Reduction gear comprising a central axis and transmission elements that are superimposed and centred via the axis

Abstract

The invention relates to a reduction gear (3) for a geared motor (1) comprising a central axis (50) for centring a first transmission element (4) and a second transmission element (7). The first transmission element (4) is spaced apart from the second transmission element (7) along a longitudinal direction (X3-X3) of the central axis and is rotatable relative to the second transmission element (7). At least one of the first transmission element (4) and the second transmission element (7) comprises a coaxial toothed wheel (42) and a pinion (44) which are superimposed along the longitudinal direction (X3-X3) of the central axis and rotate as one with one another.

Description

[0001] DESCRIPTION

[0002] TITLE: REDUCER COMPRISING A CENTRAL AXIS AND TRANSMISSION ELEMENTS SUPERIMPOSED AND CENTERED BY THE AXIS

[0003] TECHNICAL FIELD

[0004] The invention relates to a geared motor. It relates in particular to a geared motor for a cooling system for a motor vehicle.

[0005] STATE OF THE PRIOR ART

[0006] A motor reducer for a motor vehicle generally comprises an electric motor and an epicyclic reduction gear. The epicyclic reduction gear generally has a satisfactory reduction but a large footprint along the longitudinal axis of the reduction gear, which is the direction of the reduction gear's height. As a result, it is often difficult to position the electric motor and the reduction gear in the vehicle.

[0007] There are also reducers comprising stepped gears, each of which has a coaxial wheel and pinion. The reduction of these reducers is satisfactory, but they have a significant lateral bulk.

[0008] There is a need to reduce the size of a geared motor reducer, while tending to increase the reduction of the reducer and limiting the mass of the geared motor.

[0009] STATEMENT OF THE INVENTION

[0010] In this regard, the invention relates to a reducer for a geared motor. The reducer comprises a first motion transmission element with tangential meshing and a second motion transmission element with tangential meshing. The reducer also comprises a central axis for centering the first transmission element and the second transmission element.

[0011] The first transmission element is spaced from the second transmission element along a longitudinal direction of the central axis. The first transmission element is rotatably movable relative to the second transmission element. At least one of the first transmission element and the second transmission element comprises a coaxial toothed wheel and pinion which are superimposed along the longitudinal direction of the central axis and rotationally integral with each other. Thanks to the reducer according to the invention, the compactness of the reducer is increased, while having a relatively low mass and a high reduction.

[0012] In particular, the reducer according to the invention is more compact than a multi-stage gear reducer of known structure, while tending to increase the reduction of the reducer at equivalent mass of the reducers.

[0013] The reducer according to the invention is notably more compact in a direction of the height of the reducer than an epicyclic reducer of known structure, while tending to increase the reduction, at equivalent mass of the reducers.

[0014] The invention may optionally comprise one or more of the following features combined with each other or not.

[0015] According to a particular embodiment, the reducer comprises a third stepped gear mechanically engaging the first transmission element and the second transmission element. The third stepped gear comprises a coaxial toothed wheel and pinion which are superimposed along the longitudinal direction of an intermediate axis and integral with each other in rotation.

[0016] According to a particular embodiment, the central axis is an output axis of the reducer. The second transmission element is an output gear of the reducer.

[0017] According to a particular embodiment, the output gear comprises a toothed wheel and a first mechanical coupling part which is configured to engage by form cooperation a second mechanical coupling part to which the output gear is mechanically connected.

[0018] According to a particular embodiment, the reducer comprises a stepped gear train with tangential gears. The stepped gears each comprise a coaxial toothed wheel and pinion which are superimposed and integral with each other in rotation. The stepped gears are located around axes which are parallel to each other.

[0019] According to a particular embodiment, the set of gears of the reducer consists of the stepped gear train and an output gear. The pinion of each stepped gear mechanically engages the toothed wheel of one of the stepped gears of the stepped gear train or of the output gear.

[0020] The invention also relates to a console for supporting and centering at least one gear motor reducer axis. The reducer axis is a centering axis of at least one first motion transmission element and one second motion transmission element. The first transmission element and the second transmission element are spaced apart from each other along a longitudinal direction of the axis and are rotatable relative to each other.

[0021] The console comprises at least a first support plate for the second transmission element and / or the first transmission element. The first plate is configured to be traversed by the axis and to be located between the first transmission element and the second transmission element.

[0022] Thanks to the console according to the invention, the mechanical strength of the reducer and the reduction of the reducer are improved. In particular, the console limits bending of the central axis and wear of the first transmission element, the second transmission element and the central axis.

[0023] The console improves the centering of the first and second transmission elements, while limiting the vibrations of the reducer and the mechanical forces exerted on the central axis, the first transmission element and the second transmission element. For example, the console promotes the transmission of mechanical forces between the reducer and the reducer housing.

[0024] The invention also relates to a reduction device comprising a reducer as defined above and a console as defined above. The reducer axis is the central axis. The first plate is crossed by the central axis while being located axially between the first transmission element and the second transmission element.

[0025] According to a particular embodiment, the console comprises a second plate which is spaced laterally from the first plate. The second plate is a support for the third stepped gear.

[0026] Finally, the invention relates to a geared motor which comprises a reduction device as defined above, an electric motor and a housing. According to a particular embodiment, the console comprises a base which carries the first plate, the base bearing against a side wall of the housing. The console comprises feet of the console which bear against a bottom of the housing. The feet carry the first plate relative to the housing.

[0027] According to a particular embodiment, the feet of the console are each crossed by a fixing rod to fix the console to the housing.

[0028] Preferably, the console comprises at least three legs. Preferably, the fixing rods are fixing screw rods.

[0029] According to a particular embodiment, the geared motor comprises a cover, the central axis being rigidly secured to the cover. Preferably, the central axis mechanically engages the cover.

[0030] According to a particular embodiment, a centering axis of the third stepped gear is rigidly attached to the console, in particular to the second plate.

[0031] According to a particular embodiment, the axes of the stepped gears are parallel to an axis of the electric motor.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be better understood upon reading the description of exemplary embodiments, with reference to the appended drawings in which:

[0034] [Fig. 1] is a schematic perspective representation of a geared motor according to a first embodiment of the invention;

[0035] [Fig. 2] is a schematic sectional representation of the geared motor according to the first embodiment;

[0036] [Fig. 3] is a schematic representation in longitudinal section of the geared motor according to the first embodiment;

[0037] [Fig. 4] is a schematic representation of the geared motor according to the first embodiment, with the reducer in exploded view;

[0038] [Fig. 5] is a schematic perspective representation from below of a support and axis centering console of the geared motor according to the first embodiment; [Fig. 6] is a schematic perspective representation from above of the console of the geared motor according to the first embodiment.

[0039] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0040] Identical, similar or equivalent parts of the different figures bear the same numerical references so as to facilitate the passage from one figure to another. Figure 1 represents a geared motor 1 for a cooling system for a motor vehicle, typically an automobile.

[0041] With reference to figures 1 to 4, the geared motor 1 comprises a housing 10, a cover 14, an electric motor 2, a control member 16, a reducer 3 and a console 8. The geared motor 1 is used for example to actuate a cooling fluid direction valve, a radiator valve, etc.

[0042] The housing 10 comprises a side wall 11, a bottom 12 and an electrical connector 13. The side wall 11 and the bottom 12 form a single-piece housing wall in the embodiment shown. The housing 10 is configured to house the electric motor 2 and the reducer 3.

[0043] The bottom 12 comprises three blind holes which respectively form a first fixing and centering hole 12a for a motor shaft 20 of the electric motor 2, a second fixing and centering hole 12b for an input shaft 40 of the reducer 2, and a third fixing and centering hole 12c for an intermediate shaft 60.

[0044] The electrical connector 13 is configured to be connected to a control unit of the vehicle or to an electrical power source of the vehicle, for example a battery of the vehicle, to electrically power the electric motor 2.

[0045] The cover 14 comprises three blind holes which respectively form a first fixing and centering hole 14a for the motor shaft 20, a second fixing and centering hole 14b for the input shaft 40 of the reducer, and a third fixing and centering hole 14c for a central shaft 50. The cover 14 is configured to close the housing 10 in a sealed manner.

[0046] The electric motor 2 comprises the motor shaft 20 and a rotor pinion 21. The motor shaft 20 and the rotor pinion 21 are located around a longitudinal axis Xl-Xl of the motor shaft 20. The electric motor 2 is for example a brushless direct current electric motor. The electric motor 2 is configured to rotate the reducer 3.

[0047] The motor shaft 20 is fixed to the cover 14 at its upper longitudinal end, for example by fitting into the first fixing hole 14a. The motor shaft 20 of the electric motor is fixed to the bottom 12 at its lower longitudinal end, for example by snapping into the first fixing hole 12a. The input shaft 40 serves to center the rotor pinion 21.

[0048] With reference to Figure 4, the control member 16 is for example an electronic card for controlling the electric motor 2. It notably comprises a power control member for the electric motor and a means of connection and data exchange. The control member 16 is configured to control the electrical power supply of the electric motor 2 on the order of a control unit (not shown) of the vehicle.

[0049] With joint reference to Figures 2 to 4, the reducer 3 comprises a first stepped gear 4, a second stepped gear 5, a third stepped gear 6 and an output gear 7. In the embodiment shown, the set of reduction gears 3 consists of the train of stepped gears 4, 5, 6 and an output gear 7. The reducer 3 also comprises an input axis 40, a central axis 50 and an intermediate axis 60 around which the stepped gears 4, 5, 6 and the output gear 7 are located.

[0050] The reducer 3 is configured to reduce the rotational speed at the output of the reducer 3 relative to that at the output of the electric motor 2 and to increase the torque at the output of the reducer 3 relative to that at the output of the electric motor 2. The reducer 3 and the console 8 together form a reduction device for the geared motor.

[0051] Each of the stepped gears 4, 5, 6 and the output gear 7 is a tangentially meshing motion transmission element. These transmission elements are rotatable relative to each other.

[0052] Each of the stepped gears 4, 5, 6 comprises a toothed wheel 42, 52, 62 and a pinion 44, 54, 64 which are coaxial which are superimposed and integral with each other in rotation. More precisely, each of the stepped gears 4, 5, 6 is in one piece in the embodiment shown. The pinion 44, 54, 64 of each stepped gear 4, 5, 6 mechanically engages the toothed wheel 52, 62 of one of the stepped gears of the stepped gear train or of the output gear 72.

[0053] The first stepped gear 4 comprises a first cogwheel 42 and a first coaxial pinion 44 which are superimposed along the longitudinal direction X2-X2 of the input axis 40 of the reducer. The first stepped gear 4 is rotated by the electric motor 2 and it rotates the second stepped gear 5. The first cogwheel 42 mechanically engages the rotor pinion 21 which rotates it. The first pinion 44 mechanically engages and rotates a second cogwheel 52.

[0054] The second stepped gear 5 comprises the second gear wheel 52 and a second pinion 54 coaxially which are superimposed along the longitudinal direction X3-X3 of the central axis. The second stepped gear 5 is rotated by the first stepped gear 4 and it rotates the third stepped gear 6. The second pinion 44 mechanically engages and rotates a third gear wheel 62. The third stepped gear 6 comprises the third gear wheel 62 and a third pinion 64 coaxially which are superimposed along the longitudinal direction X4-X4 of the intermediate axis 60. The third stepped gear 6 is rotated by the second stepped gear 5 and it rotates the output gear 7. The third pinion 64 mechanically engages and rotates the output gear wheel 72 of the reducer.

[0055] The output gear 7 comprises an output gear wheel 72 and a first mechanical coupling part 74. The gear wheel 72 and the first mechanical coupling part 74 are coaxial around the central axis 50 and they are rigidly secured in rotation. In the embodiment shown, the output gear 7 is in one piece. In the embodiment shown, the first mechanical coupling part 74 is configured to engage by form cooperation a second mechanical coupling part to which the reducer 3 is mechanically connected, in particular by form complementarity. The output gear 7 is an output gear of the reducer 3. The axes of the stepped gears 40, 50, 60 are parallel in pairs. The axes 40, 50, 60 of the stepped gears are also parallel to the motor axis 20.

[0056] The input shaft 40 is fixed to the cover 14 at its upper longitudinal end, for example by snapping into the second fixing hole 14b. The input shaft 40 is fixed to the bottom 12 at its lower longitudinal end, for example by snapping into the second fixing hole 12b. The input shaft 40 serves for centering the first stepped gear 4.

[0057] The central shaft 50 is fixed to the cover 14 at its upper longitudinal end, for example by snap-fastening into the third fixing hole 14c. The central shaft 50 mechanically engages the output gear 7 at its lower longitudinal end, for example by a loose assembly, by being rotatable relative to the output gear 7.

[0058] The central axis 50 serves for centering the second stepped gear 5 and the output gear 7. The central axis 50 is also an output axis of the reducer, the output gear 7 being spaced from the second stepped gear 5 along the longitudinal axis X3-X3 of the central axis.

[0059] The intermediate shaft 60 is fixed to the console 8 at its upper longitudinal end, for example by snapping into an intermediate hole 86a of a second plate 86. The intermediate shaft 60 is fixed to the bottom 12 at its lower longitudinal end, for example by snapping into the third fixing hole 12c. The intermediate shaft 60 serves to center the third stepped gear 6.

[0060] With joint reference to Figures 2 to 6, the console 8 comprises a base 80, feet 82, a first plate 84, a second plate 86 and holding portions 83. The console 8 is a console for supporting and centering the central axis 50. It serves to transmit mechanical forces to the housing 10, in particular on the central axis 50 those which would tend to bend the central axis 50, and to limit the vibrations of the reducer 3. In the embodiment shown, the console 8 comprises three feet 82. The feet 82 are preferably equidistant two by two. The feet 82 each extend from the base 80 to the bottom 12 of the housing. The feet 82 are each crossed by a fixing rod to fix the console 8 to the housing 10, in particular by threaded rods of fixing screws. The feet 82 carry the base 80 relative to the bottom 12 of the housing 10. The base 80 carries the first plate 84. The base 80 includes the second plate 84.The base 80 serves as support and centering for the second stepped gear 5 and the third stepped gear 6. The upper surface and the lower surface of the base are substantially flat and perpendicular to the longitudinal axis X3-X3 of the central axis 50.

[0061] The first plate 84 is crossed by a central orifice 84a through which the central axis 50 extends. The first plate 84 is located axially between the second stepped gear 5 and the output gear 7 relative to the central axis 50. The first plate 84 has an upper surface and a substantially planar inner surface, being substantially parallel to the base 80 and perpendicular to the longitudinal axis X3-X3 of the central axis. The first plate 84 is a support plate for the output gear 7 and / or the second stepped gear 5, in particular the pinion 54 of the second stepped gear 5.

[0062] The first plate 84 is connected to the base by at least one fixing portion 83 of which there are three in the embodiment shown. Each fixing portion 83 extends substantially perpendicular to the base 80 and the first plate 82 which it mechanically connects to each other, being around the central axis 50.

[0063] The second plate 86 extends substantially parallel to the second gear 52 and the third gear 62. The second plate 86 is located on a lower surface of the base 80. It is located axially relative to the central axis 50 between the second stepped gear 5 and the third stepped gear 6. The second plate 86 comprises an intermediate orifice 86a into which the intermediate axis 60 is inserted, to fix the intermediate axis 60 to the console 8. The second plate 86 is a support for the third stepped gear 6.

[0064] In the embodiment shown, the intermediate orifice 86a is a blind hole. The second plate 86 has a truncated circular outer contour, so that the third toothed wheel 62 protrudes laterally from the second plate 86.

[0065] Thanks to the invention, the compactness of the reducer 3 is increased, while having a fairly low mass and presenting a high reduction.

[0066] In particular, the reducer 3 is more compact than a multi-stage gear reducer of known structure, while tending to increase the reduction of the reducer 3 at equivalent mass of these reducers. The reducer 3 is in particular more compact in a direction of the height of the reducer 3 than an epicyclic reducer, while tending to increase the reduction, at equivalent mass of these reducers.

[0067] By means of the bracket 8, the mechanical strength of the reducer 3 and the reduction of the reducer 3 are improved. In particular, the bracket 8 limits bending of the central shaft 50 and / or wear of the second stepped gear 5, the output gear 7 and the central shaft 50. The bracket 8 improves the centering of the second stepped gear 5 and the output gear 7, while limiting the vibrations of the reducer 3 and the mechanical forces exerted on the central shaft 50, the second stepped gear 5 and / or the output gear 7. The bracket 8 promotes the transmission of mechanical forces between the reducer 3 and the housing 10 of the reducer.

[0068] Of course, various modifications can be made by those skilled in the art to the invention which has just been described without departing from the scope of the disclosure of the invention.

[0069] Alternatively, the bottom 12 of the housing is fixed to the side wall 11 of the housing 10.

[0070] Alternatively, the electric motor 2 is, for example, a brushed motor. The electric motor 2 is, for example, single-phase or three-phase.

[0071] Alternatively, the reducer 3 comprises at least one non-stepped gear in addition to the output gear 7, for example two toothed wheels.

[0072] Alternatively, the pinion 44, 54, 64 of at least one of the stepped gears 4, 5, 6 is attached to the corresponding gear wheel 42, 52, 62. Alternatively or additionally, the first coupling portion 74 is attached to the output gear wheel 72.

[0073] Alternatively, the console 8 comprises two feet 82 or the console comprises four or more feet 82. Alternatively, the feet 82 are not fixed to the housing 10, but the console 8 only bears laterally against the housing 10, in particular against the bottom 12 of the housing.

[0074] Alternatively, the console 8 rests against the side wall 11 of the housing, for example at the level of the base 80.

[0075] Additionally or alternatively, the console 8 is fixed to the cover 14. In this case, the console 8 is configured to transmit mechanical forces from the second stepped gear 5, from the output gear 7 and / or from the central axis 50 to the cover 14, for example to the housing 10. Alternatively, the console 8 comprises a single holding portion 83 which extends circumferentially around the central axis 50, at least over the majority of the circumferential length around the central axis 50.

[0076] Alternatively, the second plate 86 has, for example, a circular outer contour, so that it substantially entirely covers the third toothed wheel 62.

[0077] Alternatively or additionally, the intermediate orifice 86 is a through orifice. In this case, the intermediate axis 60 is for example fixed at its upper end to the cover 14.

Claims

CLAIMS 1. Reducer (3) for a geared motor (1), comprising: a first transmission element (5) for movement with tangential meshing, a second transmission element (7) for movement with tangential meshing, and a central axis (50) for centering the first transmission element (5) and the second transmission element (7), the first transmission element (5) being spaced from the second transmission element (7) along a longitudinal direction (X3-X3) of the central axis, the first transmission element (5) being rotatable relative to the second transmission element (7), at least one of the first transmission element (5) and the second transmission element (7) comprising a coaxial toothed wheel (52) and pinion (54) which are superimposed along the longitudinal direction (X3-X3) of the central axis and integral with each other in rotation,the reducer (3) comprising a third stepped gear (6) mechanically engaging the first transmission element (5) and the second transmission element (7), the third stepped gear (6) comprising a coaxial toothed wheel (62) and pinion (64) which are superimposed along the longitudinal direction (X4-X4) of an intermediate axis and integral with each other in rotation., 2. Reducer (3) according to claim 1, wherein the central axis (50) is an output axis of the reducer, the second transmission element (7) being an output gear of the reducer (3).

3. Reducer (3) according to the preceding claim, wherein the output gear (7) comprises a toothed wheel (72) and a first mechanical coupling part (74) which is configured to engage by form cooperation a second mechanical coupling part to which the output gear (7) is configured to be mechanically connected.

4. Reducer (3) according to any one of the preceding claims, in which the reducer (3) comprises a train of stepped gears (4, 5, 6) with tangential gears, the stepped gears (4, 5, 6) each comprising a coaxial toothed wheel (42, 52, 62) and pinion (44, 54, 64) which are superimposed and integral with each other in rotation, the stepped gears (4, 5, 6) being located around axes (40, 50, 60) which are parallel to each other.

5. Reducer (3) according to the preceding claim, in which the set of gears of the reducer (3) consists of the stepped gear train (4, 5, 6) and an output gear (7), the pinion (44, 54, 64) of each stepped gear (4, 5, 6) mechanically engaging the toothed wheel (42, 52, 62, 72) of another of the stepped gears of the stepped gear train or of the output gear (7).

6. Reducer (3) for a geared motor (1), comprising: a first transmission element (5) for movement with tangential meshing, a second transmission element (7) for movement with tangential meshing, and a central axis (50) for centering the first transmission element (5) and the second transmission element (7), the first transmission element (5) being spaced from the second transmission element (7) along a longitudinal direction (X3-X3) of the central axis, the first transmission element (5) being rotatable relative to the second transmission element (7), at least one of the first transmission element (5) and the second transmission element (7) comprising a coaxial toothed wheel (52) and pinion (54) which are superimposed along the longitudinal direction (X3-X3) of the central axis and integral with each other in rotation, the reducer (3) comprising a stepped gear train (4, 5, 6) with tangential gears, the stepped gears (4, 5,6) each comprising a coaxial toothed wheel (42, 52, 62) and pinion (44, 54, 64) which are superimposed and integral with each other in rotation, the stepped gears (4, 5, 6) being located around axes (40, 50, 60) which are parallel to each other., 7. Reducer (3) according to the preceding claim, in which the set of gears of the reducer (3) consists of the stepped gear train (4, 5, 6) and an output gear (7), the pinion (44, 54, 64) of each stepped gear (4, 5, 6) mechanically engaging the toothed wheel (42, 52, 62, 72) of another of the stepped gears of the stepped gear train or of the output gear (7).

8. Reduction device comprising a reducer (3) according to any one of claims 1 to 7 and a console (8) for supporting and centering at least one reducer axis of a geared motor (1), the reducer axis being a centering axis of at least one first movement transmission element (5) and one second movement transmission element (7), the first transmission element (5) and the second transmission element (7) being spaced from each other along a longitudinal direction (X3-X3) of the axis and being movable in rotation relative to each other, the console (8) comprising at least one first plate (84) for supporting the second transmission element (7) and / or the first transmission element (5), the first plate (84) being configured to be traversed by the axis and to be located between the first transmission element (5) and the second transmission element (7), in which the reducer axis is the axis central (50),the first plate (84) being crossed by the central axis (50) while being located axially between the first transmission element (5) and the second transmission element (7) relative to the central axis (50)., 9. Reduction device according to the preceding claim, in which the console (8) comprises a second plate (86) which is spaced laterally from the first plate (84), the second plate (86) being a support for the third stepped gear (6).

10. Geared motor (1) comprising a reduction device according to any one of claims 8 or 9, an electric motor (2) and a housing (10), in which the console (8) comprises a base (80) which carries the first plate (84), the base (80) bearing against a side wall of the housing (10), the console (8) comprising feet (82) of the console which rest against a housing bottom, the feet (82) carrying the first plate (84) relative to the housing (10).

11. Geared motor (1) according to the preceding claim, in which the feet (82) of the console are each crossed by a fixing rod to fix the console to the housing, the console (8) preferably comprising at least three feet (82), and / or the fixing rods preferably being fixing screw rods.

12. Geared motor (1) according to any one of claims 10 or 11, in which the geared motor (1) comprises a cover (14), the central axis (50) being rigidly secured to the cover (14), in particular by mechanically engaging the cover (14), and / or in which the reducer (3) is according to claim 2, an axis (60) for centering the third stepped gear (6) being rigidly secured to the console (8), in particular to the second plate (86).

13. Geared motor (1) according to any one of the preceding claims 10 to 12, wherein the reducer (3) is according to any one of claims 4 and 5, the axes (40, 50, 60) of the stepped gears being parallel to a motor axis (20) of the electric motor.

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