WO2004054820A1

WO2004054820A1 - Wheel axle and accessory device for a wheel axle

Info

Publication number: WO2004054820A1
Application number: PCT/SE2003/001945
Authority: WO
Inventors: Timothy Kingston
Original assignee: Volvo Construction Equipment Holding Sweden Ab
Priority date: 2002-12-17
Filing date: 2003-12-12
Publication date: 2004-07-01
Also published as: AU2003287130A1; SE524425C2; SE0203733D0; SE0203733L

Abstract

The invention relates to a wheel axle (2) for a vehicle comprising an axle case (13) and a central gear (1) arranged in the axle case. Two driving axles (8, 9) extend in opposite directions from the central gear for driving two wheels. A space (14) in the axle case, in which space the central gear is arranged, is delimited from the remaining space in the axle case. A plate-shaped, surrounding element (15) is arranged in the axle case for the purpose of, together with the axle case, delimiting said central gear space (14), and the plate-shaped element is arranged in contact with inner surfaces (18, 19, 20, 21) of the axle case on opposite sides of at least one of the driving axles in order to delimit the central gear space in the direction of the wheels of the vehicle.

Description

C14214 , EJ, 12-17-02

Wheel axle and accessory device for a wheel axle

FIELD OF THE INVENTION

The present invention relates to a wheel axle for a vehicle comprising an axle case and a central gear arranged in the axle case, two driving axles extending in opposite directions from the central gear for driving two wheels, and a space in the axle case, in which space the central gear is arranged, being delimited from the remaining space in the axle case. The invention also relates to an accessory device for such a wheel axle for delimiting the central gear space.

The invention will be described below in a case where the wheel axle is applied in a machine in the form of a frame-steered vehicle, what is known as a dumper. This is not to be regarded as limiting for the invention, but it can also be applied to other types of machine, such as a wheel loader, and other types of vehicle, such as trucks .

The wheel axle includes a number of different components, such as gears, brakes and if appropriate clutches, which require lubrication and have different requirements in terms of the properties of the oil. The fact is that the requirements for lubricating oil for the central gear are different from and in certain cases conflicting with the requirements for a brake oil. In certain cases, it is therefore desirable to use different types of oil, each with properties which correspon -to the requirements of a specific component .-

When a frame-steered vehicle is turned, the front wheel axle has a different turning radius to the rear wheel axles . This results in relatively great loads on the drive line and in particular leads to a constrained torque on the central gear. In certain cases, it is therefore desirable to use what is known as hypoid oil for the central gear. However, the hypoid oil does not meet the requirements for a good brake oil particularly well. It is therefore desirable to divide the axle case into a number of spaces, and in particular a space for the central gear. In this way, it is possible to use different oils, each optimized for a specific device/function.

PRIOR 7ART

US 5,845,546 describes a wheel axle, where a central gear of hypoid type is arranged in a central space and a clutch is arranged in a delimited space on each side of the central gear space. A lower housing part delimits the central gear space in the downward direction. This lower housing part forms a container for the lubricant for the central gear. The lower housing part extends over 180° in the peripheral direction around a center line through two driving axles which extend in opposite directions from the central gear. The lower housing part is also connected to an upper housing part along a dividing plane through the center line of the driving axles in the horizontal direction. The lower housing part and the upper housing part, together with two oil seals, form the central gear space.

SUMMARY OF THE INVENTION One object of the invention is to provide a wheel axle with a delimited central gear space, where the delimitation is achieved in a simple, cost-effective and flexible way.

This object is achieved by virtue of the fact that a plate-shaped, surrounding element is arranged in the axle case for the purpose of, together with the axle case, delimiting said central gear space, and that the plate-shaped element is arranged in contact with inner surfaces of the axle case on opposite sides of at least one of the driving axles in order to delimit the central gear space in the direction of the wheels of the vehicle.

According to a preferred embodiment, the plate-shaped element extends in a direction parallel to the center line of a torque-transmitting input shaft to the central gear. The plate-shaped element preferably forms an essentially circular cross-sectional shape. The plate-shaped element therefore forms the shape of a ring. Such an annular plate is simple to produce as far as manufacturing is concerned. Moreover, only minor modifications to existing axle cases are necessary in order to seal the edges of the plate-shaped element against the axle case.

Another object of the invention is to afford opportunities for making it possible to a greater extent to select different components included in the wheel axle, such as central gear and brakes. This concerns especially the case where it is desirable to use different components which have different and in particular conflicting requirements in terms of lubricating oils.

This object is achieved by an accessory device according to claim 15. By building up the axle in various modules, it is possible, when a central gear of a special type is required, for example a hypoid gear, to modify the wheel axle simply by arranging the accessory device in the wheel axle.

Other advantageous embodiments and advantages- of these emerge from the other claims and from the description below. BRIEF DESCRIPTION OF FIGURES

The invention will be described in greater detail below with reference to the embodiment shown in the accompanying drawings, in which 5 FIG 1 shows a cross-sectional view through a wheel axle comprising a central gear, FIG 2 shows a perspective view of an accessory device, comprising a surrounding, plate-shaped element, for a wheel axle, and 10 FIG 3 shows a diagrammatic partial view of a portion of the plate-shaped element, where a driving axle is arranged in a hole through the material of the plate.

15 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Fig. 1 shows a cross-sectional view of a central gear 1 arranged in an axle case 13 of a wheel axle 2 of a vehicle. A pinion gearwheel 3 is arranged on an input shaft 4 to the central gear 1. In Figure 1, the input

20 shaft 4 forms part of what is known as a tandem gear. A shaft (not shown) is arranged in engagement with a gearwheel 5 on the input shaft for transmitting driving power from the engine of the vehicle. The pinion gearwheel 3 is in engagement with a crown gearwheel 6

25 for transmitting the driving power. From the crown gearwheel 6, the driving power is transmitted via a differential 7 to the driving axles 8, 9 and onward to the driving wheels .

30 Differential means a device which receives a torque from the engine, distributes the torque to the two wheels, and takes up differences in speed of rotation from the wheels, which originate from, for example, the - - - -vehicle being -turned on a bend. The differential 35 comprises four small conical gearwheels 10, or differential gears, which are arranged on a differential spider. Two opposite, larger conical differential gears 11, 12, which are each coupled together in a rotationally fixed manner with one of said driving axles 8, 9, run against the four small differential gears 10.

Included in the wheel axle 2 in addition to the central 5 gear 1 is a brake (not shown) arranged at each wheel . The lubricating oil requirements for the central gear 1 are different from and in certain cases conflicting with the brake oil requirements, especially in the present case where it is intended to use hypoid oil for

10 the central gear. It is therefore desirable to use different types of oil for the central gear and the brakes. A space 14 in the axle case 13, in which space the central gear 1 is arranged, is therefore delimited from the remaining space in the axle case. In other

15 words, the central space 14 is delimited in the longitudinal direction of the wheel axle and forms a separate, intermediate space in the axle case.

The invention will be explained below with reference to 20 Figures 1, 2 and 3. A plate-shaped, surrounding element 15 is arranged in the axle case 13 and, together with the inner surfaces of the axle case, delimits said central gear space 14. The plate-shaped element 15 has the shape of a ring with an essentially circular cross- 25 sectional shape. The ring therefore defines a through- opening 17, see Figure 2. The plate-shaped ring 15 has a linear extension parallel to a center line through the ring. A cross section through the material of the ring therefore shows an elongate, linear shape. 30

The plate-shaped element 15 is arranged in such a way in the axle case 13 that a center line 16 of the input shaft 14 extends through the opening 17. The plate- - -- - shaped, surrounding element 15 therefore extends- arou-nd- 35 (but not symmetrically around) the center line of the input shaft. The plate-shaped element 15 extends in a direction parallel to the center line of the input shaft 4. The plate-shaped element 15 is arranged in contact with inner surfaces 18, 19, 20, 21 of the axle case 13 on opposite sides in the horizontal direction of each of the driving axles 8 , 9 at right angles to the longitudinal direction of the driving axles . To be precise, it is the edges 28, 29 of the plate-shaped element 15 at the ends of the plate which are arranged in contact with said inner surfaces 18, 19, 20, 21. In this way, the central gear space 14 is delimited in the direction of the wheels of the vehicle. To be precise, the edges of the plate-shaped element .15 are arranged in a sealing manner against the inner surfaces of the axle case. The plate-shaped element 15 surrounds at least part of the central gear 1 and, to be precise, the differential 7 is surrounded.

The plate-shaped element 15 has two holes 22, 23 on opposite sides of said opening 17. Each of the holes 22, 23 extends through the plate-shaped element 15 transversely to its direction of extension. Each of the driving axles 8 , 9 extends through one of said holes 22, 23. A sealing ring 24 is arranged in or at each of said holes 22, 23 for sealing the respective driving axle. A support element 30, here in the form of a ring, suitably made of plastic, is arranged around each of the seals in order to provide good support for these.

That part of the axle case 13 which covers the central gear 1 is cast in one piece. At least one side 13a of the axle case 13 comprises portions 25, 26 which project inward toward the interior of the axle case and against which the plate-shaped element 15 is arranged in a sealing manner. To be precise, it is the farther side of the axle, case in relation to the .input shaft .4. which comprises said projecting portions 25, 26.

The plate-shaped element 15 is preferably made of metal material and suitably consists of a shaped metal sheet. In this way, it is simple as far as production is concerned, and thus cost-effective, to manufacture the plate-shaped element in annular form. The holes 22, 23 can be punched or cut out of the sheet .

In the present case, the axle case 13 has been modified slightly in relation to conventional axle cases in order to make it possible to accommodate the plate- shaped element 15 in a functional way. To be precise, the axle case 13 is designed with said inwardly projecting portions 25, 26 against which the plate- shaped element is intended to bear. Thanks to the fact that such small modifications of the axle case are required, manufacture can be standardized and axle cases can be manufactured which are designed so as to be capable of accommodating the plate-shaped element in a functional way even if they are not intended to be used for this. It is therefore possible to choose to manufacture only one type of axle case irrespective of which type of central gear it is intended to use. A customer thus has the option of selecting which type of central gear he wants to have and, if he selects a central gear of hypoid type, said plate-shaped element 15 is simply mounted in the axle case. The invention provides further options in that, when a central gear is exchanged, the customer could select another type of central gear which requires a separate space.

It is thus possible to use the plate-shaped, surrounding element 15 as an accessory device 27, which can therefore be selected in certain cases or omitted if it is not required for the other components in the axle case. The plate-shaped, surrounding element 15 therefore constitutes an extra article, which is easy to exchange and -to. mount. This provides a... flexible wheel axle solution.

The various side spaces in the axle case 13 can be in flow communication with one another or completely separate from and independent of one another. The axle case preferably comprises a duct which connects the various spaces on different sides of the central gear space. In the bottom and the top of the case, there are therefore ducts for connecting the spaces on the right -and the left of the axle case. According to an alternative, the side spaces can be connected via a common sump .

The invention is not to be regarded as being limited to the illustrative embodiments described above, but a number of further variants and modifications are conceivable within the scope of the patent claims below.

In the present embodiment, the plate-shaped element forms a closed, essentially circular cross-sectional shape. However, it is within the scope of the following claims to have another type of rounded shape, such as an oval shape, but more angular shapes as well, and then in particular polygonal shapes fall within said scope. Furthermore, the term surrounding does not necessarily mean a shape which is closed in the peripheral direction, but includes that the element has a discontinuity, that is to say forms part of a ring. The surrounding element preferably extends over >180°, suitably >270°, and in particular essentially 360°.

As an alternative, the support element 30 can consist of a single part, which then extends in the peripheral direction of the surrounding element and provides support to both the seals .

Claims

PATENT CLAIMS

1. A wheel axle (2) for a vehicle comprising an axle case (13) and a central gear (1) arranged, in the axle case, two driving axles (8, 9) extending in opposite directions from the central gear for driving two wheels, and a space (14) in the axle case, in which space the central gear is arranged, being delimited from the remaining space in the axle case, characterized in that a plate-shaped, surrounding element (15) is arranged in the axle case for the purpose of, together with the axle case, delimiting said central gear space (14) , and in that the plate- shaped element is arranged in contact with inner surfaces (18, 19, 20, 21) of the axle case on opposite sides of at least one of the driving axles in order to delimit the central gear space in the direction of the wheels of the vehicle.

2. The wheel axle as claimed in claim 1 , characterized in that the plate-shaped element (15) extends in a direction parallel to the center line (16) of a torque-transmitting input shaft (4) to the central gear.

3. The wheel axle as claimed in claim 1 or 2, characterized in that the plate-shaped element (15) forms a shape which is closed in the peripheral direction.

4. The wheel axle as claimed in claim 1 or 2, characterized in that the plate-shaped element (15) forms a closed, rounded shape.

5.- The- wheel axle as claimed in claim 1 - or - 2 ,- characterized in that the plate-shaped element (15) forms an essentially circular cross-sectional shape.

6. The wheel axle as claimed in any one of the preceding claims, characterized in that the plate- shaped element (15) consists of a shaped metal sheet.

7. The wheel axle as claimed in any one of the preceding claims, characterized in that the edges of the plate-shaped element (15) are arranged in a sealing manner against the axle case (13) .

8. The wheel axle as claimed in any one of the preceding claims, characterized in that the plate- shaped element (15) has two holes (22, 23) for receiving said driving axles, and in that each of the holes extends through the plate-shaped element transversely to its direction of extension.

9. The wheel axle as claimed in claim 8 , characterized in that a sealing ring (24) is arranged in or at each of said holes for sealing the respective driving axle.

10. The wheel axle as claimed in any one of the preceding claims, characterized in that the plate- shaped element (15) is arranged in the axle case in a removable manner.

11. The wheel axle as claimed in any one of the preceding claims, characterized in that at least that part of the axle case (13) which covers the central gear is cast in one piece.

12. The wheel axle as claimed in any one of the preceding claims, characterized in that the axle case

(13) comprises portions (25, 26) which project inward- toward the interior of the axle case, and in that the plate-shaped element (15) is arranged in a sealing manner against these projecting portions. lS . The wheel axle as claimed in any one of the preceding claims, characterized in that the central gear (1) is of the hypoid type.

14. A machine comprising a wheel axle as claimed in any one of the preceding claims .

15. An accessory device (27) for application in a vehicle wheel axle (2), which comprises an axle case (13) and a central gear (1) arranged in the axle case, in the case where it is desired for a space in the axle case, in which space the central gear is arranged, to be delimited from the remaining space in the axle case, characterized in that the accessory device (27) comprises a plate-shaped, surrounding element (15) designed so as, in the fitted position in the axle case, to delimit in a sealing manner together with the latter a central gear space from the remaining space in the axle case.

16. The accessory device as claimed in claim 15, characterized in that the plate-shaped element (15) forms a shape which is closed in the peripheral direction.

17. The accessory device as claimed in claim 15 or 16, characterized in that the plate-shaped element (15) forms an essentially circular cross-sectional shape.

18. The accessory device as claimed in any one of claims 15-17, characterized in that the plate-shaped element (15) consists of a shaped metal sheet.

19. The . accessory -device as claimed in any one.. - of~ claims 15-19, characterized in that the plate-shaped element (15) has two holes (22, 23) for receiving two driving axles (8, 9) which extend in opposite directions from the central gear for driving two wheels, and in that each of the holes extends through the plate-shaped element transversely to its direction of extension.

20. The accessory device as claimed in claim 19, characterized in that the accessory device comprises a sealing ring (24) arranged in or at each of said holes (22, 23) for sealing the respective driving axle.

21. The accessory device as claimed in any one of claims 15-20, characterized in that at least that part of the axle case (13) which covers the central gear is cast in one piece.