Patent Application
20090189052
This invention relates to the field of motor support devices for motor vehicle heating, ventilation and/or air-conditioning systems. More specifically, the invention relates to a support device including means for decoupling motor vibrations.
In a heating, ventilation and/or air-conditioning system, the air flow circulating in it is propelled by a blower wheel driven in rotation by a motor. The implementation of the blower wheel and the motor create vibrations. These vibrations are the source of sound and vibration (imbalance) disturbances, in the vehicle interior, of the motor housed in a motor support. The vibrations are transmitted via the motor support to the entire heating, ventilation and/or air-conditioning system and create acoustic waves that interfere with the comfort of vehicle passengers.
To overcome this, decoupling means have been provided between the motor and the motor support or between a ring housing the motor and the motor support. These decoupling means are effective only for a certain type of vibrations and do not enable the transmission of any type of vibrations to the heating, ventilation and/or air-conditioning system to be prevented. However, when an motor drives a blower wheel, a number of phenomena add up and cause a multitude of different vibrations. First, the imbalance of the wheel causes a radial movement of the motor that should be avoided. Second, a “pumping” phenomenon due to the suction of air by the blower wheel as well as the deformation of the wheel causes an axial movement of the motor. Finally, as the motor drives the blower wheel by rotation, a pitching movement or so-called tangential movement of the motor is created. Moreover, depending on the position of the motor in the heating, ventilation and/or air-conditioning system, i.e. depending on the horizontal or vertical position of the motor shaft, the phenomena mentioned above are more or less intense. Consequently, a choice is made regarding the type of vibration dealt with by the decoupling means. An example is document U.S. Pat. No. 6,279,866. This document presents two embodiments. The first embodiment involves decoupling of the motor from the motor support for radial vibrations of the motor. The other embodiment involves decoupling the motor from the motor support for axial vibrations of the motor.
This is not satisfactory from the perspective of standardization of the decoupling means used or from the perspective of its location in the motor support device. The decoupling means of the prior art are not suitable for decoupling the motor from the motor support regardless of the position of the motor, i.e. whether the motor is in the horizontal or the vertical position. Moreover, not all of the sound disturbances created by this multitude of vibrations are dealt with. The comfort of passengers in the vehicle is therefore not optimal.
The invention is intended to improve this situation.
To do this, the invention relates to a motor support device including a base, a ring extending according to an axis A and capable of housing a motor with an axis A and at least one decoupling means connecting the base and the ring, in which said ring has a first face that extends according to axis A, and said base has a second face that extends according to axis A. The decoupling means are interposed between the first and the second faces.
Other features of the invention are listed below:
The invention also relates to a process for producing the support device including the following steps:
a) molding the ring and the base with a first plastic material
b) over-molding the decoupling means with a second plastic material.
Other features and advantages of the invention will appear on examination of the following detailed description, and the appended drawings, in which:
a is a perspective view of the decoupling means according to the invention,
a is a perspective view of the ring equipped with decoupling means according to the first embodiment of the invention,
b is a top view of
a is a partial cross-section view of the base 2 of
The appended drawings may serve not only as a complement to the invention, but also contribute to its definition, where appropriate.
The ring 3 is a hollow cylinder. It extends according to an axis A and is capable of housing a motor with an axis A. By “extend”, we mean that the length of the cylinder has a direction parallel to that of the axis A. The motor, not shown, causes the rotation, during implementation, of a blower wheel housed in a housing. This blower wheel creates an air flow passing through the heating, ventilation and/or air-conditioning system.
The ring 3 has a first face 5 that extends according to the axis A. This first face 5 is the external face of the hollow cylinder. A first end 6 of the ring 3 is open and includes three shoulders 7. These shoulders 7 extend the first end 7 in a radial direction with respect to the axis A. A second open end 8, opposite the first end 7, includes three flexible tabs 9. The shoulders 7 and the flexible tabs 9 keep the motor with the axis A inside the ring 3.
The base 2 is a hollow cylinder of which the ends are open. The hollow cylinder extends according to the axis A and has a second face 10 that extends according to this axis A. This second face 10 is the internal face of the base 2.
The ring 3 is located inside the base 2 so that the first face 5 of the ring 3 is opposite the second face 10 of the base 2. Nevertheless, the ring 3 and the base 2 are not in direct contact. The ring 3 is kept inside the base 2 by the decoupling means 4.
The decoupling means 4 are contacts. The decoupling means are interposed between the first face 5 of the ring 3 and the second face 10 of the base 2. Each contact 4 has a parallelepiped shape. By “parallelepiped”, we mean a hexahedron of which the sides are parallelograms, with the opposite sides being parallel and equal. Each contact 4 therefore has a first side 11 in direct contact with the first face 5 of the ring 3 and a second side 12 in direct contact with the second face 10 of the base 2. Each contact 4 also includes a third free side 13 extending in an axial plane with respect to the axis A. This third free side 13 has at least one recess 15 extending in a direction parallel to the axis A. By “free”, we mean that the third side is not in contact with the ring 3 or the base 3. By “axial plane”, we mean any plane containing the axis A. A fourth side 14, opposite the third side 13, includes at least one recess 15 extending in a direction parallel to the axis A. It should be noted that the first 11, the second 12, the third 13 and the fourth 14 sides extend in a direction parallel to the axis A.
These decoupling means 4 ensure the decoupling between the motor, not shown, capable of being housed in the ring 3 and the base 2. More generally, the decoupling means 4 ensure the decoupling between the motor and the heating, ventilation and/or air-conditioning system in which it is integrated.
The decoupling means 4 are made of plastic material. More specifically, the decoupling means 4 re made of a damping material. By “damping”, we mean that the plastic material absorbs the vibrations of the motor so as not to transmit them to the base. An example of a damping material is natural rubber. The recess 15 formed on the third side 13 and the fourth side 14 gives the contact an H shape from a top view of the support device (
In
The first movement caused by the implementation of the motor and the blower wheel is an axial movement MA. By “axial movement”, we mean a movement in a direction parallel to the axis A. This axial movement is more specifically a so-called pumping movement caused by the rotation o the blower wheel. The trunk 21 of each contact 4 is deformed in a direction parallel to the axis A in order to attenuate this movement. The second movement is a radial movement MR. By “radial movement”, we mean a movement in a radial direction with respect to the axis A. The trunk 21 is then compressed and/or decompressed according to its thickness in order to prevent the transmission of this movement to the base 2. The third movement is a tangential movement MT. By “tangential movement”, we mean a rotation movement with respect to the axis A. The trunk 21 is also subjected to this movement and is deformed in a clockwise and/or counterclockwise direction with respect to the axis A. Consequently, the decoupling means 4 enables three-dimensional decoupling of the ring 3 subjected to the movements of the motor with respect to the base 2.
a and 2b show the ring 3 equipped with decoupling means 4. There are six decoupling means 4 in the first embodiment. Among the six contacts 4, at least two contacts 4 are distributed according to a first radial plane P1 and at least two contacts 4 are distributed according to a second radial plane P2. By “radial plane”, we mean any plane orthogonal to the axis A and extending in a radial direction with respect to the axis A. As the first radial plane P1 is distinct from the second radial plane P2, the distribution of the plurality of contacts forms at least two rows of contacts. According to
The position of the radial planes P1 and P2 is chosen so that the center of gravity G of the motor, not shown, is between these two radial planes P1 and P2. Thus, regardless of the position of use of the motor, the motor is always held correctly in the base 2. In other words, whether the axis A of the motor is in the horizontal or the vertical position, the distribution of contacts 4 ensures that the motor is held in the base 2. The presence of six contacts 4 and the distribution of these contacts help to improve the standardization of the support device. Indeed, when a support device of the prior art includes only three decoupling contacts, the center of gravity of the motor can, when the axis A of the motor is in the horizontal position, cause a force on a portion of the motor that is not opposed. In this way, the axis of the motor can be tilted with respect to the horizontal, which would cause friction of the blower wheel on the internal wall of the housing containing it. Moreover, it is advantageous to arrange the radial planes P1 and P2 at the ends of the ring 3. In this way, regardless of the motor housed in the ring 3, its center of gravity G will be between these two radial planes. Thus, a single ring 3 equipped with contacts 4 distributed according to the two radial planes P1 and P2 located at the ends of the ring 3 can be used with motors of identical size but having their center of gravity G located differently. The standardization of the support device 1 is thus improved.
The three contacts distributed according to the same radial plane are offset from one another by an angle α of 120° with respect to the axis A. This distribution of contacts of the same radial plane enables a static and dynamic balance of the motor in the planes parallel to the axis A. In general, the angular offset α is determined by the following ration: α=360/(number of contacts distributed in the same radial plane).
According to the first embodiment, each contact 4 is offset from the adjacent contact by an angle β of 600. This distribution is an improvement with regard to the balance in the plane perpendicular to the axis of the motor. By “adjacent contact”, we mean the contact that follows a preceding contact along the first face 5 of the ring 3. In general, each decoupling means 4 of a first radial plane P1 is offset by an angle β of between 0 and 120° with respect to a decoupling means 4 of a second radial plane P2.
According to a first embodiment, the ring 3 and the contacts 4 are made in one piece. By “in one piece”, we mean that the ring 3 and the contacts 4 form a single part 26. In this embodiment, the support device 1 is formed by the assembly of the base 2 to the single part 26 by means of the contacts 4. According to
According to a second embodiment, not shown, the support device 1 is obtained according to a single molding process. First, the ring 3 and the base 2 are formed by molding a first plastic material. Then, the contacts 4 are over-molded both on the base 2 and the ring 3. The contacts 4 are preferably obtained with a second plastic material, distinct from the first plastic material. In this embodiment, the attachment means formed by the lug 29 and the tab 28 are no longer present on the base 2 and the ring 3, respectively. However, the advantage obtained by the opening of the base 2 in order to attach the motor by its bottom in a testing bench remains present. In addition, the ridges 17 forming a housing 24 entirely surround the second side 12 of the associated contact 4 since it is no longer necessary to insert the second side into said housing 24. It should be noted that this production process is described as “one shot”. In other words, this process enables, by using a single molding apparatus, the support device to be obtained in which the base, the ring and the decoupling means form a single part. More specifically, the molding of the base and the ring is performed in the same mold using a first plastic material. Then, a second plastic material is introduced into the same mold in order to form the decoupling means. The decoupling means are then over-molded on the base and the ring, and the latter are still present in the mold during the over-molding of the decoupling means. In this embodiment, the ridges 17 orient the second plastic material toward the housings 24 during the over-molding of the decoupling means. In addition, the trapezoid shape of the housings 24 improves the ease of molding of the contacts 4.
According to a third embodiment, not shown, the motor support 27 is made in one piece. Thus, when the motor is housed in the ring 3 equipped with these contacts 4, said contacts are inserted into the housings 24 from the base 2 forming a single part with the hood 18. In this embodiment, the performance tests on the motor are performed before the support device 1 is placed on the motor.
According to a fourth embodiment, not shown, the support device 1 is capable of housing a two-wheel motor. In this case, the base 2 alone forms the motor support and includes means for attaching said support device to the heating, ventilation and/or air-conditioning system.
According to another alternative of the invention, the decoupling means include a single recess 15 on the third side 13. In other words, the fourth side 14 has a planar surface. The contact 4 then has a U shape.
Regardless of the embodiment or alternative envisaged, the following features apply.
The base 2 is formed by a first plastic material. Preferably, the first plastic material is polypropylene. The ring 3 is also formed by this first plastic material.
The decoupling means 4 in the form of a contact 4 are formed by a second plastic material. This second plastic material is natural rubber, polypropylene, EPDM or SEBS. It should be noted that the H shape of the decoupling means 4 enable polypropylene for example to be used as the second plastic material. Indeed, even though polypropylene does not have good elastic properties compared with those of natural rubber, it can be used to form the decoupling means 4 since the recesses 15 on the third 13 and fourth 14 sides involve flexibility of the decoupling means at the level of the trunk 21.
In addition, the H shape of the decoupling means enable the loss in elastic properties to be overcome when the temperature of the second plastic material is low, for example below 0° C. Thus, when a motor vehicle including a heating, ventilation and/or air-conditioning system equipped with a support device according to the invention is used during the winter, the H shape helps to ensure the three-dimensional decoupling of the motor from the motor support.
| Number | Date | Country | Kind |
|---|---|---|---|
| FR08/00212 | Jan 2008 | FR | national |
