Patent Application
20180361830
This document relates generally to the motor vehicle equipment field and, more particularly, to a dual electric drive A/C compressor system as well as to a method of isolating that dual electric drive A/C compressor system on a motor vehicle in order to control noise, vibration and harshness (NVH).
Conventional motor vehicles are equipped with belt-driven A/C compressors that are of three piston designs typically mounted to the power train. In contrast, hybrid electric and electric vehicles typically have a high voltage electric motor driven compressor (eA/C) that does not require direct mounting to the power train.
The next generation of electrified motor vehicles will have an increased demand for cooling. When this increased cooling demand is considered in combination with the limited packaging space on the engine block, the eA/C system integration presents an opportunity for the system to be moved off the power train. Moving the eA/C system off the power train provides an opportunity to utilize a dedicated isolation system which reduces the structure-born vibrations and acoustic radiated noise generated by the eA/C.
Due to the additional cooling of the electronics for advanced electrified vehicles, including autonomous vehicles, the thermal energy management systems now require dual eA/C units. Mounting of the dual eA/C units to the body/chassis structure of the motor vehicle faces two new challenges. The first is the loss of engine mass and the second is the loss of the power train mount isolation system which both serve to reduce eA/C system vibrations being transmitted to the motor vehicle occupants.
This document relates to a new and improved eA/C system and related method of isolating dual eA/C compressor assemblies on a motor vehicle.
In accordance with the purposes and benefits described herein, a new and improved eA/C system is provided for a motor vehicle. That eA/C system comprises a base, a first compressor assembly carried on that base, a second compressor assembly carried on that base and a control module configured to align phases and speeds of the first compressor assembly and the second compressor assembly so as to reduce NVH.
The first compressor assembly may include a first compressor and a first drive motor. The second compressor assembly may include a second compressor and a second drive motor. The control module may include a first resolver monitoring the first drive motor and a second resolver monitoring the second drive motor. In addition, the control module may include a vibration detection device monitoring the motion or vibration of the base. Further, the control module may include a controller connected to the vibration detection device, the first resolver and the second resolver.
The first resolver and the second resolver may be selected from a group of devices consisting of an analog resolver, a digital resolver, a rotary encoder or combinations thereof.
The eA/C system may further include a dampener securing the base to the motor vehicle. That dampener may be an elastomeric mounting feature to suppress transmission of noise and vibration from the base to the motor vehicle and, more particularly, the body or frame of the motor vehicle.
In accordance with an additional aspect a motor vehicle is provided equipped with the eA/C system described herein.
In accordance with still another aspect, a method is provided of isolating a dual eA/C compressor system on a motor vehicle. That method comprises the steps of mounting a first compressor assembly and a second compressor assembly on a base and reducing vibration by aligning phases and speeds of the first compressor assembly and the second compressor assembly with an isolation system. That isolation system may be dedicated for this purpose.
The method may further include the step of monitoring a first drive motor of the first compressor assembly with a first resolver. Further, the method may include the step of monitoring a second drive motor of the second compressor assembly with a second resolver.
Still further, the method may include the step of monitoring vibration of the base with a vibration monitoring device. Still further the method may include the step of configuring a control module of the isolation system to align phases and the speeds of the first compressor assembly and the second compressor assembly so as to reduce NVH. Toward this end the method may include configuring a controller of the control module to adjust the phases and speeds of the first compressor assembly and the second compressor assembly to cancel noise and vibration in response to data input from the first resolver, the second resolver and the vibration monitoring device.
Still further, the method may include the step of securing the base to the motor vehicle by means of a dampener. That dampener may take a number of forms including, but not necessarily limited to, an elastomeric mount.
In the following description, there are shown and described several preferred embodiments of the eA/C system. As it should be realized, the eA/C and the related method of isolating a dual compressor system of a motor vehicle are capable of other, different embodiments and their several details are capable of modification in various, obvious aspects all without departing from the system and method as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.
The accompanying drawing figures incorporated herein and forming a part of the specification, illustrate several aspects of the eA/C system and related method and together with the description serve to explain certain principles thereof. In the drawing figures:
Reference will now be made in detail to the present preferred embodiments of the eA/C system and the vibration isolation method, examples of which are illustrated in the accompanying drawing figures.
As illustrated in
As illustrated in
Referring back to
The control module 26 may also include a vibration detection device 32 for monitoring the vibration of the base 24 upon which the first compressor assembly 12 and second compressor assembly 14 are mounted. That vibration detection device 32 may be of a type known in the art suitable for such a use. For example, the vibration detection device 32 may comprise one or more devices for motion detection such as one or more accelerometers.
As further illustrated in
The controller 34 may be a dedicated controller exclusively adapted for aligning the phases and speeds of the first and second drive motors 18, 22. Alternatively, the controller 34 may be a multifunctional controller such as a body control module or BCM. As is known in the art, a BCM performs a number of interior body electrically based functions including, for example, interior locking, remote key entry, interior lighting, exterior lighting, windshield wiper control and the like. In some embodiments the BCM may also function to control entertainment functions (e.g. radio, CD player) and communications such as telephone and internet communications over a wireless network. In some embodiments the BCM is connected by a communication bus to other control modules that provide one or more of these additional functions.
As illustrated in
As further illustrated in
Consistent with the above description, a method is provided of isolating a dual eA/C compressor system 10 on a motor vehicle 36. That method may be broadly described as comprising the steps of mounting the first compressor assembly 12 and the second compressor assembly 14 on the base 24 and reducing vibration by aligning the phases and speeds of the first compressor assembly 12 and the second compressor assembly 14 with the control module 26. Toward this end, the method includes the step of monitoring the first drive motor 18 of the first compressor assembly 12 with the first resolver 28. Further, the method includes the step of monitoring the second drive motor 22 of the second compressor assembly 14 with the second resolver 30. In addition, the method includes monitoring vibration of the base 24 with the vibration monitoring device 32.
Still further, the method includes configuring the control module 26 to align the phases and speeds of the first compressor assembly 12 and the second compressor assembly 14 so as to reduce NVH. This includes configuring the controller 34 to adjust the phases and speeds of the first compressor assembly 12 and the second compressor assembly 14 to cancel noise and vibration in response to data input from the first resolver 28, the second resolver 30 and the vibration monitoring device 32.
In order to further isolate and control vibration, the method also includes securing the base 34 to the motor vehicle 36 by means of a dampener 38 such as the illustrated elastomeric mounts.
The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
