Differential reducer including means for collecting oil in both directions of rotation

Abstract

The present invention relates to a differential reducer (10) for a motor vehicle, the motor vehicle differential reducer comprising: a differential mechanism (12), the differential mechanism comprising a ring gear (14); a reduction mechanism (24), the reduction mechanism comprising a secondary pinion (32) and a main pinion (30); a housing (20), the housing comprising a first half-shell (20A) and a second half-shell (20B), wherein the transverse inner wall (21A, 21B) of each half-shell comprises three bearings (22, 34, 36) and a housing (38 B, 40B, 42B), each lateral inner wall (21A, 21B) has a first device for collecting and guiding the oil sprayed by the ring gear (14) rotating in a first rotation direction (R1) to the bearing housing (38A, 38B, 40A, 40B, 42A, 42B); characterized in that each inner wall (21A, 21B) includes a second device for collecting the oil sprayed substantially laterally by the ring gear (14) rotating in a second rotation direction (R2).

Description

Technical Field

[0001] This invention relates to a differential reducer for motor vehicles, the differential reducer comprising:

[0002] - A basic longitudinal differential mechanism, the basic longitudinal differential mechanism including at least one ring gear, the lower portion of which is intended to be immersed in lubricating oil;

[0003] - A reduction mechanism, comprising a secondary shaft and a main shaft, wherein a pinion on the main shaft is driven by the ring gear via the pinion on the secondary shaft;

[0004] - A housing containing the differential mechanism and the reduction gear, wherein the differential mechanism and the shafts are each supported within the housing by a pair of associated opposing bearings. The housing comprises, on one side, a first half-shell, the transverse inner wall of which comprises three housings, each housing receiving the first bearing of each pair of bearings; and on the other side, a second half-shell, the transverse inner wall of which comprises three housings, each housing receiving the second bearing of each pair of bearings.

[0005] The rotation of the ring gear in the first direction of rotation enables oil to be sprayed substantially laterally from the top of the ring gear along the direction of these reducer shafts. Each lateral inner wall has a first device for collecting and guiding the oil sprayed by the ring gear rotating in the first direction of rotation to these bearing housings. Background Technology

[0006] Numerous examples of this type of differential reducer are known. In the remainder of the specification and the claims, a differential reducer is defined as an assembly comprising: a housing containing a reducer and a differential mechanism, wherein the ring gear of the differential mechanism meshes with the pinion of the reducer's main shaft.

[0007] Conventionally, once the differential gear mechanism is installed in the two half-shells and the two half-shells are joined to form an outer shell, the outer shell is filled with lubricating oil that allows the pinion housing and rolling bearings to be lubricated by splash lubrication.

[0008] Therefore, in accordance with the rule that the lubricant level is set at the level of the lowest rolling element, the oil level in the housing is basically set at the level of the axis of rotation of the differential reducer mechanism or the axis of rotation of the ring gear.

[0009] Once the differential rotates at a speed below a predetermined speed, the pinion cover is lubricated by splash lubrication, being immersed in lubricating oil. For this purpose, the cover is an open cover that allows oil to wet the pinion.

[0010] However, this design has drawbacks once the differential rotates at high speed.

[0011] Specifically, at speeds above a predetermined threshold, the lubricating oil is subjected to centrifugal force from the ring gear and sprayed onto the walls of the housing, and specifically the walls of the half-housing. The lubricating oil then flows slowly from these walls by dripping, returning only slowly towards the bottom of the housing. As a result, the oil level in the housing housing containing the pinion gear becomes insufficient and splash lubrication of the pinion gear cannot be guaranteed.

[0012] Even if the oil level appears satisfactory when stationary, this lack of lubrication will eventually cause the rotating components of the differential to be damaged due to insufficient oil.

[0013] Therefore, the known practice is to create conduits for collecting and guiding the oil sprayed along the direction of the rolling bearing and the pinion housing. These collection conduits are oriented substantially tangentially to the bearing housing so as to collect the lubricating oil sprayed by the ring gear as it rotates in the first direction.

[0014] However, the pipes used to collect and guide the oil are not designed to collect oil sprayed by the ring gear rotating in a second direction opposite to the first direction of rotation. However, from one vehicle model to another, it may be necessary to rotate the ring gear in one direction or the other, for example, depending on the available space in the differential reducer.

[0015] To ensure proper lubrication of rotating components, it is necessary to provide different housings depending on the rotation direction of the ring gear.

[0016] However, it would be advantageous to find a solution that allows for a reduction in vehicle manufacturing costs regardless of the direction of rotation of the differential ring gear. Summary of the Invention

[0017] This invention proposes a differential reducer for motor vehicles, comprising:

[0018] - A basic longitudinal differential mechanism, the basic longitudinal differential mechanism including at least one ring gear, the lower portion of which is intended to be immersed in lubricating oil;

[0019] - A reduction mechanism, comprising a secondary shaft and a main shaft, wherein a pinion on the main shaft is driven by the ring gear via the pinion on the secondary shaft;

[0020] - A housing containing the differential mechanism and the reduction gear, wherein the differential mechanism and the shafts are each supported within the housing by a pair of associated opposing bearings. The housing comprises, on one side, a first half-shell, the transverse inner wall of which comprises three housings, each housing receiving the first bearing of each pair of bearings; and on the other side, a second half-shell, the transverse inner wall of which comprises three housings, each housing receiving the second bearing of each pair of bearings.

[0021] The rotation of the ring gear in the first direction of rotation enables oil to be sprayed substantially laterally from the top of the ring gear along the direction of these reducer shafts. Each lateral inner wall has a first device for collecting and guiding the oil sprayed by the ring gear rotating in the first direction of rotation to these bearing housings.

[0022] The feature is that each inner wall includes a second device for collecting oil that is sprayed substantially laterally from the bottom of the ring gear along the direction of the reducer shaft by the rotation of the ring gear in a second rotational direction.

[0023] Other features according to the invention:

[0024] - The second collecting device includes a lower ramp for guiding oil formed in the transverse inner wall of at least one of the half-shells, so as to guide the lubricating oil injected from the bottom of the ring gear to the pinion of the main shaft.

[0025] - The pinion of the secondary shaft is arranged at a certain distance from the oil flow flowing on the lower slope;

[0026] - The secondary axis is offset vertically above the horizontal level of the primary axis;

[0027] - The ramp is formed by ribs that extend longitudinally and protrude from the transverse inner wall;

[0028] - The housing of the bearing of the main shaft includes at least one opening in its axial face, the at least one opening being used to collect and guide oil lifted from the lower ramp by the pinion of the main shaft as the ring gear rotates in the second rotation direction;

[0029] - The periphery of the bearing housing of the secondary shaft includes at least one conduit for collecting and guiding oil lifted from the lower ramp by the pinion of the main shaft as the ring gear rotates in the second rotation direction, the conduit guiding the oil to the housing;

[0030] - The periphery of the bearing housing of the secondary shaft includes at least one surface for collecting and guiding oil injected by the pinion of the main shaft as the ring gear rotates in the second rotation direction, the surface guiding the oil to the housing;

[0031] - The periphery of the housing of the first bearing of the differential mechanism includes at least one surface for collecting and guiding oil injected by the ring gear when the ring gear rotates in the second rotation direction;

[0032] - At least one of these guide channels or one of these guide surfaces is formed by at least one rib, which extends longitudinally and protrudes from the transverse inner wall;

[0033] These first oil collection devices are generated directly within the inner walls of these semi-shells. Attached Figure Description

[0034] Other features and advantages of the invention will become apparent from the following detailed description, the understanding of which will be provided with reference to the accompanying drawings, in which:

[0035] - Figure 1 It is along Figure 2 The cross-sectional view along section line 1-1 schematically illustrates a differential reducer produced according to the teachings of the present invention;

[0036] - Figure 2 It means that the product is produced according to the teachings of the present invention. Figure 1 The front view of the inner wall of the first half-shell of the differential reducer indicates the path of the lubricating oil when the ring gear rotates in the second direction of rotation;

[0037] - Figure 3 It is similar to Figure 2 The view of the view, representing the production according to the teachings of the present invention. Figure 1 The inner walls of the second half-shell and the first half-shell of the differential reducer indicate the path of the lubricating oil when the ring gear rotates in the first direction of rotation.

[0038] - Figure 4 Is with Figure 3 The same view as the one shown, which indicates the path of the lubricating oil as the ring gear rotates in the second direction of rotation;

[0039] - Figure 5 Is with Figure 2 The same view as the one shown, which indicates the path of the lubricating oil as the ring gear rotates in the first direction of rotation. Detailed Implementation

[0040] In the following description, the same numbers or reference numerals denote parts that have the same or similar functions.

[0041] "Longitudinal direction" will be understood as the direction corresponding to the axis of the differential mechanism.

[0042] The "vertical direction" will be understood as the direction of gravity, orthogonal to the level of the lubricating oil.

[0043] "Horizontal direction" will be understood as any direction perpendicular to the longitudinal and vertical directions.

[0044] "Radial direction" will be understood as any direction perpendicular to the longitudinal axis of the axis.

[0045] "Tangent direction" will be understood as any direction perpendicular to the radial and longitudinal directions.

[0046] "Internal" will refer to the element that is close to the axis of rotation of the differential mechanism.

[0047] "External" will refer to elements that are far from the axis of rotation of the differential mechanism.

[0048] Figure 1 This schematically illustrates a differential reducer 10 used in a motor vehicle. For example, this is a rear drive shaft.

[0049] The differential reducer includes a generally longitudinal differential mechanism 12, which includes at least one ring gear 14 extending in a vertical transverse plane. The ring gear 14 abuts a cover 16 that receives a planetary pinion 18. The cover 16 of the pinion is open and, for this purpose, includes a hole (not shown) allowing lubricating oil to seep in.

[0050] In a known manner, the differential mechanism is enclosed in a housing 20 formed by two half-shells, namely a first half-shell 20A and a second half-shell 20B. The differential mechanism 12 is carried by two opposing bearings 22 (referred to as differential bearings 22) and rotates about a longitudinal axis “A” between the two half-shells 20A and 20B.

[0051] The housing 18 also includes a reduction mechanism 24, which comprises a secondary shaft 26 having a longitudinal axis "B" and a primary shaft 28 having a longitudinal axis "C". The primary shaft 28 includes a pinion 30, referred to as a primary pinion 30, which extends in a transverse vertical plane and meshes with a transverse vertical pinion 32, referred to as a secondary pinion 32, on the secondary shaft 26. The secondary pinion 32 meshes with a ring gear 14 in itself. Therefore, the primary pinion 30 is driven to rotate by the ring gear 14 via the secondary pinion 32.

[0052] from Figure 1 As can be seen, the secondary reducer shaft 26 is offset to the left in the lateral offset direction relative to the differential mechanism 12, and the main shaft 28 is also offset relative to the secondary shaft 26 in the lateral offset direction.

[0053] The main shaft 28 is supported in the housing 20 by a pair of associated opposing bearings 34, referred to as main bearings 34. Similarly, the secondary shaft 26 is supported in the housing 20 by a pair of associated opposing bearings 36, referred to as secondary bearings 36. Bearings 22, 34, and 36 are, for example, rolling bearings formed of ball bearings.

[0054] The first half-shell 20A includes a transverse inner wall 21A, which includes three shells 38A, 40A, and 42A. These three shells respectively receive a first bearing 22 of a pair of differential bearings 22, a first bearing 36 of a pair of auxiliary bearings 36, and a first bearing 34 of a pair of main bearings 34.

[0055] The second half-shell 20B includes a transverse inner wall 21B, which includes three housings 38B, 40B, and 42B, which respectively receive the second bearing 22 of a pair of differential bearings 22, the second bearing 36 of a pair of auxiliary bearings 36, and the second bearing 34 of a pair of main bearings 34.

[0056] The differential mechanism 12 and the reducer 24 are typically lubricated by oil, which fills the housing 20 to the level of... Figure 2 The horizontal line 44, marked with a dashed line, is located approximately near the rotation axis "A" of the differential mechanism 12 to facilitate lubrication of the differential mechanism via splash lubrication.

[0057] Therefore, the lower portion of the ring gear 14 is intended to be immersed in lubricating oil. In the first direction of rotation of the ring gear 14 (refer to...) Figure 2 During the clockwise rotation, the teeth of the ring gear 14 cause oil to splash from the top of the ring gear substantially laterally along the direction of the reducer shafts 26 and 28.

[0058] During the high-speed rotation of the differential mechanism 12, and therefore during the high-speed rotation of the ring gear 14, the differential mechanism 12, and more specifically the ring gear 14, may centrifuge the oil until it drips onto the inner wall of the housing 20, and more specifically onto the transverse inner walls 21A, 21B of the half-shells 20A, 20B.

[0059] This results in insufficient splashed lubricating oil at housing 24, and more particularly at the cover 16 of planetary pinion 18, which could lead to deterioration of the pinion 22 and bearings 22, 34, 36. Therefore, during high-speed operation of the differential mechanism 12, the oil level can drop below axis “A”. To ensure a continuous supply of oil to bearings 22, 34, 36 to prevent their deterioration, each transverse inner wall 21A, 21B has a first device for collecting and guiding the oil sprayed by the ring gear 14 rotating in the first direction of rotation to the housings 38A, 38B, 40A, 40B, 42A, 42B of bearings 22, 34, 36.

[0060] These first guiding and collecting devices are integrally produced with the half-shells 20A, 20B. They are, for example, ribs arranged in a projecting manner relative to the inner walls 21A, 21B and / or conduits recessed into the inner walls 21A, 21B.

[0061] Existing housing technology allows lubricating oil to be collected and guided only in one direction of rotation of the ring gear. It is now economically advantageous to use the same housing in multiple vehicle configurations. Therefore, the same housing model can be used in multiple vehicle models. Currently, depending on the configuration, the ring gear can rotate in one or the other direction of rotation. However, when the ring gear rotates in the opposite direction, the initial collection and guiding mechanism no longer allows for proper lubrication of the bearing. Therefore, until now, two different housings had to be provided depending on the direction of rotation of the ring gear.

[0062] The present invention proposes a universal housing that allows lubricating oil dripping onto the inner wall to be collected and guided toward the bearing, regardless of the rotation direction of the ring gear 14.

[0063] For this purpose, the inner walls 21A and 21B of the half-shells 20A and 20B include a second device for collecting oil that is sprayed substantially laterally from the bottom of the ring gear along the direction of the reducer shaft as the ring gear 14 rotates in a second rotational direction.

[0064] Figure 3 and Figure 4 The inner wall 21A of the first half-shell 20A is depicted. The wall includes a bell-shaped portion 46 designed to accommodate the cover 16 of the pinion gear. An upper recess 48 is provided on the periphery of the bell-shaped portion 46, designed to receive oil injected by the ring gear 14. This recess 48 forms an oil reservoir. The recess 48 is defined circumferentially by a first longitudinal radial surface 50 and a second longitudinal radial surface 52 opposing each other. The second radial surface 52 points laterally toward the main shaft 26 and the secondary shaft 28. The first radial surface 50 forms part of a first oil collection device such that oil can be collected when the ring gear 14 rotates in a first direction, while the second radial surface 52 forms part of a second oil collection device such that oil can be collected when the ring gear 14 rotates in a second direction.

[0065] A radial conduit 54, referred to as the differential conduit 54, arranged around the periphery of the housing 38A, allows oil flow to be directed downwards into the housing 38A of the first differential bearing 22. The differential conduit 54 leads to an opening 56 in the axial wall of the housing, vertically aligned with the differential bearing 22 to allow for proper lubrication of the differential bearing 22. The differential conduit 54 is recessed into the inner wall 21A of the first half-shell 20A.

[0066] Each housing 40A, 42A of the reducer mechanism 24 is also equipped with a pipe that forms part of the first oil collection device.

[0067] Therefore, the conduit 58, referred to as the secondary conduit 58, is defined by two ribs 60 protruding relative to the transverse inner wall 21A. The secondary conduit 58 extends around the periphery of the housing 40A of the first secondary bearing 36. The secondary conduit 58 extends generally tangentially from the inlet toward the outlet relative to the track of the teeth of the ring gear 14, the outlet leading to an opening 62 formed in the axial wall of the housing 40A of the first secondary bearing 36. The inlet of the secondary conduit 58 is wider than the outlet, giving it a funnel shape, allowing a large amount of oil to be collected to lubricate the first secondary bearing 36. Due to the tangential orientation of the secondary conduit relative to the ring gear 14, the secondary conduit 58 cannot collect oil when the ring gear 14 rotates in the second direction of rotation.

[0068] Similarly, the main conduit 64, referred to as the main conduit 64, is defined by two ribs 66 projecting relative to the transverse inner wall 21A. The main conduit 64 extends around the periphery of the housing 42A of the first main bearing 34. The main conduit 64 generally extends from an inlet generally pointing upward toward the ring gear 14 toward an outlet leading to an opening 68 formed in the axial wall of the housing 40A of the first secondary bearing 36. The inlet of the main conduit 64 is wider than the outlet, giving it a funnel shape, allowing a large amount of oil to be collected to lubricate the first main bearing 34. Due to the orientation of the main conduit toward the ring gear 14, the main conduit 64 is substantially unable to collect oil when the ring gear 14 rotates in the second direction of rotation.

[0069] The first half-shell 20A also includes a second device for collecting lubricating oil when the ring gear 14 rotates in a second rotational direction, such as... Figure 4 What is shown.

[0070] The second collecting device includes a lower ramp 70 for guiding oil formed in the transverse inner wall 21A of the first half-shell 20A, so as to guide lubricating oil injected from the bottom of the ring gear 14 to the main pinion 30. The ramp 70 is formed by a rib that protrudes relative to the transverse inner wall 21A. The ramp 70 points towards the top of the outer shell 20.

[0071] exist Figure 4 The first end of the ramp 70 shown on the right is positioned below the ring gear 14. The first end has an arcuate shape. This first end is arranged radially opposite to and near the teeth of the ring gear 14. Therefore, when the ring gear 14 rotates in the second direction, as indicated by arrow R2, the ring gear 14 acts as a hydraulic wheel, which generates an oil flow that rises along the ramp 70 toward the second end of the ramp.

[0072] lie in Figure 4The second end of the ramp 70 on the left side is positioned below the main pinion 30. The second end has an arcuate shape surrounding a portion of the periphery of the housing 42A of the first main bearing 34. This second end is arranged radially opposite to and near the teeth of the main pinion 30. When the main pinion 30 rotates in the same direction as the ring gear 14, the teeth of the main pinion will be propelled by oil pushed upwards by the ring gear 14 towards the top of the ramp 70 as far as the opening 68 to lubricate the first main bearing 34.

[0073] The first end of the ramp 70 is lower than the second end. Therefore, the ramp 70 has a ramp that descends from the second end toward the first end.

[0074] To allow lubricating oil to circulate along the ramp 70 to the main pinion 30, the secondary pinion 32 is arranged at a certain distance from the oil flow circulating along the lower ramp 70. This prevents most of the oil from being intercepted by the secondary pinion 32. For this purpose, the secondary shaft 26 is vertically offset above the level of the main shaft 28. As a result, the housing 40A of the secondary bearing 36 is vertically offset in the upward direction relative to the housing 42A of the main bearing 34.

[0075] A conduit 72 is arranged around the periphery of the housing 40A of the first secondary bearing 36. The conduit 72 extends tangentially to the track of the teeth of the main pinion 30 from an inlet located at the upper part of the main pinion 30 to an outlet leading to an opening 74 in the axial wall of the housing 40A of the first secondary bearing 36, so as to supply lubricating oil to the first secondary bearing 36 when the ring gear 14 rotates in the second direction. The conduit 72 is defined by two ribs projecting relative to the transverse inner wall 21A.

[0076] During the rotation of the ring gear 14 in the first direction, such as Figure 3 As indicated by arrow R1, the lubricating oil is carried by the teeth of the ring gear 14 to rise toward the top of the housing 20, as indicated by arrow "F1". A portion of the lubricating oil is sprayed onto the first radial surface 50 of the recess 48. The lubricating oil contained in the recess 48 is then guided through the differential conduit 54 to the housing 38A of the first differential bearing 22 for lubrication.

[0077] Another portion of the lubricating oil is sprayed laterally from the upper part of the ring gear 14 along the direction of the main shaft 26 and the secondary shaft 28. As indicated by arrow "F2", a portion of this sprayed lubricating oil enters the secondary conduit 58 due to its tangential orientation and is thus guided to the housing 40A of the secondary bearing 36 for lubrication.

[0078] As indicated by arrow "F3", another portion of this sprayed lubricating oil enters the main pipe 64 due to its tangential orientation and is thus guided to the housing 42A of the main bearing 34 for lubrication.

[0079] Then, the lubricating oil flows by gravity to the lower ramp 70. The oil flows by gravity along the ramp of the lower ramp 70 to the bottom of the ring gear 14, and then the lubrication cycle restarts.

[0080] During the rotation of the ring gear 14 in the second direction, such as Figure 4 As indicated by arrow R2, the ring gear 14 generates a flow of lubricating oil, indicated by arrow "F4", which rises along the ramp of the ramp 70 to the main pinion 30.

[0081] The primary pinion then, as indicated by arrow "F5", raises the lubricating oil as far as opening 68 to lubricate the first primary bearing 34, and as indicated by arrow "F6", raises the lubricating oil as far as secondary conduit 72 to lubricate the first secondary bearing 36. The first differential bearing 22 is itself lubricated by lubricating oil that is directly raised by the ring gear 14 and sprayed onto the second radial surface 52 defining the recess 48, as indicated by arrow "F7".

[0082] Figure 2 and Figure 5 The inner wall 21B of the second half-shell 20B is depicted. On this second half-shell 20B, a first oil collection device is formed only by the face of a rib, which is generally vertically oriented and extends above the associated bearing housing. The lower end of the rib is arranged to align with an opening formed in the axial plane of the associated housing to allow oil collected through said face to drain into the associated housing. The rib is integrally produced with the half-shell 20B.

[0083] Therefore, the first rib 76, referred to as the differential rib 76, extends and protrudes relative to the transverse inner wall 21B. The differential rib 76 is arranged above the housing 38B of the second differential bearing 22. The differential rib 76 extends generally vertically; Figure 2 and Figure 5 In the example depicted, the differential rib is slightly inclined. Rib 76 extends from its upper end to a free lower end 78, which is located on the upper inner wall of half-shell 20B. Shell 38B includes a radial opening 80 formed in the upper portion of the shell and aligned with the free lower end 78 of the differential rib 76. The differential rib 76 is defined by a first lateral surface 82 and a second lateral surface 84. Figure 5 As indicated, when the ring gear rotates in the first rotational direction R1, the first lateral surface 82 can intercept the oil sprayed by the ring gear 14. Figure 2 As indicated, when the ring gear rotates in the second rotation direction R2, the second lateral surface 84 is able to intercept the oil sprayed by the ring gear 14.

[0084] Therefore, the first lateral surface 82 forms part of the first oil collection device, while the second lateral surface 84 forms part of the second oil collection device.

[0085] In a variant of the invention (not shown), a first lateral surface belonging to the first collecting device is supported by a first associated rib, while a second lateral surface belonging to the second collecting device is supported by a second associated rib. The first and second ribs are arranged to form a "V" shape, the points of which are aligned with openings in the housing.

[0086] In the same manner, a second rib 86, referred to as secondary rib 86, extends and protrudes relative to the transverse inner wall 21B. Secondary rib 86 is arranged above the housing 40B of the second secondary bearing 36. Secondary rib 86 extends generally vertically; Figure 2 and Figure 5 In the example shown, the secondary rib is slightly inclined. Rib 86 extends from its upper end to a free lower end 88, which is located on the upper inner wall of the half-shell 20B. The shell 40B includes a radial opening 90 formed in the upper portion of the shell and aligned with the free lower end 88 of the secondary rib 86. The secondary rib 86 is defined by a first lateral surface 92 and a second lateral surface 94. Figure 5 As indicated, when the ring gear rotates in the first rotational direction R1, the first lateral surface 92 can intercept the oil sprayed by the ring gear 14. Figure 2 As indicated, when the ring gear 14 rotates along the second rotation direction R2, the second lateral surface 84 is able to intercept the oil injected by the main pinion 30.

[0087] Therefore, the first lateral surface 92 forms part of the first oil collection device, while the second lateral surface 94 forms part of the second oil collection device.

[0088] The housing 42B of the second main bearing 34 is supplied with lubricating oil via a groove 95, which is formed by an upward-pointing surface and extends in the form of a ramp from the end located on the inner side of the half-shell 20B to an opening 96 formed in the axial surface of the housing 42B. This groove 95 is common to both the first and second oil collection devices, because it can collect lubricating oil and guide it to the second main bearing 34 regardless of whether the ring gear 14 rotates in the direction R1 or R2.

[0089] Similar to the first half-shell 20A, the second half-shell 20B includes a lower ramp 70 for guiding oil formed in the transverse inner wall 21B of the second half-shell 20B, so as to direct lubricating oil injected from the bottom of the ring gear 14 as far as the pinion 30. The ramp 70 is formed here by a shoulder surface. The ramp 70 points towards the top of the housing 20.

[0090] exist Figure 2 and Figure 5The first end of the ramp 70 shown on the left is positioned below the ring gear 14. The first end has an arcuate shape. This first end is arranged radially opposite to and near the teeth of the ring gear 14. Therefore, when the ring gear 14 rotates in the second direction, as indicated by arrow R2, the ring gear 14 acts as a hydraulic wheel, which generates an oil flow that rises along the ramp 70 toward the second end of the ramp.

[0091] lie in Figure 2 and Figure 5 The second end of the ramp 70 on the left side is positioned below the main pinion 30. The second end has an arcuate shape surrounding a portion of the periphery of the housing 42B of the second main bearing 34. This second end is arranged radially opposite to and near the teeth of the main pinion 30. When the main pinion 30 rotates in the same direction as the ring gear 14, the teeth of the main pinion will be propelled by the ring gear 14 upwards towards the top of the ramp 70, extending as far as the opening 96, to lubricate the first main bearing 34.

[0092] The first end of the ramp 70 is lower than the second end. Therefore, the ramp 70 has a slope that descends from the second end to the first end.

[0093] To allow lubricating oil to circulate along the ramp 70 to the main pinion 30, the secondary pinion 32 is arranged at a certain distance from the oil flow circulating along the lower ramp 70. This prevents most of the oil from being intercepted by the secondary pinion 32. For this purpose, the secondary shaft 26 is vertically offset above the level of the main shaft 28. As a result, the housing 40B of the secondary bearing 36 is vertically offset in the upward direction relative to the housing 42B of the main bearing 34.

[0094] During the rotation of the ring gear 14 in the first direction, such as Figure 5 As indicated by arrow R1, the lubricating oil is carried by the teeth of the ring gear 14 to rise towards the top of the housing 20, as indicated by arrow "F'1". A portion of the lubricating oil is sprayed onto the first lateral surface 82 of the differential rib 76, as indicated by arrow "F'2". The lubricating oil collected by the differential rib 76 flows as far as the free lower end 78 and then drains through the opening 80 into the housing 38B of the second differential bearing 22 to lubricate the second differential bearing.

[0095] Another portion of the lubricating oil is sprayed laterally from the upper part of the ring gear 14 along the direction of the main shaft 26 and the secondary shaft 28. As indicated by arrow "F'3", this lubricating oil is collected by the first lateral surface 92 of the secondary rib 86. The lubricating oil collected by the secondary rib 86 flows as far as the free lower end 88, and then drains through the opening 90 into the housing 40B of the second secondary bearing 36 to lubricate the second secondary bearing.

[0096] As indicated by arrow "F'4", lubricating oil is sprayed through the secondary pinion 32 and the primary pinion 30 toward the transverse inner wall 21B portion located above the groove 95. The oil is collected by the groove 95, which guides the oil to the opening 96 in the housing 42B of the second primary bearing 34 for lubrication of the second primary bearing.

[0097] Then, the lubricating oil flows by gravity to the lower ramp 70. The oil flows by gravity along the ramp of the lower ramp 70 to the bottom of the ring gear 14, and then the lubrication cycle restarts.

[0098] During the rotation of the ring gear 14 in the second direction, such as Figure 2 As indicated by arrow R2, the ring gear 14 generates a flow of lubricating oil, indicated by arrow "F'5," which rises along the ramp 70 to the main pinion 30. The main pinion then elevates the lubricating oil to the opening 96, as indicated by arrow "F'6," to lubricate the first main bearing 34. A portion of the lubricating oil is sprayed through the main pinion 30 onto the second surface 94 of the secondary rib 86. The lubricating oil collected by the secondary rib 86 flows as far as the free lower end 88 and then drains through the opening 90 into the housing 40B of the second secondary bearing 36 to lubricate the second secondary bearing.

[0099] The second differential bearing 22 is lubricated by lubricating oil that is directly lifted by the ring gear 14 and sprayed onto the second surface 84 of the differential rib 76, as indicated by arrow "F'7". The lubricating oil collected by the differential rib 76 flows as far as the free lower end 78 and then drains through the opening 80 into the housing 38B of the second differential bearing 22 to lubricate the second differential bearing.

[0100] Therefore, the housing 20 implemented according to the teachings of the present invention can be adapted to vehicles in which the ring gear 14 rotates in one direction or the other. Thus, it is no longer necessary to design two different housings according to the rotation direction of the ring gear, thereby substantially reducing the production cost of the differential reducer.

[0101] This invention allows for more specific implementation of two circuits for lubrication based on the rotation direction of the ring gear. Each lubrication circuit is designed to lubricate each bearing of the differential reducer 10.

Claims

1. A differential reducer (10) for a motor vehicle, the differential reducer comprising: - a longitudinal differential mechanism (12) comprising at least one ring gear (14), the lower part of which is intended to be immersed in lubricating oil; - a speed reduction mechanism (24), comprising a countershaft (26) and a mainshaft (28), wherein a mainshaft pinion (30) of the mainshaft (28) is driven by the ring gear (14) via a countershaft pinion (32) of the countershaft (26); - a housing (20) containing the differential mechanism (12) and the reduction mechanism (24), the differential mechanism (12) and the main shaft (26) and the secondary shaft (28) being each supported in the housing (20) by a pair of associated relative bearings, the housing (20) comprising, on the one hand, a first half-shell (20A), the transverse inner wall (21A) of which comprises three cavities (38A, 40A, 42A), each accommodating a first bearing of each pair of bearings, and, on the other hand, a second half-shell (20B), the transverse inner wall (21B) of which comprises three cavities (38B, 40B, 42B), each accommodating a second bearing of each pair of bearings, The rotation of the ring gear (14) in the first rotation direction (R1) can laterally spray oil from the top of the ring gear (14) in the direction of the main shaft (26) and the secondary shaft (28), and each lateral inner wall (21A, 21B) has a first device for collecting and guiding the oil sprayed by the ring gear (14) rotating in the first rotation direction (R1) to the cavities (38A, 38B, 40A, 40B, 42A, 42B); Characterized in that each lateral inner wall (21A, 21B) comprises a second device for collecting oil ejected laterally from the bottom of the ring gear (14) in the direction of the primary shaft (26) and the secondary shaft (28) by the rotation of the ring gear (14) in the second rotation direction (R2).

2. The differential reducer (10) according to the preceding claim, characterized in that The second device comprises a lower slope (70) for guiding oil formed in the transverse inner wall (21A, 21B) of at least one of the first half shell (20A) and the second half shell (20B) so as to guide the lubricating oil protruding from the bottom of the ring gear (14) to the main shaft pinion (30).

3. The differential reducer (10) according to the preceding claim, characterized in that The countershaft pinion (32) is arranged at a distance from the oil flow flowing on the lower ramp (70).

4. The differential reducer (10) according to the preceding claim, characterized in that The secondary axis (26) is vertically offset above the level of the primary axis (28).

5. The differential reducer (10) according to any one of claims 2 to 4, characterized in that: The lower slope (70) is produced by a rib extending longitudinally and protruding from the corresponding transverse inner wall (21A).

6. The differential reducer (10) according to any one of claims 2 to 4, characterized in that: The housing of the bearing of the main shaft (28) includes at least one opening (68, 96) in its axial face for collecting and directing oil lifted from the lower ramp (70) by the main shaft pinion (30) when the ring gear (14) rotates in the second rotational direction (R2).

7. The differential reducer (10) according to any one of claims 2 to 4, characterized in that: The periphery of the cavity of the bearing of the secondary shaft (26) includes at least one duct (72) for collecting and guiding oil lifted from the lower ramp (70) by the main shaft pinion (30) when the ring gear (14) rotates in the second rotational direction, the duct (72) guiding the oil to the cavity of the bearing of the secondary shaft.

8. The differential reducer (10) according to any one of claims 2 to 4, characterized in that: The periphery of the cavity of the bearing of the secondary shaft (26) includes at least one surface for collecting and guiding the oil sprayed by the main shaft pinion (30) when the ring gear (14) rotates in the second rotation direction, and the surface guides the oil to the cavity of the bearing of the secondary shaft.

9. The differential reducer (10) according to any one of claims 2 to 4, characterized in that: The periphery of the housing of the first bearing of the differential mechanism includes at least one surface for collecting and guiding oil sprayed by the ring gear (14) when the ring gear rotates in the second rotation direction.

10. The differential reducer (10) according to claim 9, characterized in that: At least one of the faces is formed by at least one rib extending longitudinally and protruding from the transverse inner wall (21A, 21B).

11. The differential reducer (10) according to claim 7, characterized in that: At least one of the ducts is formed by at least one rib extending longitudinally and protruding from the transverse inner wall (21A, 21B).

12. The differential reducer (10) according to any one of claims 1 to 4, characterized in that: The first means are produced directly in the transverse inner walls (21A, 21B) of the first (20A) and second (20B) half-shells.

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