FR3104662A1 - Planet carrier comprising at least one journal mounted floating in the body of the planet carrier - Google Patents

Abstract

The invention relates to a planet carrier comprising a body (19) and at least one journal (12) arranged to carry a planet pinion (11) and ensure rotational guidance of this planet pinion (11). The body (19) of this planet carrier comprises a housing receiving the journal (12) so as to form a fit with radial clearance between the journal (12) and the body (19). This planet carrier comprises at least one axial stop configured to limit the axial displacement of the journal (12) relative to the body (19) at least in one direction of axial translation. The invention also relates to an electric parking brake actuator for a motor vehicle comprising an epicyclic reduction gear having at least one planet carrier according to the invention. Figure for abstract: Fig. 3

Description

Planetary carrier comprising at least one trunnion mounted floating in the body of the planetary carrier

The invention relates to a planet carrier for an epicyclic reduction gear, for example for a motor vehicle electric parking brake actuator or an electric brake.

State of the prior art

A conventional planetary reduction gear comprises one or more planetary gear sets each having a planet carrier carrying one or more planet pinions configured to drive the planet carrier in rotation around an axis under the action of the rotation of a planetary pinion of entry around this same axis. Typically, the planet gears of the first or only train mesh both with the input sun gear and with a coaxial ring gear. Such an assembly results in a difference in rotational speed between the input planetary gear and the planet carrier of this train. When the reducer comprises several reduction stages, that is to say several planetary gear trains mounted in series, the planet carrier of a lower stage can typically carry a planet gear meshing with planet gears of a subsequent stage.

To enable the planet gears to be driven in rotation by a corresponding planet gear, each planet gear is mounted free to rotate on a journal of the planet carrier. Such a trunnion is typically embedded in an opening in the body of the planet carrier so as to immobilize the trunnion relative to the body.

The assembly and disassembly of such a trunnion generally requires the application of a mechanical force likely to damage the trunnion and/or the body and implying in this respect precautions during the assembly and disassembly of these parts.

An object of the invention is to simplify the assembly and disassembly of a journal and of a body of a planet carrier of an epicyclic reduction gear.

To this end, the subject of the invention is a planet carrier for an epicyclic reduction gear, comprising a body and at least one pin arranged to carry a planet pinion and ensure rotational guidance of this planet pinion. According to the invention, the body comprises a housing receiving the at least trunnion so as to form an adjustment with radial play between the at least one trunnion and the body and the planet carrier comprises at least one axial stop configured to limit the axial displacement of the at least one trunnion relative to the body at least in one direction of axial translation.

Typically, within the tolerance system defined by the International Organization for Standardization (ISO), the fit between the at least one trunnion and its recess formed in the body of the planet carrier may be a standardized "H8e8" fit.

Compared with a tight fit, such a sliding fit facilitates the assembly and disassembly of the pinion and the body of the planet carrier while allowing the pin to fulfill its function of guiding in rotation the planet pinion carried by this pin, the displacement axis of the trunnion being limited by at least one axial stop.

Thus, the invention makes it possible to simplify the assembly and disassembly of these parts while limiting the risks of deterioration thereof during these operations.

In one embodiment, the at least one housing may be a cavity, the at least one axial stop comprising a bottom of this cavity.

In one embodiment, the at least one axial stop may comprise at least one face of the body and/or at least one part of the planet carrier axially fixed to the body, such as a cover or a shim.

In one embodiment, the at least one trunnion may comprise at least one shoulder and/or one or more lugs configured to cooperate with the at least one axial stop so as to limit the axial displacement of the at least one trunnion relative to the body at least in one direction of axial translation.

In one embodiment, the planet carrier may comprise at least one part axially secured to the at least one pin, this at least one part being configured to cooperate with the at least one axial stop so as to limit the axial displacement of the at least one trunnion relative to the body at least in one direction of axial translation.

In one embodiment, the body may comprise a first part and a second part axially spaced from each other, a part of the at least one pin or of a part axially fixed to the at least one pin extending between the first and the second part of the body to cooperate with the latter so that each of these parts forms an axial abutment able to limit the axial displacement of the at least one pin relative to the body in a respective direction .

In one embodiment, the planet carrier may comprise a rotation stop member arranged to prevent rotation of the at least one pin relative to the body around an axis of rotation of said planet pinion.

In one embodiment, the at least one axial stop can be configured to limit the axial displacement of the at least one pin relative to the body in two directions of axial translation.

The invention also relates to a planetary gear comprising such a planet carrier, as well as an electric parking brake actuator for a motor vehicle comprising an epicyclic gear having at least one such planetary gear.

The invention also relates to a braking device for a motor vehicle, this braking device comprising an electric parking brake actuator as defined above.

According to a first variant, this braking device may comprise, in addition to the electric parking brake actuator, a main hydraulic braking actuator.

According to a second variant, the braking device may comprise, in addition to the electric parking brake actuator, another main electric braking actuator.

Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows.

The following detailed description refers to the attached drawings in which:

is a partial schematic view in perspective and in longitudinal section of an electric parking brake, comprising an actuator provided with an epicyclic reduction gear according to the invention, the longitudinal section passing through a longitudinal axis around which the various components extend reducer;

is a schematic perspective view of a planet carrier according to the invention, comprising a body and three journals received in respective housings of the body, one of the journals carrying a planet pinion;

is a partial view in longitudinal section of a planetary gear train according to a first embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received on the one hand in a cavity of the body of this planet carrier and on the other hand in a cavity of a cover of this planet carrier, the cavity of the body of the planet carrier forming a first stop limiting the axial displacement of the journal in one direction, the cavity of the cover forming a second stop limiting the axial movement of the journal in the other direction;

is a partial view in longitudinal section of a planetary gear train according to a second embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received on the one hand in an opening passing through the body of this planet carrier and on the other hand in a cavity of a cover of this planet carrier, the planet carrier comprising a shim forming a first stop limiting the axial displacement of the trunnion in one direction, the cavity of the cover forming a second stop limiting the axial movement of the journal in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a third embodiment of the invention, this gear comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received on the one hand in a cavity of the body of this planet carrier and on the other hand in a cavity of a cover of this planet carrier, the cavity of the cover being delimited by a part of the cover forming a crown engaged radially between the journal and the planet gear, the cavity of the body of the planet carrier forming a first stop limiting the axial displacement of the trunnion in one direction, the cavity of the cover forming a second stop limiting the axial displacement of the trunnion in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a fourth embodiment of the invention, this gear comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in a cavity of the body of this planet carrier, the cavity of the body of the planet carrier forming a first stop limiting the axial displacement of the journal in one direction, the planet gear comprising a cavity forming a second stop limiting the axial displacement of the journal in the other direction;

is a partial view in longitudinal section of a planetary gear train according to a fifth embodiment of the invention, this train comprising a planet carrier and a planet gear, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the trunnion comprising a shoulder forming a head cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction;

is a partial view in longitudinal section of an epicyclic gear train according to a sixth embodiment of the invention, this train comprising a planet carrier and a planet gear, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the pin comprising a first shoulder forming a head cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the pin in one direction, the pin comprising a second shoulder forming a pin tail cooperating with the pinion so as to limit the axial movement of the journal in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a seventh embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the pin comprising a shoulder forming a head cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the pin in one direction, the pin comprising elastic lugs cooperating with an internal groove of the planet pinion so as to limit the axial displacement of the pin in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to an eighth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the trunnion comprising a shoulder forming a head cooperating with a first face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction, the trunnion comprising elastic lugs cooperating with a second face of the body of the planet carrier so as to limit the axial movement of the pin in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a ninth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the pin comprising a shoulder forming a head cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the pin in one direction, the planet carrier comprising an elastic washer mounted on the pin and cooperating with an internal groove of the satellite pinion so as to limit the axial movement of the journal in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a tenth embodiment of the invention, this train comprising a planet carrier and a planet gear, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the journal comprising a shoulder forming a head cooperating with a first face of the body of the planet carrier so as to limit the axial displacement of the journal in one direction, the planet carrier comprising an elastic washer mounted on the journal and cooperating with a second face of the body of the planet carrier so as to limit the axial movement of the journal in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to an eleventh embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the trunnion comprising lugs cooperating with an internal groove of the body of the planet carrier so as to limit the axial displacement of the trunnion in both directions;

is a partial view in longitudinal section of an epicyclic gear train according to a twelfth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of the this planet carrier, the trunnion comprising a shoulder forming a head cooperating with a first face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction, the trunnion comprising lugs cooperating with a second face of the body of the planet carrier so as to limit the axial movement of the trunnion in the other direction;

And

are each a partial view in longitudinal section of an epicyclic gear train according to a thirteenth and a fourteenth embodiment of the invention respectively, the train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in a opening passing through the body of this planet carrier, the journal comprising a shoulder forming a head cooperating with a first face of the body of the planet carrier so as to limit the axial displacement of the journal in one direction, the planet carrier comprising a washer mounted on the trunnion and cooperating with a second face of the body of the planet carrier so as to limit the axial displacement of the trunnion in the other direction;

And

are each a partial view in longitudinal section of an epicyclic gear train according to a fifteenth and a sixteenth embodiment of the invention respectively, the train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in a opening passing through the body of this planet carrier, the planet carrier comprising a washer mounted on the trunnion and cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction;

is a partial view in longitudinal section of an epicyclic gear train according to a seventeenth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of this planet carrier, the planet carrier comprising a head attached to the trunnion which cooperates with a first face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction, the trunnion comprising a shoulder cooperating with a second face of the body of the planet carrier so as to limit the axial movement of the pin in the other direction;

,

And

are each a partial view in longitudinal section of an epicyclic gear train according to an eighteenth, a nineteenth and a twentieth embodiment of the invention respectively, the train comprising a planet carrier and a planet pinion, the carrier satellite comprising a journal received in an opening passing through the body of this planet carrier, the journal comprising a flange cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the journal in one direction, the planet carrier of FIG. 22 comprising a pin cooperating with the collar of the journal and with the body of the planet carrier so as to prevent the rotation of the journal about the axis of rotation of the planet gear;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-first embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a body in two parts and a trunnion received in an opening passing axially through the two parts of this body, the trunnion comprising a flange configured axially between the two parts of the body so as to limit the axial movement of the trunnion in both directions;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-second embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a body in two parts and a journal received in an opening passing axially through the two parts of this body, the washer being mounted on the pin and configured axially between the two parts of the body so as to limit the axial displacement of the pin in both directions;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-third embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a body in two parts and a journal received in an opening passing axially through the two parts of this body, the trunnion comprising a radially projecting part cooperating with an internal groove formed by the two parts of the body so as to limit the axial movement of the trunnion in both directions;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-fourth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received on the one hand in an opening passing through the body of this planet carrier and on the other hand in a circumferential groove of the cover, the planet carrier comprising a shim forming a first stop limiting the axial movement of the pin in one direction, the circumferential groove of the cover forming a second stop limiting the axial movement of the trunnion in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-fifth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received on the one hand in an opening passing through the body of this planet carrier and on the other hand in a circumferential groove of the cover, the trunnion comprising a shoulder cooperating with a face of the body of the planet carrier so as to limit the axial displacement of the trunnion in one direction, the circumferential groove of the cover forming a stop limiting the axial movement of the pin in the other direction;

is a partial view in longitudinal section of an epicyclic gear train according to a twenty-sixth embodiment of the invention, this train comprising a planet carrier and a planet pinion, the planet carrier comprising a journal received in an opening passing through the body of this planet carrier, the trunnion comprising a radially projecting part cooperating with an internal groove of the body so as to limit the axial displacement of the trunnion in both directions.

Detailed description of embodiments

The invention relates to brakes or braking devices such as those described in the documents EP1318057, EP2932131, EP2934974, EP2935945, FR2999673 and WO201801583 which are incorporated by reference.

Figure 1 shows an electric parking brake 1 for a motor vehicle (not shown).

In this example, brake1 is a disc brake with a floating caliper2 and an actuator3.

The actuator3 comprises a piston4 movable in translation along a longitudinal axis A1. This piston4 is immobilized in rotation around this longitudinal axis A1 by any conventional means, for example by inserting fingers (not shown) of the caliper2 into notches (not shown) made in the piston4.

In the present description, the expressions “axial”, “longitudinal” or even “axially” refer to the longitudinal axis A1, to the axis of rotation of a satellite pinion along which a corresponding journal extends (see below). -after) or more generally to a direction parallel to these axes.

In a manner known per se, such a brake1 is configured to block the rotation of a brake disc (not shown) by clamping the latter between two friction pads (not shown) so as to generate a braking torque. To do this, the piston4 is moved in translation along the longitudinal axisA1, in a tightening direction going from left to right in figure1. Such a translation of the piston4 allows it to bear against one of the friction pads interposed between the piston4 and the brake disc, applying this pad against a first face of the brake disc. By reaction, the other pad interposed between the disc and a finger5 of the caliper2 forming an axial stop is pressed against a second face of the disc opposite the first face. To free the rotation of the brake disc, the piston4 is moved in translation along the longitudinal axis A1, in a direction of release going from the right to the left in figure1.

To move the piston4 in translation along the longitudinal axisA1, an input torque generated by an electric motor (not shown) is transmitted to the piston4 via planetary reduction gears belonging to the actuator3.

In this example, actuator3 includes an input gearbox6 having a single planetary gear train. This input reducer6 is configured to transmit the rotary motion of the motor shaft (not shown) to a drive shaft7 of a main reducer8 housed in the piston4. The planetary gear train of this input reducer6 makes it possible to drive the drive shaft7 in rotation around the longitudinal axisA1 at a speed of rotation lower than the speed of rotation of the motor shaft.

The drive shaft7 is provided with a first internal planetary gear9 which is integral with the drive shaft7 in rotation around the longitudinal axisA1.

The reducer8 comprises two planetary gear trains mounted in series.

The first planetary gear train of the reducer8 comprises a planet carrier10 and three planet pinions11. The planet carrier10 comprises a body having a central hole through which the drive shaft7 passes as well as three openings offset from the longitudinal axisA1. The satellite carrier10 comprises three journals12 each received in one of these off-centre openings. Each of these trunnions12 carries a respective satellite pinion11 ensuring rotational guidance of this satellite pinion11.

The piston4 forms an outer sun gear of this first planetary gear train. To this end, the piston 4 comprises an internal toothing 13 forming longitudinal grooves circumferentially spaced from each other to mesh with the planet pinions 11.

The planet gears11 meshing both with the first inner planetary gear9 and with the outer sun gear formed by the piston4, the rotation of the drive shaft7 and therefore of the first inner planetary gear9 around the longitudinal axisA1 drives each planetary gear11 d on the one hand in rotation around its trunnion12 and on the other hand along a circumferential trajectory around the longitudinal axis A1, consequently driving the satellite carrier 10 in rotation around the longitudinal axis A1.

The first planetary gear train of the main reduction gear8 thus makes it possible to drive the planet carrier10 in rotation around the longitudinal axisA1 at a speed of rotation lower than the speed of rotation of the drive shaft7.

The planet carrier10 carries a second internal planetary gear14 which are integral with each other in rotation around the longitudinal axisA1. This second inner planetary gear14 drives a second planetary gear train of the reducer8.

The second planetary gear train of the reducer8 includes a planet carrier15 and three planet pinions16. The satellite carrier15 comprises a body with three openings offset from the longitudinal axisA1. The satellite carrier15 comprises three journals17 each received in one of these off-centre openings. Each of these trunnions17 carries a respective satellite gear16 by ensuring rotational guidance of this satellite gear16.

Piston 4 also forms an outer sun gear for this second planetary gear train. More precisely, the longitudinal grooves of the internal toothing 13 are configured to mesh with the satellite pinions 16.

The planet gears16 meshing both with the second inner planetary gear14 and with the outer sun gear formed by the piston4, the rotation of the planet carrier10 and therefore of the second inner planetary gear14 around the longitudinal axisA1 drives each planetary gear16 on the one hand in rotation around its trunnion17 and on the other hand along a circumferential trajectory around the longitudinal axis A1, consequently driving the planet carrier 15 in rotation around the longitudinal axis A1.

The second planetary gear train of the main reduction gear8 thus makes it possible to drive the planet carrier15 in rotation around the longitudinal axisA1 at a speed of rotation lower than the rotation speed of the planet carrier10 and a fortiori of the drive shaft7.

To transform the rotation of the planet carrier 15 into translation of the piston 4, the internal toothing 13 of the piston 4 forms an internal thread which cooperates with an external thread of the planet carrier 15. It results from the cooperation of the outer thread of the planet carrier15 with the inner thread of the piston4 that a displacement of the planet carrier15 in rotation around the longitudinal axisA1 causes a displacement of the piston4 in translation along the longitudinal axisA1, it being understood that the piston4 is configured to slide in a casing18 of the caliper2.

In the example of figure 1, the drive shaft7 extends into the piston4 with one end housed in a cavity of the planet carrier15. Such a configuration makes it possible in particular to keep the drive shaft7 centered on the longitudinal axisA1.

Of course, in order to allow relative rotation of the drive shaft 7 with respect to the various rotating parts through which this drive shaft 7 passes, that is to say the planet carriers 10 and 15 as well as the second internal planetary pinion 14, the drive shaft 7 and the respective orifices of these rotating parts are adjusted to constitute a clearance between the drive shaft 7 and each of these parts.

The invention relates more specifically to the structure of a planet carrier of such a reducer 8 or 6, for example the planet carrier 10 of the first planetary gear train of the reducer 8.

The planet carrier10 is shown in figure 2 with a planet pinion11 carried by one of its three pins12. The satellite pinions carried by the other two journals 12 are not shown in this figure.

Figures 3 to 28 show non-limiting examples of planet carriers in accordance with the invention. As the invention relates to the structural relationship between the pins12 and the body19 of the planet carrier, each of these figures schematically represents a part of the body19 receiving a pin12 so as to illustrate the principle of maintaining this pin12 relative to the body19. Other pins not shown can be connected to the body19 according to the same principle. More generally, the principles illustrated in these figures can be implemented in any planet carrier receiving one or more (2, 3, 4, 5, 6 or more) journals to carry a corresponding planet pinion and ensure its rotational guidance.

In each of the embodiments described below, the body 19 of the planet carrier 10 comprises a housing receiving the trunnion 12 so as to form a fit with radial play between the trunnion 12 and the body 19, that is to say a sliding fit between these parts compared to a press fit as implemented in a conventional planet carrier.

Given this absence of clamping, the housing receiving the pin 12 does not as such allow the pin 12 to be held axially, that is to say along the axis A2 along which the pin 12 extends and which constitutes the axis of rotation of the satellite pinion11 carried by this journal12. The embodiments described below with reference to Figures 3 to 28 form a set of non-limiting solutions for limiting the axial displacement of pin 12 relative to body 19, at least in one direction of axial translation.

A first type of solution making it possible to limit the axial displacement of the pin 12 relative to the body 19 consists in making the housing for the pin 12 in the form of a cavity, that is to say in the form of a hollow space made in the body19. Such a hollow space is axially delimited by a cavity bottom 20 which forms an axial stop for the journal 12.

In the embodiments of Figures 3, 5 and 6, the body 19 of the planet carrier comprises such a cavity, the bottom 20 of which makes it possible to limit the axial displacement of the pin 12 relative to the body 19 in a first direction going from top to bottom in these figures.

In the examples of figures 4 and 7 to 28, the housing of the journal 12 consists of an opening passing axially through the body 19, that is to say opening out both on a first face 21 and on a second face 22 of the body 19, these faces 21 and 22 being opposite relative to each other along axis A2. In these examples, the housing of the trunnion 12 does not as such limit the axial displacement of the trunnion 12 relative to the body 19.

The description which follows proposes several solutions making it possible to limit the axial displacement of the journal 12 relative to the body 19 when the journal housing 12 forms such an opening.

In the examples of Figures 4 and 26, an axial stop is formed by a shim 23 placed facing the first face 21 of the body 19.

In the example of Figure 8, the journal 12 comprises a peened end 24 configured to allow cooperation of this end 24 with an outer face 25 of the planet pinion 11, this outer face 25 forming in this example an axial stop.

In the example of figure 9, an axial stop is formed by advantageously elastic lugs 26 machined on the journal 12, these lugs 26 being configured to cooperate with an internal circumferential groove 27 of the planet pinion 11. In this example, the lugs26 form oblique legs with respect to the axisA2. The elasticity of the lugs26 results from their geometry, the lugs26 being sized to be deformed by the satellite pinion 11 during its engagement on the journal 12 and its displacement on the latter to a relative axial position in which the lugs26 are axially located. next to the groove27 of the pinion11 and can thus be deployed in the groove27 according to the configuration of figure9. The trunnion 12 can for example comprise four elastic lugs 26 two by two spaced apart by pi/2 radians on the periphery of the trunnion 12. The lugs26 make it possible to limit the axial displacement of the pin 12 relative to the body 19 in said first direction by cooperating with the groove 27 of the pinion 11 which cooperates, if necessary, with the second face 22 of the body 19.

In the example of figure 10, an axial stop is formed by advantageously elastic lugs 26 similar to those of figure 9 but configured to cooperate with the second face 22 of body 19. In this example, a groove is made in the satellite pinion11 in order to avoid its interference with the lugs26 when the pinion11 is assembled on the journal12 (see figure10).

In the example of figure 11, an advantageously elastic washer 28 is clamped on the journal 12 and configured to cooperate with an internal circumferential groove 27 of the planet pinion 11. The elastic washer 28 is dimensioned so that, before the engagement of the satellite pinion 11 on the trunnion 12, this washer can be inserted into the groove 27 of the pinion 11 then, when the sprocket 11 is fitted on the trunnion 12 and its displacement thereon until in the assembly position of figure 11, this washer can slide on the journal 12 while being driven by the pinion 11, then, above all, when the pinion 11 is in said assembly position, this washer can enclose the journal 12 with a tightening force sufficient to hold the pinion axially11. The elastic washer 28 makes it possible to limit the axial displacement of the journal 12 relative to the body 19 in said first direction by cooperating with the groove 27 of the pinion 11 which cooperates, if necessary, with the second face 22 of the body 19.

In the example of figure 12, a spring washer 28 similar to that of figure 11 is configured to cooperate with the second face 22 of body 19. In this case, the spring washer 28 is preferably positioned on the pin 12 before the pinion 11 is fitted on the latter. In this example, a chamfer is made on the pinion 11 in order to avoid its interference with the spring washer 28 when the pinion 11 is assembled on the journal 12 (see figure 12).

In the example in figure 14, lugs 26 are machined on the journal 12, these lugs 26 being configured to cooperate with the second face 22 of the body 19. The lugs 26 in FIG. 14 form spherical portions. In this example, a groove is made in the satellite pinion11 in order to avoid its interference with the lugs26 when the pinion11 is assembled on the journal12 (see figure14). The spherical shape of the lugs make them not very deformable or even non-deformable. However, the insertion of the pin12 into its housing in the body19 is possible given the radial clearance provided between this pin12 and the body19. To facilitate the insertion of the trunnion12 into its housing given the presence of the lugs26, the body19 in this example includes a chamfer enabling the lugs26 to engage in the trunnion housing (see figure14).

In the embodiments of Figures 15 to 18, a washer 30 is tightly mounted on the pin 12 so as to cooperate with the second face 22 of the body 19, this face 22 thus forming an axial stop. The washer 30 can be interposed axially between the body 19 and the satellite pinion 11 without radial superimposition of the washer 30 and the pinion 11, as in the examples of figures 16 and 18. Alternatively, the washer 30 can be received in a groove of the planet pinion 11 (FIGS. 15 and 17).

In the examples of figures 19 and 27, pin 12 comprises a shoulder 31 defining a face configured to cooperate with second face 22 of body 19, the latter thus forming an axial stop. In this case, the journal 12 is inserted into the housing of the body 19 according to an axial translation going from the second 22 to the first face 21 of the body 19.

In the embodiments of FIGS. 20 to 22, pin 12 comprises a collar 32 formed thereon, this collar 32 being configured so as to cooperate with the second face 22 of body 19 forming an axial stop. In the example of figure 20, the satellite pinion 11 comprises a groove in which the collar 32 is housed, unlike the examples of figures 21 and 22 in which the pinion 11 and the collar 32 do not include any common part located in the same axial plane. In the example of figure22, a pin33 fixed to the body19 passes through the flange32 so as to prevent the rotation of the pin12 around the axisA2.

In each of the examples which have just been described, a means is implemented to cooperate with an axial stop formed by the body 19 of the planet carrier and/or by the planet pinion 11 so as to limit the axial displacement of the journal 12 with respect to the corps19 in said first direction (from top to bottom in the corresponding figures).

Such means can be combined with at least one other means configured to limit the axial displacement of pin 12 relative to body 19 in a second direction opposite to the first direction, in this case from bottom to top in the corresponding figures.

Thus, in the embodiments of Figures 3 to 5, and 26 and 27, a cover 36 axially fixed to body 19 is arranged facing body 19 so as to cooperate with one end of pin 12 opposite the end housed in body 19.

In the examples of figures 3 and 4, the cover 36 comprises a cavity, that is to say a hollow space axially delimited by a bottom of the cavity 37 forming an axial stop limiting the axial displacement of the journal 12 with respect to the body 19 in said second direction.

The embodiment of figure 5 makes it possible to obtain the same function with another cover geometry. In this example, the cover36 comprises a crown extending radially between the journal12 and a groove made in the satellite pinion11. This crown forms a cavity having a cavity bottom 37 forming an axial stop. Such a crown makes it possible to obtain a better alignment of the pin12 than the cavity of the cover36 of figures 3 and 4.

In the examples of Figures 26 and 27, the cover 36 comprises a circumferential groove having a bottom 38 also forming an abutment limiting the axial displacement of the pin 12 relative to the body 19 in the second direction.

The cover can thus be configured so that the circumferential groove is common to several pins 12 of the same planet carrier 10.

The function of limiting the axial displacement of the trunnion12 relative to the body19 in the second direction can also be obtained by cooperation of a head39 of the trunnion12 with an axial stop formed by the first face21 of the body19.

In the examples of Figures 7 to 12 and 14 to 16, the head39 is formed by a shoulder of the pin12.

In the example of figure 19, the head39 is a piece attached to one end of the trunnion12. In this example, the head 39 is advantageously fixed by crimping to the trunnion 12 after insertion of the latter into the corresponding housing of the body 19, given the presence of the shoulder 31 which prohibits the insertion of the trunnion 12 by axial translation in a direction going from the first21 to the second side22.

In the configuration of FIG. 6, the planet pinion 11 comprises a journal housing that does not cross this pinion axially right through. This housing thus forms a cavity having a bottom 40 forming an axial stop limiting the axial displacement of the journal 12 relative to the body 19 in the second direction.

In other embodiments such as those illustrated in Figures 13, 23 to 25 and 28, a single means can be configured to form a double axial stop limiting the axial displacement of the pin 12 relative to the body 19 both in the first and in the second sense.

In the example of figure 13, an axial stop is formed by lugs26 similar to those of figure 14 described above. In this example, the lugs26 are configured to cooperate with an internal circumferential groove29 of the body19. The body19 in this example includes a chamfer allowing the lugs26 to be engaged in the pin housing in order to facilitate the assembly of the pin12 and the body19 of the planet carrier (see figure13, and description of figure14 above).

Another type of solution, illustrated in figures 23 and 24, consists in making the body 19 in two parts, more precisely in a first part 34 and a second part 35 defining axially between them a space in which is inserted a collar 32 of the pin 12 (figure 23) – this collar 32 being similar to that of figure 21 – or a washer 30 (figure 24) mounted tight on the trunnion 12 – this washer 30 being similar to that of figure 16. This collar 32 or this washer 30 thus cooperates with respective faces of the first 34 and of the second part 35 of the body 19, each of these faces forming an axial stop in a respective direction.

The parts34 and35 of the body19 are integral with each other, axially and radially.

In the example of figure 25, pin 12 comprises a shoulder 41 forming a crown extending circumferentially projecting on the periphery of pin 12 so as to cooperate with an internal circumferential groove 29 of body 19. To allow the assembly of the pin12 with the body19, the latter comprises a first part34 assembled with the pin12 during a first step, and a second part35 assembled with the pin12 and fixed to the first part34 during a second step. The ring 41 of the journal 12 cooperates with the groove 29 constituted by the coupling of the parts 34 and 35 of the body 19 which together form a double axial stop.

Figure 28 illustrates an embodiment which differs from that of Figure 25 in that the body 19 is made in one piece. In this case, the assembly of the pin12 with the body19 can be achieved by thermal expansion or by overmolding the body19 on the pin12.

The embodiments which have just been described are in no way limiting, the planet carrier of the invention possibly comprising one or more axial pin retention means operating according to the principles which emerge from these examples. The invention covers in particular any planet carrier having one or more axial stops formed by the body of this planet carrier and/or by a cover and/or by a shim and/or by any other part configured to cooperate with one or more elements integral with the trunnion or the component, these elements possibly comprising one or both end faces of the trunnion and/or a shoulder and/or one or more lugs and/or one or more lugs and/or a washer having or not elastic properties.

Furthermore, the invention also covers a planet carrier assembled so that the trunnion 12 is capable of moderate axial translation between two axial stops configured to each limit in a respective direction the axial displacement of the trunnion 12 relative to the body 19. A certain freedom of axial movement of the trunnion12 may in some cases be desirable to allow the proper operation of this planet carrier and, in any case, does not in itself and a priori hinder its proper operation. In certain embodiments, a certain freedom of axial movement of the trunnion 12 is moreover necessary for the operation of the planet carrier, in this case in the embodiments of FIGS. 8, 9 and 11. In general, the stop(s) axles implemented in the invention are essentially intended to maintain the journal 12 with more or less precision around an axial position, relative to the body 19 and the planet pinion 11, allowing the planet carrier to operate.

Nomenclature

A1 longitudinal axis

A2 planet gear rotation axis

1 electric parking brake

2 stirrup

3 actuator

4 piston / outer planetary

5 caliper finger / axial stop

6 planetary input reducer

7 drive shaft

8 main planetary gearbox

9 first inner planetary gear of the main reducer

10 planet carrier of the first planetary gear set of the main gearbox

11 satellite pinions of the first epicyclic gear train of the main reducer

12 planet carrier trunnions10

13 internal gearing of the outer sun gear

14 second main reducer inner planetary gear

15 planet carrier of the second planetary gear of the main gearbox

16 planet gears of the second epicyclic gear train of the main reducer

17 planet carrier trunnions15

18 caliper housing

19 carrier body10

20 trunnion housing cavity bottom

21 first side of planet carrier body

22 second side of planet carrier body

23 tinsel

24 peened trunnion end

25 planet gear outer face

26 trunnion lugs

27 pinion gear internal circumferential groove

28 spring washer

29 planet carrier body inner circumferential groove

30 puck

31 trunnion shoulder

32 trunnion collar

33 anti-rotation device/pin

34 first planet carrier body part

35 second planet carrier body part

36 lid

37 lid cavity bottom

38 lid throat bottom

39 trunnion head

40 planet gear cavity bottom

41 trunnion shoulder/crown

Claims (11)

Planet carrier (10) for epicyclic reduction gear (8), comprising a body (19) and at least one journal (12) arranged to carry a planet pinion (11) and ensure rotational guidance of this planet pinion (11), this planet carrier (10) being characterized in that the body (19) comprises a housing receiving the at least trunnion (12) so as to form a fit with radial play between the at least one trunnion (12) and the body (19), and in that it comprises at least one axial stop configured to limit the axial displacement of the at least one pin (12) relative to the body (19) at least in one direction of axial translation. Planet carrier (10) according to claim 1, in which the at least one housing is a cavity, the at least one axial stop comprising a bottom (20) of this cavity. Planet carrier (10) according to Claim 1 or 2, in which the at least one axial abutment comprises at least one face (21, 22) of the body (19) and/or at least one part of the planet carrier (10) axially integral with the body (19) such as a lid (36) or a foil (23). Planet carrier (10) according to any one of Claims 1 to 3, in which the at least one journal (12) comprises at least one shoulder (24, 31, 32, 39, 41) and/or one or more lugs ( 26) configured to cooperate with the at least one axial stop so as to limit the axial displacement of the at least one pin (12) relative to the body (19) at least in one direction of axial translation. Planet carrier (10) according to any one of claims 1 to 4, comprising at least one part (28, 30, 39) axially secured to the at least one pin (12), this at least one part (28, 30, 39) being configured to cooperate with the at least one axial stop so as to limit the axial displacement of the at least one pin (12) relative to the body (19) at least in one direction of axial translation. Planet carrier (10) according to any one of claims 1 to 5, in which the body (19) comprises a first part (34) and a second part (35) axially spaced from each other, a part (32 ) of the at least one journal (12) or of a part (30) axially integral with the at least one journal (12) extending between the first (34) and the second part (35) of the body ( 19) to cooperate with them so that each of these parts (34, 35) forms an axial stop capable of limiting the axial displacement of the at least one journal (12) relative to the body (19) in one direction respective. Planet carrier (10) according to any one of claims 1 to 6, comprising a rotation stop member (33) arranged to prevent rotation of the at least one pin (12) relative to the body (19) around an axis of rotation (A2) of said planet pinion (11). Planet carrier (10) according to any one of claims 1 to 7, in which the at least one axial stop is configured to limit the axial displacement of the at least one trunnion (12) relative to the body (19) in two direction of axial translation. Planetary gear comprising a planet carrier (10) according to any one of claims 1 to 8. Actuator (3) for an electric parking brake (1) for a motor vehicle, comprising an planetary reduction gear (8) having at least one planetary gear train according to claim 9. Braking device for a motor vehicle, this braking device comprising an electric parking brake (1) comprising an actuator (3) according to claim 10.