Variable frequency compressor double helix oil groove crankshaft

Abstract

The scheme discloses a compressor variable-frequency double-helix oil groove crankshaft, which comprises a main shaft, a slave shaft and a connecting piece, the main shaft is provided with a helical oil groove, and further comprises: an oil supply channel arranged in the main shaft and having an opening at one end away from the connecting piece; a slave shaft lubricating oil hole arranged on the surface of the slave shaft; a helical oil groove far-end hole arranged at one end of the helical oil groove away from the connecting piece, the helical oil groove far-end hole penetrates the side wall of the main shaft and is connected with the oil supply channel; a helical oil groove near-end hole arranged at one end of the helical oil groove close to the connecting piece, the helical oil groove near-end hole is in communication with the slave shaft lubricating oil hole in the connecting piece; and a slave shaft lubricating diffusion slope, the slave shaft lubricating diffusion slope gradually changes from deep to shallow on the surface of the slave shaft, and the deep end is connected with the opening of the slave shaft lubricating oil hole. The scheme has the beneficial effects that the arrangement position of the oil supply channel is redesigned, the oil supply structure is optimized, and the crankshaft rotating at low speed for a long time can be better lubricated.

Description

Technical Field

[0001] This utility model relates to the field of crankshafts, specifically a compressor variable frequency double spiral oil groove crankshaft. Background Technology

[0002] A compressor generally consists of a casing, motor, cylinder, piston, control equipment, and cooling system. The motor and piston are typically connected via a crankshaft. The crankshaft includes a short shaft and a long shaft; the long shaft connects to the motor rotor, while the short shaft connects to the piston via a connecting rod. As a crucial component connecting the motor and piston, the crankshaft is driven by the motor to rotate, which in turn moves the piston. During rotation, the long shaft experiences friction with the wall of its mounting bore; the short shaft experiences friction with its mating connecting rod; and the piston experiences friction with the inner wall of the cylinder. Excessive friction can increase compressor power consumption and reduce compressor lifespan.

[0003] Chinese patent document CN209179974U, published on July 30, 2019, discloses a novel compressor crankshaft, comprising a main shaft, a driven shaft, and a connecting member disposed between the main shaft and the driven shaft. The driven shaft has an oil supply channel, and the outer surface of the end of the main shaft away from the connecting member has an annular oil groove. The main shaft also has an oil inlet hole, which communicates with the outside. The oil supply channel passes through the connecting member, and the outer surface of the driven shaft has an inclined oil groove, which communicates with the oil supply channel through a vertical through hole. A spiral oil groove is provided on the outer surface of the main shaft, with one end communicating with the oil supply channel and the other end communicating with the oil inlet hole. This invention features improved oiling efficiency and enhanced lubrication during rotation. This type of solution is commonly used in conventional compressors, where the crankshaft operates on a start-stop basis. After starting, it has a high rotational speed, resulting in sufficient centrifugal force to meet the lubrication and cooling requirements during rotation. In variable frequency compressors, the crankshaft operates at low speeds for extended periods under low power consumption conditions. As the crankshaft speed is low at this time, the centrifugal force decreases accordingly, and the oil supply decreases accordingly. Therefore, the lubrication and cooling effect on the crankshaft will be significantly worse. Summary of the Invention

[0004] Based on the above problems, this utility model provides a variable frequency double spiral oil groove crankshaft for compressors to solve the problem of poor surface lubrication of variable frequency compressor crankshafts.

[0005] To achieve the purpose of this invention, the present invention adopts the following technical solution: a compressor variable frequency double spiral oil groove crankshaft, including a main shaft, a driven shaft, and a connecting member, wherein the main shaft is provided with spiral oil grooves, and further includes:

[0006] The oil supply channel is located inside the spindle, with an opening at the end furthest from the connecting parts;

[0007] The lubrication hole for the shaft has an opening located on the surface of the shaft.

[0008] The end of the spiral oil groove away from the connector is provided with a spiral oil groove distal hole, which penetrates the side wall of the main shaft and is connected to the oil supply channel;

[0009] The spiral oil groove has a proximal end hole near the connector, and the proximal end hole of the spiral oil groove is connected to the lubricating oil hole of the driven shaft inside the connector.

[0010] Preferably, it also includes a lubrication diffusion ramp from the shaft; the lubrication diffusion ramp from deep to shallow on the surface of the shaft, with the deep end connected to the opening of the lubrication oil hole of the shaft.

[0011] Preferably, there are two or more spiral oil grooves arranged in the same direction on the side wall of the main shaft.

[0012] Preferably, all spiral oil grooves are of the same specification and are arranged at equal angles and intervals on the side wall of the main shaft.

[0013] Preferably, a connecting groove is also provided; the connecting groove is arranged around the surface of the main shaft and its depth is less than the depth of the spiral oil groove.

[0014] Preferably, the oil supply channel is a stepped hole with a wide opening and a narrow bottom, and the opening position of the far end hole of the spiral oil groove is located on the side of the wide opening of the stepped hole, close to the stepped surface.

[0015] Preferably, the stepped surface of the stepped hole is a conical surface that convexes to the bottom.

[0016] Preferably, it also includes an exhaust port; the inner end of the exhaust port is connected to the bottom of the oil supply channel, and the outer end is opened on the side surface of the connecting member on the shaft side.

[0017] Preferably, the connector includes a counterweight and a follower shaft step; the follower shaft step is a partial frustum shape, with the two end faces of the frustum coinciding with the two end faces of the connector, and the end face on the follower shaft side is larger; the follower shaft step is located opposite the center of gravity of the counterweight.

[0018] This compressor features a variable frequency double-spiral oil groove crankshaft. Lubricating oil is drawn in through the oil supply channel opening, enters two or more spiral oil grooves of the same specification along the distal end hole of the spiral oil groove, lubricating the main shaft surface. Then, it continues along the spiral oil groove into the distal end hole of the spiral oil groove, is ejected by centrifugal force from the lubrication hole on the driven shaft, and diffuses to the driven shaft surface through the lubrication diffusion slope for further lubrication. During this process, the spiral oil grooves are arranged at equal angles and intervals, providing more lubricating oil at low speeds and balancing the main shaft's center of gravity. A connecting groove is used to balance the oil volume of the two spiral oil grooves. The oil supply channel is designed with a stepped hole, which helps to create oil pressure before the steps through centrifugal force, improving the efficiency of lubricating oil overflowing from the distal end hole of the spiral oil groove at low speeds. Simultaneously, due to centrifugal force, oil and air are more easily separated at the stepped surface. Oil overflows from the distal end hole of the spiral oil groove, while air mixed with lubricating oil and drawn into the oil supply channel is guided by the conical surface and gathers at the narrow end of the stepped hole, finally being discharged through the exhaust hole. The step-down design is a weight-reduction feature that helps reduce the weight of the crankshaft, thereby reducing energy consumption during long-term crankshaft rotation and making it more suitable for low-speed, long-duration operation during variable frequency cooling.

[0019] In summary, the beneficial effects of this solution are: the layout of the oil supply channels has been redesigned, the oil supply structure has been optimized, and the crankshaft that rotates at low speeds for extended periods can receive better lubrication. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a structural schematic diagram from another perspective of the present invention;

[0022] Figure 3 This is an axial sectional view of the present invention.

[0023] Among them: main shaft 10, spiral oil groove 11, spiral oil groove proximal end hole 111, spiral oil groove distal end hole 112, connecting groove 12, driven shaft 20, driven shaft lubrication oil hole 21, driven shaft lubrication diffusion slope 22, connecting piece 30, driven shaft step 31, vent hole 32, oil supply channel 40. Detailed Implementation

[0024] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] Example 1 details a compressor variable frequency double-helix oil groove crankshaft. This crankshaft is ingeniously designed and can be effectively applied in an advanced variable frequency refrigeration device to improve its operating efficiency and stability. See also Figure 1 , Figure 2 and Figure 3As shown, the compressor variable frequency double spiral oil groove crankshaft in this example mainly consists of a main shaft 10, a driven shaft 20, and a connecting member 30 located between them. The connecting member 30 is cleverly positioned in the middle, with the main shaft 10 securely connected to the lower part of the connecting member 30, and the driven shaft 20 connected to the upper part of the connecting member 30, forming an upper and lower layout. In particular, although the axis of the main shaft 10 and the axis of the driven shaft 20 do not coincide, they remain parallel, ensuring smooth rotation; at the same time, the upper and lower end faces of the connecting member 30 are designed to be perpendicular to the axis of the main shaft 10, further enhancing the structural stability.

[0027] The connector 30 is also specially equipped with a counterweight. This design cleverly forms a gravitational balance with the driven shaft 20, which is offset to one side of the axis of the main shaft 10, effectively reducing vibration and noise during operation. When the main shaft 10 rotates around its own axis, it can stably drive the driven shaft 20 to rotate together. Conversely, the rotation of the driven shaft 20 can also be stably transmitted to the main shaft 10, realizing smooth power transmission.

[0028] Regarding the lubrication system, the spindle 10 features a meticulously designed oil supply channel 40. This channel is open at its lower end, facilitating the intake of lubricating oil from below and providing continuous lubrication for the entire crankshaft. The surface of the spindle 10 is provided with concave spiral oil grooves 11, with a proximal spiral oil groove hole 111 and a distal spiral oil groove hole 112 at its upper and lower ends, respectively. The distal spiral oil groove hole 112, located at the lower end, cleverly penetrates the side wall of the spindle 10 and is tightly connected to the oil supply channel 40, ensuring smooth flow of lubricating oil.

[0029] In addition, a driven shaft lubrication oil hole 21 is also provided on the driven shaft 20. This hole opens on the surface of the driven shaft 20, extends inward and downward, and communicates with the bottom of the near end hole 111 of the spiral oil groove, forming a complete lubrication oil passage. In this example, the lubrication oil passage of the compressor variable frequency double spiral oil groove crankshaft is as follows: lubricating oil is drawn in from the oil supply channel 40, enters the spiral oil groove 11 through the far end hole 112 of the spiral oil groove, and then flows into the driven shaft lubrication oil hole 21 through the near end hole 111 of the spiral oil groove, ultimately achieving comprehensive lubrication of the entire crankshaft.

[0030] This is the most basic embodiment of the solution. Its ingenious design and reasonable structure lay a solid foundation for the gradual optimization of subsequent embodiments.

[0031] Example 2

[0032] Example 2 illustrates another optimized and improved compressor variable frequency double helical oil groove crankshaft, which is a refined adjustment and improvement based on Example 1. Specifically, the compressor variable frequency double helical oil groove crankshaft in this example adds a key structure: a driven shaft lubrication diffusion ramp 22. The driven shaft lubrication diffusion ramp 22 is designed as a gradually changing ramp, with one end being deeper and gradually transitioning to a shallower one. The deep end is tightly connected to the driven shaft lubrication oil hole 21, ensuring smooth flow of lubricating oil. The main direction of this ramp surrounds the surface of the driven shaft 20, and its overall shape is roughly similar to a wedge-shaped groove, which helps to evenly diffuse the lubricating oil. The driven shaft lubrication diffusion ramp 22 can strictly surround the circumferential surface of the driven shaft 20, or it can be spirally surrounded to adapt to different lubrication requirements. At the same time, the shallow end of the wedge-shaped groove is flexibly designed; it can be the same width as the deep end, or it can gradually widen, or it can even be multiple wedge-shaped grooves originating from the same deep end, to increase the diffusion area of ​​the lubricating oil. However, it is important to note that the position of the shallow end must match the rotation direction of the driven shaft 20 to ensure effective lubrication. In this example, the driven shaft lubrication diffusion ramp 22 is designed as a wedge-shaped groove surrounding the circumferential surface of the driven shaft 20, which ensures both structural simplicity and efficient lubrication.

[0033] Same as Example 1.

[0034] Example 3

[0035] Example 3 showcases another meticulously designed compressor variable frequency double helical oil groove crankshaft, which features detailed improvements and comprehensive optimizations based on Example 2. Specifically, this crankshaft cleverly incorporates multiple helical oil grooves 11 on the surface of the main shaft 10. In this example of the compressor variable frequency double helical oil groove crankshaft design, the number of helical oil grooves 11 is precisely set to two, and the specifications of these two oil grooves are completely identical. They are evenly distributed on the surface of the main shaft 10 at equal angles and intervals, ensuring the balance and stability of oil supply. Each helical oil groove 11 has a helical oil groove proximal end hole 111 and a helical oil groove distal end hole 112. Both helical oil groove proximal end holes 111 are ingeniously designed to communicate with the driven shaft lubrication oil hole 21 inside the connector 30. Given that the spiral oil groove 11 plays a key role in the oil supply system by conveying lubricating oil from the oil supply channel 40 to the driven shaft 20, the design of these two spiral oil grooves 11 can theoretically significantly improve the oil supply and achieve the effect of doubling the oil supply.

[0036] Same as Example 2.

[0037] Example 4

[0038] In this embodiment, the surface structure of the spindle 10 is optimized, with the addition of a key feature: a connecting groove 12. Specifically, the connecting groove 12 is designed as an annular groove surrounding the surface of the spindle 10, its depth precisely calculated to ensure it is less than the depth of the original spiral oil grooves 11 on the spindle 10. This design aims to establish an effective communication channel between the multiple spiral oil grooves 11 through the connecting groove 12, thereby balancing the oil distribution and pressure state within each spiral oil groove 11 and improving lubrication. The number of connecting grooves 12 is not fixed and can be flexibly adjusted by those skilled in the art according to actual needs; it can be a single groove or multiple grooves as required. In this embodiment, to simplify the structure and meet basic requirements, only one connecting groove 12 is provided, and its width is designed to be slightly wider than the width of the spiral oil grooves 11 to ensure communication while also facilitating manufacturing. The connecting groove 12 is arranged around the surface of the spindle 10, forming a complete annular structure.

[0039] Same as Example 3.

[0040] Example 5

[0041] This embodiment is based on embodiment 4, and further improvements and optimizations have been made to the structure of the oil supply channel 40.

[0042] Specifically, the oil supply channel 40 adopts an innovative stepped orifice design. Its lower end (outer end) has a relatively large diameter, the middle section features a carefully designed stepped surface, while the upper end (inner end) has a smaller diameter. This unique stepped orifice structure lays the foundation for subsequent oil-gas separation operations.

[0043] Meanwhile, this embodiment also cleverly arranges the position of the distal hole 112 of the spiral oil groove, placing it below the stepped surface, specifically at the point where the diameter is about to decrease. In actual operation, when lubricating oil is drawn into the oil supply channel 40, a certain amount of air inevitably mixes in. Due to the difference in mass between lubricating oil and air, the centrifugal force acting on the lubricating oil is much greater than the centrifugal force of the air when the crankshaft rotates. At this point, by designing the stepped surface, a pressure difference is artificially created within the oil supply channel, and then pressure is released using the distal hole 112 of the spiral oil groove, allowing the lubricating oil to be preferentially ejected from the oil supply channel. The air mixed in with the lubricating oil, due to the different pressure and centrifugal force, is more likely to be squeezed into the smaller diameter area of ​​the stepped hole in the oil supply channel 40. Through this design, oil-air separation is successfully achieved, further optimizing the lubrication and cooling effect.

[0044] Same as Example 4.

[0045] Example 6

[0046] This embodiment is a further optimization and improvement based on Embodiment 5. Building upon Embodiment 5, this embodiment specifically addresses the potential air accumulation problem during equipment operation. Specifically, a key structure, an exhaust port 32, is added to the connector 30. The position of the exhaust port 32 is carefully designed: its outer end opens onto the upper end face of the connector 30, that is, the end face near the shaft 20; while the inner end of the exhaust port 32 connects to the bottom of the oil supply channel 40, more precisely, to the bottom of the small-diameter area of ​​the stepped hole in the oil supply channel 40.

[0047] During continuous operation of the equipment, the oil supply channel 40 inevitably draws in a certain amount of air while drawing in lubricating oil. As the operating time increases, more and more air is drawn into the oil supply channel 40, gradually accumulating in the small-diameter area of ​​the stepped hole in the oil supply channel 40. Due to the structural characteristics of this area, the air is difficult to expel on its own. By providing the vent hole 32, an effective outlet is provided for the air accumulated in this area, allowing it to be safely released. This ensures that air does not continue to mix with the lubricating oil, thus preventing air-mixed lubricating oil from appearing on the surface of the main shaft 10 or the driven shaft 20, ensuring the stability and reliability of the equipment operation.

[0048] To further improve equipment performance, the existing design can be further optimized. Specifically, the stepped hole structure of the oil supply channel 40 can be improved by designing its stepped surface as a conical surface that bulges upwards (i.e., on the side with the smaller diameter). This optimized conical surface design can naturally create a guiding effect, causing the oil-gas mixture to generate a specific flow trajectory as it flows through the stepped surface, thereby accelerating the separation speed of oil and gas around the stepped surface. Through this structural improvement, the overall efficiency of oil-gas separation can be effectively improved, ensuring more stable and reliable equipment operation.

[0049] Same as Example 5.

[0050] Example 7

[0051] Example 7, as a relatively complete and representative embodiment of this technical solution, further optimizes the overall design based on the core structure of Example 6. Specifically, this embodiment innovatively introduces a weight-reduction design, the core improvement of which lies in the addition of a follower shaft step 31 on the connector 30. This follower shaft step 31 adopts a frustum-shaped partial structural design, with its axis precisely aligned with the axis of the follower shaft 20 to ensure concentricity of rotation. The upper surface area of ​​the frustum is large, perfectly aligning with the upper surface of the connector 30, forming a smooth transition; while the lower surface area of ​​the frustum is small, aligning with the lower surface of the connector 30. It can even be designed so that the thickness of the frustum is less than the thickness of the connector 30, giving the lower surface of the frustum a visually lightweight, almost invisible appearance. Crucially, the follower shaft step 31 is carefully positioned opposite the center of gravity of the counterweight. This arrangement effectively counteracts the unbalanced torque during rotation, ensuring the overall stability and reliability of the rotation. Through this weight reduction design, the overall volume of connector 30 is significantly reduced and its weight is greatly reduced. For inverter air conditioners that need to operate at low speeds for a long time, this improvement not only reduces energy consumption but also significantly improves the system's operating efficiency, resulting in significant energy-saving advantages.

[0052] Same as Example 6.

[0053] In this embodiment, lubricating oil mixed with air is drawn in from the lower end of the oil supply channel 40. As the main shaft 10 rotates, oil-air separation occurs near the stepped surface of the stepped hole in the oil supply channel 40. The air is safely discharged through the exhaust hole 32 to the top of the connector 30. The lubricating oil is thrown out from the distal holes 112 of the two spiral oil grooves onto the outer wall of the main shaft 10, lubricating the entire outer wall of the main shaft 10 along the two spiral oil grooves 11. During this process, the connecting groove 12 balances the oil quantity and pressure of the two spiral oil grooves 11. The lubricating oil continues to rise along the spiral oil grooves 11, entering the depth of the connector 30 after reaching the proximal holes 111 of the two spiral oil grooves. It is then guided to the surface of the driven shaft 20 through the driven shaft lubrication hole 21, lubricating and cooling the surface of the driven shaft 20. The lubrication and cooling effect is optimized by the shaft lubrication diffusion slope 22. This solution can well meet the working requirements of crankshafts with long working hours and low speeds.

Claims

1. A compressor variable frequency double spiral oil groove crankshaft, comprising a main shaft (10), a driven shaft (20), and a connecting member (30), wherein the main shaft (10) is provided with spiral oil grooves (11), characterized in that, it further comprises... include: The oil supply channel (40) is located inside the spindle (10), with the end away from the connector (30) being open; The lubrication hole (21) of the shaft is located on the surface of the shaft (20); The spiral oil groove (11) is provided with a spiral oil groove distal hole (112) at the end away from the connector (30). The spiral oil groove distal hole (112) passes through the side wall of the main shaft (10) and is connected to the oil supply channel (40). The spiral oil groove (11) is provided with a spiral oil groove proximal hole (111) at one end near the connector (30), and the spiral oil groove proximal hole (111) and the driven shaft lubricating oil hole (21) are connected inside the connector (30).

2. The compressor variable frequency double spiral oil groove crankshaft according to claim 1, characterized in that, It also includes a lubrication diffusion ramp (22) on the shaft; the lubrication diffusion ramp (22) on the shaft (20) gradually changes from deep to shallow, and the deep end is connected to the opening of the lubrication hole (21) on the shaft.

3. A compressor variable frequency double spiral oil groove crankshaft according to claim 1 or 2, characterized in that, There are two or more spiral oil grooves (11), which are arranged in the same direction on the side wall of the main shaft (10).

4. A compressor variable frequency double spiral oil groove crankshaft according to claim 3, characterized in that, Each spiral oil groove (11) has the same specifications and is arranged at equal angles and intervals on the side wall of the main shaft (10).

5. A compressor variable frequency double spiral oil groove crankshaft according to claim 3, characterized in that, It is also provided with a connecting groove (12); the connecting groove (12) is arranged around the surface of the main shaft (10) and its depth is less than the depth of the spiral oil groove (11).

6. A compressor variable frequency double spiral oil groove crankshaft according to claim 1 or 2, characterized in that, The oil supply channel (40) is a stepped hole with a wide opening and a narrow bottom. The opening position of the spiral oil groove far end hole (112) is located on the side of the stepped hole with a wide opening, close to the stepped surface.

7. A compressor variable frequency double spiral oil groove crankshaft according to claim 6, characterized in that, The stepped surface of the stepped hole is a conical surface that bulges towards the bottom.

8. The compressor variable frequency double spiral oil groove crankshaft according to claim 1 or 2, characterized in that, It also includes an exhaust port (32); the inner end of the exhaust port (32) is connected to the bottom of the oil supply channel (40), and the outer end is opened on the side surface of the connecting member (30) from the shaft (20).

9. A compressor variable frequency double spiral oil groove crankshaft according to claim 1 or 2, characterized in that, The connector (30) includes a counterweight and a follower step (31); the follower step (31) is a partial frustum shape, and the two end faces of the frustum shape coincide with the two end faces of the connector (30), with the end face on one side of the follower (20) being larger; the follower step (31) is located opposite the center of gravity of the counterweight.

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