LUBRICANT HOLDER FOR A COOLANT COMPRESSOR

Abstract

Lubricant holder for vertical conveying of lubricant using a crankshaft of a coolant compressor includes a sleeve element having a clear cross-section, an inner element having a mantle surface extending along a longitudinal axis of the inner element from a lower to an upper end, and on which a spiral is arranged that projects away from the mantle surface, runs spirally from the lower end region to the upper end region of the mantle surface, and delimits a channel, at least in certain areas. In an operating state of the lubricant holder the inner element is arranged within the clear cross-section with its mantle surface, at least in certain areas. In the region of the upper end of the mantle surface, at least one contact section is arranged, which projects away radially beyond the mantle surface, and the progression of which deviates from the spiral-shaped progression of the spiral.

Claims

1. A lubricant holder for vertical conveying of lubricant by a crankshaft of a coolant compressor comprising: a sleeve element having a sleeve element longitudinal axis, a sleeve element upper end, a sleeve element lower end, and a clear cross-section delimited by an inner wall and extending along the sleeve element longitudinal axis from the sleeve element upper end to the sleeve element lower end; and an inner element having an inner element longitudinal axis, an inner element upper end, an inner element lower end, a mantle surface extending along the inner element lower end to the inner element upper end, and a spiral arranged on the mantle surface; wherein the spiral projects away from the mantle surface and extends in a spiral shape from a region of the inner element lower end to a region of the inner element upper end, and delimits a channel, at least in certain areas; wherein in an operating state of the lubricant holder: (a) the inner element is arranged within the clear cross-section of the sleeve element with its mantle surface, at least in certain areas, in such a manner that a gap is disposed between an outer surface of the spiral and the inner wall; (b) viewed in a direction from the sleeve element lower end to the sleeve element upper end, the inner element lower end is disposed in front of its upper end; and (c) the inner element and the sleeve element are rotatable relative to one another about at least one of the sleeve element longitudinal axis and the inner element longitudinal axis; and wherein in the region of the inner element upper end, at least one contact section is provided and projects radically beyond the mantle surface; and wherein the at least one contact section has a progression deviating from a spiral-shaped progression of the spiral.

2. The lubricant holder according to claim 1, wherein the at least one contact section, viewed along the inner element longitudinal axis, is delimited by a first boundary surface and a second boundary surface arranged one behind the other; and wherein at least one of the first boundary surface and the second boundary surface stands normal to the inner element longitudinal axis.

3. The lubricant holder according to claim 1, wherein the channel has a reduced channel cross-section in a region of the at least one contact section.

4. The lubricant holder according to claim 1, wherein the spiral directly follows the at least one contact section.

5. The lubricant holder according to claim 1, wherein the at least one contact section covers an angle range around the inner element longitudinal axis and amounts to at least 15.

6. The lubricant holder according to claim 5, wherein the angle range is at least 45.

7. The lubricant holder according to claim 5, wherein the angle range is at least 90.

8. The lubricant holder (1) according to claim 5, wherein the angle range is 360.

9. The lubricant holder according to claim 8, wherein the at least one contact section comprises at least one closed contact section entirely covering the angle range.

10. The lubricant holder according to claim 1, wherein precisely one contact section is provided.

11. The lubricant holder according to claim 1, wherein the inner element has a cavity that is open, viewed in a direction toward the inner element upper end, along the inner element longitudinal axis.

12. The lubricant holder according to claim 11, wherein at least one passage opening is provided in the region of the inner element upper end, and wherein the at least one passage opening connects the channel with the cavity.

13. A coolant compressor comprising: (a) a compressor housing configured to be hermetically encapsulated and comprising a housing interior; (b) an electrical drive unit arranged in the housing interior and comprising a rotor and a stator; (c) a crankshaft connected with the rotor in a torque-proof manner; (d) a piston/cylinder unit arranged in the housing interior and comprising a cylinder and a piston mounted in a cylinder and driven by the crankshaft for compression of coolant; and (e) the lubricant holder according to claim 1; wherein the lubricant holder is in the operating state so as to convey lubricant out of a lubricant sump formed in a bottom region of the compressor housing by way of the crankshaft; and wherein the crankshaft has at least one of a bore that runs at a slant to an axis of rotation of the crankshaft and at least one groove that stands in a fluidic connection with the clear cross-section of the sleeve element.

14. The coolant compressor according to claim 13, wherein the sleeve element of the lubricant holder is connected with the crankshaft in a torque-proof manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0066] In the drawings,

[0067] FIG. 1a shows an inner element of an embodiment of a lubricant holder according to the invention, in a side view;

[0068] FIG. 1b shows the inner element from FIG. 1a in a front view;

[0069] FIG. 1c shows the inner element from FIG. 1a in a sectional view according to the section line I-I in FIG. 1a;

[0070] FIG. 2a shows an inner element of a further embodiment of the lubricant holder according to the invention, in a side view;

[0071] FIG. 2b shows the inner element from FIG. 2a in a front view;

[0072] FIG. 2c shows the inner element from FIG. 2a in a sectional view according to the section line II-II in FIG. 2b;

[0073] FIG. 3 shows a sectional view of the embodiment of the lubricant holder according to the invention, with the inner element from FIG. 1a or FIG. 1c, wherein the lubricant holder is mounted on a crankshaft of a coolant compressor according to the invention; and

[0074] FIG. 4 shows a sectional view of a coolant compressor according to the invention, with the lubricant holder from FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0075] FIG. 1a shows a side view of an inner element 9 of an embodiment of a lubricant holder 1 according to the invention. Lubricant holder 1 is shown in FIG. 3 in a sectional view, in an operating state and fastened to a crankshaft 2 of a coolant compressor 3 according to the invention.

[0076] The lubricant holder 1 serves for vertical conveying of lubricant, in particular oil 15, from a lubricant sump 26 formed in a bottom region 25 of a compressor housing 18 of the coolant compressor 3, see also the sectional view of FIG. 4, by way of the crankshaft 2. For this purpose, the crankshaft 2 has a bore 27 that can be seen well in FIG. 3, from which bore the oil 15 can exit to locations to be lubricated, by way of exit bores 28. For optimal conveying of the oil 15, the bore 27 can be structured to run at a slant to an axis of rotation 29 of the crankshaft 2.

[0077] Furthermore, an electrical drive unit 19 having a rotor 20 and a stator 21 is arranged in the compressor housing 18, wherein the crankshaft 2 is connected with the rotor 20 in torque-proof manner. Furthermore, a piston/cylinder unit 22 is situated in the compressor housing 18, which unit comprises a piston 23 mounted so as to move in the cylinder 24 of the piston/cylinder unit 22, which piston can be driven by the crankshaft 2 for compression of coolant.

[0078] The lubricant holder 1 comprises a sleeve element 4 having a clear cross-section 5 delimited by an inner wall 33, which cross-section extends along a longitudinal axis 6 of the sleeve element 4, from an upper end 7 to a lower end 8 of the sleeve element 4. As can be seen in FIG. 3, the clear cross-section 5 can serve to hold the crankshaft 2 at the upper end 7, for example so as to produce a torque-proof connection between the sleeve element 4 and thereby the lubricant holder 1 and the crankshaft 2, for example by means of a press fit.

[0079] Furthermore, the lubricant holder 1 comprises the inner element 9, which has a mantle surface 10 that extends along a longitudinal axis 11 of the inner element 9, from a lower end 12 to an upper end 13. A spiral 14 is arranged on the mantle surface 10, which spiral projects radially outward from the mantle surface 10 and runs in spiral shape from the region of the lower end 12 to the region of the upper end 13 of the mantle surface 10from the lower end 12 to the upper end 13 of the mantle surface 10 in the exemplary embodiment shown.

[0080] For reasons of production technology, the spiral 14 can have short interruptions, which can be seen in FIG. 1a and FIG. 2a. A channel 32 having a channel cross-section 42 is formed or delimited by the spiral 14 and the mantle surface 10. In this regard, the channel 32 or a channel cross-section 42 is delimited, at least in certain areas, on two sides that lie opposite one another, by the spiral 14, and by the mantle surface 10 on a side arranged between these sides, wherein the channel 32 has no delimitation surface on the side that lies opposite the mantle surface 10, but rather is open.

[0081] In other words, the channel 32 or the channel cross-section 42 is closed on only three of four sides, and the mantle surface 10 forms a bottom of the channel 32.

[0082] In the operating state of the lubricant holder 1, the inner element 9 is arranged, with its mantle surface 10, at least in certain areasin the exemplary embodiment shown, essentially completelywithin the clear cross-section 5 of the sleeve element 4. In this regard, viewed in the direction from the lower end 8 to the upper end 7 of the sleeve element 4, the lower end 12 of the mantle surface 10 is arranged in front of its upper end 13, in other words the sleeve element 4 and the inner element 9 are oriented or aligned in the same way, as it were.

[0083] In the exemplary embodiments shown, the mantle surface 10 corresponds to the mantle of a rotating cylinder. The clear cross-section 5 of the sleeve element 4 is accordingly coordinated with the shape of the inner element 9 or the mantle surface 10, and has a corresponding cylinder shape in the region in which the inner element 9 is held in the sleeve element 4 or arranged in the clear cross-section 5 in the operating state.

[0084] The sleeve element 4 and the inner element 9 are furthermore designed in such a manner that the inner element 9 and the sleeve element 4 can be rotated relative to one another about the longitudinal axis 6 of the sleeve element 4 and/or the longitudinal axis 11 of the inner element 9. This rotation is imparted or generated during operation of the coolant compressor 3 by means of the torque-proof connection of the lubricant holder 1 with the crankshaft 2. Fundamentally, the only important thing is the relative rotation between the sleeve element 4 and the inner element 9. In other words, it would also be conceivable that the inner element 9 is driven rotationally and the sleeve element 4 is essentially fixed in place rotationally. In the exemplary embodiment shown, the sleeve element 4 is driven rotationally when the crankshaft 2 turns, while the inner element 9 is not driven, due to the torque-proof connection of the sleeve element 4 with the crankshaft 2.

[0085] In order to prevent rotational movements of the inner element 9 to the greatest possible extent, this element can be connected with the stator 21, for example, by means of a fixation means. For this purpose, the inner element 9 can have a fastening element in the form of an eye 16, for example, as can be seen well in the front view of FIG. 1b, with which eye the fixation means can be brought into engagement. In the exemplary embodiment shown in FIG. 4, a bracket 31 is provided as the fixation means, which bracket stands in engagement with the eye 16 and produces the connection of the inner element 9 with the stator 21.

[0086] As is evident from FIG. 3, for example, in the operating state the inner element 9 is arranged within the clear cross-section 5 of the sleeve element 4 in such a manner that a gap 30 having a gap width is arranged between an outer surface 34 of the spiral 14, which outer surface 34 delimits the spiral 14 radially toward the outside, and the inner wall 33. The gap 30 guarantees problem-free relative rotation of inner element 9 and sleeve element 4 relative to one another.

[0087] Accordingly, the oil 15 from the lubricant sump 26 can enter into this gap 30, as well as into the channel 32, when the inner element 9 and the sleeve element 4 project into the lubricant sump 26 at least in certain areas. In this regard, the sleeve element 4 projects into the lubricant sump 26, in particular in the region of its lower end 8, and the inner element 9 projects into it in particular in the region of the lower end 12 of its mantle surface 10. Due to the viscosity of the oil 15 or the friction between oil 15 and sleeve element 4, a corresponding centrifugal force acts on the oil 15 during rotation of the sleeve element 4. This force presses the oil 15 in the gap 30 and, in particular, in the channel 32 in the direction from the lower end 12 to the upper end 13 of the mantle surface 10, and thereby in the direction of the crankshaft 2.

[0088] In each case, the oil 15 can flow particularly well in the direction of the crankshaft 2 by way of the channel 32independent of the precise gap width. In the exemplary embodiment shown, the bore 27 of the crankshaft 2 stands in a fluidic connection with the clear cross-section 5 and thereby ultimately also with the channel 32, so that the oil 15 can get all the way into the bore 27.

[0089] In operation, tilting of the inner element 9 relative to the sleeve element 4 can occur, so that a tilt angle occurs between the longitudinal axis 6 of the sleeve element 4 and the longitudinal axis 11 of the inner element 9. In order to limit the tilt angle and thereby to prevent jamming of the inner element 9 in the sleeve element 4 or in the clear cross-section 5, according to the invention at least one contact section 35 is provided in the region of the upper end 13 of the mantle surface 10, which section projects radially beyond the mantle surface 10, and the progression of which deviates from the spiral-shaped progression of the spiral 14. In that the at least one contact section 35 projects beyond the mantle surface 10 radially, i.e. in directions standing perpendicular to the longitudinal axis 11 or mantle surface 10, the contact section 35 can make contact with the inner wall 33 in the event of tilting, and thereby limit the tilt angle in such a manner that no jamming comes about.

[0090] The deviation of the progression of the at least one contact section 35 from the progression of the spiral 14 makes it possible, in this regard, that on the one hand, the placement of the at least one contact section 35 can remain concentrated in the region of the upper end 13 of the mantle surface 10, and on the other hand, at the same time a sufficiently great angle range 36 around the longitudinal axis 11 of the inner element 9 is covered by at least one contact section 35, so as to guarantee reliable contact against the inner wall 33 in the event that tilting occurs.

[0091] Of course, multiple contact sections 35for example two, three or morecan also be provided in the region of the upper end 13 of the mantle surface 10. The inner element 9 of FIG. 1a has two contact sections 35, for example, as can be seen well in comparison with FIG. 1b. In FIG. 1a, it can be seen that the spiral 14 directly follows one of the contact sections 35, wherein the transition to this contact section 35 is indicated by a dotted line. This contact section 35 encloses an angle range 36 of approximately 100. The other one of the two contact sections 35 is arranged on the opposite side of the mantle surface 10. In other words, the two contact sections are arranged along a circular line around the longitudinal axis 11, wherein the circular line lies in a plane that stands normal to the longitudinal axis 11. The other one of the two contact sections also covers an angle range of approximately 100, so that in total, approximately 200 are covered by the two contact sections 35. The likelihood that in the event of tilting of the inner element 9, contact of one of the contact sections 35 against the inner wall 33 will come about, and that the tilt angle will be effectively limited, is correspondingly great.

[0092] Furthermore, it is also ensured by means of the placement of the at least one contact section 35 in the region of the upper end 13 of the mantle surface 10 that the at least one contact section 35 will not hinder entry of the oil 15 into the channel 32. The latter is important for reliable lubrication, in particular at low speeds of rotation, wherein the oil 15 typically does not completely fill the channel 32 or the channel cross-section 42 in this regard, when it is being conveyed in the direction of the crankshaft 2.

[0093] At the same time, the at least one contact section 35 delimits the channel 32 or the channel cross-section 42 in the region of the upper end 13 of the mantle surface 10. In FIGS. 1a and 1b as well as in the sectional view of FIG. 1c, it can be seen well that because of the contact sections 35, the channel cross-section 42 in the region of the upper end 13 of the mantle surface 10 or in the region of the contact sections 35 is clearly smaller than in a region between the upper end 13 and the lower end 12 or than in the region of the lower end 12 of the mantle surface 10. The reduced channel cross-section 42 in the region of the contact sections 35 that is achieved in this way brings about a restriction of the lubricant flow at high speeds of rotation. This result occurs because in the event of high speeds of rotation, the channel 32 is usually filled completely by the oil 15. Because of the restriction of the channel 32 in certain areas by means of the at least one contact section 35, a constriction of the channel 32 is created, which then brings about backing up of the oil 15 and thereby restriction of lubricant conveying at high speeds of rotation.

[0094] In contrast to the progression of the spiral 14, which has an incline, the contact sections 35 in the exemplary embodiment of FIGS. 1a, 1b, 1c have an essentially incline-free progression, so that the reduction in the channel cross-section 42 as described is achieved. In this regard, the contact sections 35 are configured in such a manner that they are delimited, in each instance, by a first boundary surface 40 and a second boundary surface 41, which are arranged one behind the other, viewed along the longitudinal axis 11 of the inner element 9, wherein the second boundary surface 41 stands normal to the longitudinal axis 11 of the inner element 9.

[0095] As is evident from FIG. 1c, the inner element 9 of the embodiment shown has a cavity 38, which is open in the direction toward the upper end 13 of the mantle surface 10. In this way, cost-advantageous and simple production is made possible.

[0096] FIGS. 2a, 2b, 2c relate to an inner element 9 of a further embodiment of the lubricant holder 1 according to the invention. This inner element also has the cavity 38, which is open in the direction toward the upper end 13 of the mantle surface 10. In this exemplary embodiment, only one contact section 35 is provided, which is configured as a closed contact section 37. This closed contact section 37 covers the entire angle range 36 of 360, and, in the exemplary embodiment shown, runs on a circular line that lies in a plane that stands normal to the longitudinal axis 11. Extremely great certainty of preventing undesirable jamming in the event of tilting in all directions can thereby be guaranteed.

[0097] In this case, too, the spiral 14 follows the contact section 35 directly, as is indicated with the dotted line in FIG. 2a and FIG. 2b, in each instance. Accordingly, the channel cross-section 42 narrows to zero. In order to nevertheless be able to convey oil 15 from the channel 32 further to the crankshaft 2, it is true that in principle, the gap 30 is available, but the amount conveyed per time is thereby restricted. Furthermore, back-flow through the gap 30 must be expected. For this reason, in this exemplary embodiment two passage openings 39 are provided, which are arranged to lie opposite one another in the region of the upper end 13 of the mantle surface 10, and fluidically connect the channel 32 with the cavity 38. In other words, the oil 15 can get from the channel 32 into the cavity 38 through the passage openings 39, and from theresince this cavity is open toward the top, i.e. in the direction toward the upper end 13 of the mantle surface 10into the clear cross-section 5 of the sleeve element 4 or to the crankshaft 2. This arrangement is advantageous for improved lubricant conveying.

[0098] For the remainder, what has been stated above in connection with the exemplary embodiment of FIGS. 1a, 1b, 1c also holds true for the exemplary embodiment of FIGS. 2a, 2b, 2c.

[0099] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.