10. Said shaft 16 has a drive flange 23 secured in engagement with radial teeth 24 at one of its ends .i 3 and, secured between its ends by bolts 25, a spiral bevel wheel 26 projecting through an aperture in the aforesaid web 22 and meshing with the spiral bevel pinion 19 on the input shaft The output shaft 16 is mounted near each of its ends in a tapered roller bearing 28 housed between the two parts 11 and 12 of the casing 10, the joint 29 of which lies in a plane inclined at, say, 45 degrees and passing through the centre-line of the output shaft 16. Each of the three bores where the input and output °oo, shafts 15 and 16 protrude from the casing 10 is sealed by means Po 10. indicated generally at 9 including a first annular member 0 o connected to the casing 10, said member 30 having a face labyrinth seal 31 communicating with a grease nipple 32 in said to member 30, and a bore labyrinth seal 33. Immediately outboard of the first annular member 30, a mating face labyrinth seal 34 is formed on a second annular member 35 secured to the output shaft So 0 16, or on the driving flange 17 on the input shaft 15, as the case may be. Immediately inboard of the first annular member a flinger 36 is formed on a third annular member 37 secured to the respective shaft 15 or 16. The bore labyrinth seal 33

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closely surrounds a boss 38 on the third annular member 37 Ssecured to the output shaft 16, or a boss 39 on the driving flange 17 on the input shaft 15, as the case may be. A space 27 within the sealing means 9 is drained through drillings 75. The general arrangement of the preferred gearbox thus far described is such that an electric variable-speed traction motor 40 mounted on the body (not shown) of the locomotive can be connected by way of a universally-jointed shaft 41 to the driving flange 17 on the input shaft 15, an axle of the locomotive can pass axially i 4 S £4 *5 4 *L

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4r 4 45e 4 4 -4through the ouput shaft 16, and one of the wheels 42 secured on said axle can be connected by a resilient coupling 43 to the drive flange 23 on the output shaft 16.

A first lubrication system of so-called splash type for low speed operation includes a machined shroud 44 secured in the bottom of the casing 10 so as to extend above the level of oil contained in the casing 10 and to fit closely around the lower periphery of the bevel wheel 26. An aperture 45 in that side of the shroud 44 adjacent the teeth on the bevel wheel 26 permits oil contained in the casing 10 to flow at a limited rate into said shroud 44, from which it is flung centrifugally by rotation of said wheel 26. A trough 46 formed integrally around the upper part of the interior of the casing 10 at that side of the aforesaid web 22 adjacent the bevel wheel 26 collects the oil flung there by said wheel 26, and passages 47 formed in the casing 10 lead from the trough 46 to lubrication spaces 48 for the tapered roller bearings 28 mounting the output shaft 16. Said spaces 48 are drained over a weir 49 into the bottom of the casing 10. The first lubrication 20. system also includes two short troughs 50 formed integrally within the upper part of the casing 10 at that side of the aforesaid web 22 adjacent the bevel pinion 19. Said troughs collect the oil flung there by said pinion 19, and further passages 51 formed in the casing 10 lead from said troughs 50 to a lubrication space 52 for the double tapered roller bearings mounting the input shaft 15. Said space 52 is drained over a weir 53 and then through an opening 54 in the aforesaid web 22 into the bottom of the casing 10. The first lubrication system'

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It S 54 5.4 4 4 4 4 4 i r, 1 i -I -11 i 1 i II further includes a lubrication space 55 for the parallel roller bearing 21 mounting the input shaft 15. Said space 55 receives oil running down the aforesaid web 22 after being flung into the upper parts of the casing 10, and is drained over a weir 56 into the bottom of the casing A second lubrication system for high speed operation includes twin vane-type pumps indicated generally at 57, the rotors 58 of which are mounted at the respective ends of a common drive shaft 59. This shaft is mounted inboard of the respective pumps 57 in n a ball bearing 60 and a parallel roller bearing 61 housed in the 9 casing 10. The pump drive shaft 59 is parallel to the output °04b shaft 16 and has secured on it, by means including a key 62, a helical gear 63 meshing with a helical gear 64 formed integrally on the output shaft 16. The gear 63 on the pump drive shaft 59 has a shroud 65 which extends above the level of oil contained in the casing 10 to avoid churning said oil. The pumps 57 draw oil S,,from the bottom of the casing 10 through a common tubular strainer 66, and supply it to parallel duplicated hydraulic circuits to enhance reliability. Each of the circuits comprises a pipe 67, a drilling 68 and another pipe 69 leading to a respective one of two parallel bores 70 in a manifold block 71 disposed in the top of the casing 10. Opposite ends of each bore discharge oil vertically downwards into opposite sides of the trough 46, whence the oil flows through the aforementioned passages 47 to the lubrication spaces 48 for the tapered roller bearings 28 mounting the output shaft 16. Each pipe 69 also delivers oil to a pipe 72 leading to a respective one of two

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nozzles 73 for spraying the teeth of the bevel pinion 19, and through said pipe 72 and a further pipe 74 to the lubrication space 52 for the double tapered roller bearings 20 mounting the input shaft 15. The shroud 44 fitted around the lower periphery of the bevel wheel 26 is an important feature of the second lubrication system, preventing excessive churning of the oil contained in the casing 10 and consequent heat generation. In operation, the gearbox has to cope with low speed operation as for example when the locomotive is travelling extremely slowly in 10. a marshalling yard, and with high speed operation when the locomotive is travelling at its full speed of, say, 140 miles per hour. In the latter event, the periphery of the bevel wheel 26 is moving at approximately 7000 feet per minute and effective lubrication of the gearbox is crucial. Both lubrication systems 15. remain operational at all speeds, but the low speed system alone would be inadequate for high speed operation when a high rate of oil flow is needed, and the high speed system alone would be inadequate for low speed operation due to the then insignificant delivery rate of the pumps 57.

Thus there is provided a high performance gearbox having suitably effective lubrication and sealing means.

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Claims

1. A gearbox including a casing, an input shaft mounted in bearings in said casing and carrying an input gear, and an output shaft mounted in bearings in said casing and carrying an output gear, said gearbox being provided with a first lubrication systemr for low speed operation and a second lubrication system for high speed operation, both of said systems remaining operational at oL\ c all speeds and both .~4s4b~~~oi>o common lubrication spaces for said bearings.

10. 2. A gearbox according to claim 1, wherein the first lubrication system is of splash type and the second lubtication system is of pump type. 3. A gearbox according to either of the preceding claims, wherein the second lubrication system eov! ti pumps supplying oil to parallel duplicated hydraulic circuits from each of which it is e4±e T o the bearing lubrication spaces. 4. A gearbox according to claim 3, wherein oil is delivered from each hydraulic circuit to a respective nozzle for spraying the teeth of the input gear. 5. A gearbox according to claim 3 or claim 4, wherein the pumps are mounted on a common drive shaft and draw oil through a common strainer. 6. A gearbox according to claim 5, wherein the pump drive shaft carries a gear driven by a gear on the output shaft. 7. A gearbox according to claim 6, wherein the gear carried by the pump drive shaft has a shroud to avoid churning oil contained in the casing. I 8. A gearbox according to any one of claims 3 to 7, wherein the pumps are of vane type. 9. A gearbox according to any one of the preceding claims, wherein the first lubrication system includes a close-fitting shroud for the output gear with an aperture for limiting the rate of flow into said shroud of oil contained in the casing, and a trough within the upper part of said casing for collecting oil flung centrifugally from said shroud by the output gear and for directing it specifically to the lubrication spaces for the bearings mounting the output shaft. '1 0. A gearbox according to any one of the preceding claims, wherein the first lubrication system includes means within the upper part of the casing for collecting oil flung centrifugally by the input gear and for *094 directing it specifically to the lubrication spaces for the bearings mounting the input shaft.

11. A gearbox according to any one of the preceding claims, wherein bores where the input and output shafts protrude from the casing are each sealed by means including in combination a grease-filled labyrinth seal for impeding the ingress of dirt, a labyrinth seal for impeding the egress of oil, and a flinger for impeding the egress of oil.

12. A gearbox according to any one of the preceding claims, of single reduction spiral bevel type.

13. A gearbox constructed, arranged and adapted to operate substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings. DATED: 18 November 1991 PHILLIPS ORMONDE FITZPATRICK Attorneys for: f DAVID BROWN CORPORATION PLC 39 1161b 8 i 1