A compressor and its movement

Abstract

The present invention provides a compressor core, which, according to the orifice flow principle, sets the inner diameter D of the oil guide channel and the aperture d of the oil inlet hole to 1 , the diameter of the oil outlet hole d 2 , the diameter of the oil return hole d 3 Limited to D>d 1 >d 2 >d 3 , thereby defining the relationship between the various flow paths in the internal circulation oil circuit, thereby effectively controlling the amount of refrigeration oil sprayed out through the oil return hole, and further being able to effectively suppress the sharp increase in the oil circulation amount when the speed is increased, so as to ensure that the compressor can operate stably at a high speed. In addition, the present invention also provides a compressor, which adopts the above-mentioned movement, so that even at a high speed, there will be no oil shortage inside, and it can operate safely and stably at a high speed.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a compressor and a movement thereof. Background Art

[0002] When the compressor is running, in addition to the refrigerant circulating continuously in the compression system, the refrigeration oil used to cool and lubricate the movement will also circulate continuously with the movement of the refrigerant. The amount of oil involved in the circulation is defined as the oil circulation volume.

[0003] At low speeds, due to the slow movement of the refrigerant, the oil circulation volume has always been at a low level, and the amount of oil in the compressor can meet the lubrication requirements of the movement; but at high speeds (above 90rps), due to the faster movement of the refrigerant, a large amount of oil in the compressor is brought into the compression system by the refrigerant, and the oil circulation volume will increase sharply, resulting in oil shortage in the compressor, seriously affecting the normal operation of the compressor. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a compressor and a movement thereof, which can effectively suppress the sharp increase in oil circulation volume when the speed increases, so as to ensure that the compressor can operate stably at a high speed.

[0005] Based on this, the present invention provides a movement of a compressor, comprising a crankshaft, the crankshaft comprising a lower shaft section, an oil guide cavity is provided inside the lower shaft section, an oil slinger is provided inside the oil guide cavity, an oil dispersion hole connected to the oil guide cavity is provided on the side wall of the lower shaft section, an oil inlet structure is provided at the lower end of the crankshaft, the oil inlet structure is provided with an oil inlet hole connected to the oil guide cavity, an oil outlet structure is provided at the top of the oil guide cavity, the oil outlet structure is provided with an oil outlet hole connected to the oil guide cavity, and an oil return hole connected to the oil outlet structure is also provided on the side wall of the lower shaft section;

[0006] The inner diameter of the oil guide channel is recorded as D, the diameter of the oil inlet hole is recorded as d1, the diameter of the oil outlet hole is recorded as d2, and the diameter of the oil return hole is recorded as d3. Then D, d1, d2 and d3 satisfy

[0007] The following relationship:

[0008] D>d1>d2>d3.

[0009] As a preferred solution, D, d1, d2 and d3 satisfy the following relationship:

[0010]

[0011] As a preferred embodiment, the oil guide cavity is provided with an oil baffle plate near the top thereof, and the oil baffle plate divides the oil guide cavity into a lower cavity and an upper cavity. The oil baffle plate and the upper cavity constitute the oil outlet structure, the oil flinger is arranged in the lower cavity, the oil outlet hole is arranged on the oil baffle plate, the lower cavity is connected with the upper cavity through the oil outlet hole, and the oil return hole is connected with the upper cavity.

[0012] As a preferred solution, the outer edge of the oil baffle plate is interference fit with the cavity wall of the oil guide cavity.

[0013] As a preferred solution, the oil outlet structure is a thin hole channel, and the thin hole channel and the oil guide cavity channel are connected by a

[0014] The oil outlet holes are connected, and the oil return hole is connected with the fine channel.

[0015] As a preferred solution, the oil-spinning sheet is spiral-shaped.

[0016] As a preferred solution, the oil inlet hole is a cone with a larger bottom and a smaller top, and d1 is the maximum diameter of the oil inlet hole.

[0017] Small aperture.

[0018] As a preferred solution, the taper of the oil inlet hole is 13°-14°.

[0019] As a preferred embodiment, the oil guide channel forms an opening on the lower end surface of the crankshaft, and the oil inlet structure

[0020] The structure includes a sealing plate, which blocks the opening, and the oil inlet hole is arranged on the sealing plate.

[0021] As a preferred solution, the sealing plate is provided with an oil inlet nozzle, and the oil inlet hole is provided on the oil inlet nozzle.

[0022] As a preferred embodiment, it also includes an upper bearing, a lower bearing and a cylinder, wherein the cylinder is arranged between the upper bearing and the lower bearing, and the lower shaft section passes through the upper bearing, the cylinder and the lower bearing in sequence from top to bottom and is cooperatively connected with the upper bearing and the lower bearing.

[0023] As a preferred solution, the bottom cover of the lower bearing is provided with a bottom cover, and the sealing plate is pressed against the bottom cover.

[0024] The bottom cover is provided with a through hole corresponding to the oil inlet hole between the cover and the lower end surface of the crankshaft. As a preferred solution, the oil outlet hole is higher than the cylinder.

[0025] As a preferred solution, the oil dispersion holes are distributed on the side wall of the lower shaft section between the upper bearing and the lower bearing.

[0026] As a preferred solution, an oil cup is provided on the outer sleeve of the upper bearing.

[0027] Another object of the present invention is to provide a compressor, which includes a shell and a stator, a rotor and the above-mentioned movement arranged inside the shell, the crankshaft of the movement also includes an upper shaft section, the upper shaft section passes through the stator and the rotor from bottom to top, and the rotor is tightly sleeved on the outside of the upper shaft section.

[0028] The implementation of the embodiments of the present invention has the following beneficial effects:

[0029] An embodiment of the present invention provides a compressor movement, which, based on the orifice flow principle, limits the inner diameter D of the oil guide cavity, the aperture d1 of the oil inlet hole, the aperture d2 of the oil outlet hole, and the aperture d3 of the oil return hole to D>d1>d2>d3, thereby limiting the relationship between the various flow paths in the internal circulation oil circuit, thereby effectively controlling the amount of refrigeration oil sprayed through the oil return hole, and further being able to effectively suppress the sharp increase in the oil circulation amount when the speed is increased, thereby ensuring that the compressor can operate stably at a high speed.

[0030] Furthermore, the movement provided in the embodiment of the present invention also sets the oil inlet hole to a cone with a larger bottom and a smaller top according to the flow formula, so as to increase the flow rate of the refrigeration oil when entering the oil guide cavity. As a result, the cooling and lubrication effects of the movement and the utilization rate of the refrigeration oil are significantly improved, the amount of refrigeration oil sprayed out through the oil return hole is further controlled, and the oil circulation volume is effectively suppressed.

[0031] Furthermore, the movement provided in the embodiment of the present invention is provided with an oil cup on the outer side of the upper bearing, and the oil cup separates the oil return hole and the air outlet of the cylinder on its upper and lower sides. Therefore, the refrigerant sprayed from the air outlet of the cylinder will not directly flow upward to meet the refrigeration oil sprayed through the oil return hole, thereby effectively reducing the amount of refrigeration oil carried away by the refrigerant and further suppressing the increase in oil circulation volume.

[0032] In addition, an embodiment of the present invention further provides a compressor, which adopts the above-mentioned movement, so that even at a high speed, there will be no oil shortage inside the compressor, and the compressor can operate safely, stably and at a high speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a structural schematic diagram of a compressor according to an embodiment of the present invention;

[0034] Figure 2 is a schematic structural diagram of a movement according to an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram of the shape of the vacuum chamber at different rotation speeds;

[0036] Figure 4 It is a comparison chart of oil circulation volume between the existing compressor and the compressor provided by the present invention;

[0037] Figure 5 It is a schematic diagram of the structure of the sealing plate and the oil inlet nozzle;

[0038] Figure 6 is a structural schematic diagram of a sealing plate and an oil inlet hole in an embodiment of the present invention;

[0039] Figure 7 It is a structural schematic diagram of an oil baffle and an oil outlet hole according to an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 1. Housing, 2. Stator, 3. Rotor, 4. Cylinder, 5. Upper bearing, 6. Lower bearing, 7. Crankshaft, 701. Oil guide cavity, 701a. Upper cavity, 701b. Lower cavity, 702. Oil dispersion hole, 703. Oil return hole, 8. Oil flinger, 9. Oil inlet structure, 901. Oil inlet hole, 902. Sealing plate, 903. Oil inlet nozzle, 10. Bottom cover, 11. Oil outlet structure, 111. Oil outlet hole, 12. Oil cup, 13. Oil baffle plate. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, an embodiment of the present invention provides a compressor, including a housing 1 and a movement, a stator 2 and a rotor 3 arranged inside the housing 1; wherein the movement is arranged near the bottom of the housing 1, and includes a cylinder 4, an upper bearing 5, a lower bearing 6 and a crankshaft 7, the cylinder 4 is arranged between the upper bearing 5 and the lower bearing 6, and the cylinder 4 is tightly fitted and fixed to the inner wall of the housing 1, and the upper bearing 5 and the lower bearing 6 are fastened to the cylinder 4 by bolts; the crankshaft 7 includes a lower shaft section and an upper shaft section, and the lower shaft section passes through the upper bearing 5, the lower bearing 6 and the lower bearing 6 in sequence from top to bottom. The cylinder 4 and the lower bearing 6 are connected with the upper bearing 5 and the lower bearing 6; a rolling rotor (not shown) is provided in the cylinder 4, and the rolling rotor is sleeved on the outside of the lower shaft section. Based on this, as the crankshaft 7 rotates, the rolling rotor can rotate eccentrically in the cylinder 4 to compress the refrigerant entering the cylinder 4; the stator 2 is arranged above the movement and is tightly fixed to the inner wall of the shell 1, and the upper shaft section of the crankshaft 7 passes through the stator 2 and the rotor 3 from bottom to top, and the rotor 3 is tightly sleeved on the outside of the upper shaft section and forms a motor structure with the stator 2.

[0044] like Figures 2 to 3 As shown, an oil guide cavity 701 is provided inside the lower shaft section, and an oil flinging plate 8 is provided inside the oil guide cavity 701. In the present embodiment, the oil flinging plate 8 is preferably spiral-shaped; an oil dispersion hole 702 is provided on the side wall of the lower shaft section and is connected to the oil guide cavity 701; an oil inlet structure 9 is provided on the lower end of the crankshaft 7; the oil inlet structure 9 is provided with an oil inlet hole 901 connected to the oil guide cavity 701; an oil outlet structure 11 is provided on the top of the oil guide cavity 701; the oil outlet structure 11 is provided with an oil outlet hole 111 connected to the oil guide cavity 701; an oil return hole 703 is also provided on the side wall of the lower shaft section and is connected to the oil outlet structure 11; and the oil return hole 703 is higher than the upper bearing 5 to facilitate the refrigeration oil to be sprayed out from the oil guide cavity 701.

[0045] Based on the above structure, the internal circulation oil circuit of the compressor during operation is as follows: the refrigeration oil at the bottom of the shell 1 is first sprayed upward into the oil guide cavity 701 through the oil inlet hole 901. During the rising process of the refrigeration oil, due to the centrifugal force generated by the rotation of the crankshaft 7 and the guiding effect of the oil flinger 8, the refrigeration oil will flow along the cavity wall of the oil guide cavity 701 and form a flow path with an axial cross-section that is approximately "V" or "U" shaped, that is, a vacuum cavity will be formed in the middle of the refrigeration oil; then, most of the refrigeration oil flowing along the cavity wall of the oil guide cavity 701 reaches the surface of the crankshaft 7 through the oil dispersion hole 702 for cooling and lubrication, and the remaining refrigeration oil rises to the top of the oil guide cavity 701, and is sprayed out of the oil guide cavity 701 through the oil outlet hole 111 and the oil return hole 703 in turn, and finally flows back to the bottom of the shell 1 to achieve circulation.

[0046] Based on the above oil circulation circuit, in order to minimize the amount of refrigeration oil carried away by the refrigerant and suppress the increase of the oil circulation amount, the key is to control the amount of refrigeration oil sprayed out through the oil return hole 703 as much as possible. Therefore, it is known that the inner diameter of the oil guide channel 701 is D, the aperture of the oil inlet hole 901 is d1, the aperture of the oil outlet hole 111 is d2, and the aperture of the oil return hole 703 is d3. According to the orifice flow principle - under the same flow rate, the flow rate is proportional to the aperture, then D, d1, d2 and d3 must satisfy the following relationship:

[0047] D>d1>d2>d3.

[0048] Preferably, in actual application, technicians have concluded based on work experience and a large amount of test data that when D, d1, d2 and d3 satisfy the following relationship, the oil circulation amount will not increase sharply with the increase of the compressor speed:

[0049]

[0050] like Figure 3As shown, the starting height and shape of the vacuum chamber formed by the refrigeration oil in the oil guide channel 701 are related to the rotation speed of the crankshaft 7. As the rotation speed of the crankshaft 7 increases, the starting height of the vacuum chamber becomes lower and lower, and the bottom of the vacuum chamber becomes flatter. In other words, when the rotation speed increases, the coverage of the refrigeration oil on the cavity wall of the oil guide channel 701 becomes wider and wider, so that the refrigeration oil can flow out of the oil dispersion hole 702 more smoothly, and the amount of refrigeration oil sprayed out through the oil return hole 703 will gradually decrease. Therefore, under high rotation speed conditions, the oil circulation volume of the compression system is effectively suppressed. Figure 4 It can be seen intuitively that with the increase of the rotation speed, the oil circulation amount of the compressor provided by the present invention increases smoothly.

[0051] Furthermore, according to the flow formula q=A×v (A is the orifice cross-sectional area, v is the flow velocity), it can be known that, when the flow q remains unchanged, the smaller A is, the larger v is. That is to say, if the flow area of ​​the oil inlet hole 901 becomes smaller and smaller from bottom to top, the flow velocity of the refrigeration oil when it is sprayed into the oil guide channel 701 will be greatly improved, and the flow velocity directly affects the height reached by the refrigeration oil in the oil guide channel 701. Therefore, the oil inlet hole 901 is preferably a cone with a larger bottom and a smaller top, and d1 is the minimum aperture of the oil inlet hole 901. Based on this, after the refrigeration oil enters the oil guide cavity 701 through the tapered oil inlet hole 901, it can easily rise to the top of the oil guide cavity 701, thereby improving the cooling and lubrication effect of the movement. At the same time, based on the high flow rate, the refrigeration oil can quickly cover the entire cavity wall of the oil guide cavity 701, and quickly reach the surface of the crankshaft 7 through the oil dispersion hole 702, thereby significantly improving the utilization rate of the refrigeration oil, and further controlling the amount of refrigeration oil sprayed out through the oil return hole 703, and effectively suppressing the oil circulation of the compression system. In this embodiment, the taper of the oil inlet hole 901 is preferably 13°-14°, at which time, the flow rate of the refrigeration oil when entering the oil guide cavity 701 is the fastest.

[0052] Alternatively, if Figures 5 and 6 As shown, the oil guide cavity 701 forms an opening on the lower end surface of the crankshaft 7, and the oil inlet structure 9 includes a sealing plate 902 and an oil inlet nozzle 903 arranged on the sealing plate 902. The sealing plate 902 blocks the opening, and the oil inlet hole 901 is arranged on the oil inlet nozzle 903. On this basis, the bottom fixed cover of the lower bearing 6 is provided with a bottom cover 10, and the sealing plate 902 is pressed between the bottom cover 10 and the lower end surface of the crankshaft 7. The bottom cover 10 is provided with a through hole corresponding to the oil inlet nozzle 903, and the oil inlet nozzle 903 passes through the through hole. Of course, the oil inlet structure 9 may also not be provided with the oil inlet nozzle 903, and the oil inlet hole 901 is directly arranged on the sealing plate 902. In this case, the through hole on the bottom cover 10 is directly opposite to the oil inlet hole 901.

[0053] like Figure 2As shown, in order to separate the refrigeration oil sprayed through the oil return hole 703 from the rising refrigerant and to further reduce the amount of refrigeration oil carried away by the refrigerant, an oil cup 12 is provided on the outer sleeve of the upper bearing 5. The oil cup 12 separates the oil return hole 703 and the air outlet of the cylinder 4 on its upper and lower sides. As a result, the refrigerant sprayed from the air outlet of the cylinder 4 will not directly flow upward to meet the refrigeration oil sprayed through the oil return hole 703, thereby effectively reducing the amount of refrigeration oil carried away by the refrigerant and further suppressing the increase in the oil circulation volume.

[0054] Specifically, Figure 2 and Figure 7 As shown, the oil guide cavity 701 is provided with an oil baffle plate 13 near the top thereof, the outer edge of the oil baffle plate 13 is interference fit with the cavity wall of the oil guide cavity 701, and the oil baffle plate 13 divides the oil guide cavity 701 into a lower cavity 701b and an upper cavity 701a, the oil baffle plate 13 and the upper cavity 701a constitute the above-mentioned oil outlet structure 11, the oil flinger 8 is arranged in the lower cavity 701b, the oil outlet hole 111 is arranged on the oil baffle plate 13, the lower cavity 701b is connected with the upper cavity 701a through the oil outlet hole 111, and the oil return hole 703 is connected with the upper cavity 701a.

[0055] Optionally, the oil outlet structure 11 has another form, namely, a thin channel, which is connected to the oil guide channel 701 through the oil outlet hole 111, and the oil return hole 703 is connected to the thin channel. However, compared with the oil outlet structure 11 composed of the oil baffle plate 13 and the upper channel 701a, the thin channel needs to be drilled on the top of the oil guide channel 701 using a long and thin drill bit, which is difficult to manufacture and requires high precision. Therefore, the oil outlet structure 11 composed of the oil baffle plate 13 and the upper channel 701a is more conducive to popularization and application.

[0056] Preferably, if Figure 2 As shown, in order to ensure that the cylinder 4 and the rolling rotor can be adequately cooled and lubricated, the oil outlet hole 111 must be located higher than the cylinder 4, that is, the oil outlet structure 11 must be arranged higher than the cylinder 4, and the oil holes 702 are distributed on the side wall of the lower shaft section between the upper bearing 5 and the lower bearing 6, so that the refrigeration oil in the oil guide cavity 701 can smoothly reach between the cylinder 4 and the rolling rotor.

[0057] It should be pointed out that the compressor provided by the present invention may be a single-cylinder compressor, or a dual-cylinder or multi-cylinder compressor.

[0058] In summary, the embodiment of the present invention provides a compressor movement, which has the following beneficial effects compared with the prior art:

[0059] 1. According to the orifice flow principle, the movement defines the inner diameter D of the oil guide channel 701, the aperture d1 of the oil inlet hole 901, the aperture d2 of the oil outlet hole 111, and the aperture d3 of the oil return hole 703 as D>d1>d2>d3, thereby defining the relationship between the flow paths in the internal circulation oil circuit, thereby effectively reducing the amount of refrigeration oil sprayed through the oil return hole 703, and further effectively suppressing the sharp increase in the oil circulation amount when the speed is increased, so as to ensure that the compressor can operate stably at a high speed;

[0060] 2. The conical oil inlet hole 901 increases the flow rate of the refrigeration oil when entering the oil guide cavity 701, thereby significantly improving the cooling and lubrication effect of the movement and the utilization rate of the refrigeration oil, and further controlling the amount of refrigeration oil sprayed out through the oil return hole 703, and effectively suppressing the oil circulation amount;

[0061] 3. The oil cup sleeved on the outside of the upper bearing separates the oil return hole 703 and the air outlet of the cylinder on its upper and lower sides, so that the refrigerant sprayed from the air outlet of the cylinder will not directly flow upward to meet the refrigeration oil sprayed through the oil return hole 703, effectively reducing the amount of refrigeration oil carried away by the refrigerant, and further suppressing the increase in oil circulation volume.

[0062] In addition, an embodiment of the present invention further provides a compressor, which adopts the above-mentioned movement, so that even at a high speed, there will be no oil shortage inside the compressor, and the compressor can operate safely, stably and at a high speed.

[0063] It should be understood that the present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0064] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A compressor movement, characterized in that: The crankshaft includes a lower shaft section, an oil guide cavity is provided inside the lower shaft section, an oil slinger is provided inside the oil guide cavity, an oil dispersion hole connected to the oil guide cavity is provided on the side wall of the lower shaft section, an oil inlet structure is provided at the lower end of the crankshaft, the oil inlet structure is provided with an oil inlet hole connected to the oil guide cavity, an oil outlet structure is provided at the top of the oil guide cavity, the oil outlet structure is provided with an oil outlet hole connected to the oil guide cavity, and an oil return hole connected to the oil outlet structure is also provided on the side wall of the lower shaft section; The inner diameter of the oil guide channel is recorded as D, the diameter of the oil inlet hole is recorded as d1, the diameter of the oil outlet hole is recorded as d2, and the diameter of the oil return hole is recorded as d3. Then, D, d1, d2 and d3 satisfy the following relationship: D>d1>d2>d3.

2. The compressor movement according to claim 1, characterized in that: The following relationship is satisfied between D, d1, d2 and d3:

3. The compressor movement according to claim 1, characterized in that: The oil guide cavity is provided with an oil baffle plate near the top thereof, and the oil baffle plate divides the oil guide cavity into a lower cavity and an upper cavity. The oil baffle plate and the upper cavity constitute the oil outlet structure, the oil flinger is arranged in the lower cavity, the oil outlet hole is arranged on the oil baffle plate, the lower cavity is connected with the upper cavity through the oil outlet hole, and the oil return hole is connected with the upper cavity.

4. The compressor movement according to claim 3, characterized in that: The outer edge of the oil baffle plate is interference fit with the cavity wall of the oil guide cavity.

5. The compressor movement according to claim 1, characterized in that: The oil outlet structure is a thin hole channel, the thin hole channel is connected with the oil guide cavity channel through the oil outlet hole, and the oil return hole is connected with the thin hole channel.

6. The compressor movement according to claim 1, characterized in that: The oil-slinging sheet is spiral-shaped.

7. The compressor movement according to claim 1, characterized in that: The oil inlet hole is in a cone shape with a larger bottom and a smaller top, and d1 is the minimum aperture of the oil inlet hole.

8. The compressor movement according to claim 7, characterized in that: The taper of the oil inlet hole is 13°-14°.

9. The compressor movement according to claim 1, characterized in that: The oil guide cavity forms an opening on the lower end surface of the crankshaft, and the oil inlet structure includes a sealing plate, which blocks the opening, and the oil inlet hole is arranged on the sealing plate.

10. The compressor movement according to claim 9, characterized in that: The sealing plate is provided with an oil inlet nozzle, and the oil inlet hole is arranged on the oil inlet nozzle.

11. The compressor movement according to claim 9, characterized in that: It also includes an upper bearing, a lower bearing and a cylinder, wherein the cylinder is arranged between the upper bearing and the lower bearing, and the lower shaft section passes through the upper bearing, the cylinder and the lower bearing in sequence from top to bottom and is connected with the upper bearing and the lower bearing.

12. The compressor movement according to claim 11, characterized in that: The bottom cover of the lower bearing is provided with a bottom cover, the sealing plate is pressed between the bottom cover and the lower end surface of the crankshaft, and the bottom cover is provided with a through hole corresponding to the oil inlet hole.

13. The compressor movement according to claim 11, characterized in that: The oil outlet hole is higher than the cylinder.

14. The compressor movement according to claim 11, characterized in that: The oil dispersion holes are distributed on the side wall of the lower shaft section between the upper bearing and the lower bearing.

15. The compressor movement according to claim 11, characterized in that: An oil cup is sleeved outside the upper bearing.

16. A compressor, characterized in that: It includes a shell, a stator and a rotor arranged inside the shell, and a movement as described in any one of claims 1-15, the crankshaft of the movement also includes an upper shaft section, the upper shaft section passes through the stator and the rotor from bottom to top, and the rotor is tightly sleeved on the outside of the upper shaft section.

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