Various exemplary embodiments relate to screw compressor rotors used to compress fluids.
Rotary screw compressors typically include two or more intermeshing rotors positioned in a housing. A male rotor includes one or more lobes that mate with grooves of a female rotor. The housing defines a chamber in which the male and female rotors are positioned. The chamber is dimensioned closely with the outer diameters of the male and female rotor, generally shaped as a pair of cylinders that are parallel and intersecting. An inlet is provided for the introduction of fluid to the rotors and an outlet is provided for discharging the compressed fluid.
The rotors include a driving mechanism, for example gears, that drive and synchronize the movement of the male and female rotors. During rotation, the intermeshing male and female rotors form cells of varying sizes to first receive the inlet fluid and then compress, thus increasing the pressure of, the fluid as it moves toward the outlet. Dry compressors can utilize one or more gears connected to a shaft to drive and synchronize rotation of the rotors. Wet compressors can utilize a fluid, for example oil, to space and driver the rotors.
The profiles of the male and female rotors can be generated a number of ways. One way is to define one of the two rotors and then derive the other profile using conjugation. Another method includes defining a rack curve for the rotors, and using the rack curve to define the male and female rotors. This method is described, for example in: U.S. Pat. No. 4,643,654; WO 97/43550; and GB 2,418,455. Another method of defining male and female rotor profiles by enveloping a rack curve is described in U.S. Pat. No. 8,702,409, the disclosure of which is hereby incorporated by reference in its entirety.
Various exemplary embodiments relate to a screw compressor or expander having a female rotor including a first section having a right-hand first groove and a second section having a left-hand second groove. The first groove has a first variable helix, the second groove has a second variable helix, and the female rotor has a first variable profile and a first variable outer diameter. A male rotor includes a third section having a left-hand first lobe and a fourth section having a right-hand second lobe. The first lobe has a third variable helix, the second lobe has a fourth variable helix, and the male rotor has a second variable profile and a second variable outer diameter.
Various exemplary embodiments relate to a screw compressor or expander having a female rotor including a first section, a second section, and a first central section. The first section having a set of right-hand first grooves, the second section having a set of left-hand second grooves corresponding to the set of first grooves. The first grooves have a first variable helix, the second grooves have a second variable helix, and the female rotor has a first variable profile. A male rotor includes a third section, a fourth section, and a second central section positioned between the third and fourth sections. The third section having a set of left-hand first lobes and the fourth section having a set of right-hand second lobes corresponding to the set of first lobes. The first lobes have a third variable helix, the second lobes have a fourth variable helix, and the male rotor has a second variable profile. The female rotor transitions to a substantially circular cross section at the first central section and the male rotor transitions to a substantially circular cross section at the second central section.
Various exemplary embodiments relate to a screw compressor or expander having a female rotor including a first section having a first groove with a right-hand first variable helical profile and a second section having a second groove with a left-hand second variable helical profile. A male rotor including a third section having a first lobe with a right-hand third variable helical profile and a fourth section having a second lobe with a left-hand fourth variable helical profile.
Various exemplary embodiments relate to a screw compressor or expander including a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes with a variable profile extending along the first axial length. A female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves with a variable profile extending along the second axial length. The set of grooves mating with the set of lobes. At least a portion of the male rotor and the female rotor each have a non-cylindrical configuration with a non-constant outer diameter.
Various exemplary embodiments relate to a screw compressor or expander including a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes with a variable profile extending along at least a portion of the first axial length. A female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves with a variable profile extending along at least a portion of the second axial length, the set of grooves mating with the set of lobes. The male rotor and the female rotor transition to a substantially circular cross section near the outlet portion.
Various exemplary embodiments relate to a screw compressor or expander including a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes extending along at least a portion of the first axial length. A female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves extending along at least a portion of the second axial length, the set of grooves mating with the set of lobes. The male rotor and the female rotor have a first section with a first profile defined by a first rack having a first set of X and Y coordinates and a second section with a second profile defined by a second rack different than the first rack having a second set of X and Y coordinates.
Various exemplary embodiments relate to a method of designing a set of screw compressor or expander rotors. A first rack is established for a male and female rotor. The first rack having at least one curved segment with a first crest having a first set of X and Y coordinates. The first rack is scaled in the X and Y directions to create a second rack having at least one curved segment with a second crest having a second set of X and Y coordinates. The X coordinate of the second crest is spaced from the X coordinate of the first crest.
Various exemplary embodiments relate to a method of designing a set of screw compressor or expander rotors. A first rack is established for a male and female rotor. The first rack having at least one curved segment with a first crest having a first set of a X and Y coordinates. A second rack is established for a male and female rotor. The second rack having at least one curved segment with a second crest having a second set of a X and Y coordinates, wherein the X coordinate of the second crest is spaced from the X coordinate of the first crest.
Various exemplary embodiments relate to a screw compressor or expander including a male rotor having a first axial length and a set of lobes with a first helical profile extending along the first axial length. A female rotor having a second axial length and a set of grooves with a second helical profile extending along the second axial length. The set of grooves mating with the set of lobes. The first helical profile is non-continuously variable over the first axial length.
Various exemplary embodiments relate to a screw compressor or expander including a male rotor having a lobe with a first helical profile extending between a first position proximate to an inlet portion and a second position proximate an outlet portion. A female rotor having a groove with a second helical profile extending between a third position proximate an inlet portion and a fourth position proximate an outlet portion, the groove mating with the lobes. A wrap-angle curve of the male rotor lobe includes a convex portion.
Various exemplary embodiments relate to a screw compressor or expander including a female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section having a first curved transition connecting the first and second groove. A male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section having a second curved transition connecting the first and second lobes.
Various exemplary embodiments relate to a screw compressor or expander including a female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section. A male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section. One of the first and second central sections includes a pocket.
Various exemplary embodiments relate to a screw compressor or expander including a housing having an inlet port, a discharge port, and a body at least partially defining a compression chamber having a first portion and a second portion. A female rotor rotatably positioned in the first portion of the compression chamber, the female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section having a first curved transition connecting the first and second groove. A male rotor rotatably positioned in the first portion of the compression chamber, the male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section having a second curved transition connecting the first and second lobes.
The aspects and features of various exemplary embodiments will be more apparent from the description of those exemplary embodiments taken with reference to the accompanying drawings, in which:
As best shown in
The male rotor 10 includes a pitch circumference Cp10. The radius Rp10 of the pitch circumference Cp10 is proportional to the number of lobes 12 of the male rotor 10. Each lobe 12 of the male rotor 10 extends prevalently outside the corresponding pitch circumference Cp10 until reaching an outer circumference Ce10 of the male rotor 10. The remaining part of the lobe 12 of the male rotor 10 extends inside the corresponding pitch circumference Cp10 until reaching a root circumference Cf10 of the male rotor 10. The radius Rf10 of the root circumference Cf10 is smaller than the radius Rp10 of the pitch circumference Cp10, which is in turn smaller than the radius Re10 of the outer circumference Ce10 of the male rotor 10. The distance between the pitch circumference Cp10 and the outer circumference Ce10 of the male rotor 10 is defined as the addendum of the male rotor 10. The male addendum corresponds to the difference between the value of the radius Re10 of the outer circumference Ce10 and the value of the radius Rp10 of the pitch circumference Cp10 of the male rotor 10. Each lobe 12 of the male rotor 10 has a first thickness T10 measured on the respective pitch circumference Cp10 that extends from a first mid-point between two lobes to an adjacent midpoint between two lobes, or the pith circumference Cp10 divided by the number of lobes, in this case 120° of the pitch circumference Cp10.
The female rotor 14 includes a pitch circumference Cp14. The measure of the radius Rp14 of the circumference Cp14 of the female rotor 14 is proportional to the number of grooves 16 of the female rotor. Each groove 16 extends prevalently inside the corresponding pitch circumference Cp14 until reaching a root circumference Cf14 of the female rotor 14. The remaining part of the groove 16 of the female rotor 14 extends outside the corresponding pitch circumference Cp14 until reaching an outer circumference Ce14 of the female rotor 14. The radius Rf14 of the root circumference Cf14 is smaller than the radius Rp14 of the pitch circumference Cp14, which is in turn smaller than the radius Re14 of the outer circumference Ce14 of the female rotor 14. The distance between the pitch circumference Cp14 and the outer circumference Ce14 of the female rotor 14 is defined as the addendum of the female rotor 14. The female addendum corresponds to the difference between the value of the radius Re14 of the outer circumference Ce14 and the value of the radius Rp14 of the pitch circumference Cp14 of the female rotor 14. The space between each groove 16 of the female rotor 14 has a second thickness T14 measured on the respective pitch circumference Cp14 that extends from a first mid-point between two grooves to an adjacent midpoint between two grooves, or the pith circumference Cp14 divided by the number of grooves 16, in this case 72° of the pitch circumference Cp14.
Various exemplary embodiments are directed to a rotor combination where at least one of the rotors has a varied profile and/or outer diameter.
When comparing
The rotors 110, 114 shown in
The variable profile can result in lower radial leakage and short sealing lines in a compressor. In certain embodiments, the profile can be varied to eliminate the blow hole on the discharge end. A compressor can also be created with little or no discharge end clearance and no trap pocket. The varied profile can also result in a large discharge port. Some exemplary advantages of using the variable profile configuration can include faster compression, lower leakage, and higher performance. The variable profile configuration can also result in higher efficiency, higher speeds, decreased port losses at maximum speeds, and higher internal pressure ratios from a single stage.
Various exemplary embodiments are directed to designing and creating a rotor with a variable profile. In one exemplary method, a rack curve is created that is used to create the male lobes and female grooves for a given rotor section. A rack is substantially equal to the lobe thickness T10 and groove thickness T14 shown in
One exemplary embodiment includes creating a variable profile rotor by scaling the X and Y coordinates of a rack.
In certain embodiments, only discrete points along the rack curve will be known, and different methods of interpolation and/or curve fitting can be used to determine the connections between these points. For example, linear interpolation, polynomial interpolation, and spline interpolation can be used to determine the rack curves.
Other exemplary embodiments are directed to set of rotors having a variable helix.
Varying the helical pattern of the rotors as discussed above can provide a number of advantages over the constant helical rotor or a continuously variable helical rotor.
Other advantages can include decreased leakage due to a reduction in the sealing line length. The sealing line of a rotor is considered the line of closest proximity between intermeshed lobes and grooves. Because the rotors are not in direct contact with one another, the sealing line represents the closed point of contact and is determinative of the amount of leakage that will occur between intermesh rotors. The variable helical profile has a decreasing sealing line length from the inlet end of the compressor to the discharge end. For the same rotation angle of the groove, the sealing line for a given cell is shorter in the variable helix rotor than in the fixed helix rotor, resulting in less leakage. The reduction of the sealing line length is in a position where greater pressure is developed and gas leakage is most critical. Other advantages of the rotors include increased discharge port area and improved high speed performance.
Other exemplary embodiments are directed to a set of rotors having a double helix configuration.
The male and female rotors 610, 614 each have a double helix configuration. The male rotor 610 includes a first section 610A having a left-hand helical profile and a second section 610B having a right-hand helical profile. The first and second sections 610A, 610B of the male rotor 610 meet at a central section 610C. Similarly, the female rotor 614 includes a first section 614A having a right-hand helical profile and a second section 614B having a left-hand helical profile, with the first and second sections 614A, 614B meeting at a central section 614C. Inlet portions 622 are provided at both ends of the rotors 610, 614 and a discharge portion 624 is positioned in the central sections 610C, 614C of the rotors 610, 614.
Using a double helix as shown above can provide a number of advantages. Larger displacement can be achieved for a given rotor center distance. Positioning the air inlet on both sides of the compressor with a single, central discharge point can eliminate the need for a discharge end clearance which can reduce leakage and increase performance. The double helix configuration can reduce or eliminate the axial load on the rotors, which typically results from the compressed air pressing in a single direction. The air inlet on both sides can also cool the bearings and simplify the sealing at the ends of the rotors due to the reduced heat and pressure. In various exemplary embodiments, a herringbone gear is used to maintain no axial load, for example with a dry compressor or blower. The housing can also be simplified as both ends can mirror each other and the axial bearing can be eliminated. The rotors can be driven from either end. In various embodiments, a single intake port can deliver fluid to both ends.
Advantages of using the double helix configuration can include lower leakage and higher performance. The double helix configuration can also result in higher efficiency, cost reduction, for example due to the simplified assembly, and easier maintenance.
Various exemplary embodiments are directed to combining one or more of the rotor features discussed above. For example, a combination of the variable helix features discussed with respect to
In other embodiments, the variable profile features discussed with respect to
The profile of lobes 1012 and grooves 1016 varies between the first and second inlet portions 1022 and the outlet portion 1024, as does the outer diameter of the male rotor 1010 and the female rotor 1012, while the rotation axis of the two rotors is maintained substantially parallel. The outer diameter of the male and female rotors can be decreased in a conical configuration, an ogive configuration, a complex curve configuration, or any other type of configuration according to the teachings herein.
In an exemplary embodiment, the male rotor 1010 profile is varied down to a substantially cylindrical portion 1026 and the female rotor is varied down to a substantially cylindrical portion 1028. In some exemplary embodiments, the addendum of the male and female rotors 1010, 1014 is reduced to substantially zero, with the outer diameter substantially equaling the pitch diameter. The male and female cylindrical portions 1026, 1028 can be used as a bearing surface for a journal bearing support in a housing.
The profile of lobes 1112 and grooves 1116 varies between the first and second inlet portions 1122 and the outlet portion 1124, as does the outer diameter of the male rotor 1110 and the female rotor 1112, while the rotation axis of the two rotors is maintained substantially parallel. The male rotor 110 profile is varied down to a substantially cylindrical portion 1126 and the female rotor 1114 is varied down to a substantially cylindrical portion 1128. In this embodiment, the lobes 1112 and grooves 1116 on the right hand portions of the rotors 1100A, 1114A are offset from the corresponding lobes 1112 and grooves 1116 on the left hand portions of the rotors 1110B, 1114B. For example, the male rotor first and second sections 1110A, 1110B can each include five equally spaced lobes 1112. In the configuration shown in
The combination rotors shown in
Although some combinations of the exemplary embodiments are specifically shown and described, applicant understands that other combinations of the exemplary embodiments can also be made.
The foregoing detailed description of the certain exemplary embodiments has been provided for the purpose of explaining the principles of the application and examples of practical implementation, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with various modifications as are suited to the particular use contemplated. This description is not necessarily intended to be exhaustive or to limit the application to the exemplary embodiments disclosed. Any of the embodiments and/or elements disclosed herein may be combined with one another to form various additional embodiments not specifically disclosed. Accordingly, additional embodiments are possible and are intended to be encompassed within this specification and the scope of the appended claims. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way.
As used in this application, the terms “front,” “rear,” “upper,” “lower,” “upwardly,” “downwardly,” and other orientational descriptors are intended to facilitate the description of the exemplary embodiments of the present application, and are not intended to limit the structure of the exemplary embodiments to any particular position or orientation. Terms of degree, such as “substantially” or “approximately” are understood by those of ordinary skill to refer to reasonable ranges outside of the given value, for example, general tolerances associated with manufacturing, assembly, and use of the described embodiments.
Various exemplary embodiments relate to a screw compressor or expander comprising: a female rotor including a first section having a right-hand first groove and a second section having a left-hand second groove, wherein the first groove has a first variable helix, the second groove has a second variable helix, and the female rotor has a first variable profile and a first variable outer diameter; and a male rotor including a third section having a left-hand first lobe and a fourth section having a right-hand second lobe, wherein the first lobe has a third variable helix, the second lobe has a fourth variable helix, and the male rotor has a second variable profile and a second variable outer diameter.
The screw compressor or expander, wherein the first and third variable helix each include a fast-slow-fast transition. The screw compressor or expander, wherein the first and third variable helix each include a slow-fast-slow transition. The screw compressor or expander, wherein a wrap-angle curve of the first section includes a convex portion and a concave portion. The screw compressor or expander, wherein the female rotor includes a first central section positioned between the first section and the second section and the male rotor includes a second central section positioned between the third section and the fourth section. The screw compressor or expander, wherein the first and second section of the female rotor and the third and fourth section of the male rotor each have a conical configuration in which the outer diameters of the female and male rotors each decrease in a linear fashion toward the first and second central sections respectively. The screw compressor or expander, wherein the first and second section of the female rotor and the third and fourth section of the male rotor each have a curvilinear configuration in which the outer diameter of the female and male rotors each decrease in a curved fashion toward the first and second central sections, respectively. The screw compressor or expander, wherein the outer diameter of the male rotor equals a male rotor pitch diameter at the second central section. The screw compressor or expander of claim 5, wherein the female rotor transitions to a substantially circular cross section at the first central section and the male rotor transitions to a substantially circular cross section at the second central section. The screw compressor or expander, wherein the female rotor has a first axis of rotation and the male rotor has a second axis of rotation that is parallel to the first axis of rotation. The screw compressor or expander, wherein the first and second lobes are corresponding lobes and the first lobe is angularly offset from the second lobe.
Various exemplary embodiments relate to a screw compressor or expander comprising: a female rotor including a first section, a second section, and a first central section, the first section having a set of right-hand first grooves, the second section having a set of left-hand second grooves corresponding to the set of first grooves, wherein the first grooves have a first variable helix, the second grooves have a second variable helix, and the female rotor has a first variable profile; and a male rotor including a third section, a fourth section, and a second central section positioned between the third and fourth sections, the third section having a set of left-hand first lobes and the fourth section having a set of right-hand second lobes corresponding to the set of first lobes, wherein the first lobes have a third variable helix, the second lobes have a fourth variable helix, and the male rotor has a second variable profile, wherein the female rotor transitions to a substantially circular cross section at the first central section and the male rotor transitions to a substantially circular cross section at the second central section.
The screw compressor or expander, wherein the lobes of the first set of lobes corresponding to the lobes of the second set of lobes are angularly offset. The screw compressor or expander, wherein the lobes of the first set of lobes corresponding to the lobes of the second set of lobes are offset by a half a lobe rotation. The screw compressor or expander, further comprising a housing having a journal bearing engaging at least the first center section.
Various exemplary embodiments relate to a screw compressor or expander comprising: a female rotor including a first section having a first groove with a right-hand first variable helical profile and a second section having a second groove with a left-hand second variable helical profile; and a male rotor including a third section having a first lobe with a right-hand third variable helical profile and a fourth section having a second lobe with a left-hand fourth variable helical profile.
The screw compressor or expander, wherein the female rotor includes a first curved transition connecting the first and second groove in a first central section and the male rotor includes a second curved transition connecting the first and second lobes in a second central section. The screw compressor or expander, wherein the first, second, third and fourth variable helical profiles are each non-continuously variable. The screw compressor or expander, wherein the first, second, third and fourth variable helical profiles are each continuously variable.
Various exemplary embodiments relate to a screw compressor or expander comprising: a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes with a variable profile extending along the first axial length; and a female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves with a variable profile extending along the second axial length, the set of grooves mating with the set of lobes, wherein at least a portion of the male rotor and the female rotor each have a non-cylindrical configuration with a non-constant outer diameter.
The screw compressor or expander of, wherein the male rotor and the female rotor each have a conical configuration in which the outer diameters of the female and male rotors each decrease in a linear fashion along at least a portion of the respective axial length from the inlet portion to the outlet portion. The screw compressor or expander, wherein the male rotor and the female rotor have an ogive configuration where the outer diameter of the rotor decreases in an arc along at least a portion of the respective axial length from the inlet portion to the outlet portion. The screw compressor or expander, wherein the male rotor and the female rotor each have a complex curve configuration in which the outer diameter of the rotor decreases in a curve having at least two different radii of curvature along at least a portion of the respective axial length from the inlet portion to the outlet portion. The screw compressor or expander, wherein the addendum of the male rotor and of the female rotor decreases along the first axial length. The screw compressor or expander, wherein the outer diameter of the male rotor equals a male rotor pitch diameter at the outlet portion. The screw compressor or expander, wherein a tip width of the male lobes widens along at least a portion of the axial length from the inlet portion to the outlet portion. The screw compressor or expander, further comprising a compression chamber having a non-cylindrical first portion and a non-cylindrical second portion. The screw compressor, wherein the non-cylindrical second portion has a substantially conical configuration. The screw compressor, wherein the non-cylindrical second portion has a substantially ogive configuration. The screw compressor or expander, wherein a rotation axis of the male rotor and a rotation axis of the female rotor are parallel.
Various exemplary embodiments relate to a screw compressor or expander comprising: a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes with a variable profile extending along at least a portion of the first axial length; and a female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves with a variable profile extending along at least a portion of the second axial length, the set of grooves mating with the set of lobes, wherein the male rotor and the female rotor transition to a substantially circular cross section near the outlet portion.
The screw compressor or expander, wherein the male rotor has a first outer diameter and a first pitch diameter less than the first outer diameter near the inlet portion and a second outer diameter substantially equal to the first pitch diameter at the outlet portion. The screw compressor or expander, wherein the male rotor has a non-constant outer diameter. The screw compressor or expander, wherein the male rotor has a conical configuration where the outer diameter of the rotor decreases in a linear fashion along at least a portion of the first axial length. The screw compressor or expander, wherein the male rotor has a curved configuration where the outer diameter of the rotor decreases in a curved fashion along at least a portion of the first axial length. The screw compressor or expander, wherein a rotation axis of the male rotor and a rotation axis of the female rotor are parallel.
Various exemplary embodiments relate to a screw compressor or expander comprising: a male rotor having a first axial length extending from an inlet portion to an outlet portion and a set of lobes extending along at least a portion of the first axial length; and a female rotor having a second axial length extending from the inlet portion to the outlet portion and a set of grooves extending along at least a portion of the second axial length, the set of grooves mating with the set of lobes, wherein the male rotor and the female rotor have a first section with a first profile defined by a first rack having a first set of X and Y coordinates and a second section with a second profile defined by a second rack different than the first rack having a second set of X and Y coordinates.
The screw compressor or expander, wherein the second rack is scaled from the first rack in the X and Y direction.
Various exemplary embodiments relate to a method of designing a set of screw compressor or expander rotors comprising: establishing a first rack for a male and female rotor, the first rack having at least one curved segment with a first crest having a first set of X and Y coordinates; and scaling the first rack in the X and Y directions to create a second rack having at least one curved segment with a second crest having a second set of X and Y coordinates, wherein the X coordinate of the second crest is spaced from the X coordinate of the first crest.
The method above, further comprising separating the second rack at a portion along the curved segment and offsetting the second rack in the Y direction to create a first inner point, a second inner point, a first end point, and a second end point. The method above, further comprising connecting the first inner point and the second inner point and extending a first end point and the second end point to extend the Y height of the second rack to substantially equal the Y height of the first rack. The method above, further comprising using an interpolation method to connect points on the rack to create the second rack curve. The method above, further comprising scaling the first or second rack in both the X and Y directions to create a third rack having an X coordinate of substantially zero.
Various exemplary embodiments relate to a method of designing a set of screw compressor or expander rotors comprising: establishing a first rack for a male and female rotor, the first rack having at least one curved segment with a first crest having a first set of a X and Y coordinates; and establishing a second rack for a male and female rotor, the second rack having at least one curved segment with a second crest having a second set of a X and Y coordinates, wherein the X coordinate of the second crest is spaced from the X coordinate of the first crest.
The method above, wherein the first rack has a first height in the Y direction and the second rack has a second height in the Y direction equal to the first height. The method above, further comprising using interpolation to define the male and female rotor between the first rack and the second rack.
Various exemplary embodiments relate to a screw compressor or expander comprising: a male rotor having a first axial length and a set of lobes with a first helical profile extending along the first axial length; and a female rotor having a second axial length and a set of grooves with a second helical profile extending along the second axial length, the set of grooves mating with the set of lobes, wherein the first helical profile is non-continuously variable over the first axial length.
The screw compressor or expander, wherein the first helical profile includes a fast-slow-fast transition. The screw compressor or expander, wherein the first helical profile includes a slow-fast-slow transition. The screw compressor or expander, wherein a wrap-angle curve of the male rotor includes a convex portion and a concave portion. The screw compressor or expander, wherein the male rotor has an inlet portion and an outlet portion defining the first axial length. The screw compressor or expander, wherein a wrap-angle curve of the male rotor includes a first point positioned between the inlet portion and the outlet portion and a second point positioned between the first point and the outlet portion, and wherein the slope of a line tangent to the first point is less than the slope of a line tangent to the second point. The screw compressor or expander, wherein the male rotor and the female rotor are rotatably positioned in a housing having an inlet port and an outlet port.
Various exemplary embodiments relate to a screw compressor or expander comprising: a male rotor having a lobe with a first helical profile extending between a first position proximate to an inlet portion and a second position proximate an outlet portion; and a female rotor having a groove with a second helical profile extending between a third position proximate an inlet portion and a fourth position proximate an outlet portion, the groove mating with the lobes, wherein a wrap-angle curve of the male rotor lobe includes a convex portion.
The screw compressor or expander, wherein the wrap-angle includes a first point positioned between the first position and the second position and a second point positioned between the first point and the second position, and wherein the slope of a line tangent to the second point is less than the slope of a line tangent to the first point. The screw compressor or expander, wherein the slope of the lines tangential to each point on the wrap angle curve decreases from the first position to the second position. The screw compressor or expander, wherein the first helical profile includes a slow-fast transition. The screw compressor or expander, wherein the wrap-angle curve further comprises a third point and a fourth point, and the slope of a line tangent to the third point is greater than the slope of a line tangent to the second point. The screw compressor or expander, wherein the third point is positioned between the second point and the second position and the fourth point is positioned between the third point and the second position. The screw compressor or expander, wherein the first helical profile includes a fast-slow-fast transition. The screw compressor or expander, wherein the first helical profile includes a slow-fast-slow transition.
Various exemplary embodiments relate to a screw compressor or expander comprising: a female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section having a first curved transition connecting the first and second groove; and a male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section having a second curved transition connecting the first and second lobes. The screw compressor or expander, wherein the first and second curved transitions each have a substantially U-shaped configuration.
The screw compressor or expander, wherein the first and second curved transitions each have a substantially rounded configuration. The screw compressor or expander, wherein at least one of the first and second curved transitions includes a pocket. The screw compressor or expander, wherein the pocket is formed in a surface of the first curved transition. The screw compressor or expander, wherein the male rotor includes a first inlet portion, a second inlet portion, and a discharge portion. The screw compressor or expander, further comprising a housing at least partially defining a compression chamber for receiving the male rotor and the female rotor. The screw compressor or expander, wherein the housing includes a first inlet port, a second inlet port, and a discharge port.
Various exemplary embodiments relate to a screw compressor or expander comprising: a female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section; and a male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section, wherein one of the first and second central sections includes a pocket.
The screw compressor or expander, wherein the first central section includes a first curved transition connecting the first and second groove. The screw compressor or expander, wherein the pocket is formed in the first curved transition. The screw compressor or expander, wherein the second central section includes a second curved transition connecting the first and second lobes. The screw compressor or expander, wherein the male rotor includes a first inlet portion, a second inlet portion, and a discharge portion. The screw compressor or expander, further comprising a housing at least partially defining a compression chamber for receiving the male rotor and the female rotor. The screw compressor or expander, wherein the housing includes a first inlet port, a second inlet port, and a discharge port.
Various exemplary embodiments relate to a screw compressor or expander comprising: a housing having an inlet port, a discharge port, and a body at least partially defining a compression chamber having a first portion and a second portion; a female rotor rotatably positioned in the first portion of the compression chamber, the female rotor including a first section having a first groove with a right-hand helical profile, a second section having a second groove with a left-hand helical profile, and a first central section having a first curved transition connecting the first and second groove; and a male rotor rotatably positioned in the first portion of the compression chamber, the male rotor including a third section having a first lobe with a right-hand helical profile, a fourth section having a second lobe with a left-hand helical profile, and a second central section having a second curved transition connecting the first and second lobes.
The screw compressor or expander, wherein at least one of the first and second curved transitions includes a pocket. The screw compressor or expander, wherein the pocket is formed in the first curved transition. The screw compressor or expander, wherein the first and second curved transitions have a substantially U-shaped configuration. The screw compressor or expander, wherein the housing includes a second inlet port.
The present application is a continuation under 35 U.S.C. § 120 of U.S. patent application Ser. No. 17/229,331, filed Apr. 13, 2021, and titled “COMPLEX SCREW ROTORS,” which in turn is a continuation of U.S. patent application Ser. No. 15/760,086, filed Mar. 14, 2018, and titled “COMPLEX SCREW ROTORS,” which in turn is a U.S. national stage entry of International Patent Application No. PCT/US2016/059613, filed on Oct. 29, 2016, which claims priority to United States Patent Application Nos. 62/248,785, 62/248,811, 62/248,832 and 62/248,858, filed on Oct. 30, 2015, the entire contents of all of which are fully incorporated herein by reference.
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Number | Date | Country | |
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20230272797 A1 | Aug 2023 | US |
Number | Date | Country | |
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62248785 | Oct 2015 | US | |
62248811 | Oct 2015 | US | |
62248832 | Oct 2015 | US | |
62248858 | Oct 2015 | US |
Number | Date | Country | |
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Parent | 17229331 | Apr 2021 | US |
Child | 18312057 | US | |
Parent | 15760086 | US | |
Child | 17229331 | US |