GB2535816A

GB2535816A - Housing element for a differential gear of a vehicle

Info

Publication number: GB2535816A
Application number: GB1510780.8A
Authority: GB
Inventors: Mane Ajinkya; Burkhardt Peter; Ruoss Markus; Schreiber Frank
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2015-06-19
Filing date: 2015-06-19
Publication date: 2016-08-31
Also published as: GB201510780D0

Abstract

The invention relates to a housing element 14 for a differential gear of a vehicle. the housing element 14 comprising an inner surface 20 bounding at least partially a receiving space 22 for at least one gearwheel 22 of the differential gear. wherein the inner surface 20 has at least one protrusion 26 configured to catch and guide splash oil, preferably via plural protrusions directing it towards an oil channel 28.

Description

Housing Element for a Differential Gear of a Vehicle The invention relates to a housing element for a differential gear of a vehicle according to the preamble of patent claim 1.

GB 1172952 A shows a differential gear for a vehicle, the differential gear comprising a housing, a pinion gear, and a pinion bearing for mounting the pinion gear in the housing. The differential gear further comprises a crown wheel mounted in the housing for rotation in mesh with the pinion gear, and a thrust block acting against the back of the crown wheel near the pinion gear. The differential gear further comprises a channel in the thrust block opening in a direction opposite the normal direction of rotation of the crown wheel so that lubricating oil in the lower part of the housing is swept by the crown wheel into the channel. Moreover, the differential gear comprises a tube connecting the channel to the pinion bearing to supply lubricating oil to the pinion bearing.

Usually, a differential gear comprises at least one housing element having at least one inner surface bounding at least partially a receiving space for at least one gear wheel of the differential gear. In the completely assembled state of the differential gear the at least one gear wheel is rotatably arranged in the receiving space, wherein, for example, the gear wheel is rotatably mounted on the housing element or another housing element of the differential gear by means of at least one bearing.

It is an object of the present invention to provide a housing element of the aforementioned kind, by means of which housing element a particularly advantageous lubrication of the differential gear can be realized.

This object is solved by a housing element having the features of patent claim 1. Advantageous embodiments with expedient developments of the invention are indicated in the other patent claims.

In order to provide a housing element of the kind indicated in the preamble of patent claim 1, by means of which housing element a particularly advantageous lubrication of the differential gear can be realized, according to the invention the inner surface has at least one protrusion configured to catch and guide splash oil.

For example, in the completely assembled state of the differential gear, the at least one gear wheel is rotatably arranged in the receiving space. During operation of the differential gear oil for lubricating the differential gear, in particular at least one bearing of the differential gear, is stirred or swirled up by the gear wheel, which is, for example, configured as a crown wheel. The stirred up oil is also referred to as splash oil, wherein at least a portion of the stirred up oil or splash oil can be caught and guided by means of the protrusion. Thereby, the splash oil can be purposefully guided to at least one location at which a particularly advantageous and sufficient lubrication can be realized by means of the oil. For example, at least one bearing, in particular a roller bearing, is arranged at said location so that the roller bearing can be lubricated by the caught and guided oil.

The invention also relates to a differential gear for a vehicle, in particular a motor vehicle, the differential gear comprising at least one housing element according to the present invention. Advantages and advantageous embodiments of the housing element according to the present invention are to be regarded as advantages and advantageous embodiments of the differential gear according to the present invention and vice versa.

For example, the housing element is configured as a housing cover. In the completely assembled state of the differential gear, the differential gear comprises the housing cover and at least one second housing element bounding a portion, in particular a major portion, of the receiving space. The second housing element has at least one through opening via which said gear wheel can be arranged in the receiving space. The housing cover is configured to cover at least a portion, in particular a major portion, of said through opening thereby shutting the second housing element.

Further advantages, features, and details of the invention derive from the following description of a preferred embodiment as well as from the drawing. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respectively indicated combination but also in other combination or taken alone without leaving the scope of the invention.

The drawing shows in: Fig. 1 a schematic and perspective sectional view of a housing of a differential gear for a vehicle, the housing comprising at least one housing element having an inner surface bounding at least partially a receiving space for at least one gear wheel of the differential gear, wherein the inner surface has a plurality of protrusions configured to catch and guide splash oil; Fig. 2 a schematic front view of the housing element; and Fig. 3 a further schematic and perspective sectional view of the housing according to Fig. 1, wherein said gear wheel is arranged in the receiving space.

In the figures the same elements or elements having the same function are indicated by the same reference signs.

Figs. 1 and 3 show a housing 10 for a differential gear of a vehicle, in particular a motor vehicle. For example, the motor vehicle is configured as a commercial vehicle such as a truck. The vehicle comprises at least one motor which is configured as, for example, an internal combustion engine. The motor comprises at least one output shaft by means of which torques can be provided by the motor. Said torques provided by the output shaft can be transferred to a gear wheel 12 (Fig. 3) of the differential gear. As can be seen from Fig. 3, the gear wheel 12 is configured as a crown wheel which is also referred to as a ring gear.

The housing 10 comprises a first housing element in the form of a housing cover 14, and a second housing element 16. The housing elements (housing cover 14 and second housing element 16) have respective inner surfaces 18 and 20 each bounding respective portions of a receiving space 22 in which -in the completely assembled state of the differential gear -the gear wheel 12 (ring gear) is rotatable arranged. For example, said torques can be transferred to the gear wheel 12 by means of at least one gear wheel in the form of a pinion gear which is not shown in the figures. In the completely assembled state of the vehicle the pinion gear is rotatably mounted on the housing element 16, wherein the pinion gear meshes with the ring gear (gear wheel 12). The pinion gear is connected to a pinion shaft in a rotationally fixed manner wherein said pinion shaft can be driven by said output shaft of the engine. For example, the pinion gear is rotatably mounted on the second housing element 16 via said pinion shaft which is, for example, rotatably mounted on the second housing element 16 by means of at least one bearing, in particular a roller bearing. Thus, the ring gear can be driven by the output shaft via the pinion gear and the pinion shaft.

For example, the ring gear is connected to a differential cage in a rotational fixed manner, wherein said differential cage is not shown in the figures. Moreover, for example, at least two compensating gears are rotatably mounted on said differential cage by means of respective bolts so that the compensating gears can rotate in relation to the differential cage. Moreover, the differential gears can be driven by the differential cage and, thus, by the ring gear via said bolts.

For example, the differential gear is a component of an axle, in particular a rear axle of the vehicle. The rear axle further comprises at least two wheels by means of which the vehicle can be driven. In the completely assembled state of the vehicle the wheels are connected to respective axle shafts via which the wheels can be driven by said motor.

The differential gear further comprises at least two side gears meshing with the respective compensating gears. Said side gears are connected to the respective axle shafts in a rotationally fixed manner so that the axle shafts and, thus, the respective wheels can be driven by said side gears. Since the side gears mesh with the compensating gears, the side gears can be driven by the compensating gears. Thus, the wheels can be driven via the axle shafts, the side gears, the compensating gears, the bolts, the differential cage, the ring gear, the pinion, and the pinion shaft by means of the output shaft and, thus, the motor. In order to keep friction and wear of the differential gear particularly low, a lubricant in the form of oil is arranged in the receiving space 22. The oil is used to lubricate the ring gear, the pinion gear and, for example, the at least one bearing. For example, in the housing 10 a plurality of bearings such as roller bearings or glide bearings can be arranged, wherein said bearings need to be lubricated by the oil.

As can be seen from Figs. 1 to 3, the second housing element 16 comprises a through opening 24 via which said bearings and the gear wheel 12 can be arranged in the receiving space 22. For example, the housing cover 14 is configured to be reversibly connected to the second housing element 16 so that the housing cover 14 can be connected to and dismounted from the second housing element 16 in a non-destructive manner. When the housing cover 14 is mounted on the second housing element 16 the through opening 24 is covered and, thus, closed by means of the housing cover 14.

In order to realize a particularly advantageous lubrication of the differential gear, in particular the gear wheel 12 and said bearings, the inner surface 18 has a plurality of protrusions 26 configured to catch and guide splash oil. The oil arranged in the receiving space 22 forms an oil sump on the bottom 28 of the housing 10. During operation of the differential gear the gear wheel 12 splashes in said oil sump thereby stirring or swirling up oil. The stirred up oil is also referred to as splash oil, wherein at least a portion of the splash oil is caught and guided by means of the protrusions 26. Thus, the direction of movement of the splash oil can be affected, i.e. changed by means of the protrusions 26 acting as catching and guiding elements. The movement of the splash oil is illustrated in Figs. 1 and 3 by means of directional arrows.

The second housing element 16 comprises at least one oil channel 30. As can be seen from Fig. 1, the protrusions 26 are configured to guide the oil to the oil channel 30 which I turn guides the oil to at least one location at which at least one component such as one of said bearings of the differential gear can be lubricated by the caught and guided oil. In other words, as soon as the stirred up oil will hit at least one of the protrusions 26 at high speed, the oil will splash and be guided to the oil channel 30. Thus, a particularly high amount of splash oil can be purposefully guided to, for example, the bearings so as to sufficiently lubricate the bearings. Thus, a particularly advantageous and sufficient lubrication of that bearings and the differential gear as a whole can be realized.

As can be seen from Fig. 2, the protrusions 26 are arranged one after another along a straight line, for example. Moreover, the protrusions 26 can have a rectangular shape. Alternatively or additionally, the respective protrusion 26 can comprise a draft and/or at least one angular dent to purposefully deflect the oil. Since the protrusions 26 are provided on the housing cover 14 and not on the second housing element 16 the housing 10 can be manufactured in a cost-effective way so that using the protrusions 26 will cause almost no additional weight or cost.

List of reference signs housing 12 gear wheel 14 housing cover 16 second housing element 18 surface surface 22 receiving space 24 through opening 26 protrusions 28 Bottom oil channel

Claims

Claims 1. A housing element (14) for a differential gear of a vehicle, the housing element (14) comprising an inner surface (20) bounding at least partially a receiving space (22) for at least one gearwheel (22) of the differential gear, characterized in that the inner surface (20) has at least one protrusion (26) configured to catch and guide splash oil.
2. The housing element (14) according to claim 1, characterized in that the inner surface (20) has a plurality of protrusions (26) configured to catch and guide splash oil.
3. The housing element (14) according to claim 2, characterized in that the protrusions (26) are arranged one after another along a straight line.
4. The housing element (14) according to any one of the preceding claims, characterized in that the protrusion (26) has a rectangular shape.
5. The housing element (14) according to any one of the preceding claims, characterized in that the protrusion (26) is configured to guide the oil to at least one oil channel (28) of the differential gear.
6. The housing element (14) according to any one of the preceding claims, characterized in that the housing element (14) is configured as a housing cover (14).
7. A differential gear for a vehicle, in particular a motor vehicle, the differential gear comprising at least one housing element (14) according to any one of the preceding claims.