VIRABREQUIM E COMPRESSOR ROTATIVO

Abstract

Provided in the present invention are a crankshaft and a rotary compressor. The outer peripheral surface of an eccentric part of the crankshaft is provided with a groove, the groove comprising an opening and a bottom surface. The orthographic projection of the opening on a cross section of the eccentric part comprises an arc group, wherein the total length of the arc group is smaller than the circumference of the eccentric part; the orthographic projection of the bottom surface on the cross section of the eccentric part comprises a curve group, wherein the curve group comprises at least one curve, and the curve comprises a first end point and a second end point. The connecting line between the first end point and the center of the eccentric part is a first line segment, and the connecting line between the second end point and the center of the eccentric part is a second line segment; the included angle α between the two line segments satisfies 0°<α≤180°, and the minimum distance r between the curve and the center of the eccentric part satisfies 1 / 2≤r / R<1, wherein R represents the radius of the eccentric part. The present solution improves the lubricating effect between the eccentric part and a piston, and improves compressor performance.

Description

1 / 14 “CRANKSHAFT AND ROTARY COMPRESSOR TECHNICAL FIELD

[0001] The present invention relates to the field of compressor technology, and particularly to a crankshaft and a rotary compressor. TECHNICAL OVERVIEW

[0002] Rotary compressors comprise a crankshaft, a piston, and a cylinder. The crankshaft has an eccentric section, and the piston is arranged in the cylinder over the eccentric section, with a very small clearance being left between the piston and the eccentric section. The eccentric section can be rotated to rotate the piston. However, during rotation, the eccentric section tends to encounter significant friction with the piston, which leads to considerable power losses due to friction and degrades compressor performance. SUMMARY

[0003] Provided here are a crankshaft and a rotary compressor, which overcome the problem described above of significant friction between an eccentric section and a piston.

[0004] To this end, the present invention provides a crankshaft including an eccentric section that defines a recess in its circumference, the recess defining an opening on an outer circumferential surface of the eccentric section and a lower surface within the eccentric section, wherein an orthogonal projection of the opening onto a cross-section of the eccentric section includes a set of arcs including at least one arc and having Petition 870250084170, dated 09 / 18 / 2025, page 8 / 34 2 / 14 a total length less than the perimeter of the eccentric section, the cross-section of the eccentric section perpendicular to a geometric axis of the eccentric section; and wherein an orthogonal projection of the lower surface onto the cross-section of the eccentric section includes a set of curves including at least one curve having a first endpoint and a second endpoint, the first endpoint connected to the center of a circle defined by the eccentric section by a first straight line segment, the second endpoint connected to the center of the circle defined by the eccentric section by a second straight line segment, the first straight line segment and the second straight line segment defining an angle of α between them, which satisfies 00 < α < 1800, the curve spaced from the center of the circle defined by the eccentric section by a minimum distance of r, which satisfies 1 / 2 < r / R < 1, where R represents the radius of the eccentric section.

[0005] Optionally, each of at least one curve can be an arc.

[0006] Optionally, the set of curves may include at least two curves, which are arcs joined end to end.

[0007] Optionally, the recess may extend through the upper and lower end faces of the eccentric section.

[0008] Optionally, the recess may be perpendicular to the upper and lower end faces of the eccentric section.

[0009] Optionally, the recess may be Petition 870250084170, dated 09 / 18 / 2025, p. 9 / 34 3 / 14 extends helically around the circumference of the eccentric section.

[0010] Optionally, the recess may extend helically in an opposite direction to the direction in which the eccentric section rotates.

[0011] Optionally, the orthogonal projection of the lower surface onto the cross-section of the eccentric section may additionally include a set of line segments including at least one line segment having a third endpoint and a fourth endpoint, the third endpoint connected to the center of the circle defined by the eccentric section by a third line segment, the fourth endpoint connected to the center of the circle defined by the eccentric section by a fourth line segment, the third and fourth line segments defining an angle between them, which is equal to α, the line segment spaced from the center of the circle defined by the eccentric section by a minimum distance, which is equal to r.

[0012] The present invention also provides a rotary compressor including the crankshaft as defined in any of the preceding paragraphs.

[0013] Optionally, the rotary compressor may additionally include a housing, a piston, an upper cylinder cap, a cylinder and a lower cylinder cap, in which the eccentric section of the crankshaft and piston are mounted inside the cylinder; the piston is disposed over the eccentric section with a clearance being left between the piston and the eccentric section; the eccentric section is used to drive the rotation of the piston; Petition 870250084170, dated 09 / 18 / 2025, page 10 / 34 4 / 14 The upper cylinder cap is attached to an upper end face of the cylinder; the lower cylinder cap is attached to a lower end face of the cylinder; An oil inlet is provided on a geometric axis of the crankshaft, and an oil outlet is provided on the eccentric section in communication with the oil inlet; and a lower portion of the housing defines an oil tank, and the oil inlet is used to drain lubricating oil from the oil tank.

[0014] In the crankshaft and rotary compressor of the present invention, during the rotation of the piston driven by the eccentric section, the presence of the recess in the eccentric section leads to a smaller contact area and therefore reduced friction between the eccentric section and the piston. In addition, lubricating oil can be introduced into the recess to improve (reinforce) the lubrication between the eccentric section and the piston and reduce power losses due to friction, improving compressor performance. Setting the angle α between the first straight segment and the second straight segment within 00 < α < 1800 can prevent a loss of power from the eccentric section to drive the piston rotation due to an excessively large value of α.Setting the minimum distance r between the curve and the center of the circle defined by the eccentric section within 1 / 2 ^ r / R < 1 may take into account the robustness (strength) of the crankshaft and lubrication of the recess, and preventing the recess from becoming excessively deep. Petition 870250084170, dated 09 / 18 / 2025, page 11 / 34 5 / 14 large or small. An excessively large recess depth can lead to reduced crankshaft robustness. An inadequate recess depth may prevent it from containing sufficient lubricating oil necessary for desirable lubrication. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a crankshaft in accordance with an embodiment of the present invention, taken through an eccentric section thereof.

[0016] Figure 2 is a schematic diagram showing a crankshaft in accordance with an embodiment of the present invention, which has an eccentric section defining a recess therein.

[0017] Figure 3 is a schematic view to the right of Figure 2.

[0018] Figure 4 is a schematic diagram showing a crankshaft in accordance with an embodiment of the present invention, which has an eccentric section defining two recesses therein.

[0019] Figure 5 is a schematic view to the right of Figure 4.

[0020] Figure 6 is a schematic diagram showing a crankshaft in accordance with an embodiment of the present invention, which has an eccentric section defining a recess therein.

[0021] Figure 7 is a schematic view to the right of Figure 6.

[0022] Figure 8 is a schematic view. Petition 870250084170, dated 09 / 18 / 2025, page 12 / 34 6 / 14 partial of a rotary compressor in accordance with an embodiment of the present invention. List of Reference Numerals 1: crankshaft; 2: recess; 3: upper cylinder cap; 4: cylinder; 5: lower cylinder cap; 11: eccentric section; 111: outer circumferential surface; 112: lower end face; 113: oil outlet; 21: opening; 22: bottom surface. DETAILED DESCRIPTION

[0023] The objectives, advantages, and characteristics of the present invention will become more evident upon reading the detailed description below of the rotary crankshafts and compressors described herein, with reference to the accompanying drawings. Note that the figures are provided in a rather simplified manner, not necessarily to exact scale, for the sole purpose of assisting in explaining the disclosed embodiments in a more convenient and clearer way.

[0024] As used herein, the terms first, second, and similar terms are employed solely for ease of description and reference, and should not be interpreted as denoting or implying relative importance or as implicitly indicating the numerical numeral of the referenced items. Accordingly, defining an item as first, second, or similar is an explicit or implicit indication of the presence of one or more such items.

[0025] As shown in Figures 1 through 7, embodiments of the present invention provide a Petition 870250084170, dated 09 / 18 / 2025, page 13 / 34 7 / 14 crankshaft (1) including an eccentric section (11), the eccentric section (11) defining a recess (2) in its circumference. The recess (2) has an opening (21) and a bottom surface (22). The opening (21) is defined on an outer circumferential surface (111) of the eccentric section (11), and the bottom surface (22) is located inside the eccentric section (11). An orthogonal projection of the opening (21) onto a cross-section of the eccentric section (11) includes a set of arcs, the set of arcs including at least one arc. The total length of the set of arcs is less than a perimeter of the eccentric section (11). The cross-section of the eccentric section (11) is defined perpendicularly to a geometric axis of the eccentric section (11).An orthogonal projection of the lower surface (22) onto the cross-section of the eccentric section (11) includes a set of curves, the set of curves including at least one curve having a first endpoint and a second endpoint. A first line segment connects the first endpoint and a center of a circle defined by the eccentric section (11). A second line segment connects the second endpoint and the center of the circle defined by the eccentric section (11). The first and second line segments define an angle α between them, which satisfies 00 < α ^ 1800. A minimum distance between the curve and the center of the circle defined by the eccentric section (11) is equal to ar, which satisfies 1 / 2 ^ r / R < 1, where R represents a radius of the eccentric section (11). The outer circumferential surface (111) refers to a side wall surface of the eccentric section (11) and the outer circumferential surface (111) is perpendicular. Petition 870250084170, dated 09 / 18 / 2025, p. 14 / 34 8 / 14 for both of an upper end face and a lower end face (112) of the eccentric section (11).

[0026] In the crankshaft (1) in accordance with these embodiments of the present invention, a recess (2) is provided in the eccentric section (11) of the crankshaft (1), during rotation of a piston driven by the eccentric section (11), the presence of the recess (2) leads to a smaller contact area between the eccentric section (11) and the piston and, consequently, reduced friction between the eccentric section (11) and the piston. In addition, lubricating oil can be introduced into the recess (2) to improve lubrication between the eccentric section (11) and the piston and reduce power losses due to friction, improving compressor performance. Setting the angle α between the first and second straight segments within 00< α ^ 1800 can prevent a loss of power from the eccentric section (11) to drive piston rotation due to an excessively large value of α.Setting the minimum distance r between the curve and the center of the circle defined by the eccentric section (11) within 1 / 2 ^ r / R < 1 may take into account the robustness (strength) of the crankshaft (1) and lubrication of the recess (2) and avoidance of the recess (2) having an excessively large or small depth. An excessively large depth of the recess (2) may lead to reduced robustness of the crankshaft (1). An inadequate depth of the recess (2) may prevent the recess (2) from containing sufficient lubricating oil necessary for the provision of desirable lubrication.

[0027] Optionally, as shown in the Figure Petition 870250084170, dated 09 / 18 / 2025, page 15 / 34 9 / 14 1. The set of curves can be a set of arcs. In this case, each of the previously mentioned curve(s) is / are an arc. If the orthogonal projection of the lower surface (22) of the recess (2) onto the cross-section of the eccentric section (11) is an arc, then the recess (2) will have a constant depth throughout its entire length. This facilitates machining the recess (2) on the eccentric section (11). If the orthogonal projection of the lower surface (22) of the recess (2) onto the cross-section of the eccentric section (11) is a curve, then the recess (2) will either have a constant depth throughout its entire length or not. In the latter case, machining the recess (2) may require changing the depth of cut of the milling cutter used and therefore be more difficult. Alternatively, the recess (2) can be formed directly by casting (molding).

[0028] Optionally, as shown in Figures 1 and 5, the set of curves may include at least two curves, which are arcs joined end to end. This facilitates machining of the recess (2). As shown in Figure 1, the set of arcs includes three arcs N1, N2 and N3. In alternative embodiments, two or more arcs may be spaced apart. That is to say, two or more recesses (2) may be spaced circumferentially around the eccentric section (11).

[0029] Optionally, as shown in Figures 1 and 2, the recess (2) may extend through the upper end face and the lower end face (112) of the eccentric section (11). This makes it possible for the opening (21) of the recess (2) to have an area Petition 870250084170, dated 09 / 18 / 2025, p. 16 / 34 10 / 14 larger, which makes the recess (2) easier to machine.

[0030] Optionally, as shown in Figures 2 and 4, the recess (2) may be perpendicular to the upper end face and to the lower end face (112) of the eccentric section (11). This makes the recess (2) easier to machine.

[0031] Optionally, as shown in Figures 1 and 6, the recess (2) may extend helically around the circumference of the eccentric section (11). Referring to Figures 6 and 7, if the crankshaft (1) is designed to rotate counterclockwise, then the recess (2) may extend helically clockwise from the side of a longer section of the crankshaft (1) to the side of a shorter section thereof. This ensures more lubricating oil is stored in the recess (2) during rotation of the eccentric section (11).

[0032] Optionally, referring to Figure 1, the orthogonal projection of the lower surface (22) onto the cross-section of the eccentric section (11) may additionally include a set of line segments, the set of line segments includes at least one line segment having a third endpoint and a fourth endpoint. A third line segment connects the third endpoint and the center of the circle defined by the eccentric section (11), and a fourth line segment connects the fourth endpoint and the center of the circle defined by the eccentric section (11). The third and fourth line segments define an angle between them, which is equal to α. The minimum distance between the line segment and the center of the circle defined by the eccentric section (11) is r. Petition 870250084170, dated 09 / 18 / 2025, page 17 / 34 11 / 14 Alternatively, the orthogonal projection of the lower surface (22) of the recess (2) onto the cross-section of the eccentric section (11) may be a combination of curved and straight lines (segments). In this way, crankshafts (1) of various shapes may be provided and, consequently, compressors of various shapes with different performance specifications as such.

[0033] As shown in Figure 8, based on the same inventive concept of the crankshaft (1) as discussed above, embodiments of the present invention also provide a rotary compressor including the crankshaft (1) as defined in any of the preceding paragraphs.

[0034] In the crankshaft (1) of the rotary compressor in accordance with these embodiments of the present invention, a recess (2) is provided in the eccentric section (11) of the crankshaft (1), during rotation of a piston driven by the eccentric section (11), the presence of the recess (2) leads to a smaller contact area between the eccentric section (11) and the piston and, consequently, to reduced friction between the eccentric section (11) and the piston. In addition, lubricating oil can be introduced into the recess (2) to improve lubrication between the eccentric section (11) and the piston and reduce power losses due to friction, improving compressor performance. Setting the angle α between the first and second straight line segments within 00 < α ^ 1800 can prevent a loss of power from the eccentric section (11) to drive the piston rotation due to an excessively high α value. Setting the minimum distance r Petition 870250084170, dated 09 / 18 / 2025, page 18 / 34 12 / 14 between the curve and the center of the circle defined by the eccentric section (11) within 1 / 2 < r / R < 1 can take into account the robustness (resistance) of the crankshaft (1) and the lubrication of the recess (2) and prevent the recess (2) from having an excessively large or small depth. An excessively large depth of the recess (2) can lead to reduced robustness of the crankshaft (1). An inadequate depth of the recess (2) may prevent it from containing sufficient lubricating oil necessary for the provision of desirable lubrication.

[0035] Optionally, as shown in Figures 1 and 8, the rotary compressor may additionally include a housing, the piston, an upper cylinder cap (3), a cylinder (4) and a lower cylinder cap (5). The eccentric section (11) of the crankshaft (1) and piston are mounted inside the cylinder (4), and the piston is disposed over the eccentric section (11), with a clearance being left between the piston and the eccentric section (11). The eccentric section (11) is used to drive the rotation of the piston. The upper cylinder cap (3) is fixed to an upper end face of the cylinder (4), and the lower cylinder cap (5) is fixed to a lower end face (112) of the cylinder (4). An oil inlet is provided on a geometric axis of the crankshaft (1), and an oil outlet (113) is provided on the eccentric section (11), the oil outlet (113) is in communication with the oil inlet.A lower portion of the housing houses an oil tank, and the oil inlet is used to drain lubricating oil from the oil tank. Petition 870250084170, dated 09 / 18 / 2025, p. 19 / 34 13 / 14 lubricating oil flows through the oil inlet and oil outlet to the gap between the eccentric section (11) and the piston and then to the recess (2), leading to (resulting in) improved lubrication between the eccentric section (11) and the piston, which reduces power losses due to friction and improves compressor performance.

[0036] Therefore, in the crankshaft (1) and rotary compressor of the present invention, a recess (2) is provided in the eccentric section (11) of the crankshaft (1), during rotation of the piston driven by the eccentric section (11), the presence of the recess (2) leads to a smaller contact area between the eccentric section (11) and the piston and therefore reduced friction between the eccentric section (11) and the piston. In addition, lubricating oil can be introduced into the recess (2) to improve (reinforce) lubrication between the eccentric section (11) and the piston and reduce power losses due to friction, improving compressor performance. Setting the angle α between the first and second straight segments within 00< α ^ 1800 can prevent a loss of power from the eccentric section (11) to drive the piston rotation due to an excessively large value of α.Setting the minimum distance r between the curve and the center of the circle defined by the eccentric section (11) within 1 / 2 ^ r / R < 1 can take into account crankshaft robustness (1) and recess lubrication (2) and prevent recess (2) from having an excessively large or small depth. An excessively large depth of recess (2) can lead to reduced crankshaft robustness. Petition 870250084170, dated 09 / 18 / 2025, page 20 / 34 14 / 14 (1). Inadequate recess depth (2) may prevent recess (2) from containing sufficient lubricating oil necessary to provide desirable lubrication.

[0037] The above descriptions are merely a few preferred embodiments of the present invention, which are not intended to limit the scope of the present invention in any way. Any and all alterations and modifications made by those with common knowledge of the prior art, in light of the above teachings, are intended to fall within the scope of the present invention. Petition 870250084170, dated 09 / 18 / 2025, page 21 / 34

Claims

1 / 3 CLAIMS 1. A crankshaft characterized in that it comprises an eccentric section, a circumference of the eccentric section provided with a recess, the recess defining an opening and a lower surface, the opening formed on an external circumferential surface of the eccentric section and the lower surface formed within the eccentric section; wherein an orthogonal projection of the opening onto a cross-section of the eccentric section comprises a set of arcs, the set of arcs comprising at least one arc, the set of arcs having a total length less than the perimeter of the eccentric section, and the cross-section of the eccentric section perpendicular to a geometric axis of the eccentric section;(e) wherein an orthogonal projection of the lower surface onto the cross-section of the eccentric section comprises a set of curves, the set of curves comprising at least one curve, each curve having a first endpoint and a second endpoint, the first endpoint connected to the center of a circle defined by the eccentric section by a first straight line segment, the second endpoint connected to the center of the circle defined by the eccentric section by a second straight line segment, the first straight line segment and the second straight line segment defining an angle of α between them, which satisfies 00 < α < 1800, the curve spaced from the center of the circle defined by the eccentric section by a minimum distance of r, which satisfies 1 / 2 ^ r / R < 1, where R represents a radius of the eccentric section. Petition 870250084170, dated 09 / 18 / 2025, page 22 / 34 2 / 3; 2. The crankshaft according to claim 1, characterized in that each of at least one curve is an arc.

3. The crankshaft according to claim 1, characterized in that the set of curves comprises at least two curves, which are arcs joined end to end.

4. The crankshaft according to claim 1, characterized in that the recess extends through both an upper end face and a lower end face of the eccentric section.

5. The crankshaft according to claim 1, characterized in that the recess is perpendicular to both an upper end face and a lower end face of the eccentric section.

6. The crankshaft according to claim 1, characterized in that the recess extends helically around the circumference of the eccentric section.

7. The crankshaft according to claim 6, characterized in that the recess extends helically in a direction opposite to the direction in which the eccentric section rotates.

8. The crankshaft according to claim 1, characterized in that the orthogonal projection of the lower surface onto the cross-section of the eccentric section additionally comprises a set of straight line segments, the set of straight line segments comprising at least one straight line segment having a third endpoint and a fourth endpoint, the third endpoint connected to the center of the circle defined by the eccentric section by a third straight line segment, the fourth endpoint connected to the center of the circle defined by the eccentric section by a fourth straight line segment, the third straight line segment and the fourth straight line segment defining an angle between them, which is equal to α, the straight line segment spaced from the center of the circle defined by the eccentric section by a minimum distance, which is equal to r.

9. A rotary compressor, characterized in that it comprises the crankshaft as defined in any one of claims 1 through 8.

10. The rotary compressor according to claim 9, characterized in that it further comprises a housing, a piston, an upper cylinder cap, a cylinder and a lower cylinder cap, wherein the eccentric section of the crankshaft and piston are mounted within the cylinder; the piston is disposed on the eccentric section, a clearance is left between the piston and the eccentric section; the eccentric section is used to drive the rotation of the piston; the upper cylinder cap is fixed to a face of the upper end of the cylinder; the lower cylinder cap is fixed to a face of the lower end of the cylinder; an oil inlet is provided on a geometric axis of the crankshaft, an oil outlet is provided on the eccentric section, and the oil outlet is in communication with the oil inlet; and: a lower portion of the housing defines an oil tank, and the oil inlet is used to drain lubricating oil from the oil tank.Petition 870250084170, dated 09 / 18 / 2025, pp. 24 / 34.

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