hydraulic anti-vibration mount

Abstract

An anti-vibration mount (10; 100) is adapted to filter and dampen vibrations between a first element (M) and a second element (CV). The anti-vibration mount (10; 100) comprises a first armature (12) for attachment to the first element (M), a second armature (14) for attachment to the second element (CV), an intermediate piece (16), a first elastomer body (18) connecting the first armature (12) and the intermediate piece (16), a second elastomer body (20) connecting the intermediate piece (16) and the second armature (14), and a hydraulic damping circuit (46) comprising a first hydraulic chamber (50), a second hydraulic chamber (50), and a channel (48) connecting the first and second hydraulic chambers (50) together. The hydraulic circuit (46) is made between one of the first and second reinforcement pieces (12; 14), on the one hand, and the intermediate piece (16), on the other. Figure from the abstract: [Fig. 8]

Description

Title of the invention: Hydraulic anti-vibration mount technical field

[0001] The present invention relates to the field of anti-vibration mounts for motor vehicles, in particular anti-vibration mounts for electric motors. More specifically, it relates to a hydraulic anti-vibration mount that provides damping and filtering of high-frequency vibrations. Previous technique

[0002] The electric motor mounts with which electric vehicles are equipped, whether for traction or air conditioning or heat pump compressors, mainly generate high frequency and low amplitude vibrations.

[0003] However, to properly maintain these motors and ensure the lifespan of their suspension, the motor mounts must be sufficiently rigid. Such rigidity is not conducive to filtering high-frequency vibrations.

[0004] This is why the supports for electric motors can be of the double filtration type to filter high frequency vibrations.

[0005] Such a known support comprises a first armature intended to be fixed to the electric motor, a second armature intended to be fixed to the body of the motor vehicle, an intermediate piece, a first elastomer body connecting the first armature to the intermediate piece and a second elastomer body connecting the second armature to the intermediate piece.

[0006] US patent 4403762 describes an example of such a known support.

[0007] However, such an anti-vibration support does not allow for the effective treatment of transient vibrations which excite the low-frequency natural modes of the motor on the anti-vibration supports.

[0008] These transient vibrations appear, for example, during motor start-ups, sudden changes in motor load, and transitions between "motor" and "generator" modes, due to the near-instantaneous torque variations inherent in electric motors. Similarly, in the case of imperfect balancing of the electric motor rotor, vibrations at the rotor's rotational frequency excite the electric motor's natural modes on its anti-vibration mounts when their frequencies coincide.

[0009] There is therefore a need to improve known anti-vibration devices. Summary

[0010] This disclosure improves the situation.

[0011] A suitable anti-vibration mount is proposed to filter and dampen vibrations between a first element, in particular an electric motor, and a second element, in particular a motor vehicle chassis, the anti-vibration support comprising: a first frame intended to be fixed to the first element; a second frame intended to be attached to the second element; an intermediate room; a first elastomer body connecting the first armature and the intermediate piece; a second elastomer body connecting the intermediate piece and the second armature; and a hydraulic damping circuit comprising a first hydraulic chamber, a second hydraulic chamber, and a channel connecting the first and second hydraulic chambers together, the hydraulic circuit being made between one of the first and second reinforcement pieces, on the one hand, and the intermediate piece, on the other hand.

[0012] Thus, advantageously, the anti-vibration device allows: - maintaining the electric motor under torque, in the quasi-static frequency domain, and ensuring endurance, by an optimized static stiffness of the elastomer; - Damping of the low-frequency natural modes of the electric motor thanks to the properties of the hydraulic damping circuit, integrated into the anti-vibration mount; and - filtering of high frequencies, thanks to the suspended mass of the intermediate piece.

[0013] The anti-vibration device according to the invention may have one or more of the following characteristics, taken alone or in combination: - the hydraulic damping circuit is made between the first armature and the intermediate piece; - the first elastomer body forms two cavities connected by a recess, the cavities and the recess forming, with the intermediate piece, the hydraulic chambers and the channel, respectively; - the first elastomer body is overmolded onto an insert forming windows similar to the cross-section of the cavities and / or a recess of substantially identical shape to the recess in the first elastomer body; - the first elastomer body forms at least one bead in the vicinity of each of its longitudinal ends, each bead being pressed against a radially internal surface of the intermediate part to seal the hydraulic damping circuit; - the hydraulic damping circuit is made between the intermediate piece and the second frame; - the second elastomer body has two windows in fluid communication via a recess on the intermediate piece, the windows and the recess forming, with the second reinforcement, the hydraulic chambers and the channel, respectively; - the second elastomer body is overmolded onto at least one insert forming windows of a similar shape to the windows in the second elastomer body; - the first elastomer body has a first ring in contact with the first armature, a second ring in contact with the intermediate piece and at least one arm between the first and second rings; - the second elastomer body has a first ring in contact with the intermediate piece, a second ring in contact with the second armature and at least one arm between the first and second rings.

[0014] According to another aspect, a motor vehicle is described comprising a body, an electric motor and at least one anti-vibration support as described above, in all its combinations, between the electric motor and the body. Brief description of the drawings

[0015] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0016] [Fig. 1] is a schematic diagram showing a vehicle whose powertrain is supported by one or more anti-vibration mounts.

[0017] [Fig.2] schematically represents in perspective a first example of support anti-vibration system that can be implemented in the vehicle of [Fig.1].

[0018] [Fig.3] schematically represents, from a first perspective, an exploded view of the first example of anti-vibration support of [Fig.2].

[0019] [Fig.4] schematically represents, from a second perspective, an exploded view from the first example of anti-vibration support in [Fig.2].

[0020] [Fig.5] schematically represents in perspective an intermediate part that can be implemented in the first example of anti-vibration support.

[0021] [Fig.6] schematically represents in perspective a subset of the first example of anti-vibration support.

[0022] [Fig.7] schematically represents in perspective a second example of support anti-vibration, which can be implemented in the vehicle of [Fig.1].

[0023] [Fig.8] schematically represents, from a first perspective, an exploded view of the second example of anti-vibration support of [Fig.7].

[0024] [Fig.9] schematically represents, from a second perspective, an exploded view of the second example of anti-vibration support in [Fig.7].

[0025] [Fig. 10] schematically represents in perspective view a subset of the second example of anti-vibration support. Description of the implementation methods

[0026] In the different figures, the same references designate identical or similar elements.

[0027] Fig. 1 shows very schematically a vehicle V, in particular a motor vehicle, comprising a body CV (or a chassis) and a powertrain M connected to the body CV by one or more anti-vibration mounts 1 0, 100.

[0028] The powertrain M may, in particular, be an electric motor unit, or, where applicable, a hybrid motor unit comprising an internal combustion engine and an electric motor used for propelling the vehicle. In both cases, the operation of the electric motor generates vibrations of relatively high frequencies, typically above 600 Hz or more generally in the range of 200 Hz to 3000 Hz.

[0029] Figure 2 illustrates a first example of an anti-vibration mount 10. As illustrated, the anti-vibration mount 10 is in the form of a sleeve, generally cylindrical in shape, centered on an axis A, for example substantially horizontal. Each sleeve-shaped anti-vibration mount 10 can be fitted into a housing integral with the housing CV or, preferably, with the engine M.

[0030] As can be seen in [Fig.3] and [Fig.4], in particular, each anti-vibration mount 10 essentially comprises: - a first armature 12; - a second armature 14; - an intermediate piece 16; - a first elastomer body 18, connecting the first armature 12 to the intermediate piece 16; and - a second elastomer body 20, connecting the intermediate piece 16 to the second armature 14. Here, the second elastomer body 20 includes two coaxial inserts 22, 24. For example, the second elastomer body 20 is overmolded onto the two inserts 22, 24.

[0031] The first armature 12 here has a substantially cylindrical shape, with its axis aligned with the axis A of the anti-vibration support 10, and a central opening of substantially cylindrical shape, also with its axis aligned with the axis A of the anti-vibration support 10. The first armature 12 is, for example, made of metallic material. Here, the cross-section of the first armature 12 is circular. Alternatively, however, the cross-section of the first armature 12 is non-circular.

[0032] Similarly, the second bracket 14 is substantially cylindrical in shape, with its axis aligned with the axis A of the anti-vibration support 10, and has a central opening that is also substantially cylindrical in shape, with its axis aligned with the axis A of the anti-vibration support 10. The second bracket 14 is, for example, made of metallic material. The second bracket 14 extends radially around the first bracket 12.

[0033] The intermediate piece 16 also has a generally cylindrical shape, with axis A of the anti-vibration support 10, with a central opening of substantially cylindrical shape, with axis A of the anti-vibration support 10. The intermediate piece 16 is rigid, in particular with respect to the first and second elastomer bodies 18, 20. For example, the intermediate piece 16 is made of metal.

[0034] The intermediate piece 16 further has, on its radially outer surface, a recess 26. As can be seen in particular in [Fig. 5], the recess 26 extends in a serpentine fashion between two ends 26a, 26b. In particular, here, the recess 26 comprises three parallel segments extending substantially parallel to the axis A of the anti-vibration support 10, connected by two semi-circular portions. This maximizes the length of the recess 26, between the two ends 26a, 26b, for the same portion of the radially external surface of the intermediate piece 16. As can be seen in [Fig.5], a first end 26a of the recess 26 is close to a first longitudinal end of the intermediate piece 16, the second end 26b of the recess 26 being close to a second longitudinal end of the intermediate piece 16, opposite to the first longitudinal end of the intermediate piece 16.

[0035] The first elastomer body 18 connects (or fixes) together the first armature 12 and the intermediate piece 16. For example, the first elastomer body 18 is overmolded onto the first armature 12 and the intermediate piece 16. Here, the first elastomer body 18 forms a first central ring 28 all around the first armature 12, a second radially external ring 30 in contact with the entire radially internal surface of the intermediate piece 16, and radial arms 32 between the first and second rings 28, 30. The radial arms 32 are, for example, angularly equidistant around the axis A of the anti-vibration support 10. Here, the first elastomer body 18 forms four radial arms 32.

[0036] Similarly, the second elastomer body 20 connects (or fixes) together the intermediate piece 16 and the second reinforcement 14. For example, the second elastomer body 20 is overmolded onto the second reinforcement 14 and the intermediate piece 16. Here, the second elastomer body 20 forms a first, central ring 34 around the intermediate piece 16, a second, radially external ring 36 in contact with the entire radially internal surface of the second reinforcement 14, and radial arms 38 between the first and second rings 28, 30 . The radial arms 3 8 are for example equidistributed angularly around the axis A of the anti-vibration support 10. Here, the second elastomer body 20 forms four radial arms 3 8.

[0037] Furthermore, as can be seen in particular on [Fig.3], [Fig.4] and [Fig.6], the second elastomer body 20 forms two windows 40, here equidistant angularly in the second elastomer body 20. Similar windows 42, 44 are made in the inserts 22, 24, which essentially aim to maintain the shape of the windows 40 in the second elastomer body 20.

[0038] The assembly of the anti-vibration device can be carried out, in particular, by overmolding: - the first elastomer body 18 on the first armature 12, on the one hand, and on the intermediate piece 16, on the other hand; and by overmolding - the second elastomer body 20 on the intermediate piece 16, on the one hand, and on the second reinforcement 14, on the other hand. The second elastomer body 20 can simultaneously be overmolded onto the first and second inserts 22, 24.

[0039] Once the anti-vibration device 10 is assembled, the intermediate piece 16 and the second elastomer body 20 define a hydraulic damping circuit 46. Thus, as can be partially seen in [Fig.6], the recess 26 in the radially outer surface of the intermediate piece is closed by the second elastomer body 20 to form a channel 48 connecting two hydraulic chambers 50, each delimited by a respective window 40 in the second elastomer body 20, the radially outer surface of the intermediate piece 16 and the radially inner surface of the second armature 14 (not shown in [Fig.6].

[0040] The hydraulic circuit 46 is for example filled with glycol.

[0041] As explained previously, the stiffness of the first and second elastomer bodies 18, 20 ensures the maintenance of the motor in the quasi-static frequency domain and the endurance.

[0042] High frequencies are filtered by means of the intermediate piece 16, suspended between the first and second elastomer bodies 18, 20. The intermediate piece 16 thus forms a vibrating mass suspended between the two elastomer bodies 18, 20, one of which is fixed to the motor M and the other to the body CV of the motor vehicle V via the first and second armatures 12, 14, respectively. The mass of the intermediate piece 16 and the stiffness of the elastomer bodies 18, 20 are advantageously chosen so that the resonant frequency of the intermediate piece 16 is adjusted according to the frequencies to be filtered. The frequencies to be filtered are, for example, greater than 200 Hz. The mass of the intermediate piece 16 and the stiffness of the elastomer bodies 18, 20 can thus be advantageously chosen so that the resonant frequency of the intermediate piece 16 is slightly lower than the frequencies to be filtered. For example, the resonant frequency is less than 90% of the lowest frequency to be filtered, preferably less than 80% of this lowest frequency, and preferably even less than 70% of this lowest frequency. Thus, as an example, to filter frequencies above 200 Hz, the mass of the intermediate piece 16 and the stiffness of the elastomer bodies 18, 20 are preferably chosen so that the resonant frequency of the intermediate piece 16 is less than 180 Hz, preferably less than 160 Hz, and preferably even less than 140 Hz.

[0043] The hydraulic circuit 46 is a damping circuit known as a "beater effect" circuit, designed to dampen low-frequency vibrations. The expansion stiffness of the chambers 50 and the dimensions of the channel 48 allow the resonant frequency of the fluid in the hydraulic circuit to be adjusted. This resonant frequency can be chosen, for example, between 10 Hz and 50 Hz, depending on the frequency of the natural modes to be damped.

[0044] It should be noted that the damping of low frequencies by the hydraulic circuit 46 has practically no effect on the damping of high frequencies by the oscillations of the intermediate piece 16 between the two elastomer bodies 18, 20 and vice versa.

[0045] In the following, a second example of an anti-vibration device 100 is described opposite [Fig. 7] to [Fig. 10]. In this description, elements identical or having the same function as the components of the first example of an anti-vibration device 10, described previously, bear the same reference numeral. For the sake of brevity, these components, identical in both examples of anti-vibration devices 10 and 100, are not described in detail in the second example of an anti-vibration device 10.

[0046] Each anti-vibration mount 10 0, as illustrated, essentially comprises: - a first armature 12; - a second armature 14; - an intermediate piece 16; - a first elastomer body 18, connecting the first armature 12 to the intermediate piece 16; and - a second elastomer body 20, connecting the intermediate piece 16 to the second armature 14. Here, the first elastomer body 18 includes an insert 102. For example, the first elastomer body 18 is overmolded onto the insert 102.

[0047] The first armature 12 here has a substantially cylindrical shape, with its axis aligned with the axis A of the anti-vibration support 10, and a central opening of substantially cylindrical shape, also with its axis aligned with the axis A of the anti-vibration support 10. Here, the cross-section of The first reinforcement 12 is non-circular, generally triangular in shape with truncated angles. Alternatively, however, the cross-section of the first reinforcement 12 is circular.

[0048] The intermediate piece 16 here has a generally cylindrical shape, with axis A of the first example of the anti-vibration support 10. The intermediate piece 16 is also, here, smooth on its radially external surface.

[0049] As can be seen in particular in [Fig. 10], the first elastomer body 18 here has a different shape from the first elastomer body 18 of the first example of anti-vibration support 10. The first elastomer body 18 is overmolded on the first armature 12 and the intermediate piece 16. Here, the first elastomer body 18 is further overmolded on the insert 102. The first elastomer body 18 forms a first central ring 104 around the first armature 12, a second radially external ring 106 in contact with the radially internal surface of the intermediate piece 16, and radial arms 108 between the first and second rings 104, 106. The radial arms 108 are, for example, two in number. The insert 102 is for example overmolded by the second ring 106 of the first elastomer body 18.

[0050] In the second ring 104, the first elastomer body 18 has two cavities 110 and a recess 112 extending in a serpentine fashion between the cavities 110. The insert 102 also has two windows 114 with a cross-section similar to the cavities 110, connected by a recess 116 similar to the recess 112 in the first elastomer body 18. The insert 102 thus helps to maintain the shape of the cavities 110 and the recess 112 in the first elastomer body 18.

[0051] Furthermore, in the vicinity of its longitudinal ends, the first elastomer body 18 forms peripheral ridges 116 intended to be pressed against the radially internal surface of the insert 16, to ensure the sealing of the hydraulic circuit 46. Here, the hydraulic circuit 46 is formed of: - two hydraulic chambers 50 defined by the cavities 110 and the radially internal surface of the intermediate piece 16, on the one hand, and of - of the channel 48 defined by the recess 112 in the first elastomer body, on the one hand, and by the radially internal surface of the intermediate piece 16.

[0052] This hydraulic circuit 46 operates substantially as in the first example of an anti-vibration device 10.

[0053] The second elastomer body 20 here has a significantly simpler shape than in the first example of an anti-vibration device 10. It comprises a first ring 28 in contact with the intermediate piece 16, a second ring 30 in contact with the second armature 14, and radial arms 38 extending between the first and second rings 28, 30. The radial arms 38 are, for example substantially equidistributed angularly around the axis A of the anti-vibration device 100. For example, the second elastomer body 20 has four radial arms 38

[0054] The assembly of the anti-vibration device 1 O can be carried out, in particular, by overmolding: - the first elastomer body 18 on the first armature 12, on the one hand, and on the intermediate piece 16, on the other hand; and by overmolding - the second elastomer body 20 on the intermediate piece 16, on the one hand, and on the second armature 14, on the other hand. The first elastomer body 18 can simultaneously be overmolded onto the insert 102.

[0055] This disclosure is not limited to the examples described above but is, on the contrary, susceptible to numerous variants accessible to the person qualified in the technical field.

Claims

Demands

1. Anti-vibration mount (10; 100) adapted for filtering and damping vibrations between a first element (M), in particular an electric motor, and a second element (CV), in particular a motor vehicle chassis, the anti-vibration mount (10; 100) comprising: a first armature (12) intended to be fixed to the first element (M); a second armature (14) intended to be fixed to the second element (CV); an intermediate piece (16); a first elastomer body (18) connecting the first armature (12) and the intermediate piece (16); a second elastomer body (20) connecting the intermediate piece (16) and the second armature (14); and a hydraulic damping circuit (46) comprising a first hydraulic chamber (50), a second hydraulic chamber (50), and a channel (48) connecting the first and second hydraulic chambers (50) together, the hydraulic circuit (46) being made between one of the first and second reinforcement piece (12;14), on the one hand, and the intermediate piece (16), on the other hand.;

2. Anti-vibration support according to claim 1, in which the hydraulic damping circuit (46) is made between the first armature (12) and the intermediate piece (16).

3. Anti-vibration support according to claim 2, wherein the first elastomer body (18) forms two cavities (110) connected by a recess (112), the cavities (110) and the recess (112) forming, with the intermediate piece (16), the hydraulic chambers (50) and the channel (46), respectively.

4. Anti-vibration support according to claim 3, wherein the first elastomer body (18) is overmolded on an insert (102) forming windows (114) similar to the cross-section of the cavities (110) and / or a recess (116) of substantially identical shape to the recess (112) in the first elastomer body (18).

5. Anti-vibration support according to claim 3 or 4, wherein the first elastomer body (18) forms at least one bead (116) in the vicinity of each of its longitudinal ends, each bead (116) being pressed against a radially internal surface of the intermediate part (16) to seal the hydraulic damping circuit (46).

6. Anti-vibration support according to claim 1, wherein the hydraulic damping circuit (46) is made between the intermediate piece (16) and the second frame (14).

7. Anti-vibration support according to claim 6, wherein the second elastomer body (20) has two windows (40) in fluid communication via a recess (26) on the intermediate piece (16), the windows (40) and the recess (26) forming, with the second frame (14), the hydraulic chambers (50) and the channel (46), respectively.

8. Anti-vibration support according to claim 7, wherein the second elastomer body (20) is overmolded on at least one insert (22; 24) forming windows (42; 44) of similar shape to the windows (40) in the second elastomer body (20).

9. Anti-vibration support according to any one of the preceding claims, wherein the first elastomer body (18) has a first ring (28) in contact with the first armature (12), a second ring (30) in contact with the intermediate piece (16) and at least one arm (32) between the first and second rings (28; 30).

10. Anti-vibration support according to any one of the preceding claims, wherein the second elastomer body (20) has a first ring (34) in contact with the intermediate piece (16), a second ring (36) in contact with the second armature (14) and at least one arm (38) between the first and second rings (34; 36).

11. Motor vehicle comprising a body (CV), an electric motor (M) and at least one anti-vibration mount (10; 100) according to any one of the preceding claims, between the electric motor (M) and the body (CV).

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