Scroll type device incorporating spinning or co-rotating scrolls

Abstract

A co-rotating scroll is disclosed having a motor having a shaft, a drive scroll connected to the shaft for moving the drive scroll, a driven scroll connected to the drive scroll to be moved by the drive scroll, and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

Claims

1. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

2. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll, the idler shaft having a hole therein and a bearing, the hole for reducing centrifugal force on the bearing.

3. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll, the idler shaft having a bearing having a bearing cover and a bearing shield for retaining grease within the bearing.

4. A co-rotating scroll comprising: a motor having a shaft; a drive scroll having an involute with the drive scroll connected to the shaft for moving the drive scroll; a weight position on the involute of the drive scroll for dynamically balancing the drive scroll; a driven scroll having an involute with the driven scroll connected to the drive scroll to be moved by the drive scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

5. A co-rotating scroll comprising: a motor having a shaft; a drive scroll having an involute with the drive scroll connected to the shaft for moving the drive scroll; a driven scroll having an involute with the driven scroll connected to the drive scroll to be moved by the drive scroll; a counterweight position on the involute of the driven scroll for dynamically balancing the driven scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

6. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll; and an outlet having a labyrinth seal.

7. A co-rotating scroll comprising: a motor having a shaft; a motor shaft bearing; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll, the idler shaft having a bearing; and a spring for pre-loading the motor shaft bearing for reducing any axial load on the idler shaft bearing.

8. A co-rotating scroll comprising: a motor having a shaft with the shaft having an opening there through for allowing a working fluid to pass there through; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; a cross hole for delivering the working fluid to the drive scroll and the driven scroll; and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

9. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; and a bellows for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

10. A co-rotating scroll comprising: a motor; a drive scroll magnetically coupled to the motor for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; and a bellows for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

11. A co-rotating scroll comprising: a motor; a drive scroll magnetically coupled to the motor for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; a bellows for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll; and a pin for aligning the driven scroll relative to the drive scroll.

12. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; a slot formed in the drive scroll; and a pin for insertion into the slot for aligning the driven scroll relative to the drive scroll.

13. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; a slot formed in the drive scroll, the slot having a lead; and a pin for insertion into the lead and the slot for aligning the driven scroll relative to the drive scroll.

14. A co-rotating scroll comprising: a motor having a shaft; a drive scroll connected to the shaft for moving the drive scroll; a driven scroll connected to the drive scroll to be moved by the drive scroll; a slot formed in the drive scroll, the slot having a raised portion; a pin for insertion into the slot for aligning the driven scroll relative to the drive scroll; and a second slot cut into the raised portion of the slot for balancing the drive scroll.

15. The co-rotating scroll of claim 8 and including a bellows provided between the drive scroll and the driven scroll at the location of its cross hole to confine the working fluid during usage of the said scroll and to maintain alignment between the scrolls and to assist in the transfer of torque.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows a sectional view through a motor and a scroll center line of a co-rotating scroll with an idler type alignment between the co-rotating scrolls;

[0022] FIG. 2 shows a sectional view of the co-rotating scrolls taken along the plane of line 2-2 of FIG. 1;

[0023] FIG. 3 shows all alternative sectional view of the co-rotating scrolls taken along the plane of line 3-3 of FIG. 1;

[0024] FIG. 4A shows an Idler shaft construction which includes bearing covers for retaining bearing grease on the outboard side of the idler shaft bearings and bearing shields for grease retention on the inboard side of the bearings;

[0025] FIG. 4B shows an alternate view of a bearing shield used for grease retention on the outboard side of the idler shaft bearings;

[0026] FIG. 5 shows a sectional view of a tip seal taken along the plane of line 5-5 of FIG. 3;

[0027] FIG. 6 shows a sectional view a pre-load spring used for pre-loading a bearing;

[0028] FIG. 7 shows a sectional view of a labyrinth shaft seal on a shaft of a discharge of the co-rotating scroll device of the present disclosure;

[0029] FIG. 8 shows a sectional view of an inlet of the co-rotating scroll device of the present disclosure;

[0030] FIG. 9 shows a cross-sectional view of another embodiment of a co-rotating scroll device having a bellows instead of idler shafts;

[0031] FIG. 10 shows an enlarged sectional view of the bellows shown in FIG. 9;

[0032] FIG. 11 shows a co-rotating scroll device having a pin for positioning a drive scroll relative to a driven scroll;

[0033] FIG. 12 shows the co-rotating scroll device of FIG. 11 having the pin removed;

[0034] FIG. 13 shows another embodiment of a co-rotating scroll constructed according to the present disclosure in which alignment slots and pins are used to align a drive scroll relative to a driven scroll;

[0035] FIG. 14 shows a side view of a drive scroll used in the co-rotating scroll shown in FIG. 13;

[0036] FIGS. 15 and 15A shows a side view of driven scroll used in the co-rotating scroll shown in FIG. 13; and

[0037] FIG. 16 shows a bellows providing to add flexure to the internal aspects of the scrolls.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] Referring now to the drawings, wherein like numbers refer to like items, number 10 identifies a preferred embodiment of a co-rotating scroll device constructed according to the present disclosure. In FIG. 1, the co-rotating scroll device 10 is shown to comprise a drive scroll 12 which is driven by a center shaft 14. The center shaft 14 is supported by a front bearing 16 and a rear bearing 18. An electric motor 20 is used to drive the center shaft 14. The bearings 16 and 18 and the electric motor 20 are mounted in a housing 22. A second scroll or driven scroll 24 is driven by the drive scroll 12 through the use of idler shafts 26, of which only one idler shaft 26 is shown in this view. By way of example there may be three idler shafts 26 that are spaced 120 apart. The idler shaft 26 is supported by a first bearing 28 in the drive scroll 12 and a second bearing 30 in the driven scroll 24. A shaft 32 is connected to the driven scroll 24. A center line 34 of the shaft 32 is offset from a center line 36 of the center shaft 14. The center line 34 being offset as compared to the center line 36 is used to form a compression chamber 38. The shaft 32 is supported by a first shaft bearing 40 and a second shaft bearing 42. The shaft 32 has a center opening 44 formed therein for discharging a working fluid as in the case where the co-rotating scroll 10 is a compressor or a vacuum pump. The center opening 44 may also function as an inlet in the case where the co-rotating scroll 10 is an expander. To seal any working fluid within the center opening 44 of the shaft 32 a labyrinth seal 46 is used. The labyrinth seal 46 is positioned between the first bearing 40 and the second bearing 42.

[0039] FIG. 2 illustrates a cross-sectional view of the co-rotating scroll 10 taken along the plane of line 2-2 of FIG. 1. The co-rotating scroll 10 has the compression chamber 38 formed between the drive scroll 12 and the driven scroll 24. The compression chamber 38 is also formed by a first involute 46 on the drive scroll 12 and a second involute 48 on the driven scroll 24. The three idler shafts 26 are shown being positioned approximately 120 apart. In order to balance the rotary motion of the drive scroll 12 a pair of balance weights 50 and 52 are located co-axially with the first involute 46 to dynamically balance the drive scroll 12. Also, a pair of counterweights 54 and 56 are positioned on the driven scroll 24 to dynamically balance the driven scroll 24.

[0040] With reference now to FIG. 3, another cross-sectional view of the co-rotating scroll 10 is shown which is taken along the plane of line 3-3 of FIG. 1. In this particular view the co-rotating scroll 10 has the compression chamber 38 formed between the drive scroll 12 and the driven scroll 24. The compression chamber 38 is also formed by a first involute 46 on the drive scroll 12 and a second involute 48 on the driven scroll 24. As is known, a working fluid (not shown) may enter from the drive scroll 12 make its way around the first involute 46 to be transferred through the second involute 48 of the driven scroll 24 to pass through the center opening 44 (FIG. 1) of the shaft 32 (FIG. 1). The three idler shafts 26 are shown being positioned approximately 120 apart. The co-rotating scroll 10 also has a pair of holes or apertures 58 and 60 that are used for alignment purposes during assembly of the co-rotating scroll 10, as will be explained more fully herein.

[0041] FIG. 4A depicts one of the idler shafts 26. The idler shaft 26 has the first grease bearing 28 and the second grease bearing 30 retained in place by use of a first bearing cover 70 in the drive scroll 12 and a second bearing cover 72 in the driven scroll 24. The first grease bearing 28 also has a bearing shield 74 and the second grease bearing 30 has a bearing shield 76. The shields 74 and 76 are used to retain any grease contained within the grease bearings 28 and 30. The idler shaft 26 may have a channel, hole, or opening 78 formed therein to provide for a lighter idler shaft 26. The lighter weight idler shaft 26 reduces the load from centrifugal force on the bearings 28 and 30. The idler shaft 26 is retained on the bearing 28 by use of a lock nut 80 and a lock washer 82. The bearing 30 also has a lock nut 84 and a lock washer 86.

[0042] With reference now to FIG. 4B, an alternative embodiment of a first grease bearing 90 and a second grease bearing 92 are shown. In this embodiment, the first grease bearing 90 has a bearing shield 94 in the drive scroll 12 instead of the first bearing cover 70. The second grease bearing 92 also has a bearing shield 96 in the driven scroll 24 instead of the second bearing cover 72.

[0043] FIG. 5 shows the co-rotating scroll 10 with the drive scroll 12 having a pair of tapered tip seals 100 and 102 and the driven scroll 24 having a pair of tapered tip seals 104 and 106. The tapered seals 100, 102, 104, and 106 will each have centrifugal forces acting radially outward. This is shown as an arrow 108. The seals 100, 102, 104, and 106 will each also have a force in an axial direction. This indicated by an arrow 110. The force in the axial direction 110 will self-actuate the tip seals 100, 102, 104, and 106. The tip seals 100 and 104 are also shown in FIG. 1. Further, as illustrated in FIG. 1, there may be more than the four tip seals 100, 102, 104, and 106 which are shown in FIG. 5. The tips seals 100, 102, 104, and 106 are used to form a gas tight chamber, such as the compression chamber 38, as the scrolls 12 and 24 mesh together.

[0044] The idler shafts 26 of the co-rotating scroll 10 are used to align the driven scroll 24 relative to the drive scroll 12. The channel 78 in each of the idler shafts 26 is used to reduce the centrifugal force on the bearings 28 and 30. Reducing the centrifugal force will provide longer life for the bearings 28 and 30. The bearings covers 70 and 72 and the bearings shields 74, 76. 94, and 96 allow for the retention of any grease in the bearings 28 and 30. This also provides for longer life for the bearings 28 and 30. The weights 50 and 52 and the counterweights 54 and 56 provide for the ability to dynamically balance the scrolls 12 and 24. The tapered tip seals 100, 102, 104, and 106 are self-actuating in the axial direction by way of the centrifugal force acting on the seals 100, 102, 104, and 106. Also, the labyrinth seal 46 insures that any discharge gas or inlet gas is limited to flow through the center opening 44.

[0045] FIG. 6 illustrates how the idler shaft bearings 28 and 30 may have a reduced axial load to prolong the life of the bearings 28 and 30. The idler shaft bearing 28 rotates about a center line 120 of the drive scroll 12. The mass of the idler shaft bearing 28 is a major radial load on the bearing 28 due to centrifugal forces. If the bearing 28 is smaller then a smaller centrifugal force will be placed on the bearing 28. This will provide a longer life for the bearing 28. Since the axial thrust from pressure on the drive scroll 12 and the driven scroll 24 must be supported, it would be beneficial to reduce the amount of this axial load that must be borne by the bearings 28 and 30. In order to reduce the amount of the axial load a pre-load spring 122 is used with the front bearing 16. The front bearing 16 has a small clearance 124 on the an outside diameter 126. The pre-load spring 122 will place a small negative load on the idler shaft bearings 28 and 30. In operation, the pre-load force from the spring 122 must be overcome before any positive force is placed on the bearings 28 and 30. The resulting axial load on the bearings 28 and 30 is reduced so that the bearings 28 and 30 can be made smaller and lighter. By way of example only, the spring 122 may be a wave washer or a Bellville washer. Again, having smaller and lighter bearings 28 and 30 will increase the longevity of the bearings 28 and 30.

[0046] With particular reference now to FIG. 7, the labyrinth seal 46 is shown surrounding the shaft 32. The seal 46 is a mechanical seal that provides a twisted or tortuous path to help prevent any leakage. The seal 46 may include grooves 140 that provide a difficult path that a fluid must pass through in order to escape the seal 46. The seal 46 does not contact the shaft 32 and the seal 46 does not wear out. The seal 46 is used to seal any working fluid (not shown) that flows in the center opening 44 formed in the shaft 32. The seal 46 is also mounted between the first shaft bearing 40 and the second shaft bearing 42. Since the seal 46 does not contact the shaft 32, any fluid, such as oil lubricating the bearings 40 and 42, is prevented from leaking out of the seal 46. The grooves 140 are used to trap any fluid that may escape the bearings 40 and 42. The drive scroll 12, the driven scroll 24, and the tip seal 104 are also shown in this particular view.

[0047] FIG. 8 illustrates an alternate embodiment of an inlet (or discharge) 160 to the device 10 through the center shaft 14 of the motor 20 with the shaft 14 being a hollow shaft 162. A cross hole 164 is used to deliver working fluid (not shown) to an outer area of the scrolls 12 and 24. A labyrinth or shaft seal (not shown) may be used to seal working fluid from ambient air.

[0048] Referring now to FIGS. 9 and 10, another embodiment of a co-rotating scroll 200 constructed according to the present disclosure is depicted. The co-rotating scroll 200 has a motor 202 that is isolated from any working fluid (not shown) of the scroll 200 by use of a magnetic coupling 204. A drive scroll 206 is driven by a center shaft 208 connected to the magnetic coupling 204. The center shaft 208 is supported by a front bearing 210 and a rear bearing 212. The bearings 210 and 212 are mounted in a housing 214. A second scroll or driven scroll 216 is driven by the drive scroll 206. A bellows 218 is positioned between the drive scroll 206 and the driven scroll 216. The bellows 218 is used in place of any idler shafts to drive the driven scroll 216. The bellows 218 is stiff in the angular or torsional direction, but is flexible in the radial direction. This transmits torque from the drive scroll 206 to the driven scroll 216. This also provides an offset between an axis of rotation between the scrolls 206 and 216. The housing 214 encloses the scrolls 206 and 216, the bearings 210 and 212, and the bellows 218 and ensures that there is no leakage of the working fluid to the atmosphere. The co-rotating scroll 200 also has an inlet 220. The co-rotating scroll 200 is an example of another construction of aligning and driving the driven scroll 216 without the use of any idler shafts, such as the idler shafts 26.

[0049] One disadvantage associated with the use of the co-rotating scroll 200 is that it is difficult to align the drive scroll 206 and the driven scroll 216. Idler shafts achieve the necessary alignment easily since bearing bores can be precision located relative to the scroll profile. To overcome this alignment problem in the co-rotating scroll 200, one or more bellows alignment pins 222, as illustrated in FIG. 11, are employed. The pin 222 is inserted into a precision machined hole 224 so that the precise desired alignment is achieved during assembly of the co-rotating scroll 200. The pin 222 is inserted during assembly prior to the bellows 218 and the housing 214 being completely tightened. Use of the pin 222 fixes the location of the driven scroll 216 relative to the driving scroll 206. The pin 222 is removed during the assembly process so that the scrolls 206 and 216 are free to rotate during use of the scroll 200.

[0050] In FIG. 12, a first plug 226 is used to plug the hole 224 and a second plug 228 is used to plug the hole 224 after the pin 222 has been removed during the assembly of the co-rotating scroll 200. The plugs 226 and 228 are used so that there is no leakage to the atmosphere of any working fluid after the pin 222 has been removed and the co-rotating scroll 200 is placed into service or use. Again, by using the pin 222, the scrolls 206 and 216 are capable of being aligned.

[0051] As has been discussed and shown, pre-loading the shaft bearing with a spring so that the axial load on the idler shaft bearings is reduced provides for the use of smaller bearings and improved longevity of the bearings. Routing the inlet or discharge in the case of an expander through the shaft to simplify the separation of working fluid from surrounding ambient air is beneficial. Driving and aligning one scroll with respect to another scroll using a flexible bellows instead of idler shafts is also beneficial in the design of co-rotating scrolls. Also, being able to position one scroll with respect to the other scroll using alignment pins during assembly assists in reducing or eliminating any alignment problems. This also allows a co-rotating scroll device that has a flexible bellows design or construction.

[0052] With reference now to FIG. 13, another embodiment of a co-rotating scroll device 300 is shown. The co-rotating scroll device 300 comprises a drive scroll 302 that is used to drive a driven scroll 304. The drive scroll 302 is connected to a motor 306. The drive scroll 302 is contained within a housing 308. The motor 306 may be attached to a motor mount 310. A pin 312 is inserted or pressed into the driven scroll 304 to align the scrolls 302 and 304 with respect to each other. Another pin 314 is also used to align the scrolls 302 and 304. Although two pins 312 and 314 are shown in this particular view, as will be explained in detail herein, it is possible that more pins may be used to align the two scrolls 302 and 304.

[0053] The co-rotating scroll 300 also has other components such as a bearing plate 316, a discharge plate 318, a pair of O-rings 320 and 322 to seal the scroll 300, a tip seal 324, a centering spring 326, and a bearing 328. However, the important component with respect to the scroll 300 is the use of the pins 312 and 314. Also, other components are shown, but such components have not been identified.

[0054] FIG. 14 illustrates the drive scroll 302 having twelve slots 330 positioned around the scroll 302. The slots 330 are used to use the pins 312 and 314. Although twelve slots 330 are shown, it is possible to have fewer slots, such as any number of slots from three to eleven. The slots 330 are rounded and have a diameter such that when a pin 312 (FIG. 13) is pressed into the driven scroll 304 (FIG. 13), the two scrolls 302 and 304 will be aligned with respect to each other. The slots 330 also has a lead in I configuration 332 so that the transition into the slots 330 by the pin 312 is smooth. The pin 312 is pressed into a hole 334 in the scroll 302. The pin 312 has a diameter such that the diameter of the slots 330 and the diameter of the pin 312 are equivalent to the desired offset between the scrolls 302 and 304.

[0055] With reference now to FIG. 15, the slots 330 are shown being placed in a raised portion 336 of the drive scroll 302 for dynamically balancing the drive scroll 302. A rib 338 is also located on the driven scroll 304 for balancing the driven scroll 304.

[0056] By use of the rounded slots 330 and the pins 312 and 314, a co-rotating scroll may be constructed for aligning the drive scroll 302 and the driven scroll 304. The lead in configuration 332 in the rounded slots 330 is also used to provide for smooth insertion of the pins 312 and 314 into the rounded slots 330. The scrolls 302 and 304 may be balanced by cutting slots into the raised portion of the rounded slots 330.

[0057] As has been described, using a series of rounded slots and pins provides for driving and aligning the drive scroll and the driven scroll. The use of a lead into the rounded slots provides for a smooth entry of the pins into the slots. Also, the drive scroll may be balanced by cutting slots into the raised portion of the rounded slots. Ribs may also be used to dynamically balance the driven scroll.

[0058] FIG. 16 shows the application of a bellows or a flexure means internally of the scroll to prevent leakage of the working fluid during usage of the device. Also the bellows helps to maintain scroll alignment and to transfer torque.

[0059] From the aforementioned description, a co-rotating scroll device from the machine class of scroll compressors, pumps, and expanders has been described. This co-rotating scroll device is capable of expanding or compressing a fluid cyclically to evacuate a line, device, or space connected to the co-rotating scroll device without intrusion of the nearby atmosphere. The co-rotating scroll device receives its motive power directly from a motor or alternatively from a motor connected to a magnetic coupling, further minimizing the incidence of atmospheric intrusion within the housing and the working fluid. The present disclosure and its various components may adapt existing equipment and may be manufactured from many materials including but not limited to metal sheets and foils, elastomers, steel plates, polymers, high density polyethylene, polypropylene, polyvinyl chloride, nylon, ferrous and non-ferrous metals, various alloys, and composites.

[0060] From all that has been said, it will be clear that there has thus been shown and described herein a co-rotating scroll device. It will become apparent to those skilled in the art, however, that many changes, modifications, variations, and other uses and applications of the subject co-rotating scroll device are possible and contemplated. All changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the disclosure are deemed to be covered by the disclosure, which is limited only by the claims which follow.