Driveshaft assemblies and compressors including the same
A driveshaft assembly for a compressor includes an unloader assembly and a driveshaft. The unloader assembly includes an unloader and a counterweight. The unloader assembly is rotationally supported by a bearing. The unloader includes a flank surface that is slidably engaged with a flank surface on the driveshaft.
1. A driveshaft assembly comprising:
a bearing including an inner bearing surface;
a driveshaft having a longitudinal axis and having an outer surface, the outer surface including a flank surface and a secondary surface; and
an unloader assembly comprising:
an unloader including an inner surface and an outer surface, the outer surface is rotationally supported with the bearing inner surface and the inner surface includes a flank surface and a secondary surface, wherein the flank surface is slidably engaged with the flank surface of the driveshaft along a direction that is perpendicular to the longitudinal axis of the driveshaft; and
a counterweight connected to the unloader and extending radially outward relative to the unloader.
2. The driveshaft assembly of claim 1 , wherein when a driveshaft speed increases in rotational speed from a first speed to a second speed, higher than the first speed, the flank surface of the unloader slides along the flank surface of the driveshaft, until the driveshaft reaches a transition speed, and when the driveshaft reaches the transition speed the unloader is restricted from sliding any further along the flank surface of the driveshaft.
3. The driveshaft assembly of claim 1 , wherein at least one of the flank surface of the unloader and the flank surface of the driveshaft is curved.
4. The driveshaft assembly of claim 1 , wherein the driveshaft is rotatable at a first speed range and a second speed range higher than the first speed range, wherein when the driveshaft is rotating at the first speed range the secondary surface of the driveshaft is not in contact with the secondary surface of the unloader, and when the driveshaft is rotating at the second speed range the secondary surface of the driveshaft is in contact with the secondary surface of the unloader assembly.
5. The driveshaft assembly of claim 1 , wherein the driveshaft is drivingly engaged with an orbiting scroll that is meshed with a non-orbiting scroll, and wherein the driveshaft is rotatable at a first speed range and a second speed range higher than the first speed range, wherein when the driveshaft is rotating at the first speed range at least a portion of a scroll flank surface of a non-orbiting scroll contacts a scroll flank surface of an orbiting scroll, and when the driveshaft is rotating at the second speed range the scroll flank surface of the non-orbiting scroll and the scroll flank surface of the orbiting scroll are separated by a scroll separation distance.
6. The driveshaft assembly of claim 1 , wherein the flank surface of the unloader and the flank surface of the driveshaft are slidably engaged along the direction that includes a chord of the driveshaft and aligned between a first and second radial end of the counterweight.
7. The driveshaft assembly of claim 1 , wherein an inner radius of the secondary surface of the unloader assembly is between 0.01-2 mm greater than a radius of the secondary surface of the driveshaft.
8. The driveshaft assembly of claim 1 , wherein a width of the flank surface of the driveshaft is less than a width of the flank surface of the unloader assembly along a chord direction that is perpendicular to a longitudinal axis of the driveshaft.
9. The driveshaft assembly of claim 1 , wherein the unloader extends in an axial direction between a first axial end and a second axial end, wherein the counterweight is connected to at least one of the first axial end or the second axial end.
10. The driveshaft assembly of claim 1 , wherein the counterweight extends radially outward from the unloader between a first circumferential position and a second circumferential position spanning an angle less than 180 degrees.
11. The driveshaft assembly of claim 1 , wherein the unloader includes an outer radius and wherein the counterweight includes an outer radius, wherein the outer radius of the counterweight is 1.5-5 times greater than the outer radius of the unloader.
12. The driveshaft assembly of claim 1 , wherein the secondary surface of the driveshaft is cylindrical and the secondary surface of the unloader is cylindrical.
13. A compressor comprising:
a shell;
a scroll assembly disposed within the shell, the scroll assembly comprising:
a non-orbiting scroll; and
an orbiting scroll; and
a driveshaft assembly comprising:
a bearing including an inner bearing surface;
a driveshaft having a longitudinal axis and having an outer surface, the outer surface including a secondary surface and a flank surface; and
an unloader assembly comprising:
an unloader including an inner surface and an outer surface, the outer surface is rotationally supported with the bearing inner surface and the inner surface includes a secondary surface and a flank surface, wherein the flank surface is slidably engaged with the flank surface of the driveshaft along a direction that is perpendicular to the longitudinal axis of the driveshaft; and
a counterweight connected to the unloader and extending radially outward relative to the unloader.
14. The compressor of claim 13 , wherein the driveshaft is rotatable at a first speed range and a second speed range higher than the first speed range, wherein when the driveshaft is rotating at the first speed range at least a portion of a scroll flank surface of the non-orbiting scroll contacts a scroll flank surface of the orbiting scroll, and when the driveshaft is rotating at the second speed range, the scroll flank surface of the non-orbiting scroll and the scroll flank surface of the orbiting scroll are separated by a scroll separation distance.
15. The compressor of claim 13 , wherein when the driveshaft increases in rotational speed from a first speed to a second speed higher than the first speed, the flank surface of the unloader slides along the flank surface of the driveshaft, until the driveshaft reaches a transition speed, and when the driveshaft reaches the transition speed the unloader is restricted from sliding any further along the flank surface of the driveshaft.
16. The compressor of claim 13 , wherein at least one of the flank surface of the unloader and the flank surface of the driveshaft is curved.
17. The compressor of claim 13 , wherein the driveshaft is rotatable at a first speed range and a second speed range higher than the first speed range, wherein when the driveshaft is rotating at the first speed range the secondary surface of the driveshaft is not in contact with the secondary surface of the unloader, and when the driveshaft is rotating at the second speed range the secondary surface of the driveshaft is in contact with the secondary surface of the unloader assembly.
18. The compressor of claim 13 , wherein the flank surface of the unloader and the flank surface of the driveshaft are slidably engaged along the direction that includes a chord of the driveshaft and that is aligned between a first and second radial end of the counterweight.
19. A method of assembling a driveshaft assembly for rotating an orbiting scroll relative to a non-orbiting scroll:
inserting a bearing assembly that defines a bearing opening, within an opening defined within a first hub;
inserting an unloader of an unloader assembly within the bearing opening such that a counterweight of the unloader assembly is disposed outside of the bearing opening; and
inserting a driveshaft within an unloader opening defined by the unloader assembly, wherein a flank surface of the driveshaft is in contact with a flank surface of the unloader, and wherein a secondary surface of the driveshaft is arranged in proximity to a secondary surface of the unloader.
20. The method of claim 19 , wherein the driveshaft is rotatable at a first speed range and a second speed range higher than the first speed range, wherein when the driveshaft is rotating at the first speed range at least a portion of a scroll flank surface of the non-orbiting scroll contacts a scroll flank surface of the orbiting scroll, and when the driveshaft is rotating at the second speed range the scroll flank surface of the non-orbiting scroll and the scroll flank surface of the orbiting scroll are separated by a scroll separation distance.
21. A driveshaft assembly comprising:
a bearing including an inner bearing surface;
a driveshaft having a longitudinal axis and having an outer surface, the outer surface including a flank surface and a secondary surface; and
an unloader assembly comprising:
an unloader including an inner surface and an outer surface, the outer surface is rotationally supported with the bearing inner surface and the inner surface surrounds the driveshaft, wherein the unloader moves relative to the driveshaft when the driveshaft is rotating in a first speed range; and
a counterweight connected to the unloader and extending radially outward relative to the unloader.