Linear electromagnetic machine system
A linear electromagnetic machine includes a stator, a translator, and a bearing system. The bearing system maintains alignment against lateral displacement of the translator relative to the stator, as the translator reciprocates axially. More particularly, the bearing system maintains a motor air gap between the stator and a magnetic section of the translator. The stator includes a plurality of stator teeth and windings, which form a plurality of phases. The stator teeth and windings are arranged using a hoop stack with spines to form a stator bore and define the motor air gap. The bearing system can include bearing housings that are configured to form a bearing interface with a surface of the translator. The bearing interface can include a contact bearing or a non-contact bearing, such as a gas bearing. Current is controlled in the phases to convert between electrical energy and kinetic energy of the translator.
1. A stator for a linear electromagnetic machine, the stator comprising:
a plurality of winding hoops arranged axially in an array;
a plurality of sets of stator teeth, each set of which corresponds to a respective winding hoop of the plurality of winding hoops, wherein:
each set of stator teeth of the plurality of sets of stator teeth engages with the respective winding hoop;
at least one set of stator teeth of the plurality of sets of stator teeth is arranged azimuthally to form a set of azimuthal gaps between adiacent stator teeth;
at least one azimuthal gap of the set of azimuthal gaps is relatively larger than another azimuthal gaps of the set of azimuthal gaps; and
the at least one azimuthal gap provides an anti-clocking force on a translator configured to move axially alarm the stator;
a plurality of winding coils, each winding coil arranged along a respective set of stator teeth of the plurality of sets of stator teeth;
at least one end plate arranged at a first longitudinal end of the array; and
at least one spine extending axially along the plurality of winding hoops and constraining azimuthal and radial alignment of the plurality of winding hoops.
2. The stator of claim 1 , wherein each end plate of the at least one end plate is configured to be coupled to a respective bearing housing.
3. The stator of claim 1 , wherein a first tooth of a set of stator teeth of the plurality of sets of stator teeth comprises:
a first axial feature arranged on a first axial side and configured to engage a second stator tooth of a first axially adjacent set of teeth; and
a second axial feature arranged on a second axial side and configured to engage a third stator tooth of a second axially adjacent set of teeth, wherein the second axial side is opposite the first axial side.
4. The stator of claim 1 , wherein:
each set of stator teeth of the plurality of sets of stator teeth is arranged azimuthally;
the plurality of sets of stator teeth are arranged axially with each other; and
the plurality of sets of stator teeth, when arranged, form a stator bore.
5. The stator of claim 1 , wherein the plurality of sets of stator teeth and the plurality of winding hoops are configured to provide the anti-clocking force on the translator without contacting the translator, and wherein the translator interfaces to the stator only by gap interfaces.
6. The stator of claim 1 , further comprising at least one tie rod extending axially from the at least one end plate to a second longitudinal end of the array, the at least one tie rod configured to provide structural support to the stator.
7. The stator of claim 1 , wherein each stator tooth of the plurality of sets of stator teeth comprises a mounting feature configured to engage with a winding hoop of the plurality of winding hoops.
8. The stator of claim 7 , wherein:
each winding hoop comprises a respective set of features arranged azimuthally; and
for each respective set of stator teeth of the plurality of sets of stator teeth, each mounting feature of each stator tooth is configured to engage with a feature of the respective set of features.
9. A linear electromagnetic machine (LEM) comprising:
a stator comprising:
a plurality of winding hoops arranged axially in an array;
a plurality of sets of stator teeth, each set of which corresponds to a respective winding hoop of the plurality of winding hoops, wherein:
each set of stator teeth of the plurality of sets of stator teeth engages with the respective winding hoop;
at least one set of stator teeth of the plurality of sets of stator teeth is arranged azimuthally to form a set of azimuthal gaps between adiacent stator teeth; and
at least one azimuthal gap of the set of azimuthal gaps is relatively larger than another azimuthal gaps of the set of azimuthal gaps;
a plurality of winding coils, each winding coil arranged along a respective set of stator teeth of the plurality of sets of stator teeth;
at least one end plate arranged at a first longitudinal end of the array; and
at least one spine extending axially along the plurality of winding hoops and constraining azimuthal and radial alignment of the plurality of winding hoops; and
a translator configured to move axially along the stator, wherein the translator and the stator form gap interfaces without contact, and wherein the at least one azimuthal gap provides the anti-clocking force on the translator.
10. The LEM of claim 9 , wherein each end plate of the at least one end plate is configured to be coupled to a respective bearing housing.
11. The LEM of claim 9 , wherein a first tooth of a set of stator teeth of the plurality of sets of stator teeth comprises:
a first axial feature arranged on a first axial side and configured to engage a second stator tooth of a first axially adjacent set of teeth; and
a second axial feature arranged on a second axial side and configured to engage a third stator tooth of a second axially adjacent set of teeth, wherein the second axial side is opposite the first axial side.
12. The LEM of claim 9 , wherein:
each set of stator teeth of the plurality of sets of stator teeth is arranged azimuthally;
the plurality of sets of stator teeth are arranged axially with each other; and
the plurality of sets of stator teeth, when arranged, form a stator bore.
13. The LEM of claim 11 , further comprising at least one tie rod extending axially from the at least one end plate to a second longitudinal end of the array, the at least one tie rod configured to provide structural support to the stator.
14. The LEM of claim 9 , wherein each stator tooth of the plurality of sets of stator teeth comprises a mounting feature configured to engage with a winding hoop of the plurality of winding hoops.
15. The LEM of claim 14 , wherein:
each winding hoop comprises a respective set of features arranged azimuthally; and
for each respective set of stator teeth of the plurality of sets of stator teeth, each mounting feature of each stator tooth is configured to engage with a feature of the respective set of features.
16. A device comprising:
a stator comprising:
a plurality of winding hoops arranged axially in an array;
a plurality of sets of stator teeth, each set of which corresponds to a respective winding hoop of the plurality of winding hoops, wherein:
each set of stator teeth of the plurality of sets of stator teeth engages with the respective winding hoop;
at least one set of stator teeth of the plurality of sets of stator teeth is arranged azimuthally to form a set of azimuthal gaps between adiacent stator teeth; and
at least one azimuthal gap of the set of azimuthal gaps is relatively larger than another azimuthal gaps of the set of azimuthal gaps;
a plurality of winding coils, each winding coil arranged along a respective set of stator teeth of the plurality of sets of stator teeth, wherein each winding coil is configured to be coupled to a power electronics system;
at least one end plate arranged at a first longitudinal end of the array; and
at least one spine extending axially along the plurality of winding hoops and constraining azimuthal and radial alignment of the plurality of winding hoops; and
a translator configured to move axially along the stator, wherein the translator and the stator form gap interfaces without contact and wherein the at least one azimuthal gap provides the anti-clocking force on the translator, and wherein the translator comprises:
a first piston attached at a first axial end defining a reaction section; and
a second piston attached at a second axial end opposite the first axial end, defining a gas spring.