Pneumatically tuned vehicle powertrain mounts
A system for securing a powertrain component to a body structure of a vehicle may include first and second mounts each having a base and a first elastomeric barrier secured to and extending from the base defining an air filled chamber, and a connector coupling the air filled chambers, the connector sized to provide an associated air volume that reduces stiffness of the first elastomeric barrier at an excitation frequency corresponding to a target engine speed. The air filled chambers may be hermetically sealed and pressurized above atmospheric pressure. The system may include a fluid-filled switchable mount having a decoupler air pocket selectively coupled to a vacuum source or atmosphere with an expander integrated with the mount or as a separate component coupled between the decoupler air pocket and the vacuum source. The expander may be implemented as a Helmholtz resonator or may include an in-line expansion chamber.
1. A system, comprising:
a vacuum source; and
a powertrain mount comprising:
a channel plate defining an air channel and a fluid channel and cooperating with
an elastomeric decoupler forming an air pocket coupled to the air channel and vacuum source;
an elastomeric cover forming a fluid chamber surrounding sides and top of the decoupler and coupling a reservoir via the fluid channel; and
an expander defining an expansion chamber coupled to the air channel.
2. The system of claim 1 wherein the expander has a volume of at least ten times greater than a volume of the air pocket of the elastomeric decoupler.
3. The system of claim 1 wherein the expander includes a first port coupled to the air pocket and a second port coupled to a connector and valve associated with the vacuum source.
4. The system of claim 1 wherein the expansion chamber of the expander is coupled to a connector by a single input/output port, the connector disposed between the vacuum source and the air channel.
5. The system of claim 4 , the expansion chamber being tuned based on an air column within the connector to reduce stiffness within a predetermined decoupler excitation frequency range.
6. The system of claim 1 wherein the expander is integrated within a cap secured to the channel plate.
7. The system of claim 1 wherein the expander is disposed between a connector and valve associated with the vacuum source.
8. The system of claim 7 wherein the valve operates to alternatively couple the connector to the vacuum source or to atmosphere.
9. A powertrain mount comprising:
a channel plate;
an elastomeric decoupler cooperating with the channel plate forming an air pocket coupled to a channel plate air channel;
an elastomeric cover forming a fluid chamber that surrounds sides and top of the elastomeric decoupler and is coupled to a fluid reservoir via a channel plate fluid channel; and
an expander coupled to the channel plate air channel.
10. The powertrain mount of claim 9 wherein the expander has a volume at least ten times greater than the air pocket.
11. The powertrain mount of claim 9 wherein the expander has a single input/output port.
12. The powertrain mount of claim 9 wherein the expander is coupled to the channel plate air channel by a connector, and wherein the expander is tuned based on an air column within the connector to reduce stiffness within a predetermined decoupler excitation frequency range.
13. A system comprising:
a powertrain mount comprising:
a channel plate having an air channel and a fluid channel and cooperating with an elastomeric decoupler forming an air pocket coupled to the air channel;
an elastomeric cover containing fluid surrounding sides and top of the decoupler and coupled to the fluid channel; and
an expander coupled to the air channel.
14. The system of claim 13 further comprising a vacuum source coupled to the air channel.
15. The system of claim 13 wherein the expander has a volume of at least ten times greater than a volume of the air pocket of the elastomeric decoupler.
16. The system of claim 13 further comprising a connector connecting the expander to the air channel, wherein the expander comprises a single input/output port.
17. The system of claim 13 further comprising:
a vacuum source coupled to the air channel;
a valve connected to the vacuum source; and
a connector connecting the expander to the valve.