Patent Description:
In the structure of a rotary compressor, a high-speed rotating airflow is formed when a balance weight is rotated, so that refrigerator oil droplets carried in a refrigerant gradually deviates from an axial center of the compressor under a centrifugal action, and move towards a wall surface of a shell, thus achieving an effect of oil-gas separation. At present, the refrigerator oil tends to accumulate at a position close to an exhaust side of a stator to form a secondary source of oil droplets, resulting in a large discharge amount of oil and a lowered oil level in an oil sump. <CIT> and <CIT> relate to compressors with rotor assemblies having crankshafts that are in contact with the elements surrounding it. <CIT> and <CIT> relate to compressors with rotor assemblies having a hole and gas hole respectively which adjoins a crankshaft of the rotor assembly.

Aspects of the invention are set out in the appended set of claims. The present invention aims to solve at least one of the technical problems in the existing technology. Therefore, according to an aspect of the present invention, a rotor assembly is provided, which can reduce a discharge amount of refrigerator oil in the compressor.

The present invention further provides a compressor comprising the rotor assembly, according to another aspect thereof.

A rotor assembly according to a first aspect of the present invention is set out in claim <NUM>.

The rotor assembly according to the embodiment of the present invention at least has the following beneficial effects: rotation of the balance weight may cause gas in a rotation area of the balance weight to be pushed to the outside, and a local negative pressure is formed in the rotation area. When the balance weight is covered by the oil baffle shield, there is a local low pressure at the central opening of the oil baffle shield. And on an inner wall surface of the oil baffle shield, since a refrigerant cannot smoothly flow out, a local high pressure is formed close to a side wall due to a stagnation effect, which may push the refrigerant to flow from one side close to the oil baffle shield to one side away from the oil baffle shield through the vent hole, thus achieving an effect of increasing a flow rate of the vent flow. When a rotor is in a high-speed rotating state, and oil droplets carried in the refrigerant may be separated during a process of passing through the vent hole, and thrown to the outside of the rotor in a concentrated way at an outlet of the vent hole. Then the oil droplets dropped back to the oil sump from an air gap between an outer edge of the stator and an inner wall surface of a shell, thus reducing a discharge amount of oil.

According to some embodiments, a minimum axial clearance between the oil baffle portion and the rotor core is no more than <NUM>.

According to some embodiments, the mounting portion is fixed to the balance weight by bonding or a screw.

According to some embodiments, a diameter of a maximum inscribed circle of the vent hole is no less than <NUM>.

According to some embodiments, the rotor core is provided with a plurality of vent holes, and the plurality of vent holes are evenly distributed along a circumferential direction of the rotor core.

According to some embodiments, a minimum turning diameter of the balance weight is D, a diameter of the central opening is e, and e≤D.

A compressor according to an embodiment of a second aspect of the present invention includes the rotor assembly according to the embodiment of the first aspect of the present invention.

The compressor according to the embodiment of the present invention at least has the following beneficial effects: by adopting the rotor assembly of the embodiment according to the first aspect of the present invention, the flow rate of the vent hole can be increased, thus improving the oil return capacity of the air gap between the outer edge of the stator and the inner wall surface of the shell.

Additional aspects and advantages of the present invention will be explained in part in the following description, which can become apparent from the following description or be understood through practice of the present invention.

The present invention is further described hereinafter with reference to the drawings and the embodiments, where:.

Reference numerals shown in the figures are described as follows:.

Embodiments of the present invention are described below in detail, illustrations of which are shown in the accompanying drawings, where identical or similar reference numerals denote identical or similar elements or elements having the same or similar functions. The embodiments described below by reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that any orientation/position related description, such as the orientational or positional relationship, such as, up, down, front, rear, left, right, and the like, is based on the orientational or positional relationship shown in the accompanying drawings, is only for the purpose of facilitating the description of the present invention and simplifying the description, and does not indicate or imply that the device or element must have a specific orientation or position, be constructed and operated in a specific orientation or position, and therefore shall not be understood as a limitation to the present invention.

In the description of the present invention, several means one or more, a plurality of means more than two, greater than, less than, more than, and the like are understood as not including this number, while above, below, within, and the like are understood as including this number. If there are the descriptions of first and second, it is only for the purpose of distinguishing technical features, and shall not be understood as indicating or implying relative importance, implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

In the description of the present invention, words such as setup, installation, and connection shall be understood in a broad sense unless otherwise expressly limited, and a person skilled in the art may reasonably determine the specific meaning of the above words in the present invention with reference to the context of the technical scheme.

At present, in a structure of a rotary compressor, the compressor includes a shell, a motor and a compression structure. An internal cavity is formed in the closed shell, the motor and the compression structure are both arranged in the cavity and connected by a crankshaft, and the compression structure is driven by the crankshaft to compress a refrigerant during operation of the motor.

The motor includes a stator, a rotor, and assemblies of the stator and the rotor. The cavity is generally divided into three parts by the motor, which are namely a motor lower cavity, a motor cavity and a motor upper cavity. In most cases, the refrigerant compressed to a high pressure needs to pass through the motor cavity to enter a discharge port of the compressor, and then enter an air conditioning system.

As a core component of the compressor, the motor provides rotary power for the compressor, and a performance of the motor directly affects a performance of the compressor. The compressor includes the motor and a compression structure located at one axial end of the motor, and a refrigerant in a high-pressure cavity in the compression structure and the refrigerator oil inside the compressor may flow through the motor.

When the rotor in the motor is rotated at a high speed relative to the stator, an oil-gas mixture of the refrigerant and the oil at one end of the compression structure may flow to an axial end surface of the rotor. Meanwhile, under an action of a centrifugal force generated during high-speed rotation of the rotor, the oil-gas mixture may be thrown to the shell of the compressor, and then discharged to the outside through an exhaust port on the shell, thus affecting a discharge amount of oil of the compressor.

The rotor of the motor is in a high-speed rotating state when the compressor is operated. At least one of two axial ends of the rotor is provided with a balance weight, and the balance weight generally has an irregular shape. An example of arranging one balance weight at each of two axial ends of the rotor is taken for description below.

The compression structure compresses a low-temperature refrigerant into a high-pressure oil-gas mixture and discharges the high-pressure oil-gas mixture into the shell, and the high-pressure oil-gas mixture in the shell flows through an airflow central opening on the rotor and then reaches an exhaust pipe. When the rotor drives the balance weights at upper and lower ends of the rotor to return, the balance weights may stir an airflow in the shell, and a high-speed rotating airflow is formed when the balance weights are rotating, so that oil droplets carried in the refrigerant are gradually deviated from an axial center of the compressor under a centrifugal action, and move towards a side wall surface of the shell, thus achieving an effect of oil-gas separation.

However, a low-pressure area is formed at a leeward end of the upper balance weight, and a high-pressure area is formed at a windward end of the lower balance weight. Therefore, a flow rate of the refrigerant at the airflow central openings close to the low-pressure area of the upper balance weight and the high-pressure area of the lower balance weight is very large, which causes discharge of a large amount of oil carried in the refrigerant, resulting in a sharply increased discharge rate of oil, a chaotic flow field and a low energy efficiency of the compressor.

In addition, the oil of the compressor may be scattered everywhere in the compressor under a carrying action of the refrigerant, and whether the oil may rapidly return to the oil sump to ensure a certain operating oil level is an important guarantee for reliable lubrication and normal operation of the compressor.

Under a centrifugal action, the oil tends to aggregate close to an inner wall surface of the shell. A main channel for the oil to return to the oil sump is an air gap formed between an outer edge of the stator of the motor and the inner wall surface of the shell, and the oil sump of the compressor is located at the bottom of the shell. In order to ensure that the oil drops back to the oil sump through the air gap, it is generally expected that a flowing direction of the refrigerant in the air gap is the same as an oil return direction, thus promoting the oil return.

Otherwise, the oil is easy to accumulate at a position close to an exhaust side of the stator to form a secondary source of oil droplets, resulting in a large discharge amount of oil and a lowered oil level in the oil sump. Therefore, it is necessary to adjust a circulation capability of the refrigerant by lower and upper pressure characteristics of the rotor of the motor, so as to improve a fluidity of the oil at the air gap, thus improving the oil return efficiency.

With reference to <FIG>, it may be understood that the rotor assembly according to the embodiment includes a crankshaft <NUM>, a rotor core <NUM>, a balance weight <NUM> and an oil baffle shield <NUM>. The crankshaft <NUM> extends or penetrates through the rotor core <NUM>, and the balance weight <NUM> is mounted at a lower end of the rotor core <NUM>, which means that the balance weight <NUM> is located at one end of the rotor core <NUM> close to an oil sump <NUM> (referring to <FIG>). The oil baffle shield <NUM> is mounted on the balance weight <NUM>, the oil baffle shield <NUM> is covered on the balance weight <NUM>. The oil baffle shield <NUM> is also provided with a central opening <NUM>, and the crankshaft <NUM> extends or penetrates through the central opening <NUM>. The rotor core <NUM> is provided with a vent hole <NUM> extending or penetrating through the rotor core <NUM>, and an axial direction of the vent hole <NUM> is parallel to an axial direction of the rotor core <NUM>, which means that the vent hole <NUM> extends or penetrates through the rotor core <NUM> along the axial direction of the rotor core <NUM>. Moreover, an accommodating space <NUM> is defined between the oil baffle shield <NUM> and the rotor core <NUM>, and the accommodating space <NUM> is communicated with the vent hole <NUM>, so that the oil can enter the vent hole <NUM> from the accommodating space <NUM>, and be discharged through the vent hole <NUM>.

It should be noted that the oil baffle shield <NUM> may also be mounted on the crankshaft <NUM>, as long as it is ensured that the balance weight <NUM> is wrapped, and it is ensured that a high pressure is formed on an inner wall surface of the oil baffle shield <NUM>.

It may be understood that rotation of the balance weight <NUM> may cause gas in a rotation area of the balance weight to be pushed to the outside, and a local negative pressure is formed in the rotation area. Therefore, there are local negative pressures on both upper and lower sides of the rotor. When the negative pressure on one side is lower, and a pressure difference is formed, the refrigerant may flow from a high-pressure side to a low-pressure side, and the larger the pressure difference is, the larger the flow rate is.

With reference to <FIG>, it may be understood that since another part of the oil baffle shield <NUM> is contacted with the balance weight <NUM>, it can be considered that this part of area contacted with the balance weight <NUM> is not affected by an airflow, so that pressure distribution inside the oil baffle shield <NUM> is only analyzed for this part of area not contacted with the balance weight <NUM>.

With reference to <FIG>, it may be understood that inside the oil baffle shield <NUM>, a pressure near a side wall surface of the oil baffle shield <NUM> is high, but a pressure on a central part of the oil baffle shield <NUM> is low. It is this pressure distribution characteristic that can provide a high pressure for a bottom inlet of the vent hole <NUM> of the rotor core <NUM>, so that the refrigerant flows upwardly from a lower end of the vent hole <NUM>.

With reference to <FIG>, it may be understood that in an upper left corner area in the drawing, a darker-color position is a position corresponding to a windward side of the balance weight <NUM>, where the airflow impacts a head of the balance weight <NUM>, which causes stagnation of the airflow, thus generating a high pressure. With reference to <FIG>, a pressure at this position ranges from <NUM> e04 Pa to <NUM> e04 Pa, which is ranged between <NUM>,<NUM> Pa and <NUM>,<NUM> Pa.

With reference to <FIG>, it may be understood that in a lower right corner area in the drawing, a darker-color position is a position corresponding to a leeward side of the balance weight <NUM>, that is, the position where lower and smaller arc part joins the upper and larger arc part, and the balance weight <NUM> is rotated to form a relatively increased space at the position of the leeward side, thus generating a low pressure. With reference to <FIG>, a pressure at this position ranges from <NUM> e4 Pa to <NUM> e4 Pa, which is ranged between <NUM>,<NUM> Pa and <NUM>,<NUM> Pa.

It may be understood that, for the rotor assembly according to the embodiment, the oil baffle shield <NUM> covers the balance weight <NUM>, and there is a local low pressure at a central position of the oil baffle shield <NUM>, which means that a local low pressure is formed at the central opening <NUM>. However, an inner wall surface of the oil baffle shield <NUM> baffles the refrigerant, so that the refrigerant cannot smoothly flow out. A local high pressure is formed close to a side wall due to a stagnation effect, which may push the refrigerant to flow from one side with the oil baffle shield <NUM> to one side without the oil baffle shield <NUM>, which means to push the refrigerant to flow from one side close to the oil baffle shield <NUM> to one side away from the oil baffle shield <NUM> through the vent hole <NUM>, thus achieving an effect of increasing a flow rate of the refrigerant.

However, a rotor is in a high-speed rotating state, and oil droplets carried in the refrigerant may be separated during a process of passing through the vent hole <NUM>, and thrown to the outside of the rotor collectively at an outlet of the vent hole <NUM>, which means that the oil droplets flow along an radial direction of the rotor core <NUM> from one side of the vent hole <NUM> away from the oil baffle shield under an action of centrifugal force, thus reducing a discharge amount of oil.

Moreover, since the flow rate of the refrigerant is increased, the oil may be driven to flow back to the oil sump <NUM> along the air gap formed between the outer edge of the stator and the inner wall surface of the shell, thus promoting the oil return.

For the rotor assembly according to an embodiment, the vent holes <NUM> are arranged in the rotor core <NUM>, in the way of the vent holes <NUM> penetrating through the rotor core <NUM> along an axial direction of the rotor core <NUM>, and the oil baffle shield <NUM> covering outside the balance weight <NUM> is additionally arranged on the balance weight <NUM>, so that the flow rate of the refrigerant of the vent hole <NUM> is increased by utilizing an low and upper pressure difference characteristic of the rotor, thus improving the oil return capacity of a trimming of the stator (the air gap between the outer edge of the stator and the inner wall surface of the shell), and reducing the discharge amount of oil.

With reference to Table <NUM>, Table <NUM> shows an improvement effect of a throughput of the motor. Effects of a scheme before improvement, a scheme of separately adding the oil baffle shield <NUM>, and a scheme of adding a combination of the oil baffle shield <NUM> and the vent hole <NUM> of the rotor are compared through tests, and reference is made by a parameter index of through-flow ratio. A physical meaning of the through-flow ratio refers to a mass percentage of an exhaust amount of the refrigerant passing through the stator and the vent hole <NUM> of the rotor to a total exhaust amount of the compressor.

With reference to Table <NUM>, it may be understood that the through-flow ratio before improvement is <NUM>%, the through-flow ratio of separately adding the oil baffle shield <NUM> is <NUM>%, and the through-flow ratio of adding the combination of the oil baffle shield <NUM> and the vent hole <NUM> of the rotor is <NUM>%. When only the oil baffle shield <NUM> is added, but no vent hole <NUM> is formed in the rotor core <NUM>, the refrigerant cannot be pushed to flow from one side of the rotor core <NUM> close to the oil baffle shield <NUM> to one side of the rotor core away from the oil baffle shield <NUM>. Instead, the refrigerant is retained in the oil baffle shield <NUM>, which reduces the flow rate of the refrigerant, so that the through-flow ratio of the scheme of separately adding the oil baffle shield <NUM> is reduced compared with that of the scheme before improvement.

However, for the scheme of adding the combination of the oil baffle shield <NUM> and the vent hole <NUM> of the rotor, the refrigerant is baffled by the inner wall surface of the oil baffle shield <NUM>, so that the refrigerant cannot smoothly flow out. The local high pressure is formed close to the side wall due to the stagnation effect, and in addition, the rotor core <NUM> is provided with the vent hole <NUM> penetrating through the rotor core <NUM> along the axial direction of the rotor core <NUM>, so that the refrigerant is guided to flow from one side with the oil baffle shield <NUM> to one side without the oil baffle shield <NUM> through the vent hole <NUM>, which means to push the refrigerant to flow from one side close to the oil baffle shield <NUM> to one side away from the oil baffle shield <NUM> through the vent hole <NUM>, thus achieving the effect of increasing the flow rate of the refrigerant.

Since the flow rate of the refrigerant is increased, the refrigerant may more easily drive the oil to flow back to the oil sump <NUM> along the air gap formed between the outer edge of the stator and the inner wall surface of the shell, thus promoting the oil return.

With reference to Table <NUM>, Table <NUM> shows improvement effects of discharge amounts of oil of three different models. More particularly, actually measured discharge amounts of oil of model <NUM>, model <NUM> and model <NUM> before and after improvement are respectively compared in tests. These three models are scroll compressors with a high back pressure but different discharge amounts. A scheme after improvement is the rotor assembly according to the embodiment, and the rotor assembly includes the rotor core <NUM> with the vent hole <NUM> and the oil baffle shield <NUM> arranged on the balance weight <NUM>.

With reference to Table <NUM>, it may be understood that the measured discharge amount of oil of model <NUM> before improvement is <NUM>%, and the measured discharge amount of oil after improvement is <NUM>%, so that the discharge amount of oil is reduced by <NUM>%. The measured discharge amount of oil of model <NUM> before improvement is <NUM>%, and the measured discharge amount of oil after improvement is <NUM>%, so that the discharge amount of oil is reduced by <NUM>%. The measured discharge amount of oil of model <NUM> before improvement is <NUM>%, and the measured discharge amount of oil after improvement is <NUM>%, so that the discharge amount of oil is reduced by <NUM>%.

It can be seen from the above analysis that although different models have different reduced ranges in discharge amount of oil after improvement, there are improvement effects, that is to say, the rotor assembly according to the embodiment significantly reduces the discharge amount of oil, thus significantly improving the energy efficiency.

With reference to <FIG> and <FIG>, it may be understood that the oil baffle shield <NUM> includes an oil baffle portion <NUM> and a mounting portion <NUM>. The mounting portion <NUM> is located between the rotor and the oil sump <NUM> of the compressor, which means that the mounting portion <NUM> is located at one end of the balance weight <NUM> close to the oil sump <NUM>, which also means that the mounting portion <NUM> is located at one end of the balance weight <NUM> away from the rotor core <NUM>. It may be understood that the mounting portion <NUM> can reduce an airflow flowing out through the central opening <NUM> of the oil baffle shield <NUM>, so that an effect of forming the high pressure on the inner wall surface of the oil baffle shield <NUM> is ensured, thus increasing a throughput of the motor.

With reference to <FIG>, it may be understood that the oil baffle portion <NUM> is in an annular shape, and located on an outer peripheral side of the balance weight <NUM>, which baffles the escape of the oil from an area surrounded by the oil baffle shield <NUM> at the outer peripheral side of the balance weight <NUM>. The mounting portion <NUM> is arranged at a lower edge of the oil baffle portion <NUM>, and the mounting portion <NUM> is connected to the balance weight <NUM>.

With reference to <FIG>, it may be understood that the mounting portion <NUM> is provided with a mounting hole <NUM>, and fixed on the balance weight <NUM> by a screw <NUM>, which means that the screw <NUM> penetrates through the mounting hole <NUM>, and then threadedly connected to the balance weight <NUM>. Quick assembly and disassembly may be realized via mounting by the screw <NUM>, so that it is convenient for cleaning the oil baffle shield <NUM> or replacing the oil baffle shield <NUM>.

With reference to <FIG>, it may be understood that the mounting portion <NUM> and the oil baffle portion <NUM> may form an angle close to vertical, which may be understood that the mounting portion <NUM> bends from one end of the oil baffle portion <NUM> away from the rotor core <NUM> towards the central part of the rotor core <NUM>, which also means that the oil baffle portion <NUM> extends to an end surface of the balance weight <NUM>, while the mounting portion <NUM> extends along the radial direction of the rotor core <NUM> towards the axial direction of the rotor core <NUM>. The mounting portion <NUM> is provided with the mounting hole <NUM>, and fixed on the end surface of the balance weight <NUM> by the screw <NUM>.

In addition, it should be noted that the mounting portion <NUM> may also be fixed on the balance weight <NUM> by bonding, which means that the mounting portion <NUM> is bonded to the balance weight <NUM>. Certainly, the oil baffle portion <NUM> attached to the balance weight <NUM> may also be bonded to the balance weight <NUM>, or the mounting portion <NUM> and the oil baffle portion <NUM> are both bonded to the balance weight <NUM>.

The oil baffle portion <NUM> is located at one end of the mounting portion <NUM> away from an axis of the rotor core <NUM>, and the oil baffle portion <NUM> extends towards a side surface of the balance weight <NUM>, and is attached to the side surface of the balance weight <NUM>. The oil baffle portion <NUM> is arranged to baffle the refrigerant, so that the refrigerant cannot smoothly flow out. The local high pressure is formed close to the side wall due to the stagnation effect, which may push the refrigerant to flow from one side with the oil baffle shield <NUM> to one side without the oil baffle shield <NUM>, which means to push the refrigerant to flow from one side close to the oil baffle shield <NUM> to one side away from the oil baffle shield through the vent hole <NUM>, thus achieving the effect of increasing the flow rate of the refrigerant.

With reference to <FIG>, it may be understood that in the axial direction of the rotor core <NUM>, a minimum distance between the oil baffle portion <NUM> and the rotor core <NUM> is L. According to the technical principle, there is the high pressure on the side wall surface of the oil baffle shield <NUM>. If an assembly clearance is too large, which means that the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is too large, a local leakage amount will be increased, there will be a high-speed airflow flowing outwardly, which may impact the airflow at the lower part of the motor, finally resulting in unstable oil level and deteriorated oil discharge. Therefore, it is of great significance to reasonably set the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> to maintain oil level stability and reduce oil discharge deterioration.

With reference to <FIG>, it may be understood that <FIG> shows different minimum distances L between the oil baffle portion <NUM> and the rotor core <NUM> and simulation results of corresponding impact powers of leaked airflow. The abscissa shows different axial assembly clearances, which are namely the minimum distances L between the oil baffle portion <NUM> and the rotor core <NUM> in the axial direction of the rotor core <NUM>. The ordinate shows the impact powers of leaked airflow, and the histogram shows impact energies (powers) of leaked airflow under the three axial assembly clearances.

With reference to <FIG>, it may be understood that when the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is <NUM>, the impact power of leaked airflow is <NUM> W, when the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is <NUM>, the impact power of leaked airflow is <NUM> W, and when the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is <NUM>, the impact power of leaked airflow is <NUM> W.

It may be understood that in some embodiments, the minimum axial clearance between the oil baffle portion <NUM> and the rotor core <NUM> is set to be no more than <NUM>, which means that if the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is set to be less than or equal to <NUM>, it may improve local leakage, and reduce the high-speed airflow flowing outwardly, thus reducing the impact on the airflow at the lower portion of the motor, and maintaining the oil level stability and reducing the oil discharge deterioration.

It may be understood that in some embodiments, the minimum axial clearance between the oil baffle portion <NUM> and the rotor core <NUM> is set to be no more than <NUM>, which means that the minimum distance L between the oil baffle portion <NUM> and the rotor core <NUM> is set to be less than or equal to <NUM>, which can improve local leakage, and reduce the high-speed airflow flowing outwardly, thus reducing the impact on the airflow at the lower portion of the motor, and maintaining the oil level stability and reducing the oil discharge deterioration. Therefore, the leakage may be basically ensured to be acceptable.

With reference to <FIG>, it may be understood that in a cross section of the vent hole <NUM>, the vent hole <NUM> is in a curved strip-hole shape, which means that a long edge of the vent hole <NUM> is in an arc shape, a circle center of the arc coincides with a circle center of the rotor core <NUM>, and end portions of two long edges are connected by short edges in a semicircle shape, thus forming the closed vent hole <NUM> composed of arc lines. A maximum inscribed circle <NUM> can be drawn in the vent hole <NUM>, and a diameter of the maximum inscribed circle <NUM> is ϕ. According to multiple tests, when the diameter ϕ of the maximum inscribed circle <NUM> is no less than <NUM>, which means that ϕ is greater than or equal to <NUM>, the refrigerant and the oil flow out smoothly. However, if the diameter ϕ of the maximum inscribed circle <NUM> is less than <NUM>, a channel is easy to be blocked by the oil, which reduces a circulation capacity of the refrigerant.

It should be noted that the vent hole <NUM> may also be in other shapes, such as a waist-shaped hole (the waist-shaped hole is also called an oblong hole, and the waist-shaped hole is composed of semi-circular arcs at two ends and parallel planes in the middle, with the diameter ϕ of the maximum inscribed circle <NUM> equal to the diameter of the semi-circular arcs), a circular hole (with the diameter ϕ of the maximum inscribed circle <NUM> equal to a diameter of the circular hole) and a square hole (with the diameter ϕ of the maximum inscribed circle <NUM> equal to a length of a shortest edge of the square hole), or an irregularly-shaped hole.

With reference to <FIG>, it may be understood that the rotor core <NUM> is provided with a plurality of vent holes <NUM>, which means that at least two vent holes <NUM> of the rotor core <NUM> are provided, and the plurality of vent holes <NUM> are evenly distributed along a circumferential direction of the rotor core <NUM>. The premise of promoting increase of the ventilation flow rate of the refrigerant at the vent hole by a pressure difference between upper and lower end surfaces of the rotor core <NUM> is that the rotor is provided with the vent hole <NUM> penetrating through in an axial direction. The flow rate of the vent refrigerant at the vent hole can be increased by arranging the plurality of vent holes <NUM>. Moreover, even distribution of the plurality of vent holes <NUM> along the circumferential direction of the rotor core <NUM> may make an acting force of the refrigerant on the rotor core <NUM> more uniform, thus reducing an eccentric force caused by uneven distribution of the vent holes <NUM>.

For example, with reference to <FIG>, six vent holes <NUM> are evenly distributed on the rotor core <NUM>. The pressure difference between the upper and lower end surfaces of the rotor core <NUM> promotes the vent refrigerant to flow out from the six vent holes <NUM>, which increases the flow rate of the vent refrigerant. Moreover, the six vent holes <NUM> are evenly distributed along the circumferential direction of the rotor core <NUM>, such that the flow rate of the vent refrigerant out from the six vent holes <NUM> is relatively uniform, which makes the rotor core <NUM> uniformly stressed in the circumferential direction and reduces the generation of the eccentric force.

It should be noted that the rotor core <NUM> may also be provided with other numbers of vent holes <NUM>, for example, two, three, four or more than five, and the above drawings are only for illustration, not as a limitation of the embodiments.

With reference to <FIG>, it may be understood that when the rotor core <NUM> rotates, an inner edge and an outer edge of the vent hole <NUM> respectively form two revolving tracks, where a diameter of the revolving track formed by the inner edge of the vent hole <NUM> is d.

With reference to <FIG>, it may be understood that the mounting portion <NUM> of the oil baffle shield <NUM> is horizontally arranged, which may be understood that if the mounting portion <NUM> is located in a reference plane, the reference plane intersects with the crankshaft <NUM>, and a cross section formed by the intersection is a cross section of the crankshaft <NUM> in the reference plane, and a diameter of the crankshaft <NUM> in the cross section at this position is f.

It should be noted that in an actual product, the mounting portion <NUM> has a certain thickness. When a conical section of the crankshaft <NUM> intersects with the above-mentioned reference plane, the reference plane refers to a plane where a middle position of the mounting portion <NUM> is located, that is, a plane where a middle position of an upper plane and a lower plane of the mounting portion <NUM> is located.

With reference to <FIG>, it may be understood that a diameter of the central opening <NUM> of the oil baffle shield <NUM> is e, and the central opening <NUM> is defined by the mounting portion <NUM>, or it may be understood that the central opening <NUM> is arranged on the mounting portion <NUM>. Then, the position of the central opening <NUM> is corresponding to the position of the crankshaft <NUM>, and a difference between the diameter e of the central opening <NUM> and the diameter f of the crankshaft <NUM> is greater than or equal to <NUM>, that is, e≥f+<NUM>.

In addition, with reference to <FIG> and <FIG>, it may be understood that the diameter e of the central opening <NUM> is greater than or equal to d, i.e., e≥d.

By setting e≥f+<NUM>, there is enough space between the crankshaft <NUM> and the oil baffle shield <NUM> to allow enough refrigerant to enter the space enclosed by the oil baffle shield <NUM>, that is, the diameter of the central opening <NUM> is set to be large enough to allow refrigerant to enter from the central opening <NUM>, thus reducing the obstruction of the oil baffle shield <NUM> to the direction in which a refrigerant enters. Therefore, e≥f+<NUM> limits that a gap between the central opening <NUM> of the oil baffle shield <NUM> and the annular channel formed by the crankshaft <NUM> is no less than <NUM>, which guarantees a through-flow capacity thereof and reduces the resistance.

By setting e≥d, the oil baffle shield <NUM> may reduce the obstruction of the vent hole <NUM>, so that part of the refrigerant may directly enter the vent hole <NUM> from the central opening <NUM>, and then directly enter the vent holes <NUM> under the action of the pressure difference between the upper and lower sides of the rotor core <NUM>, and then be discharged from the upper end of the vent hole <NUM>, so that the air flow does not need to be blown to the side wall of the oil baffle shield <NUM>, the movement distance is reduced, and the discharge efficiency of the refrigerant is improved. Therefore, e≥d is to ensure that the channel between the central opening <NUM> in the oil baffle shield <NUM> and the crankshaft <NUM> can overlap with an axial projection plane of the vent hole <NUM>. If there is no overlap, a flow path of the air flow into the rotor core <NUM> will increase and the ventilation flow of the rotor core <NUM> will decrease.

With reference to <FIG>, it may be understood that if a minimum rotation radius of the balance weight <NUM> is R, then a minimum slewing diameter of the balance weight <NUM> is D, which is equal to 2R, and the diameter e of the central opening <NUM> and the minimum slewing diameter D of the balance weight <NUM> meet the condition that: the diameter e of the central opening <NUM> is less than or equal to the minimum slewing diameter D of the balance weight <NUM>, i.e., e≤D.

By setting e≤D, the diameter of the central opening <NUM> of the oil baffle shield <NUM> is smaller than the diameter of the inner wall surface of the balance weight <NUM>, so that the air flow out of the central opening <NUM> between the mounting portion <NUM> of the oil baffle shield <NUM> and the balance weight <NUM> is reduced, and the effect of high pressure is ensured to be formed on the inner wall surface of the oil baffle shield <NUM>, thereby increasing the throughput of the motor.

The compressor of the embodiment of the present invention includes the rotor assembly of the embodiment of the present invention. According to the compressor of the embodiment of the present invention, by adopting the rotor assembly of the embodiment according to the first aspect of the present invention, the flow rate of the vent hole <NUM> can be increased, thereby improving the oil return capacity of the air gap between the outer edge of the stator and the inner wall surface of the shell.

It should be noted that the compressor of the embodiment of the present invention may include a scroll compressor, a rolling rotor compressor and the like. The rolling rotor compressor belongs to one rotary compressor.

With reference to <FIG>, taking the scroll compressor as an example, the scroll compressor includes a shell, a compression assembly, a motor assembly, a crankshaft <NUM> (shaft portion) and other components.

The shell includes a cylinder <NUM>, an upper cover <NUM> and a lower cover <NUM>. The cylinder <NUM> is penetrated in the axial direction. The upper cover <NUM> is arranged on an upper portion of the cylinder <NUM> and fixed to the upper portion of the cylinder <NUM> by welding, for example. The lower cover <NUM> is arranged on a lower portion of the cylinder <NUM> and fixed to the lower portion of the cylinder <NUM> by welding, for example. In this way, the cylinder <NUM>, the upper cover <NUM> and the lower cover <NUM> together form a closed mounting space. Components, such as the compressor assembly, the motor assembly, the crankshaft <NUM> and the like, are respectively mounted in the mounting space. The lower cover <NUM> of the shell is recessed downward, thereby forming an oil sump <NUM> for storing oil at the bottom portion of the shell.

The compression assembly is fixed in the shell. The compression assembly mainly includes a fixed scroll plate <NUM>, a movable scroll plate <NUM> and a main frame <NUM>. The fixed scroll plate <NUM> includes a fixed scroll plate body and spiral fixed scroll teeth extending from the fixed scroll plate body. The movable scroll plate <NUM> includes a movable scroll plate body and spiral movable scroll teeth extending from the movable scroll plate body. A compression cavity is formed by the mutual meshing of the fixed scroll teeth on the fixed scroll plate <NUM> and the movable scroll teeth on the movable scroll plate <NUM>.

The fixed scroll plate body, the cylinder <NUM> of the shell and the upper cover <NUM> of the shell are enclosed together to form an exhaust cavity. The exhaust cavity is located above the fixed scroll plate body. In addition, the fixed scroll plate body is provided with an exhaust port and an air inlet. The exhaust port is communicated with the compression cavity and the exhaust cavity. The exhaust port may be arranged in a middle of an upper portion of the fixed scroll plate body. The exhaust port is used for discharging a high-pressure refrigerant in a high-pressure area of the compression cavity into the exhaust cavity. The air inlet is arranged at an edge of the fixed scroll plate body and used for communicating the compression cavity with an air suction pipe.

The main frame <NUM> is mounted at a lower portion of the movable scroll plate <NUM>. The main frame <NUM>, the fixed scroll plate <NUM> and movable scroll plate <NUM> together form a back-pressure chamber. In some examples, the back-pressure chamber is annularly arranged. The back-pressure chamber is filled with gas, which may be the refrigerant from the compression cavity or the gas provided by an external device of the scroll compressor. This gas provides a back pressure to the movable scroll plate body of the movable scroll plate <NUM>, so that the movable scroll plate <NUM> and the fixed scroll plate <NUM> are hermetically abutted.

The motor assembly includes a stator assembly <NUM> and a rotor assembly. The stator assembly <NUM> is fixed on an inner wall surface of the cylinder <NUM> of the shell, and the rotor assembly is located in a middle portion of the stator assembly <NUM>. The crankshaft <NUM> passes through a shaft hole in the middle portion of the rotor assembly and is fixed to the rotor assembly. When the scroll compressor is powered on, the stator assembly <NUM> drives the rotor assembly to rotate, and the crankshaft <NUM> rotates with the rotation of the rotor assembly.

In order to suppress oscillating of the crankshaft <NUM> when rotating, a sub-frame <NUM> is mounted on the cylinder <NUM> below the motor assembly, and the sub-frame <NUM> is fixed to the cylinder <NUM> of the shell. A first end portion of the crankshaft <NUM> passes through the sub-frame <NUM> and extends toward the lower cover <NUM>. In this way, the sub-frame <NUM> supports the crankshaft <NUM> in the radial direction of the crankshaft <NUM>, thereby suppressing the jitter generated when the crankshaft <NUM> rotates.

Claim 1:
A rotor assembly for a motor for
a compressor comprising an oil sump, the rotor assembly comprising:
a crankshaft (<NUM>);
a rotor core (<NUM>) provided with a vent hole (<NUM>), wherein the vent hole (<NUM>) extends through the rotor core (<NUM>) along an axial direction of the rotor core (<NUM>);
a balance weight (<NUM>) arranged at a first end of the rotor core (<NUM>), the first end of the rotor core configured to be close to the oil sump (<NUM>) of the compressor; and
an oil baffle shield (<NUM>), wherein the oil baffle shield (<NUM>) is configured to cover the balance weight (<NUM>) and is provided with a central opening (<NUM>), wherein the crankshaft (<NUM>) extends through the central opening (<NUM>),
wherein an accommodating space (<NUM>) is defined between the oil baffle shield (<NUM>) and the rotor core (<NUM>), and the accommodating space (<NUM>) is in fluid communication with the vent hole (<NUM>), wherein the oil baffle shield (<NUM>) comprises an oil baffle portion (<NUM>) and a mounting portion (<NUM>), the oil baffle portion (<NUM>) is in an annular shape, the mounting portion (<NUM>) is arranged at a first end of the oil baffle portion (<NUM>) away from the rotor core, and the mounting portion (<NUM>) is connected to the balance weight (<NUM>), wherein the central opening <NUM> is defined by the mounting portion <NUM>, characterized in that;
an inner edge of the vent hole (<NUM>) has a rotation diameter of d, the central opening (<NUM>) has a diameter of e, a part of the crankshaft (<NUM>) corresponding to the mounting portion (<NUM>) has a diameter of f, and
e≥d, and e ≥ f + <NUM>.