Compressor and refrigeration apparatus

Abstract

The application discloses a compressor and refrigeration equipment, and belongs to the technical field of compressors. The compressor comprises a shell, a motor assembly and a pump body assembly, the number of stator slots is Q, the number of pole pairs of a rotor core is P, the greatest common divisor of the number of stator slots Q and the number of pole pairs of the rotor core P is G, the maximum height of the rotor core is H1, the diameter of the maximum circumscribed circle of the rotor core is D1, each core unit is provided with a mounting slot, the maximum length of each permanent magnet is L, the maximum height of a cylinder is H2, the outer diameter of a roller is D2, the inner diameter of a compression cavity is D3, and the following conditions are met: 0.95<=<=1.85. The application improves the effective magnetic load in a unit volume of the rotor without increasing the axial size of the core, so that the motor meets the required output torque of the compressor while the axial size of the core is small and the structure is compact.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a compressor and refrigeration equipment. Background Technology

[0002] In related technologies, increasing the torque of a motor is typically achieved by either increasing the axial dimension of the iron core or increasing the amount of permanent magnets. However, the former increases the motor size and rotor inertia, thereby weakening the compressor's dynamic response and increasing the required installation space, while the latter significantly increases material costs. Existing motors often optimize slot-pole fit or permanent magnet quantity from only a single dimension, making it difficult to achieve a balance between output torque, permanent magnet quantity, and compressor displacement. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a compressor that can meet the output torque required by the compressor while maintaining a small axial dimension of the iron core and a compact structure, without increasing the axial dimension of the iron core.

[0004] The present invention also proposes a refrigeration device comprising the above-described compressor.

[0005] According to a first aspect of the present invention, a compressor includes: a housing, a motor assembly, and a pump assembly. The motor assembly is disposed within the housing and includes a stator core, a rotor core, and a plurality of permanent magnets. The rotor core is disposed within the inner hole of the stator core. The stator core includes a stator yoke and a plurality of stator teeth. The plurality of stator teeth are arranged circumferentially spaced along the stator yoke. A stator slot is defined between two adjacent stator teeth circumferentially along the stator yoke. The number of stator slots is Q. The number of pole pairs of the rotor core is P. The greatest common divisor of the number of stator slots Q and the number of pole pairs P of the rotor core is G. The maximum height of the rotor core along its own rotation axis is H1. The diameter of the largest circumscribed circle of the rotor core is D1. The rotor core includes 2P core units, which are arranged circumferentially along the rotation axis. Each core unit has a mounting slots, and multiple permanent magnets are installed in the a mounting slots one-to-one. On the projection plane perpendicular to the rotation axis, the maximum length of each permanent magnet is L. The pump assembly is located inside the housing and on one side of the axial direction of the motor assembly. The pump assembly includes a cylinder and a roller. The maximum height of the cylinder along the rotation axis is H2. The cylinder has a compression chamber, and the roller is rotatably disposed in the compression chamber. The outer diameter of the roller is D2, and the inner diameter of the compression chamber is D3, satisfying: 0.95≤ ≤1.85.

[0006] The compressor according to embodiments of the present invention has at least the following beneficial effects: The compressor of this invention is designed by associating the number of pole pairs P of the rotor core, the number of stator slots Q, the greatest common divisor G of the two, the number of mounting slots a of each core unit, and the maximum length L of the permanent magnet. Furthermore, the above parameters are designed to satisfy the following relationship with the maximum circumscribed circle diameter D1 of the rotor core, the maximum axial height H1 of the rotor core, the maximum axial height H2 of the cylinder, the outer diameter D2 of the rollers, and the inner diameter D3 of the compression chamber: 0.95 ≤ With a magnetic flux density ≤1.85, the effective magnetic load per unit volume of the rotor is increased by optimizing the combination of the greatest common divisor G, the number of mounting slots a, and the maximum length L of the permanent magnet, without increasing the axial dimension of the iron core. This allows the motor to meet the output torque required by the compressor while maintaining a small axial dimension of the iron core and a compact structure, thus avoiding problems such as increased motor size and increased rotor inertia caused by increasing the axial dimension of the iron core. At the same time, the above relationship links the rotor magnetic load parameter 2GaL with the cylinder height H2, roller outer diameter D2, and compression chamber inner diameter D3 of the compressor pump body, so that the magnetic flux density design of the motor matches the actual displacement requirements of the compressor. While meeting the output torque requirements, it avoids excessive increase in the amount of permanent magnets, thus avoiding a significant increase in material costs caused by excessive increase in the amount of permanent magnets.

[0007] According to some embodiments of the present invention, the motor assembly further includes enameled wire, which is wound around the stator teeth through the stator slots to form a winding, wherein the number of series turns of the winding in each phase is M, satisfying: 2.2≤ ≤4.

[0008] According to some embodiments of the present invention, the number of turns of the winding in each stator tooth is N, the number of parallel branches of the winding is b, and the connection mode coefficient of the winding is c. When the winding is star-connected in series, the connection mode coefficient c = 1; when the winding is delta-connected in series, the connection mode coefficient c = 1.732, satisfying: .

[0009] According to some embodiments of the present invention, the number of series turns M of the winding in each phase satisfies: 150 ≤ M ≤ 400.

[0010] According to some embodiments of the present invention, the DC bus voltage driving the motor assembly (200) is Udc, satisfying: 34≤ ≤55.

[0011] According to some embodiments of the present invention, the remanence of the permanent magnet is Br, which satisfies: 195≤2×G×a×L×Br≤250.

[0012] According to some embodiments of the present invention, the diameter of the largest inscribed circle of the stator core is D4, satisfying: 4.76≤ ≤6.5.

[0013] According to some embodiments of the present invention, the number of stator slots is Q, satisfying: 15 ≤ Q ≤ 18; and / or, The number of pole pairs P of the rotor core satisfies: 5 ≤ P ≤ 6; and / or, The greatest common divisor of the number of stator slots Q and the number of pole pairs P of the rotor core is G, satisfying: 4 ≤ G ≤ 6; and / or, The number of slots per pole and per phase of the motor assembly is q, and the number of phases of the motor assembly is m, satisfying: .

[0014] According to some embodiments of the present invention, the maximum height H1 of the rotor core along its own axis of rotation and the diameter D1 of the maximum circumscribed circle of the rotor core satisfy: 0.65≤D1 / H1≤3.6.

[0015] A refrigeration apparatus according to a second aspect of the present invention includes the compressor described in the first aspect embodiment.

[0016] The refrigeration device according to embodiments of the present invention has at least the following beneficial effects: The refrigeration equipment of this invention adopts the compressor of the first aspect embodiment. By optimizing the parameter design of the compressor, the compressor can output a driving torque that matches the large displacement pump body with a compact axial dimension, thereby reducing the installation space occupied by the compressor in the refrigeration equipment, which is conducive to the miniaturization of the refrigeration equipment and reduces the overall manufacturing cost of the refrigeration equipment; in addition, the overall energy efficiency ratio of the refrigeration equipment is improved.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the internal structure of a compressor according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the assembly of the motor assembly and the pump body assembly according to an embodiment of the present invention; Figure 3This is an axial schematic diagram of a motor assembly according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the assembly of the stator core and rotor core according to an embodiment of the present invention; Figure 5 This is a graph showing the relationship between equation (1) and motor cost and output torque in one embodiment of the present invention. Figure 6 This is a graph showing the relationship between equation (2) and motor efficiency and maximum operating frequency in one embodiment of the present invention. Figure 7 This is a graph showing the relationship between equation (3) and the high-frequency operating range and the cost-effectiveness of the frequency converter in one embodiment of the present invention. Figure 8 This is a graph showing the relationship between the equation 2×G×a×L×Br and the motor cost-effectiveness and permanent magnet torque in one embodiment of the present invention. Figure 9 This is a graph showing the relationship between equation (4) and the air gap balance coefficient and rotor magnetic field in one embodiment of the present invention.

[0019] Icon labels: Casing 100; Motor assembly 200; stator 210; stator core 211; inner hole 212; stator yoke 213; stator teeth 214; stator slot 215; rotor 220; rotor core 221; permanent magnet 222; core unit 223; mounting slot 224; connecting hole 225; Pump body assembly 300; cylinder 310; compression chamber 311; roller 320; crankshaft 330; 400 windings; Rotation axis X; maximum circumscribed circle R1 of rotor core; maximum inscribed circle R2 of stator core. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] In the description of this invention, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0023] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0024] In related technologies, some solutions shorten the iron core length to balance cost-effectiveness, but due to insufficient magnetic load, the motor output torque is difficult to meet the requirements; other solutions compensate for the insufficient torque caused by the short iron core by increasing the magnetic flux density, but this will lead to an increase in the back electromotive force of the motor, which will cause the weak magnetic current required by the motor to increase sharply when running at high speed, thus severely compressing the high-frequency operating range of the compressor.

[0025] To address the aforementioned technical problems, some embodiments of the present invention provide a compressor suitable for refrigeration equipment. This compressor can meet the required output torque of the compressor while maintaining a small axial dimension and compact structure of the motor, without increasing the axial dimension of the iron core. See details below. Figures 1 to 4 The compressor is described below.

[0026] Reference Figure 1 As shown, in this embodiment of the invention, the compressor includes a housing 100, a motor assembly 200, and a pump assembly 300. The compressor also includes a liquid receiver and a refrigerant pipe connecting the liquid receiver and the housing 100. Specifically, the housing 100 is generally cylindrical in shape and has an inner cavity. The motor assembly 200 and the pump assembly 300 are both installed within the inner cavity of the housing 100. The liquid receiver is located radially outward of the housing 100. The housing 100 can be arranged horizontally or vertically. It is understood that if the housing 100 is arranged vertically, the compressor is a vertical compressor; if the housing 100 is arranged horizontally, the compressor is a horizontal compressor.

[0027] Continue to refer to Figure 1 As shown, in this embodiment of the invention, the compressor is a vertical compressor, and the motor assembly 200 is located above the pump body assembly 300, that is, the pump body assembly 300 is located on one axial side of the motor assembly 200. In this embodiment, the pump body assembly 300 is a single-cylinder structure, which includes a cylinder 310 and a roller 320. (Combined with...) Figure 2 It is understood that the cylinder 310 is provided with a compression chamber 311, which extends through the upper and lower end faces of the cylinder 310. The roller 320 has a cylindrical structure and is rotatably disposed within the compression chamber 311, with its central axis offset from the central axis of the compression chamber 311.

[0028] The pump body assembly 300 may further include an upper bearing, a lower bearing, and a crankshaft 330. The upper bearing is located on the upper side of the cylinder 310 and covers the upper opening of the compression chamber 311, i.e., the upper bearing is located on the side of the cylinder 310 closest to the motor assembly 200. The lower bearing is located on the lower side of the cylinder 310 and covers the lower opening of the compression chamber 311, i.e., the lower bearing is located on the side of the cylinder 310 away from the motor assembly 200. The eccentric portion of the crankshaft 330 is located inside the compression chamber 311 and is rotatably connected to the roller 320.

[0029] Reference Figure 1 and Figure 2 As shown, in this embodiment of the invention, the motor assembly 200 is located above the upper bearing. Specifically, the motor assembly 200 includes a stator 210 and a rotor 220. The stator 210 is fixedly connected to the inner peripheral wall of the housing 100, and the rotor 220 is rotatably disposed in the inner hole 212 of the stator 210. The top end of the crankshaft 330 passes through the connecting hole 225 of the rotor 220 and is fixedly connected to the rotor 220. Wherein, combined with Figure 3 It can be understood that the stator 210 includes a stator core 211 and a winding 400. The stator core 211 is formed by stacking multiple silicon steel sheets axially. It can be radially divided into a stator yoke 213 and stator teeth 214. The stator yoke 213 is located in the outer circumferential region of the stator core 211 and has a ring-shaped structure. The stator teeth 214 extend radially inward from the stator yoke 213. Multiple stator teeth 214 are arranged circumferentially along the stator yoke 213. The space enclosed between two adjacent stator teeth 214 is the stator slot 215, which is used to accommodate the winding 400. The number of stator slots 215 is Q, reflecting the distribution density of the stator slots 215 along the circumferential direction of the stator 210.

[0030] Reference Figure 3 As shown, in this embodiment of the invention, the rotor 220 includes a rotor core 221 and multiple permanent magnets 222. The rotor core 221 is also formed by stacking multiple silicon steel sheets axially. A connecting hole 225 is provided at the center of the rotor core 221 for interference fit with the crankshaft 330. The rotor core 221 has multiple mounting slots 224 spaced apart along its circumference. The mounting slots 224 penetrate the entire rotor core 221 along the axial direction of the rotor 220, and the multiple permanent magnets 222 are embedded in the mounting slots 224 one by one. Among them, two adjacent magnets with opposite magnetic directions form a pair of poles, and the number of pole pairs of the rotor core 221 is P. For the surface-mounted rotor 220 structure, a groove is opened on the outer circumferential surface of the rotor core 221 as a mounting slot 224, and the permanent magnets 222 are then embedded in the groove and fixed by adhesive or sheathing. The magnetic pole formation method is similar to that of the built-in type.

[0031] In this embodiment of the invention, the greatest common divisor of the number of stator slots 215, Q, and the number of pole pairs P of the rotor core 221 is G. This G represents the number of unit motors in the motor and reflects the symmetrical repetition number of stator slots 215 and rotor poles 220 along the circumference. A larger G value indicates higher repeatability of the slot and pole distribution on the motor circumference and better symmetry of the winding 400 distribution. (Refer to...) Figure 3 As shown, the rotor core 221 can be divided into 2P core units 223 along the circumference of the rotation axis X. The 2P core units 223 are arranged sequentially along the circumference of the rotation axis X and spliced ​​end to end to form a complete annular structure of the rotor core 221, where P is the number of pole pairs of the rotor 220, and 2P is the total number of magnetic poles of the rotor 220 along the circumference. Each core unit 223 covers the angular range corresponding to one magnetic pole in the circumferential direction.

[0032] Continue to refer to Figure 3 As shown, in this embodiment of the invention, each core unit 223 is provided with a mounting slots 224. The a mounting slots 224 are arranged at intervals along the circumferential range covered by the core unit 223. Multiple permanent magnets 222 are installed one-to-one in the a mounting slots 224, that is, one permanent magnet 222 is embedded in each mounting slot 224. The a permanent magnets 222 in the same core unit 223 together constitute the magnetic source of the magnetic pole. Figure 4 It can be understood that the permanent magnet 222 is elongated in shape, and the maximum length of each permanent magnet 222 on the projection plane perpendicular to the rotation axis X is L. It should be noted that all dimensional parameters mentioned below in this application are in millimeters (mm).

[0033] Reference Figure 2 As shown, in this embodiment of the invention, the maximum height of the rotor core 221 along its own rotation axis X is H1, and the diameter of the maximum circumscribed circle R1 of the rotor core 221 is D1. These two factors together determine the overall shape of the rotor 220. The maximum height of the cylinder 310 along its rotation axis X is H2, the outer diameter of the roller 320 is D2, and the inner diameter of the compression chamber 311 is D3. It can be understood that the compressor displacement is related to the cylinder 310 height H2, the cylinder 310 inner diameter D3, and the roller 320 outer diameter D2. The ratio of H2×D3 / D2 is positively correlated with the compressor displacement. The larger the displacement, the greater the refrigerant mass flow rate circulated per unit time, and the stronger the compressor's cooling or heating capacity. At the same time, the load torque that the motor needs to overcome also increases.

[0034] For large-displacement single-cylinder compressors, the motor needs to output a large driving torque within a limited radial and axial space. If the torque is increased simply by increasing the axial height H1 of the rotor core 221, it will lead to an increase in the overall axial dimension of the compressor and an increase in the rotational inertia of the rotor 220, affecting the compressor's dynamic response characteristics and installation adaptability. If the torque is increased simply by increasing the amount of permanent magnets 222, it will lead to an increase in the cost of permanent magnet materials, compressing the product's cost-effectiveness.

[0035] Based on this, the above parameters satisfy: 0.95≤ ≤1.85; (1) This embodiment achieves the coupling and matching of motor magnetic load, motor body and compressor displacement by satisfying the above relationship (1). Among them, the numerator 2×G×a×L of the above relationship (1) represents the total amount of permanent magnets 222 in rotor 220. The coefficient 2 corresponds to the two magnetic poles with opposite magnetization directions in a pair of poles. G reflects the number of iron core units 223, that is, the number of repetitions along the circumference. a is the number of permanent magnets 222 in each iron core unit 223. L is the maximum length of a single permanent magnet 222 along the projection plane perpendicular to the rotation axis X. The value obtained by multiplying the four is positively correlated with the cumulative length of permanent magnets 222 laid on rotor 220 along the circumference, thereby reflecting the strength of the magnetic field of rotor 220 and the output level of motor.

[0036] The denominator of the above relation (1) contains D1×π×H1 H2×D3 / D2 represents the lateral surface area of ​​the outer cylinder of the rotor core 221, reflecting the overall size of the motor; H2×D3 / D2 represents the size characteristics of the compression chamber 311 of the cylinder 310, which is positively correlated with the compressor displacement. It can be seen that the ratio of the numerator to the denominator of the above relationship (1) reflects the magnetic load level of the rotor 220 under unit motor size and unit compressor displacement.

[0037] When the value of this relationship is less than 0.95, the magnetic flux density of the motor is too low relative to the required cooling capacity of the compressor, and the output torque is insufficient to drive the large displacement pump body. The starting performance and steady-state operation performance of the compressor cannot meet the usage requirements. When the value of this relationship is greater than 1.85, the magnetic flux density and output torque capacity of the motor are too high, but the amount of permanent magnet material used on rotor 220 is too large, and the cost of the motor increases.

[0038] Therefore, by reasonably limiting the range of values ​​for the above-mentioned relation (1), and under the premise of adopting a compact motor structure with a small axial dimension, this embodiment of the invention takes into account the balance between the motor output torque, the amount of permanent magnets 222 and the compressor displacement by coordinating the selection of the greatest common divisor G, the number a of permanent magnets 222 in each core unit 223, the maximum length L of a single permanent magnet 222 along the projection plane perpendicular to the rotation axis X, the diameter D1 of the maximum outer circle of the rotor core 221, the axial height H1 of the rotor core 221 and the outer diameter D2 of the pump body parameters roller 320, the height H2 of the cylinder 310, and the inner diameter D3 of the cylinder 310. This satisfies the high torque output requirements of a large displacement single-cylinder compressor while suppressing the increase in the rotational inertia of the rotor 220 and the cost of permanent magnet materials, thereby improving the overall cost-effectiveness of the compressor and its refrigeration system.

[0039] Combination Figure 5 It can be seen that as the value of relation (1) increases, the output torque of the motor shows a monotonically increasing trend, that is, the magnetic load level and output capacity of the motor increase with the ratio between the total amount of permanent magnet 222 and the motor body and compressor displacement; the motor cost shows a U-shaped change trend of first decreasing and then increasing, reaching the lowest point when the value of relation (1) is about 1.5. When the value of relation (1) is less than 0.95, the output torque is insufficient to drive the large displacement pump body, and at this time the motor cost is at a high level because the output capacity is insufficient and needs to be compensated by other means; when the value of relation (1) is greater than 1.85, although the output torque is further improved, the increase in the amount of permanent magnet 222 causes the motor cost to rise rapidly. Therefore, by controlling the value of relation (1) in the range of 0.95 to 1.85, the output torque level meets the driving requirements of the large displacement single-cylinder compressor, while the motor cost is in a low range, reflecting the balance between the motor output capacity and manufacturing cost.

[0040] The compressor of this embodiment of the invention is designed by associating the number of pole pairs P of the rotor core 221, the number Q of the stator slots 215, the greatest common divisor G of the two, the number a of the mounting slots 224 of each core unit 223, and the maximum length L of the permanent magnet 222. Furthermore, the above parameters are designed to satisfy the following relationship with the maximum circumscribed circle R1 diameter D1 of the rotor core 221, the maximum axial height H1 of the rotor core 221, the maximum axial height H2 of the cylinder 310, the outer diameter D2 of the roller 320, and the inner diameter D3 of the compression chamber 311: 0.95 ≤ ≤1.85, thus without increasing the axial dimension of the iron core, by optimizing the combination of the greatest common divisor G, the number of mounting slots 224 a, and the maximum length L of the permanent magnet 222, the effective magnetic load per unit volume of the rotor 220 is increased, so that the motor meets the output torque required by the compressor under the premise of a small axial dimension of the iron core and a compact structure, thereby avoiding problems such as increased motor volume and increased rotational inertia of the rotor 220 caused by increasing the axial dimension of the iron core; at the same time, the above relationship (1) associates the magnetic load parameter 2GaL of the rotor 220 with the height H2 of the cylinder 310 of the compressor pump body, the outer diameter D2 of the roller 320, and the inner diameter D3 of the compression chamber 311, so that the magnetic density design of the motor matches the actual displacement requirement of the compressor, while meeting the output torque requirement, avoiding excessive increase in the amount of permanent magnet 222, thereby avoiding a significant increase in material cost caused by excessive increase in the amount of permanent magnet 222.

[0041] In this embodiment of the invention, the motor assembly 200 further includes enameled wire, which is wound around the stator teeth 214 through the stator slots 215 to form a winding 400. The number of series turns in each phase winding 400 is M, satisfying: 2.2≤ ≤4; (2).

[0042] The number of series turns in each phase winding 400 refers to the total number of enameled wire turns connected in series along the current path in the same phase winding 400. The number of series turns M characterizes the magnetomotive force level established by each phase winding 400 in the magnetic circuit. The value of M directly affects the motor's back electromotive force coefficient, inductance parameters, and the magnitude of the phase current under rated operating conditions, thus affecting the motor's efficiency and operating range. The number of series turns M in each phase winding 400 can be derived from a formula or directly obtained by disassembling and counting the winding 400 structure or by electrical measurement after the motor winding is completed.

[0043] It should be noted that the numerator 2×G×a×L×M of the above relationship (2) is the coupling product of the total quantity parameter of the permanent magnet 222 of the rotor 220 (2×G×a×L) and the number of turns M of the winding 400 of the stator 210. The product of the two represents the degree of coupling between the magnetomotive force and the magnetic flux established by the motor in the air gap, and is positively correlated with the back electromotive force level and the efficiency level under rated operating conditions of the motor. The coefficient 1000 in the denominator of the above relationship (2) is used to normalize the dimensions so that the value of the relationship falls within the numerical range that is convenient for engineering use.

[0044] Specifically, the ratio of the numerator to the denominator of the above relationship (2) reflects the comprehensive coupling level of the motor's magnetic load and electrical load under unit compressor displacement. When the value of the above relationship (2) is greater than 4.0, the back electromotive force and magnetic load of the motor under rated operating conditions are relatively high, and the motor efficiency is relatively good. However, the weak magnetic current required for the motor to run at high speed in the constant power range increases, the inverter loss increases accordingly, the maximum operating frequency decreases due to the limitation of the motor's own parameters, and the high-frequency operating range of the compressor narrows, which is insufficient to meet the wide-band operation requirements of the application scenario. When the value of the above relationship (2) is less than 2.2, the back electromotive force of the motor is relatively low, the high-frequency operating range of the compressor is widened, but the phase current under rated operating conditions increases, the copper loss increases, and the motor efficiency decreases.

[0045] Therefore, the embodiments of the present invention reasonably limit the range of values ​​of the above-mentioned relation (2), and through the coordinated selection of the number G of iron core units 223, the number a of permanent magnets 222 in each iron core unit 223, the maximum length L of a single permanent magnet 222 along the projection plane perpendicular to the rotation axis X, the number of series turns M of each phase winding 400 and the pump body parameters H2, D3 and D2, take into account the balance between motor efficiency and compressor high-frequency operating range.

[0046] Combination Figure 6 It can be seen that as the value of relation (2) increases, the motor efficiency shows a monotonically increasing trend, that is, the increased coupling level between the motor magnetic load and the 400 turns M of the winding improves the efficiency of the motor under rated conditions; the high-frequency operating range shows a monotonically decreasing trend, that is, the increase in the motor back electromotive force increases the demand for field weakening during high-speed operation, and the maximum operating frequency decreases. When the value of relation (2) is less than 2.2, the motor efficiency is at a low level, which is insufficient to meet the energy efficiency threshold of the air conditioning system; when the value of relation (2) is greater than 4.0, although the motor efficiency is at a high level, the maximum operating frequency decreases, and the high-frequency operating range of the compressor narrows. Therefore, by controlling the value of relation (2) within the range of 2.2 to 4.0, both the motor efficiency and the high-frequency operating range are at an acceptable level, reflecting the balance between motor efficiency and compressor operating range.

[0047] In this embodiment of the invention, the winding 400 is wound on each stator tooth 214 in a concentrated manner, that is, a set of coils is wound separately on each stator tooth 214. The number of turns of the winding 400 on each stator tooth 214 is N, which reflects the electromagnetic effect capability of the coil on a single stator tooth 214. The larger N is, the stronger the magnetomotive force established by a single coil, but at the same time, the area of ​​the stator slot 215 occupied is also larger, which is subject to the dual constraints of the area of ​​the stator slot 215 and the diameter of the enameled wire.

[0048] In this embodiment of the invention, the number of parallel branches of winding 400 is b, which refers to the number of branches connected in parallel within the same phase winding 400. Dividing each phase winding 400 into multiple parallel branches can reduce the current carried by a single branch, thereby reducing the requirements for the enameled wire diameter. Simultaneously, the existence of parallel branches also affects the equivalent series turns of each phase winding 400. The connection mode coefficient of winding 400 is c, used to characterize the conversion relationship between phase voltage and line voltage under different connection modes. When winding 400 is star-connected in series, the connection mode coefficient c = 1; when winding 400 is delta-connected in series, the connection mode coefficient c = 1.732, satisfying: .

[0049] Specifically, in one example, the number of series turns M of each phase winding 400 can be calculated by substituting the number of stator teeth 214 turns N, the number of core units 223 G, the number of parallel branches b, and the wiring method coefficient c into the above formula. Using this formula, the number of series turns M of each phase winding 400 can be pre-calculated and adjusted based on the predetermined number of stator teeth 214 turns N, the number of parallel branches b, and the wiring method during the design stage of the motor winding 400, providing a basis for the design of electromagnetic parameters such as back electromotive force and inductance. In another example, the number of series turns M of each phase winding 400 can be directly obtained by disassembling and counting the winding 400 structure or by electrical measurement. The number of series turns M of each phase winding 400 satisfies: 150 ≤ M ≤ 400.

[0050] In this embodiment of the invention, the DC bus voltage of the drive motor assembly 200 is Udc, measured in volts (V), which satisfies: 34≤ ≤55; (3) It should be noted that the compressor in the air conditioning system is not directly connected to the industrial frequency AC power grid, but is driven and controlled by a frequency converter. The value of the DC bus voltage Udc determines the upper limit of the phase voltage amplitude that the frequency converter can output, and thus determines the upper limit of the back electromotive force (EMF) allowed for the motor when running at high speed. Understandably, the back EMF level is related to four factors: the total amount of permanent magnets 222 in the rotor 220 (2×G×a×L), the rotor 220 size (D1×π×H1), and the number of 400 series turns per phase winding (M). The back EMF increases with the increase in the amount of permanent magnets 222 and the rotor 220 size, and also with the increase in the number of series turns (M). Simultaneously, the compressor's displacement characteristic H2×D3 / D2 determines the load torque that needs to be overcome per unit speed; the larger the displacement, the lower the maximum allowable speed for the same power.

[0051] Based on this, the numerator of the above relationship (3) is the product of the total amount of permanent magnets 222 in rotor 220, the rotor 220 body size, and the DC bus voltage Udc, which is positively correlated with Udc; the denominator is the product of the number of 400 series turns M of each phase winding and the compressor displacement characteristics, which is negatively correlated with the motor back EMF carrying capacity corresponding to Udc. The ratio of the numerator to the denominator reflects the matching level between the DC bus voltage Udc and the motor magnetic load and body size under a given compressor displacement and 400 turns of winding.

[0052] When the value of the above relationship (3) is less than 34, the DC bus voltage Udc is low, the withstand voltage level of the inverter's electrical control components (such as rectifier bridge, bus capacitor, IGBT power module, etc.) is low, and the cost is relatively good. However, the compressor's high-frequency operation capability is limited by the voltage limit corresponding to Udc, and the highest operating frequency is insufficient to meet the air conditioning system's usage requirements under wide frequency band conditions. When the value of the above relationship (3) is greater than 55, the DC bus voltage Udc is high, the withstand voltage level and capacity requirements of the inverter's electrical control components increase, the cost increases, and the cost-effectiveness decreases. Although the compressor's operating range is widened, the overall cost-effectiveness is insufficient.

[0053] Therefore, the embodiments of the present invention achieve a match between the motor magnetic load, motor body, winding 400 turns M, compressor displacement and inverter DC bus voltage Udc by reasonably limiting the value range of the above relationship (3), thus taking into account the balance between the high-frequency operating range of the compressor and the electrical control cost of the inverter.

[0054] Combination Figure 7 It can be seen that as the value of relation (3) increases, the high-frequency operating range shows a monotonically increasing trend, that is, the increase of DC bus voltage Udc increases the upper limit of the phase voltage amplitude that the inverter can output, and the highest operating frequency of the motor increases accordingly; the cost-effectiveness of the inverter shows a monotonically decreasing trend, that is, the increase of Udc increases the withstand voltage level and capacity requirements of the inverter's electrical control components, the inverter cost increases, and the cost-effectiveness decreases. When the value of relation (3) is less than 34, the high-frequency operating range is at a low level, and the highest operating frequency is insufficient to meet the usage requirements of the air conditioning system under wide frequency band conditions; when the value of relation (3) is greater than 55, although the high-frequency operating range is further widened, the cost-effectiveness of the inverter decreases. Therefore, by controlling the value of relation (3) within the range of 34 to 55, both the high-frequency operating range and the cost-effectiveness of the inverter are at an acceptable level, reflecting the balance between the compressor's high-frequency operating capability and the inverter's electrical control cost.

[0055] In this embodiment of the invention, the remanence of the permanent magnet 222 is Br, measured in Tesla (T), which satisfies the following condition: 195 ≤ 2 × G × a × L × Br ≤ 250, where the dimension of 2 × G × a × L × Br is mm·T. It should be noted that the higher the remanence Br, the stronger the air gap magnetic flux that the permanent magnet 222 can establish within the same volume, and the greater the permanent magnet torque of the motor. The product of the total amount of permanent magnets 222 used in the rotor 220 (2 × G × a × L) and the remanence Br reflects the coupling level between the total amount of permanent magnets 222 and the magnetic properties of the material, that is, the total magnetic flux level that the permanent magnets 222 can provide within a given size.

[0056] It should be noted that the remanence Br of permanent magnet 222 is an inherent magnetic property parameter of the permanent magnet material itself, and its value is mainly determined by the material grade used in permanent magnet 222. In engineering implementation, the value of Br is usually obtained directly from the material specifications provided by the permanent magnet supplier. When it is necessary to verify or retest the remanence Br of the physical permanent magnet 22, the industry-standard hysteresis loop test method can be used.

[0057] When the product of the two is greater than 250, the amount of permanent magnet 222 and the remanence level are relatively high, the magnetic load of the motor is increased, and the permanent magnet torque is correspondingly increased. However, the cost of the selected permanent magnet material increases, and the increase in the amount of permanent magnet 222 also leads to a further increase in material cost, resulting in a decrease in the cost-effectiveness of the motor. When the product of the two is less than 195, the amount of permanent magnet 222 and the remanence level are relatively low, the motor cost decreases, but the air gap magnetic flux density is insufficient, and the permanent magnet torque is insufficient to meet the usage requirements. Therefore, this embodiment of the invention achieves a balance between the cost of permanent magnet materials, the level of permanent magnet torque, and the operating range of the motor by reasonably limiting the range of the product of the total amount parameter 2×G×a×L of the rotor 220 permanent magnet 222 and the remanence Br.

[0058] Combination Figure 8 It can be seen that as the value of 2×G×a×L×Br increases, the permanent magnet torque exhibits a monotonically increasing trend. This means that the increased coupling level between the total amount of permanent magnet 222 and the remanent magnet Br leads to an increase in the air gap magnetic flux density of the motor, resulting in a corresponding increase in permanent magnet torque. Conversely, the motor's cost-effectiveness exhibits a monotonically decreasing trend. This means that the increased amount of permanent magnet 222 and the use of high-grade permanent magnet materials increase the motor cost and decrease the cost-effectiveness. When the value of 2×G×a×L×Br is less than 195, the permanent magnet torque is insufficient to meet customer requirements. When the value of 2×G×a×L×Br is greater than 250, although the permanent magnet torque is further improved, the motor's cost-effectiveness decreases. Therefore, controlling the value of 2×G×a×L×Br within the range of 195 to 250 ensures that both the permanent magnet torque level and the motor's cost-effectiveness are within an acceptable range, reflecting the balance between the amount of permanent magnet material used, the permanent magnet torque, and the motor cost.

[0059] Reference Figure 4 As shown, in this embodiment of the invention, the diameter of the largest inscribed circle R2 of the stator core 211 is D4, which satisfies: 4.76≤ ≤6.5; (4) It should be noted that the diameter D4 of the largest inscribed circle R2 of the stator core 211 is the diameter of the circle enclosed by the tips of all the stator teeth 214 on the radially inner side of the stator core 211, i.e., the diameter of the inner circle of the stator 210. The diameter D1 of the largest outer circle of the rotor core 221 is the diameter of the outer circle of the rotor 220. The annular space formed radially between the inner circle of the stator 210 and the outer circle of the rotor 220 is the air gap of the motor, and the radial thickness of the air gap is the length of the air gap of the motor, which is equal to (D4-D1) / 2.

[0060] Understandably, reducing the air gap length (D4-D1) / 2 is a direct way to increase the motor's magnetic flux density. Alternatively, the air gap flux level can be increased by increasing the total amount of permanent magnets 222 (2×G×a×L) or by enlarging the outer diameter D1 of the rotor 220. However, the reduction in air gap length is limited by the precision of the stator 210 and rotor 220 machining and assembly; the air gap balance coefficient is typically used to evaluate the machining uniformity of the air gap.

[0061] In the above equation (4), the denominator D1×(D4-D1) / 2 is the product of the outer diameter D1 of the rotor 220 and the air gap length, which characterizes the geometric features of the air gap magnetic circuit. The ratio of the numerator to the denominator of the above equation (4) reflects the matching level between the total amount of permanent magnets 222 and the air gap magnetic reluctance. When the value of equation (4) is less than 4.76, the air gap length between the stator and rotor 220 is too large, the air gap magnetic reluctance is large, and the magnetic field of the rotor 220 is insufficient to establish the permanent magnet torque required for the normal operation of the compressor in the air gap. When the value of equation (4) is greater than 6.5, the air gap length is too small, the output torque established by the magnetic field of the rotor 220 meets the operating requirements of the compressor, but it puts forward higher requirements on the machining accuracy and assembly accuracy of the stator and rotor 220.

[0062] Therefore, the embodiments of the present invention achieve a balance between air gap magnetic flux density, processing and assembly accuracy and manufacturing cost by reasonably limiting the range of values ​​of the above relationship (4).

[0063] Combination Figure 9It can be seen that as the value of relation (4) increases, the magnetic field of rotor 220 shows a monotonically increasing trend, that is, the improvement of the matching level between the total amount of permanent magnet 222 and the air gap magnetic resistance increases the air gap magnetic flux density; the air gap balance coefficient shows a monotonically increasing trend, that is, the reduction of the air gap length increases the precision requirements for the processing and assembly of stator and rotor 220, and the uniformity of the air gap distribution along the circumference decreases. When the value of relation (4) is less than 4.76, the air gap length is too large, and the magnetic field of rotor 220 is insufficient to establish the permanent magnet torque required for the normal operation of the compressor; when the value of relation (4) is greater than 6.5, although the magnetic field of rotor 220 is further improved, the air gap balance coefficient increases, and the cogging torque, torque pulsation, noise and unbalanced electromagnetic pull increase accordingly, resulting in increased manufacturing defect rate and manufacturing cost. Therefore, by controlling the value of relation (4) within the range of 4.76 to 6.5, the magnetic field level of rotor 220 and the air gap balance coefficient are both within an acceptable range, reflecting the balance between air gap magnetic flux density, processing and assembly accuracy and manufacturing cost.

[0064] In this embodiment of the invention, the number of stator slots 215 is Q, satisfying: 15 ≤ Q ≤ 18. It is understood that when the number of stator slots 215 is too small, the circumferential angle corresponding to each stator tooth 214 is too large, and the distribution performance of the winding 400 decreases. Conversely, when the number of stator slots 215 is too large, the opening width and slot area of ​​each stator slot 215 are too small, increasing the difficulty of the winding process. Therefore, this embodiment achieves a balance between the distribution performance of the winding 400 and the feasibility of the winding process by reasonably limiting the range of the number Q of stator slots 215.

[0065] In this embodiment of the invention, the number of pole pairs P of the rotor core 221 satisfies: 5 ≤ P ≤ 6. It is understood that when the number of pole pairs P of the rotor core 221 is too small, the electrical frequency of the motor is low, and the required phase current at the same speed is large; conversely, when the number of pole pairs P of the rotor core 221 is too large, the processing and assembly difficulty of the permanent magnet 222 increases, and the iron loss increases with the increase of the electrical frequency. Therefore, this embodiment achieves a balance between electrical frequency, phase current, and iron loss by reasonably limiting the range of values ​​for the number of pole pairs P of the rotor core 221.

[0066] In this embodiment of the invention, the greatest common divisor (GCD) of the number of stator slots 215 (Q) and the number of pole pairs P of the rotor core 221 is G, satisfying: 4 ≤ G ≤ 6. It is understood that when the GCD is too small, the circumferential symmetry of the motor decreases, and the symmetry of the radial electromagnetic force and torque pulsation decreases; conversely, when the GCD is too large, the corresponding pole-slot matching selection space is limited. Therefore, this embodiment ensures the symmetry of the winding 400 distribution and the balance of the radial electromagnetic force by reasonably limiting the range of the GCD.

[0067] In this embodiment of the invention, the number of slots per pole per phase of the motor assembly 200 is q, and the number of phases of the motor assembly 200 is m, satisfying: .

[0068] It should be noted that the number of slots per pole per phase, 'q', represents the number of stator slots 215 occupied by each phase winding 400 under each magnetic pole. This is a key parameter for determining whether the motor is an integer-slot motor or a fractional-slot motor. When q is an integer, it corresponds to an integer-slot winding 400; when q is a fraction, it corresponds to a fractional-slot winding 400. Under the constraints of 15≤Q≤18, 5≤P≤6, and m=3, the calculated result of q is a fraction, meaning the motor in this embodiment is a fractional-slot motor.

[0069] Reference Figure 2 and Figure 4 As shown, in this embodiment of the invention, the maximum height H1 of the rotor core 221 along its own rotation axis X and the diameter D1 of the maximum circumscribed circle R1 of the rotor core 221 satisfy: 0.65≤D1 / H1≤3.6. It can be understood that D1 / H1 is the ratio of the radial dimension to the axial dimension of the rotor core 221, reflecting the flatness of the rotor 220. When D1 / H1 is large, the radial dimension is much larger than the axial dimension, and the rotor 220 becomes flat. The rotor 220 needs to bear a large radial air gap flux within a limited axial length, exacerbating the edge effect of the air gap flux at the axial end and increasing end leakage flux. Simultaneously, the excessively large radial dimension of the rotor 220 leads to an increase in the rotor's rotational inertia, reducing the dynamic response of the compressor during startup and frequency conversion adjustment. The increased radial dimension of the rotor 220 also places higher demands on the outer diameter of the stator core 211, increasing the overall radial dimension of the compressor.

[0070] Conversely, when D1 / H1 is small, the axial dimension is much larger than the radial dimension, the rotor 220 becomes elongated, the overall axial dimension of the compressor increases, occupying more installation space and overall machine layout area. The uniformity of the magnetic field distribution along the axial direction of the elongated iron core decreases, making it more difficult to control the coaxiality after stacking, and increasing the difficulty of manufacturing processes. In addition, the moment of inertia of the elongated rotor 220 is unevenly distributed along the axial direction, resulting in a decrease in the compressor's response characteristics under dynamic operating conditions.

[0071] To this end, this application reasonably limits the range of D1 / H1 values. On the one hand, the radial dimension D1 of rotor 220 is fully utilized to expand the effective area through which the air gap magnetic flux passes, enabling the establishment of air gap magnetic flux density and permanent magnet torque that meet the requirements of large-displacement single-cylinder compressors under flattening. On the other hand, the axial dimension H1 of rotor 220 is controlled, reducing the overall axial dimension of the compressor and the moment of inertia of rotor 220, thus improving the dynamic response characteristics and installation adaptability of the compressor. In addition, the difficulty of coaxiality control after silicon steel sheet stacking is reduced, the uniformity of magnetic field distribution along the axial direction is ensured, and the manufacturing process and operational stability of the motor are improved.

[0072] Embodiments of the present invention also provide a refrigeration device, including the compressor described in the above embodiments.

[0073] The refrigeration equipment of this invention adopts the compressor of the above embodiment. By optimizing the parameter design of the compressor, the compressor can output a driving torque that matches the large displacement pump body with a compact axial dimension, thereby reducing the installation space occupied by the compressor in the refrigeration equipment, which is conducive to the miniaturization of the refrigeration equipment and reduces the overall manufacturing cost of the refrigeration equipment; in addition, the overall energy efficiency ratio of the refrigeration equipment is improved.

[0074] Since the refrigeration equipment adopts all the technical solutions of the compressor in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments, and will not be repeated here. Of course, the present invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A compressor, characterized in that, include: case; A motor assembly is disposed within the housing. The motor assembly includes a stator core, a rotor core, and multiple permanent magnets. The rotor core is disposed within the inner hole of the stator core. The stator core includes a stator yoke and multiple stator teeth. The multiple stator teeth are arranged circumferentially along the stator yoke. A stator slot is defined between two adjacent stator teeth along the circumferential direction of the stator yoke. The number of stator slots is Q. The number of pole pairs of the rotor core is P. The greatest common divisor of the number of stator slots Q and the number of pole pairs P of the rotor core is G. The maximum height of the rotor core along its own rotation axis is H1. The diameter of the maximum circumscribed circle of the rotor core is D1. The rotor core includes 2P core units, which are arranged circumferentially along the rotation axis. Each core unit has a mounting slot. Multiple permanent magnets are installed one-to-one in the a mounting slots. On the projection plane perpendicular to the rotation axis, the maximum length of each permanent magnet is L. A pump body assembly is disposed within the housing and located on one axial side of the motor assembly. The pump body assembly includes a cylinder and a roller. The maximum height of the cylinder along the rotation axis is H2. The cylinder has a compression chamber, and the roller is rotatably disposed within the compression chamber. The outer diameter of the roller is D2, and the inner diameter of the compression chamber is D3, satisfying the following: 0.95≤ ≤1.85。 2. The compressor according to claim 1, characterized in that, The motor assembly also includes enameled wire, which is wound around the stator teeth through the stator slots to form a winding. The number of series turns of the winding in each phase is M, satisfying the following: 2.2≤ ≤4。 3. The compressor according to claim 2, characterized in that, The number of turns of the winding in each stator tooth is N, the number of parallel branches of the winding is b, and the connection mode coefficient of the winding is c. When the winding is connected in star series, the connection mode coefficient c = 1; when the winding is connected in delta series, the connection mode coefficient c = 1.732, satisfying: 。 4. The compressor according to claim 2, characterized in that, The number of series turns M of the winding in each phase satisfies: 150 ≤ M ≤ 400.

5. The compressor according to claim 2, characterized in that, The DC bus voltage driving the motor assembly is Udc, which satisfies: 34≤ ≤55。 6. The compressor according to claim 1, characterized in that, The remanence of the permanent magnet is Br, satisfying: 195≤2×G×a×L×Br≤250.

7. The compressor according to claim 1, characterized in that, The diameter of the largest inscribed circle of the stator core is D4, which satisfies: 4.76≤ ≤6.5。 8. The compressor according to claim 1, characterized in that, The number of stator slots is Q, satisfying: 15 ≤ Q ≤ 18; and / or, The number of pole pairs P of the rotor core satisfies: 5 ≤ P ≤ 6; and / or, The greatest common divisor of the number of stator slots Q and the number of pole pairs P of the rotor core is G, satisfying: 4 ≤ G ≤ 6; and / or, The number of slots per pole per phase of the motor assembly is q, and the number of phases of the motor assembly is m, satisfying: 。 9. The compressor according to claim 1, characterized in that, The maximum height H1 of the rotor core along its own axis of rotation and the diameter D1 of the maximum circumscribed circle of the rotor core satisfy: 0.65≤D1 / H1≤3.

6.

10. A refrigeration device, characterized in that, Includes the compressor as described in any one of claims 1 to 9.

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