What is claimed is:
1. An air suspension for a vehicle, comprising:
at least one air spring per wheel of at least one vehicle axle;
at least one accumulator;
a pump having a pressure side connected to one of the accumulator and the air spring;
a circuit arrangement connecting the air spring, the pump and the accumulator;
an integrated pressure sensor; and
at least one valve connecting an intake side of the pump to one of the accumulator and the air spring to form a closed compressed-air system;
wherein the pump includes air-guided interior pump chambers arranged between the intake side and the pressure side having a pressure-tight configuration.
2. The air suspension according to claim 1, wherein fresh air is configured to be drawn in between the intake side of the pump and the valve.
3. The air suspension according to claim 2, further comprising one of a non-return valve configured to draw in the fresh air and to open in a suction direction and a discharge valve configured to draw in the fresh air.
4. The air suspension according to claim 1, wherein the compressed-air system is configured to be precharged to a basic pressure corresponding to an average vehicle load.
5. The air suspension according to claim 1, wherein the valve includes a 42 directional control valve configured to connect the accumulator to the pressure side of the pump and the air spring to the intake side of the pump in a flow-through, neutral position and to connect the accumulator to the intake side of the pump and the air spring to the pressure side of the pump in an externally actuated, flow-through position.
6. The air suspension according to claim 1, further comprising a pressure tank, the pump being integrated in the pressure tank.
7. The air suspension according to claim 1, further comprising a connecting line including an integrated bypass line arranged between the intake side of the pump and the pressure side of the pump, the bypass valve being configured to at least intermittently open the connecting line during an acceleration operation of a pump drive.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electrically tunable inductive device comprising:
an electromagnet comprising a silicon-steel electromagnet core and a bias coil cooperating therewith to define opposing magnetic poles for generating a variable magnetic field;
said electromagnet core comprising a pair of opposing legs and a bight portion therebetween defining a horseshoe shape; and
an inductor being tunable based upon the variable magnetic field within the inductor and comprising
an inductor core having a toroidal shape and fixed at a position adjacent the opposing magnetic poles of said electromagnet, and
an inductor coil around at least a portion of the inductor core.
2. The electrically tunable inductive device of claim 1, wherein said inductor core is positioned between ends of the opposing legs of said electromagnet core.
3. The electrically tunable inductive device of claim 2, wherein said bias coil surrounds said bight portion of said core.
4. The electrically tunable inductive device of claim 1, wherein the inductor core comprises a ferrite core.
5. The electrically tunable inductive device of claim 1, wherein the inductor core comprises a nickel zinc ferrite core.
6. The electrically tunable inductive device of claim 1, wherein the inductor core comprises a powdered iron core.
7. The electrically tunable inductive device of claim 1, further comprising a radio frequency (RF) feed connected to the inductor coil and a capacitor connected therebetween.
8. An electrically tunable inductive device comprising:
an electromagnet comprising an electromagnet core and a bias coil cooperating therewith to define opposing magnetic poles for generating a variable magnetic field, said electromagnet core comprising a pair of opposing legs and a bight portion therebetween defining a horseshoe shape, said bias coil surrounding said bight portion of said electromagnet core; and
an inductor being tunable based upon the variable magnetic field and comprising
a ferrite inductor core fixed at a position between ends of the opposing legs of said electromagnet core; and
an inductor coil around at least a portion of the inductor core.
9. The electrically tunable inductive device of claim 8, wherein said inductor core has a toroidal shape.
10. The electrically tunable inductive device of claim 8, wherein the electromagnet core comprises a silicon-steel core.
11. The electrically tunable inductive device of claim 8, further comprising a radio frequency (RF) feed connected to the inductor coil and a capacitor connected therebetween.
12. A band-stop tunable filter comprising:
an electrically tunable inductive device including
an electromagnet comprising an electromagnet core and a bias coil cooperating therewith to define opposing magnetic poles, and
a tunable inductor comprising
an inductor core having a toroidal shape and fixed at a position adjacent the opposing magnetic poles of said electromagnet, and
an inductor coil around at least a portion of said inductor core;
a radio frequency (RF) feed connected to said inductor coil; and
a control signal feed connected to said bias coil.
13. The band-stop tunable filter of claim 12, wherein said electromagnet core comprises a pair of opposing legs and a bight portion therebetween defining a horseshoe shape.
14. The band-stop tunable filter of claim 13, wherein said inductor core is positioned between ends of the opposing legs of said electromagnet core.
15. The band-stop tunable filter of claim 14, wherein said bias coil surrounds said bight portion of said electromagnet core.
16. The band-stop tunable filter of claim 12, wherein said electromagnet core comprises a silicon-steel core.
17. A method of making an electrically tunable inductive device comprising:
providing an electromagnet comprising a silicon-steel electromagnet core and a bias coil cooperating therewith to define opposing magnetic poles for generating a variable magnetic field by at least forming the electromagnet core with a pair of opposing legs and a bight portion therebetween defining a horseshoe shape; and
providing an inductor being tunable based upon the variable magnetic field and comprising
an inductor core having a toroidal shape and fixed at a position adjacent the opposing magnetic poles of the electromagnet, and
an inductor coil around at least a portion of the inductor core.
18. The method of claim 17 wherein providing the inductor includes positioning the inductor core between ends of the opposing legs of the electromagnet core.
19. The method of claim 18, wherein providing the electromagnet includes wrapping the bight portion of the electromagnet core with the bias coil.
20. The method of claim 17, further comprising connecting a radio frequency (RF) feed to the inductor coil and a capacitor therebetween.
21. A method of making an electrically tunable inductive device comprising:
providing an electromagnet comprising an electromagnet core and a bias coil cooperating therewith to define opposing magnetic poles for generating a variable magnetic field;
providing an inductor being tunable based upon the variable magnetic field and comprising
an inductor core having a toroidal shape and fixed at a position adjacent the opposing magnetic poles of the electromagnet, and
an inductor coil around at least a portion of the inductor core; and
connecting a radio frequency (RF) feed to the inductor coil and a capacitor therebetween.