Coupling device for splined parts of a mechanical assembly.

Abstract

A mechanical assembly comprising two parts, namely a sliding sleeve (1) and a shaft (8) having a main axis (X1), and a coupling sleeve mounted on the sliding sleeve and arranged to allow the transmission of a rotational motion between the two parts. The sleeve has a surface with splines (3.1.1, 3.1.2) to engage with splines (8.1) on the shaft and with raised features to form a helical connection along the main axis X1 with the raised features of the sliding sleeve, so as to convert a translational motion about the main axis of the sleeve relative to the shaft into at least one rotational motion about the main axis in order to facilitate the engagement of the splines of the sleeve and the shaft regardless of the angular positions of the main parts. An actuator and a vehicle comprising such a mechanical assembly. FIGURE IN THE ABRIDGED: Fig. 4

Description

Title of the invention: Coupling device for grooved parts of a mechanical assembly.

[0001] The present invention relates to the field of mechanics and more particularly to that of rotating couplings.

[0002] BACKGROUND OF THE INVENTION

[0003] Mechanical assemblies containing elements for transmitting rotational motion between two parts are known. An example of such a transmission is the use of splines to transmit rotational motion between a shaft and a hub. In this configuration, the shaft is splined externally and the hub is splined internally, so that they can mesh together. It should be noted that an externally splined shaft has external splines, the splines being longitudinal grooves, each separated from the adjacent spline by a longitudinal tooth designed to engage with an internal spline of the hub. The internal splines of the hub are each separated from the adjacent spline by a tooth designed to engage with one of the external splines of the shaft. In common parlance, the term "spline" refers indifferently to the spline itself or to the tooth bordered by two splines.

[0004] This spline engagement often results in the coupling of a splined slider moving axially on a splined shaft. This coupling requires alignment of the teeth and splines so that the slider can engage with the shaft splines. This operation can be performed manually by an operator when the mechanism is stationary. When the mechanism is in motion, the slider's engagement is possible and commonly facilitated by releasing a brake, thus freeing the rotation of one of the parts, and by machining the spline inlets to flare out (and thereby chamfer the ends of the teeth) to aid the teeth's engagement in the splines. This method is not optimal because it is subject to trial and error and is not without risk to the operator.

[0005] SUBJECT OF THE INVENTION

[0006] The invention is notably aimed at improving the mutual engagement of grooved parts. Summary of the invention

[0007] To this end, the invention provides a mechanical assembly comprising a first main part and a second main part, substantially cylindrical about a principal axis, and a substantially annular connecting element, the connecting element being a coupling sleeve mounted on the first main part and arranged to allow the transmission of a rotational movement between the first main part and the second main part, characterized in that the sleeve has an internal surface and an external surface, a first of these surfaces is provided with grooves to collaborate with grooves present on the second main part in order to transmit the rotational movement between the sleeve and the second main part, the first main part and the second surface of the sleeve comprise reliefs arranged to collaborate mutually by forming a helical connection along axis XI,so as to convert a translational movement along the XI axis of the sleeve relative to the first main part into at least one rotational movement along the XI axis in order to facilitate the engagement of the splines of the sleeve and the second main part regardless of the angular positions and the freedom of rotation of the main parts during the relative engagement of the sleeve and the second main part.

[0008] Thus, the invention is a mechanical assembly by means of splines of a first main part such as a shaft and of a second main part such as a hub (or vice versa) allowing to promote the mutual engagement, along a main axis, of the splines carried by the shaft and of the splines carried by the hub, regardless of the angular position of the hub or of the shaft around the main axis.

[0009] According to optional features, used individually or in whole or in combination: - the first main part includes a bore, housing the socket and the second main part, the bore having an inner surface provided with one of the reliefs forming the helical connection along axis XI; - the reliefs forming the helical connection include a helical groove extending over the outer surface of the sleeve, and an outgrowth extending from the inner surface of the first main part to cooperate with the helical groove during the movement of the sleeve in order to impose a helical movement on said sleeve; - the sleeve is mobile in the bore of the first element according to a helical displacement along the axis XI, between an advanced position close to one end of the main part through which the second main part is introduced into the bore, and a receding position far from said end of the main part; - the assembly includes a spring mounted between a stop and the socket to return the socket to the forward position; - the first main part has an outer surface equipped with a wheel linking said first main part in rotation to at least one auxiliary part; - the wheel includes grooves arranged on an inner surface and capable of collaborating with outer grooves present on the outer face of the first main part.

[0010] The invention also includes an actuator comprising a driving shaft and a driven shaft forming the main parts of a mechanical assembly as defined above.

[0011] The invention also includes a vehicle comprising such an actuator.

[0012] Other features and advantages of the invention will become apparent from the following description of particular and non-limiting embodiments of the invention. Brief description of the drawings

[0013] Reference will be made to the attached drawings, among which:

[0014] [Fig-1] is a cross-sectional view of a hub forming a sliding part of a mechanical assembly according to the invention, according to a first embodiment;

[0015] [Fig. 2a] is a first perspective view of a hood intended to be placed on the portable player;

[0016] [Fig. 2b] is a second perspective view of the hood of [Fig. 2a];

[0017] [Fig.3] is a perspective view of a coupling socket fitted to the portable to form the mechanical assembly according to the invention;

[0018] [Fig.4] is a perspective and longitudinal sectional view of the assembly mechanical according to the invention, comprising the player and a shaft;

[0019] [Fig.5] is a perspective view of this tree;

[0020] [Fig.6] is an axial cross-sectional view of the coupling sleeve;

[0021] [Fig.7] is a partial axial cross-sectional view of the portable player;

[0022] [Fig. 8a] is an axial cross-sectional view showing the beginning of the insertion of the shaft into the slider;

[0023] [Fig. 8b] is an axial cross-sectional view showing the end of the insertion of the shaft into the slider;

[0024] [Fig.9] is an axial cross-sectional view showing an example of integration of the invention in a rotating assembly;

[0025] [Fig. 10a] is an axial cross-sectional view of the assembly according to a second embodiment;

[0026] [Fig. 10b] is a cross-sectional view of part of the assembly according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] With reference to [Fig. 1], the invention relates to a mechanism for assembling a first main part and a second main part. The first main part is a slider 1 of substantially tubular shape along a main axis XI. The slider 1 has a main body 2 comprising a tubular part 2.1 having a first end 2.2 and a second end 2.3 here both open, an outer surface 2.4, and an inner surface 2.5 delimiting a bore 2.5.1.

[0028] The outer surface 2.4 is provided at the first end 2.2 with a collar 2.6 extending radially. This collar 2.6 has an annular face 2.6.1 normal to the axis XI forming a front face of the main body 2.

[0029] The inner surface 2.5 is provided with an annular step 2.7, projecting inwards, forming a shoulder in the bore 2.5.1, and with two cylindrical protrusions 2.8 extending from the inner surface 2.5 towards the inside of the bore 2.5.1.

[0030] According to the first embodiment shown in Figures 2 to 8b, the bore 2.5.1 of the slider 1 receives, by sliding and rotating about the axis XI, a coupling sleeve 3 of substantially annular shape with a circular cross-section centered on the axis XL. The coupling sleeve 3 comprises an inner face 3.1, an outer face 3.2, a first end 3.3 and a second end 3.4.

[0031] The internal surface 3.1 of the coupling sleeve 3 is provided with grooves. These grooves comprise an alternation of longitudinal teeth 3.1.1 and longitudinal grooves 3.1.2 extending along the axis XI from one end to the other of the coupling sleeve 3. At the first end 3.3, the longitudinal teeth 3.1.1 have an upper chamfer 3.1.3.

[0032] The external surface 3.2 of the coupling sleeve 3 has two helical grooves 3.5 having a constant width and extending around and along the coupling sleeve 3 from one end to the other of the coupling sleeve 3. The width of the grooves 3.5 is greater than the diameter of the protrusions 2.8 present on the internal surface 2.5 of the main body 2. In addition, these grooves 3.5 have a depth greater than the height of these same protrusions 2.8.

[0033] When installing the coupling sleeve 3 in the bore 2.5.1 of the main body 2, each protrusion 2.8 is positioned in one of the helical grooves 3.5.

[0034] With particular reference to figures 2a and 2b, the portable player 1 also includes a cover 4 having a discoidal base 4.1 comprising a first face 4.1.1, a second face 4.1.2 and an internal cylindrical face 4.1.3. The cover 4 includes an annular part 4.2 extending coaxially to the base 4.1 and perpendicularly from the first face 4.1.1 of the base and having a face with an internal cylindrical surface in line with the internal cylindrical surface 4.1.3.

[0035] The hood 4 is positioned at the first end 2.2 of the main body 2, along the axis XI, the annular part 4.2 is inserted into the bore 2.5.1 of the slider 1, the first face 4.1.1 being placed against the face 2.6.1 of the main body 2.

[0036] The cover 4 is held in position by screws 5, for example, three of them. The screws 5 pass through the base of the cover 4 and are screwed into threaded holes 4.3 in the collar 2.6 of the main body 2.

[0037] A compression spring 6 is disposed inside the bore 2.5.1 along the axis XL. This spring 6 has a first end 6.1 placed in contact with the second end 3.4 of the coupling sleeve 3, and a second end 6.2 in contact with the annular part 4.2 of the hood 4.

[0038] The spring 6 is thus arranged to apply a constraint to the coupling sleeve 3 along the axis XI in the direction of the second end 2.3 of the main body 2 to press the coupling sleeve 3 against the step 2.7.

[0039] A transmission wheel 7 is assembled here around the main body 2, which is fixed and rotates relative to it. Splines 2.10 positioned on the outer surface 2.4 of the tubular portion 2.1 of the main body 2 of the sliding bearing 1 cooperate with internal splines 7.1 belonging to the wheel 7. The engagement of the splines 2.10 of the sliding bearing and the splines 7.1 of the wheel 7 allows the transmission of a rotational motion between said sliding bearing 1 and said wheel 7, while also permitting axial movement of the sliding bearing 1 relative to the wheel 7. This wheel 7 is intended to transmit this rotational motion to another part of the mechanism, and for example to an auxiliary part such as a gear meshing with the wheel 7, a pulley driven by the wheel 7 via a chain or belt, a crank linked in rotation to the wheel 7, etc.

[0040] The second main part is a transmission shaft 8, visible in figures 4 to 8b, having a splined end section provided with external splines 8.1, comprising longitudinal teeth 8.1.1 and longitudinal grooves 8.1.2.

[0041] The shaft 8 has a chamfer 8.2 at the level of the grooved end section, extending over each of the longitudinal teeth 8.1.1.

[0042] The grooved end section of the shaft 8 is suitable for being inserted into the slider 1 by the second open end 2.3 of the main body 2, along the direction of the axis XI (see [Fig.4]).

[0043] When the shaft 8 is inserted into the bore 2.5.1 of the main body, it moves in translation along the axis XI and possibly in rotation around this same axis XL. At some point during its translation, the shaft 8 comes into contact with the first end 3.3 of the coupling sleeve 3 (see [Fig. 8a]).

[0044] At this moment, if the longitudinal grooves 3.1.2 of the splines of the coupling sleeve 3 are aligned with the longitudinal teeth 8.1.1 of the splines 8.1 of the shaft 8 so that it can engage with the shaft, the shaft 8 continues its translation until the coupling sleeve 3 and the shaft 8 are meshed (see [Fig. 8b]). Note that it is possible to determine a maximum axial stroke of the coupling sleeve 3 to guarantee the engagement of the shaft 8 in the coupling sleeve 3 as a function of the stiffness of the spring 6 and the angle of the helical grooves 3.5.

[0045] If the splines of the coupling sleeve 3 and the shaft 8 are not aligned and the translation of the shaft 8 creates a contact between the longitudinal teeth 8.1.1 of the splines of said shaft 8 and the longitudinal teeth 3.1.1 of said coupling sleeve 3, the shaft 8 exerts an axial thrust on the coupling sleeve 3.

[0046] The coupling sleeve 3 being held in axial position by the spring 6, if the thrust of the shaft 8 on the first end 3.3 of the coupling sleeve 3 is greater than the thrust produced by the spring 6 on the second end 3.4 of the coupling sleeve 3 then, said coupling sleeve 3 makes a translational movement along the axis XI towards the first end 2.2 of the main body 2 against the force exerted by the spring 6.

[0047] When the coupling sleeve 3 makes its translational movement, the protrusions 2.8 belonging to the inner surface of the main body 2 and positioned in the helical grooves 3.5 of the outer surface 3.2 of the coupling sleeve 3 impose on the coupling sleeve 3 a rotation which combines with the translational movement to cause a helical movement of the coupling sleeve 3 along the axis XL. Indeed, each helical groove 3.5 present on the outer surface 3.2 of the sleeve 3 acts as a cam track along which the protrusion 2.8 moves.

[0048] During the helical movement of the coupling sleeve 3, the shaft 8, in relative axial displacement with respect to the sliding sleeve 1, remains in contact with the first end 3.3 of said coupling sleeve 3: the movement of the coupling sleeve 3 with respect to the shaft 8 is a rotation about the axis XL

[0049] During this rotation, the internal splines of the coupling sleeve 3 rotate relative to the splines 8.1 of the shaft 8 along the axis XI, until the alignment of these splines is achieved, i.e., when the longitudinal grooves 3.1.2 of the coupling sleeve 3 are opposite the longitudinal teeth 8.1.1. When the splines are thus aligned, the spring 6 continues to apply a constraint to the coupling sleeve 3 towards the step 2.7, holding it in its position while the splined end of the shaft 8 engages in the splines of the sleeve 3. When the coupling is no longer loaded, the spring 6 can push the coupling sleeve 3 back to the step 2.7.

[0050] This mechanical assembly thus allows the rotational coupling of the shaft 8 in the slider 1, regardless of the angular orientation of the shaft 8 with respect to the slider 1.

[0051] Once engaged, the rotational movement of the shaft 8 is transmitted to the coupling sleeve 3 which transmits the rotational movement to the main body 2 of the slider 1, which in turn transmits this rotational movement to the wheel 7.

[0052] Indeed, the angle formed by each helical groove 3.5 of the coupling sleeve 3 and the axis XI is sufficiently small both so that a translational movement applied to the coupling sleeve 3 can be converted into a rotational movement, and so that a rotational movement applied to the coupling sleeve 3 cannot be converted into a translational movement. Thus, the rotation applied by the shaft 8 to the coupling sleeve 3 is directly transmitted to the main body 2.

[0053] The use of the invention is envisaged within a vehicle between a driving shaft and a driven shaft of an actuator such as that of a clutch.

[0054] In particular, it is possible to implement this mechanical assembly on a motor shaft in order to engage or disengage it from a rotating drive to place or not the actuator in a maintenance mode.

[0055] It is also envisaged that the player 1 of the assembly can be operated by means of a lever applying a translational movement to it.

[0056] With reference to [Fig. 9], an example of an implementation of the invention in a vehicle actuator is disclosed, in which the sliding element is placed in the center of a housing, the body of the sliding element being mounted for rotation relative to the housing and connected to a gear. In this configuration, it is envisaged that the cover could be replaced by a retaining ring (for example, a spring ring) positioned in a groove to retain the spring. It is also envisaged in this example that the driving shaft, having external splines that cooperate with the coupling sleeve 3, is provided with an internal bore along its axis, having an inner surface with splines.

[0057] According to the second embodiment shown in figures 10a and 10b, the slider includes, in addition to the coupling sleeve 3, an outer sleeve 3' mounted for rotation and translation around the main body 2'.

[0058] The outer sleeve 3' comprises an inner face 3.1', and an outer face 3.2'.

[0059] The outer surface 3.2' of the outer sleeve 3' is provided with grooves. The 3.1' internal surface of the 3' coupling sleeve has two 3.5' helical grooves of constant width extending around and along the 3' coupling sleeve.

[0060] In this embodiment, the main body 2' has on its outer face 2.4 two protrusions 2.8' similar to the protrusions 2.8 of the first embodiment. These protrusions 2.8', just as in the first embodiment, are positioned in the helical groove 3.5' of the outer sleeve 3'.

[0061] A spring 6' is arranged to apply a constraint to the sleeve 3' along the axis XI in the direction of the first end 2.3 of the main body 2', in a manner similar to the spring 6 of the first embodiment, to press the coupling sleeve 3' against an axial stop linked to the main body 2'. The spring 6' is placed between said sleeve 3' and a retaining ring 10'.

[0062] The sleeve 3 of the second embodiment comprising internal grooves differs from the sleeve 3 of the first embodiment in that it has a guide groove 3.6' extending beyond the other internal grooves (3.1.1 and 3.1.2 in the first embodiment) and protruding from said sleeve 3. This guide groove 3.6' has a beveled end 3.6.1', forming a point.

[0063] During the insertion of the shaft 8, this beveled end 3.6.1' faces the splines of the shaft 8, which also have a similarly beveled end. Thus, the guide spline 3.6' comes into contact with one of the splines of the shaft 8, each at its beveled end, and their beveled (pointed) shape allows the guide sleeve 3.6' to pass to one side or the other of the spline of the shaft 8 it encounters.

[0064] Therefore, depending on which side of the shaft spline 8 the guide spline 3.6' passes through, the bushing 3 is rotated in two possible directions, and three events can then occur: - if the sleeve 3 is made to rotate in a first direction of rotation corresponding to the direction provided by its helical connection described previously, according to an operating logic analogous to the coupling sleeve 3 of the first embodiment, only the sleeve 3 will perform the rotational movement around the X axis combined with a translational movement thanks to said helical connection, and this, until the splines of the sleeve 3 are inserted into those of the shaft 8; - if the sleeve 3 is caused to rotate in a second direction corresponding to the opposite direction to that provided by its helical connection, it will then drive with it the main body 2', which, collaborating with the outer sleeve 3' by a helical connection similar to that of the sleeve 3 but oriented to operate in the second direction of rotation, will induce in this outer sleeve 3' a rotational movement in this second direction of rotation combined with a translational movement, and this until the splines of the sleeve 3 are inserted into those of the shaft 8; - if the chamfered ends of the guide splines 3.6' and the shaft 8 are perfectly aligned, a difference in stiffness between the springs collaborating with the bushings 3 and 3' will allow the bushing 3 to rotate in a specific direction, in order to ensure the insertion of the splines of the bushing 3 into those of the shaft 8.

[0065] The main body 2' is here placed against a control shaft 9' at its first end 2.1'.

[0066] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0067] In particular, although in the invention the number of protrusions 2.8 and helical grooves is two, more or fewer protrusions and helical grooves can be provided.

[0068] Although the protrusions 2.8 have a cylindrical shape, it is possible that these protrusions have another shape that can collaborate with the groove on the outer surface of the coupling sleeve, such as a hemisphere for example; it can also be a helical tab which would amount to a screw bolt device between the coupling sleeve and the main body.

[0069] The mechanical assembly according to the invention is usable in any type of mechanism, and in particular in an actuator, a brake, a clutch, a motor...

[0070] The mechanical assembly according to the invention is applicable to all types of vehicles, and in particular to aerial, land, marine vehicles...

Claims

Demands

1. Mechanical assembly comprising a first main part (1) and a second main part (8) substantially cylindrical about a principal axis (XI), and at least one connecting element (3) substantially annular, the connecting element being a coupling sleeve mounted on the first main part and arranged to allow the transmission of a rotational motion between the first main part and the second main part, characterized in that the sleeve has an internal surface (3.1) and an external surface (3.2), a first of these surfaces is provided with grooves (3.1.1, 3.1.2) to collaborate with grooves (8.1) present on the second main part in order to transmit the rotational motion between the sleeve and the second main part, the first main part and the second surface of the sleeve comprise reliefs (2.8, 3.5) arranged to collaborate mutually by forming a helical link along the main axis, so as to convert a translational movement along the main axis of the bushing relative to the first main part into at least one rotational movement around the main axis in order to promote the engagement of the splines of the bushing and the second main part regardless of the angular positions and rotational freedom of the main parts during the relative engagement of the bushing and the second main part.

2. Mechanical assembly according to the preceding claim, wherein the first main part comprises a bore (2.5.1), receiving the bushing and the second main part, the bore having an inner surface (2.5) provided with one of the reliefs (2.8) forming the helical connection along the axis XI.

3. Mechanical assembly according to claim 2, wherein the reliefs forming the helical connection comprise a helical groove (3.5) extending over the outer surface of the bushing, and an outgrowth (2.8) extending from the inner surface of the first main part to cooperate with the helical groove during the movement of the bushing in order to impose a helical movement on said bushing.

4. Mechanical assembly according to any one of claims 2 and 3, wherein the bushing is movable in the bore of the first element according to a helical displacement along the main axis (XI), between an advanced position close to one end of the main part through which the second main part is introduced into the bore, and a recoiled position far from said end of the main part.

5. Mechanical assembly according to claim 4, comprising a spring (6) mounted between a stop and the bushing to return the bushing to the forward position.

6. Mechanical assembly according to any one of the preceding claims, wherein the first main part has an outer surface (2.4) equipped with a wheel (7) connecting said first main part in rotation to at least one auxiliary part.

7. Mechanical assembly according to claim 6, wherein the wheel comprises splines arranged on an inner surface and capable of collaborating with outer splines (2.10) present on the outer face of the first main part.

8. Actuator comprising a driving shaft and a driven shaft forming the main parts of a mechanical assembly according to any one of the preceding claims.

9. Vehicle comprising an actuator according to claim 8.

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