GB2036207A

GB2036207A - Lubrication of differential mechanism

Info

Publication number: GB2036207A
Application number: GB7939813A
Authority: GB
Original assignee: Volvo Car BV
Current assignee: Volvo Car BV
Priority date: 1978-11-17
Filing date: 1979-11-16
Publication date: 1980-06-25
Also published as: DE2945226C2; DE2945226A1; NL168595C; FR2441769B1; IT1119496B; IT7969228A0; JPS5563039A; GB2036207B; NL7811352A; FR2441769A1

Abstract

A differential mechanism includes a pinion housing 11 which has passages in its walls by which oil spray from the differential casing 23 is directed into the area of the planet pinions 8, 9 and pinion wheels 6, 7. The walls of the passages are formed by structural parts, of the pinion housing 11 (Fig. 2), which are blade-shaped as shown at 19 and 20 and have walls inclined in the normal direction of rotation of the housing 11 so as to cause a forced feed of oil spray from the differential casing to the pinions. <IMAGE>

Description

SPECIFICATION Differential mechanism This invention relates to a differential mechanism, comprising a differential casing supporting an input shaft driving a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft.

It is known to provide the shell of the pinion housing, which is situated between flanges, with openings. Said openings, however, must not be made too large as sufficient material must be provided to obtain the required strength.

Moreover the centrifugal action has to be taken into account, by which oil drops are deflected away and do not effect lubrication.

An object of the invention is to promote a good lubrication of the differnetial pinions and bearings by a special configuration of the openings in the wall of the pinion housing.

According to the invention there is a differential mechanism substantially comprising a differential casing supporting an input shaft adapted to drive a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft, in which the walls of said openings are formed in such a way that a blade shape is effected by which, during rotation of the pinion housing in the oil spray of the differential casing, said oil spray is forcedly fed to the planet pinions inside the pinion housing.

Preferably the walls of said openings are inclined in the direction of rotation of the pinion housing.

This construction ensures that the size of the openings remains sufficiently broad whilst, at the same time, maintaining the required strength of the housing.

In the drawings: Figure 1 shows a schematically horizontal cross section through a differential mechanism embodying the invention, the pinion housing being a section on line 1-1 of Fig. 2, Figure 2 is a cross section of the pinion housing on line 11-11 of Fig. 1; and Figure 3 is a vertical section through the housing on line 111-111 shown in Fig. 2.

A differential mechanism comprises, as indicated in Fig. 1, a pinion 2 located at the end of an input shaft or a driving shaft 1, said pinion meshing with a sun wheel 3 via a right angle bevel gear system, said sun wheel 3 being rotatably supported in an opening in a differential casing 23. A planet pinion 6 is mounted in a freely rotatable manner within the outer periphery of the sun wheel 3, said pinion 6 being connected to an output shaft 4 projecting outwardly through the sun wheel 3.

The other planet pinion 7 is integral with an output shaft 5 projecting through a pinion housing 11 from the differential casing 23, diametrically opposite the output shaft 4.

Both pinion wheels 6 and 7 mesh with one another via two differential pinions 8 and 9 which can rotate about common shaft 10 supported by the pinion housing 11.

Said pinion housing 11 comprises two flanges 12 and 13 connected by two shell portions 14 having bores for the pinion shaft.

At both sides of both shell portions 14 long bolts 15 extend which together with nuts 16 secure the pinion housing 11 to the sun wheel 3. The remaining bolt connections are shorter and only connect the flange 12 of the pinion housing to the sun wheel 3. Of the eight holes 18 visible in Figure 2 only the four holes at both sides of both shell portion 14 receive long bolts, and the remaining four are meant for receiving shorter bolts. The pinion housing can also be connected with the sun wheel by different bolt patterns.

The special arrangement of the invention is to be seen in the blade-shaped shell portions 19 and 20 visible in Figs. 2 and 3 not only forming the normal connections between both flanges 12 and 13 of the pinion housing but as well having, seen in cross section, flanks 21, 22 which are directed such that, in relationship to the normal direction of rotation with the hands of a clock in Fig. 2, a passage opening 23 for the oil spray is obtained which is as large as possible.

The shell portions 19 and 20 form walls of openings 23 etc., in the pinion housing and the walls of these openings are so shaped and inclined in relation to the normal direction of rotation of the pinion housing as to direct oil spray from the differential casing into the planet pinions.

As can be seen in Fig. 2 the face 22 of each shell portion 20 is at an angle of 81 to the axis of the drive shaft and the face 21 is at an angle of 9 to the same axis.

It should be noted that the section of Fig. 3 is shown without the holes 18.

1. A differential mechanism subtantiaily comprising a differential casing supporting an input shaft adapted to drive a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft, in which the walls of said openings are formed in such a way that a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Differential mechanism This invention relates to a differential mechanism, comprising a differential casing supporting an input shaft driving a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft. It is known to provide the shell of the pinion housing, which is situated between flanges, with openings. Said openings, however, must not be made too large as sufficient material must be provided to obtain the required strength. Moreover the centrifugal action has to be taken into account, by which oil drops are deflected away and do not effect lubrication. An object of the invention is to promote a good lubrication of the differnetial pinions and bearings by a special configuration of the openings in the wall of the pinion housing. According to the invention there is a differential mechanism substantially comprising a differential casing supporting an input shaft adapted to drive a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft, in which the walls of said openings are formed in such a way that a blade shape is effected by which, during rotation of the pinion housing in the oil spray of the differential casing, said oil spray is forcedly fed to the planet pinions inside the pinion housing. Preferably the walls of said openings are inclined in the direction of rotation of the pinion housing. This construction ensures that the size of the openings remains sufficiently broad whilst, at the same time, maintaining the required strength of the housing. In the drawings: Figure 1 shows a schematically horizontal cross section through a differential mechanism embodying the invention, the pinion housing being a section on line 1-1 of Fig. 2, Figure 2 is a cross section of the pinion housing on line 11-11 of Fig. 1; and Figure 3 is a vertical section through the housing on line 111-111 shown in Fig. 2. A differential mechanism comprises, as indicated in Fig. 1, a pinion 2 located at the end of an input shaft or a driving shaft 1, said pinion meshing with a sun wheel 3 via a right angle bevel gear system, said sun wheel 3 being rotatably supported in an opening in a differential casing 23. A planet pinion 6 is mounted in a freely rotatable manner within the outer periphery of the sun wheel 3, said pinion 6 being connected to an output shaft 4 projecting outwardly through the sun wheel 3. The other planet pinion 7 is integral with an output shaft 5 projecting through a pinion housing 11 from the differential casing 23, diametrically opposite the output shaft 4. Both pinion wheels 6 and 7 mesh with one another via two differential pinions 8 and 9 which can rotate about common shaft 10 supported by the pinion housing 11. Said pinion housing 11 comprises two flanges 12 and 13 connected by two shell portions 14 having bores for the pinion shaft. At both sides of both shell portions 14 long bolts 15 extend which together with nuts 16 secure the pinion housing 11 to the sun wheel 3. The remaining bolt connections are shorter and only connect the flange 12 of the pinion housing to the sun wheel 3. Of the eight holes 18 visible in Figure 2 only the four holes at both sides of both shell portion 14 receive long bolts, and the remaining four are meant for receiving shorter bolts. The pinion housing can also be connected with the sun wheel by different bolt patterns. The special arrangement of the invention is to be seen in the blade-shaped shell portions 19 and 20 visible in Figs. 2 and 3 not only forming the normal connections between both flanges 12 and 13 of the pinion housing but as well having, seen in cross section, flanks 21, 22 which are directed such that, in relationship to the normal direction of rotation with the hands of a clock in Fig. 2, a passage opening 23 for the oil spray is obtained which is as large as possible. The shell portions 19 and 20 form walls of openings 23 etc., in the pinion housing and the walls of these openings are so shaped and inclined in relation to the normal direction of rotation of the pinion housing as to direct oil spray from the differential casing into the planet pinions. As can be seen in Fig. 2 the face 22 of each shell portion 20 is at an angle of 81 to the axis of the drive shaft and the face 21 is at an angle of 9 to the same axis. It should be noted that the section of Fig. 3 is shown without the holes 18. CLAIMS

1. A differential mechanism subtantiaily comprising a differential casing supporting an input shaft adapted to drive a bevel gear wheel, said gear wheel being connected to a pinion housing, in which one or more openings are provided in the pinion housing so that lubricant can reach planet pinions located in the pinion housing and in mesh with the output shafts via differential pinions located on a pinion shaft, in which the walls of said openings are formed in such a way that a blade-shape is effected by which, during rotation of the pin ion housing in the oil spray of the differential casing, said oil spray is forcedly fed to the planet pinions inside the pinion housing.

2. A differential mechanism according to claim 1 and in which the walls of said openings are inclined in the normal direction of rotation of the pinion housing.

3. A differential mechanism according to claim 1 in which said blade shape is formed by shell portions between flanges of the pinion housing, which, seen in cross section, have flanks which are positioned and shaped so that in relationship to the direction of rotation a maximum passage opening for the oil spray is obtained.

4. A differential mechanism according to claim 3 and in which the adjacent flanks of the shell positions forming the sides of the passage opening are at 9 and 81 respectively to axis of the drive shaft.

5. A differential mechanism substantially as hereinbefore particularly described and as illustrated in the accompanying drawings.