EP3464956A1

EP3464956A1 - Ring target of a rotation sensor

Info

Publication number: EP3464956A1
Application number: EP17727649.0A
Authority: EP
Inventors: Walter Bertolino; Olivier DOINET
Original assignee: PSA Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2016-06-07
Filing date: 2017-05-11
Publication date: 2019-04-10
Also published as: FR3052215A1; FR3052215B1; WO2017212132A1

Abstract

The invention relates to a ring target (1) of a rotation sensor in a lubricating atmosphere, comprising scoops (2) and a rim (3) having a first upstream face (4) and a second downstream face (5). The rim (3) is such that the scoops (2) project out from the first upstream face (4), each of said scoops (2) being aligned with a hole (6) that extends through the rim (3). In addition, the scoops (2) are all oriented in a given rotation direction (7) of the target (1).

Description

TARGET ROTATION SENSOR

The invention relates to an annular target rotation sensor integrated in a gearbox, and a vehicle comprising such a gearbox.

The invention aims including but not limited to, applications in the field of motor vehicle transmission systems and in particular the gearboxes of these vehicles.

In this area, effective lubrication of rotating parts conditions the life of transmissions, as well as a limitation of mechanical losses by friction. Complex bodies, such as gearboxes, are sensitive to these two phenomena due to the large number of parts fitted in rotation in a mechanically and thermally stressed environment, for example gears and bearings. The lubrication circuit of such a gearbox most often comprises gears performing a splash lubrication in a reserve 16 of oil, the oil then being projected onto a crankcase or gearbox cover, and then collected. by gravity and directed towards bodies such as bearings.

The gearboxes are, moreover, more and more often equipped with devices for taking speed information on the primary shaft. This makes it possible, for example, for a computer controlling a clutch, to obtain the speed of rotation of the primary shaft and to compare it to a rotational speed of a propulsion motor, and to deduce from this, by comparison of these two speeds, a slip of the clutch. These gearboxes can be coupled to one or more engines, such as a combustion engine and an electric propulsion motor for a hybrid vehicle, the coupling between these gearboxes and these engines being most often carried out by at least one of these clutches. controlled. For this purpose, it is known to use annular rotational sensor targets on a gearbox primary shaft, the target being connected to the primary shaft, and the sensor being fixed on a housing or cover of the gearbox. Such targets are known to have a full or open rim.

[0006] Patent document FR-A-2 739 672 discloses a device for taking speed information on the primary shaft of a gearbox using a sensor detecting the passage of a target. metal linked in rotation to said primary shaft. A disadvantage of these targets is that even with the perforated rim, the target being rotated with the primary shaft, it is difficult, if not impossible, that the oil or oil mist can cross the rim of the target in an axial direction to this target. This implies either difficulties of implantation of this target in the gearbox, or an altered lubrication of organs masked by this target, such as a bearing of the primary shaft, or again, a complex lubrication circuit coming from a hollow tree.

DE-A-102009012579 discloses a target whose geometry forms scoops on its circumference, to remount the oil by bubbling.

A disadvantage of this target is that the oil is projected radially, and does not promote the lubrication of members located axially nearby. Another disadvantage is that this splash lubrication decreases the efficiency of the transmission by increasing its drag.

The object of the invention is to overcome the aforementioned drawbacks.

[001 1] For this purpose, the subject of the invention is an annular target of a rotation sensor in a lubricating atmosphere, comprising scoops and a rim, the rim having a first upstream face and a second downstream face, the scoops projecting from the first upstream face and each corresponding to a hole passing through the rim, the scoops being furthermore all oriented in a determined direction of rotation of the target.

By lubricating atmosphere is meant throughout this document, an atmosphere charged with lubricant, such as oil, that is to say a gas containing lubricant droplets, lubricant projections, lubricant jets, lubricant vapors, or forming a lubricant slurry, but remaining a gas.

The terms upstream and downstream must be included throughout this document, relative to the direction of the gas passing through the rim. The upstream face is the face of the rim on the side which captures the gas, the upstream zone being the entire volume upstream of the upstream face and delimited by at least one plane coinciding with the upstream face, the downstream face being the face of the rim on the gas discharge side, the downstream zone being the entire volume downstream of the downstream face and defined by at least one plane coinciding with the downstream face.

Indeed, in this lubricating atmosphere, scoops projecting from the upstream face and oriented in the direction of rotation of the target determined, will capture the gas of the lubricating atmosphere under the effect of the rotation of the target , gas that will cross the rim through the holes passing from the upstream face to the downstream face. The gas is then forced through the rim and a gas convection movement is created between an upstream zone on the side of the upstream face, and a downstream zone on the side of the downstream face. Since this gas is loaded with lubricant, the amount of lubricant in the downstream zone will be increased. Thus, we see that this embodiment allows the passage of lubricant through the rim of the target, which allows a more easy target implantation in an environment requiring lubrication of the downstream zone. In addition, rotation of the target in the gas generates much less drag than rotation of the target in an oil bath for bubbling lubrication. In one embodiment, the scoops form gills through the rim.

Indeed, this form is a simple embodiment of the scoops, nevertheless ensuring the effectiveness of the latter.

In one embodiment, the speed sensor is positioned vis-à-vis the scoops, the scoops being the parts of the target detected by the speed sensor. Indeed, these projecting scoops of the upstream face are excrescences which can be used advantageously for the detection of speed, the speed sensor is then positioned vis-à-vis these growths. The scoops then have a dual function of lubrication and detection, which allows to lighten the target and reduce it in size. In a variant, the target comprises a magnetic ring or notches integral with the rim, the speed sensor being positioned vis-à-vis the ring, the latter being the portion of the target detected by the sensor of speed.

In one embodiment, the annular target consists of a stamped steel sheet. Indeed, the steel sheet allows the realization of the target in one piece, because the stamping, particularly suitable for sheet metal parts, allows the punching and cutting of the sheet to achieve scoops and holes in the same sheet and incidentally at the same time. Note that it is advantageous to use a magnetic or electromagnetic type sensor, which comes to detect either scoops or indentations or recesses made in the ring, this ring then being the continuity of the rim and made in the same sheet.

In a variant, this ring is attached to the sheet steel rim, in particular by clamping, welding, clipping, or crimping. In a variant, the rim is made of polyamide and made in one piece by molding with the scoops.

In a variant, the polyamide rim comprises a centering hub reinforced by a metal core.

The invention also relates to a gearbox of a vehicle comprising a primary shaft, with the previously described target integral with the primary shaft.

Indeed, the primary shaft, which is also the input shaft rotatably connected to the clutch of an engine, rotates mainly in the same direction, and always in the same direction for a heat engine. Since the scoops are oriented in the determined direction of rotation of the target, the lubrication of the downstream zone is degraded if the target rotates in a direction opposite to the determined direction, so that it is advantageous to position this target on the primary shaft. turning mostly to always see in the determined direction.

According to one embodiment, the gearbox comprises a member rotating relative to the primary shaft, and the target adjacent the member by the second downstream face.

The term "the target adjoins the organ" throughout this document, the fact that the target is close to the body and that the gas loaded with oil and propelled by the target can reach this organ .

Indeed, the lubrication is useful when there is a relative movement between two parts. In this embodiment, the relative movement is a rotational movement between the primary shaft and the member. In addition, the gas loaded with oil passing through the rim makes it possible to provide this lubrication in the downstream zone, and thus makes it possible to lubricate a member adjoining the target by the downstream face, that is to say located in the downstream zone. .

According to one embodiment, the member is a bearing of the primary shaft. Indeed, this type of member requires sufficient lubrication but not excessive, and is difficult to determine by the current digital means. The target of the invention, when it abuts the bearing, allows such lubrication.

In a variant, the member is a bearing of a crazy gear of the primary shaft. According to one embodiment, the gearbox comprises a gearbox housing housing a bearing of the primary shaft near an end of the primary shaft, the housing is closed by a cover on the side of the gearbox. at the end, the cover has a reserve of lubricant collected, and a lubricant supply of the lubricant reserve collected for the organ opens out near the scoops, on the side of the upstream face. Indeed, in the gearbox, the lubricant is sprayed on the housing walls, by bubbling the gears in a lubricant bath. This lubricant is then partly collected by a particular form of the housing, or a specific part, to the pool of lubricant collected, this reserve for supplying a lubricant circuit comprising for example a hollow shaft. It is then advantageous to use this pool of collected lubricant to route the lubricant near the scoops, thus increasing the efficiency of the target for the lubrication of the downstream zone.

In a variant, the bearing of the primary shaft is the bearing.

According to one embodiment, the end of the primary shaft is provided with a coaxial screw and secured to the primary shaft, the screw comprising a screw head, the target being fixed around or in the head. quote.

Indeed, the small space available in the gearbox to accommodate this target may lead to having a target whose central portion extends axially to seek a fixation on the primary shaft set back from the target. When a screw as described is present, it is advantageous that the target is fixed on the periphery of the screw head, or in the footprint of the screw head, so as to have a target as simple as possible. Another advantage is that it does not increase the number of parts to be mounted, the screw can be delivered on a mounting line with the target already mounted on the screw.

In a variant, the end is provided with this screw, and the target is clamped between the screw head and the end. In a variant, the target is fixed on or around the end of said primary shaft.

In a variant, the member is the bearing, and the target is fixed on the inner ring of the bearing. An advantage of this variant is that it does not increase the number of parts to be mounted, the bearing can be delivered on the assembly line with the target already mounted on the inner ring of the bearing. Another advantage is that the target is closer to the area to be lubricated, including the balls, rollers, or needles. It will be advantageous for the scoops to be positioned opposite balls, rollers, or needles. The invention also relates to a power train comprising a gearbox as defined above.

The invention also relates to a vehicle comprising a gearbox as defined above.

Other features, objects and advantages of the invention will become apparent on reading the description of the nonlimiting exemplary embodiments which will follow, with reference to the appended FIGS. 1 to 3, which represent:

- Figure 1: target according to one embodiment of the invention, front view and in section.

- Figure 2: perspective view of a scoop of the target according to one embodiment of the invention. - Figure 3: overview of the integrated target in a gearbox

The assembly shown in FIG. 1 comprises an annular target 1 of a rotation sensor (not shown) in a lubricating atmosphere, comprising scoops 2 and a rim 3, the rim 3 having a first upstream face 4 and a second downstream face 5, the scoops 2 projecting from the first upstream face 4 and each corresponding to a hole 6 passing through the rim 3, the scoops 2 being furthermore all oriented in a determined direction of rotation 7 of the target 1. There are also represented the direction of circulation 19 of the gas of the lubricating atmosphere, and the upstream zones 14 and downstream 15. This target 1 comprises for example a centering hub. The scoops 2 projecting from the upstream face 4 and oriented in the determined direction of rotation 7 of the target 1, will capture the gas of the lubricating atmosphere under the effect of the rotation of the target 1, which gas will pass through the rim 3 through the holes 6 passing from the upstream face 4 to the downstream face 5. The gas is then forced through the rim 3 and a gas convection movement is created between the upstream zone 14 of the side of the upstream face 4 and the downstream zone 15 on the side of the downstream face 5. This gas being loaded with lubricant, the amount of lubricant of the downstream zone 15 will be increased. It will be noted that if the scoops 2 operate only in the determined direction of rotation 7 of the target 1, the rotation sensor (not shown) detects the rotation of the target 1 in both directions of rotation. However, this target 1 being in a lubricating atmosphere, even if the target 1 rotates in the opposite direction to the determined direction of rotation 7, the lubrication is not absent from the downstream zone 15, and allows operation for a duration limited in these conditions.

FIG. 2 shows a perspective view of one of the scoops 2, the scoop 2 being seen from the upstream zone 14. This scoop 2 is in the form of a hearing and has a gas inlet mouth 20 whose input section 21 is close to a plane orthogonal to the rim 3. The scoops 2 projecting from the upstream face 4 are oriented in the determined direction of rotation 7 of the target 1, that is to say that the inlet mouth 20 and its inlet section 21 are oriented so as to oppose the direction of rotation determined 7. Thus, when the target 1 rotates in the determined direction of rotation 7, the inlet section 21 will capture the surrounding gas and force it to cross the rim through the hole 6 of the rim 3. The disposition of the scoops on the rim, their number, and their geometry, are empirical characteristics defined for each type of gearbox and each usage profile, during debugging tests. Figure 1 shows for example scoops 2 symmetrical all located on the same radius of the target 1, but they could be distributed over several different radii, and non-symmetrical shape.

The annular target 1 consists of a stamped steel sheet. The target 1 is made in one piece, punching and cutting the sheet to make the gills 2 and the holes 6 in the same sheet. A sensor of the magnetic (not shown) or electromagnetic type is used which detects either the openings 2, or notches or recesses (not shown) made in a ring 8, this ring 8 then being the continuity of the rim 3 and made in this same sheet. In a variant, not shown, this ring 8 is attached by clamping, welding, crimping or clipping on the rim 3. In a variant, not shown, the target 1 comprises a magnetic ring 8 or indentations or recesses, integral with the rim 3, the speed sensor being positioned vis-à-vis the ring 8, which last being the part of the target 1 detected by the speed sensor. In a variant, not shown, the rim 3 is made of polyamide and made in one piece by molding with the scoops 2.

The assembly shown in Figure 3 comprises a gearbox of a vehicle comprising a primary shaft 9, with the target 1 previously described integral with the primary shaft 9. The primary shaft 9, which is also the l input shaft rotatably connected to the clutch of an engine, rotates mainly in the same direction of rotation determined 7, and always in the same direction of rotation determined 7 for a heat engine. This gearbox comprises a member 10 rotating relative to the primary shaft 9, and the target 1 adjoins the member 10 by the second downstream face 5. In this example, the member 10 is a bearing of the primary shaft 9, but can also be a rolling of a crazy gear, or any rotating member requiring lubrication.

The assembly shown in FIG. 3 further comprises a casing 1 1 of gear box housing a bearing of the primary shaft 9 near an end 12 of the primary shaft 9, the housing 1 1 is closed by a cover 13 on the side of the end 12, the cover 13 has a reserve 16 of collected lubricant, and a lubricant inlet 17 of the reserve 16 of lubricant collected for the member 10 opens near the scoops 2, the side of the upstream face 4. This lubricant inlet 17 is here a small hole drilled in a wall of the reserve 16 of lubricant, this small hole being in charge of lubricant, and therefore in the lower part of the reserve 16. This small hole is ideally placed in the upstream zone 14 and in front of the scoops 2. The jet of lubricant, or drops of lubricant, coming out of this small hole, will be captured by the scoops 2 and will thus lubricate the member 10, here a bearing of the primary shaft 9 and which is also the bearing of the primary tree 9.

The lubricant is sprayed on the walls of the housing 1 1, by bubbling the gears in a lubricant bath. This lubricant is then partly collected by a particular form of the housing 1 1, or a specific part such as a deflector or plastic deflector (not shown), to the pool 16 of lubricant collected. This reserve 16 makes it possible to feed by gravity a lubricant circuit comprising, for example, a fixed nozzle 25 for supplying the lubricant into the end 12 of the hollow primary shaft 9, this end having a screw 18 that is coaxial with the shaft. hollow primary 9, this screw 18 comprises a coaxial through hole 24, a nozzle 22 disposed in extension of the cannula 25, this nozzle 22 having an axial bore communicating in the through coaxial hole 24 and an elastic lip bearing radially in the through hole 24. The fixed cannula 25 is fixed on the reserve 16 of the cover 13. [0056] This screw 18 comprising a screw head, and the target 1 is fixed around or in the screw head. This fixing can be done by crimping, clipping, gluing, clamping. This screw 18 makes it possible both to axially block the stack of parts on the primary shaft 9, such as the bearing and idle gears, and let the lubricant pass through its through hole 24. [0057] In a variant, no shown, the target 1 is clamped between the screw head and the end 12.

In a variant, not shown, the target 1 is fixed on or around the end 12 of the primary shaft 9.

In a variant, not shown, the member 10 is the bearing, and the target 1 is fixed on the inner ring of the bearing. In particular, a groove can be machined on the inner ring and the rim of the target is clipped into this groove.

The invention also relates to a power train comprising a gearbox as defined above, in particular comprising a heat engine. The invention also relates to a vehicle comprising a gearbox as defined above.

Claims

1. Annular target (1) of a rotation sensor in a lubricating atmosphere, comprising scoops (2) and a rim (3), said rim (3) having a first upstream face (4) and a second downstream face (5) , characterized in that said scoops (2) project from said first upstream face (4), said scoops (2) each being in correspondence with a hole (6) passing through said rim (3), and in that said scoops (2) are all oriented in a determined direction of rotation (7) of said target (1).

2. Annular target (1) according to claim (1) characterized in that the scoops (2) form gills through said rim (3).

3. Annular target (1) according to claims 1 or 2, characterized in that said speed sensor is positioned opposite said scoops (2), said scoops (2) being the parts of said target (1) detected by said speed sensor.

4. Annular target (1) according to one of the preceding claims, characterized in that it consists of a pressed steel sheet.

5. Gearbox of a vehicle comprising a primary shaft (9), characterized in that a target (1) according to one of the preceding claims is integral with said primary shaft (9).

6. Gearbox according to claim 5 comprising a member (10) rotating relative to said primary shaft (9), characterized in that said target (1) adjoins said member (10) by said second downstream face (5).

7. Gearbox according to claim 6 comprising a gearbox housing (1 1) housing a bearing of said primary shaft (9) near one end (12) of said primary shaft (9), said housing (1 1 ) being closed by a cover (13) on the side of said end (12), said cover (13) having a reserve (16) of collected lubricant, characterized in that an inlet (17) of lubricant from said reserve (16 ) of lubricant collected for said member (10) opens near said scoops (2), on the side of said upstream face (4).

8. Gearbox according to claim 6 or 7, comprising a gearbox housing (1 1) housing a bearing of said primary shaft (9) near one end (12) of said primary shaft (9), characterized in that said end (12) is provided with a screw (18) coaxial and integral with said primary shaft (9), said screw (18) comprising a screw head, and characterized in that said target (1) is fixed around or in said screw head.

9. Gearbox according to claim 6 or 7, comprising a gearbox housing (1 1) housing a bearing of said primary shaft (9) near one end (12) of said primary shaft (9), characterized in that said end (12) is provided with a screw (18) coaxial and integral with said primary shaft (9), said screw (18) comprising a screw head, and characterized in that said target (1) is fixed by tightening said screw (18) between said screw head and said end (12).

10. Gearbox according to claim 8 or 9, characterized in that said member (10) is said bearing of the primary shaft, in particular a primary shaft bearing.