Electric machines, compressors and refrigeration plants

Abstract

The application provides a motor, a compressor and a refrigeration device. The motor according to the application comprises a rotor and a stator, and a permanent magnet in the rotor contains a cerium element. According to the mass percentage x% of the cerium element, the number Q of stator teeth, the phase number m of stator windings and the magnetic pole width b of the motor are designed to satisfy the relationship Q / m≤3 and the relationship bm≥3040 / (165-x) m When the number Q of stator teeth and the phase number m of stator windings satisfy the relationship Q / m≤3 and the magnetic pole width b satisfies the relationship bm≥3040 / (165-x) m , the efficiency and reliability of the motor can be optimal, and the cost of the motor is the lowest. The application further provides a compressor and a refrigeration device comprising the above permanent magnet motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressors, and in particular relates to a motor, a compressor and a refrigeration device. Background Art

[0002] Currently, in the field of household air conditioner compressors, fixed-speed models are gradually withdrawing from the market, and variable-frequency motors have become the mainstream technology. To adapt to the application environment of household air conditioners, the permanent magnets of variable-frequency motors are mostly neodymium iron boron permanent magnets containing heavy rare earth elements and high coercivity. Neodymium iron boron permanent magnets are based on the intermetallic compound Nd2Fe 14 B-based permanent magnet materials are primarily composed of neodymium, iron, and boron. To achieve different performance characteristics, other rare earth metals, such as dysprosium and praseodymium, can partially replace the neodymium in permanent magnets. With the annual increase in the number of variable-frequency motors, the consumption of heavy rare earth elements (particularly dysprosium and terbium) is also increasing. To reduce the use of heavy rare earth elements, new technologies are needed.

[0003] Compared with praseodymium and neodymium, cerium has obvious cost advantages. However, compared with the same praseodymium and neodymium, the remanence of the corresponding rare earth magnet is r and intrinsic coercivity H cj Therefore, in order to meet the application requirements of motor performance in the whole machine, it is necessary to redesign the motor structure according to the content of rare earth element cerium in the permanent magnet. Summary of the Invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention provides a motor that improves motor efficiency and cost-effectiveness by designing the motor structure according to the cerium content in the permanent magnet.

[0005] The present invention also provides a compressor comprising the motor of the present invention.

[0006] The present invention also provides a refrigeration device comprising the compressor of the present invention.

[0007] A first aspect of the present invention provides a motor comprising a rotor and a stator;

[0008] The rotor includes a rotor core and a plurality of permanent magnets disposed on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0009] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0010] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0011] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0012] The width of the rotor's magnetic pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x).

[0013] One of the technical solutions of the present invention regarding the motor has at least the following beneficial effects:

[0014] One of the core components of an air conditioner is the compressor, which is equipped with a motor. The torque of the motor is generated by the interaction between the magnetic field strength of the NdFeB magnet in the motor and the magnetic field strength generated by the stator in the current. In order to meet the demagnetization current requirements of air conditioner manufacturers, the intrinsic coercive force of the NdFeB permanent magnets used in the inverter models of general compressor manufacturers is ≥1830kA / m. The permanent magnets with this intrinsic coercive force contain a large proportion of praseodymium, neodymium and heavy rare earth elements. In order to reduce the dependence on praseodymium, neodymium and heavy rare earth elements, magnets containing cerium can be used, but the use of cerium will lead to a decrease in intrinsic coercive force. The intrinsic coercive force of permanent magnets containing cerium is in the range of 1500≤H cj The intrinsic coercivity is between 1800kA / m and 1800kA / m, lower than the NdFeB permanent magnets with an intrinsic coercivity of 1830kA / m or higher used in inverter models by typical compressor manufacturers. This reduction in intrinsic coercivity reduces the demagnetization capability of the motor by over 40% under existing motor designs. Using cerium-containing rare earth magnets requires a new motor design.

[0015] To this end, the present invention provides a motor comprising a rotor and a stator, wherein:

[0016] The rotor includes a rotor core and a plurality of permanent magnets disposed on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0017] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0018] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0019] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0020] The width of the rotor's magnetic pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x).

[0021] In the motor of the present invention, the permanent magnet contains x% of cerium by mass, thereby reducing the use of praseodymium, neodymium and heavy rare earth elements, effectively controlling the cost. r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which adjusts the number of stator teeth Q, the number of phases m of the stator winding and the pole width b according to the mass percentage x% of the cerium element in the permanent magnet. m The design is carried out, when the number of stator teeth Q and the number of phases m of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When ≥3040 / (165-x), the efficiency and reliability of the motor can be optimized, while the motor cost is the lowest.

[0022] The torque of the motor is generated by the interaction between the magnetic field strength of the magnets in the motor and the magnetic field strength generated by the stator in the current. The excitation of the motor is provided by the permanent magnets in the rotor. The remanence of the permanent magnets B r The number of magnetic poles of the rotor is P, and the magnetic pole width is b. m , then the magnetic flux that the permanent magnet can provide is 2P×b m ×B r Due to the use of rare earth magnets containing cerium, B r The value decreases accordingly, and the permanent magnet excitation decreases as a whole. In the motor of the present invention, when the pole width b m Satisfy relationship b m When ≥3040 / (165-x), the magnetic properties of the magnet can meet the efficiency requirements of the motor.

[0023] According to some embodiments of the present invention, the number Q of the stator teeth is 9.

[0024] According to some embodiments of the present invention, the number Q of the stator teeth is 6.

[0025] According to some embodiments of the present invention, the number m of phases of the stator winding is 3.

[0026] The number Q of stator teeth and the number m of phases of the stator winding satisfy the relationship Q / m≤3. This design is suitable for the case where the cerium content x% in the permanent magnet is 3% to 10%. At the same time, limiting Q / m≤3 is conducive to broadening the scope of use of the product and is suitable for popularization.

[0027] According to some embodiments of the present invention, the number of magnetic pole pairs of the rotor is P, and P≤3.

[0028] As mentioned above, the torque of the motor is generated by the interaction between the magnetic field strength of the magnets in the motor and the magnetic field strength generated by the stator in the current. The excitation of the motor is provided by the permanent magnets in the rotor, and the residual magnetism B r The number of magnetic poles of the rotor is P, and the magnetic pole width is b. m , then the magnetic flux that the permanent magnet can provide is 2P×b m ×B r Due to the use of rare earth magnets containing cerium, B r The value decreases accordingly, and the permanent magnet excitation decreases as a whole. In the motor of the present invention, the permanent magnet is a magnet containing cerium element, and with the corresponding number of magnetic poles P, a corresponding B r With H cj When the motor is used, the cost is lower and the motor is more cost-effective.

[0029] According to some embodiments of the present invention, the coils on the stator teeth in each phase of the stator winding are connected in series.

[0030] At the same power level, series windings used on motors with relatively thicker wire diameters can achieve higher back electromotive force and improve the efficiency of medium and low frequency motors.

[0031] According to some embodiments of the present invention, the coils on the stator teeth in each phase of the stator winding are connected in parallel.

[0032] At the same power level, using parallel windings on motors with relatively thinner wire diameters can appropriately reduce the back electromotive force, which is beneficial to improving the efficiency of high-frequency motors.

[0033] According to some embodiments of the present invention, the magnetic pole width b m Satisfaction relationship: b m ≤3900 / (165-x).

[0034] According to some embodiments of the present invention, the efficiency of the motor is ≥ 91.5%.

[0035] The efficiency of a motor is the efficiency under rated voltage, frequency and load conditions.

[0036] According to some embodiments of the present invention, the permanent magnet contains dysprosium, and the content of the dysprosium is less than 3 wt %.

[0037] According to some embodiments of the present invention, the permanent magnet contains dysprosium, and the content of the dysprosium is less than 2.3 wt %.

[0038] According to some embodiments of the present invention, the permanent magnet contains dysprosium, and the content of the dysprosium is about 2.25 wt %.

[0039] According to some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the sum of the praseodymium and neodymium elements is 20 wt % to 32 wt %.

[0040] According to some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the total content of the praseodymium and neodymium elements is 25 wt % to 32 wt %.

[0041] According to some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the total content of the praseodymium and neodymium elements is 25 wt %.

[0042] According to some embodiments of the present invention, the permanent magnet contains cobalt element, and the content of the cobalt element is 1 wt% to 2 wt%.

[0043] According to some embodiments of the present invention, a plurality of slots are provided on the end surface of the rotor core along the circumference of the rotor core, and each of the permanent magnets is correspondingly embedded in each of the slots.

[0044] According to some embodiments of the present invention, the slot is V-shaped.

[0045] According to some embodiments of the present invention, the V-shaped opening faces the motor stator.

[0046] Since the intrinsic coercive force of rare earth magnets containing cerium is lower than that of conventional rare earth magnets, directly using rare earth magnets containing cerium will reduce the demagnetization ability of the motor. However, the V-shaped slot can enhance the motor's anti-demagnetization ability, making the motor's demagnetization ability no less than that of conventional rare earth magnets.

[0047] According to some embodiments of the present invention, the motor of the present invention is a permanent magnet synchronous motor.

[0048] A second aspect of the present invention provides a compressor, comprising the motor.

[0049] One of the technical solutions of the present invention regarding the compressor has at least the following beneficial effects:

[0050] The compressor of the present invention comprises the motor described above, which includes a rotor and a stator.

[0051] The rotor includes a rotor core and a plurality of permanent magnets disposed on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0052] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0053] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0054] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0055] The width of the rotor's magnetic pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x).

[0056] In the motor of the compressor of the present invention, the permanent magnet contains x% of cerium by mass, thereby reducing the use of praseodymium, neodymium and heavy rare earth elements, effectively controlling the cost. r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which adjusts the number of stator teeth Q, the number of phases m of the stator winding and the pole width b according to the mass percentage x% of the cerium element in the permanent magnet. m The design is carried out, when the number of stator teeth Q and the number of phases m of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When the ratio is ≥3040 / (165-x), the motor efficiency and reliability can be optimized while the motor cost is minimized. Consequently, the compressor efficiency is higher and the cost is lower.

[0057] A third aspect of the present invention provides a refrigeration device, which includes the compressor.

[0058] One of the technical solutions of the present invention regarding refrigeration equipment has at least the following beneficial effects:

[0059] The refrigeration equipment of the present invention, because it uses the compressor of the present invention, has all the effects and advantages of the above-mentioned motor and compressor. Specifically:

[0060] The refrigeration equipment of the present invention comprises the aforementioned compressor and a motor, wherein the motor comprises a rotor and a stator.

[0061] The rotor includes a rotor core and a plurality of permanent magnets disposed on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0062] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0063] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0064] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0065] The width of the rotor's magnetic pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x).

[0066] In the motor of the refrigeration equipment of the present invention, the permanent magnet contains x% of cerium by mass. The addition of cerium will cause the remanence of the magnet B r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which adjusts the number of stator teeth Q, the number of phases m of the stator winding and the pole width b according to the mass percentage x% of the cerium element in the permanent magnet. m The development and design are carried out. When the number of stator teeth Q and the number of phases m of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When the ratio is ≥3040 / (165-x), the motor's efficiency and reliability are optimized, while the motor cost is minimized. This, in turn, leads to higher compressor efficiency and lower costs, ultimately improving the performance of the refrigeration equipment.

[0067] According to some embodiments of the present invention, the refrigeration device is an air conditioner.

[0068] According to some embodiments of the present invention, the air conditioner is a household air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a structural schematic diagram of the motor of the present invention.

[0070] Figure 2 It is a partial structural diagram of the permanent magnets and slots in the motor of the present invention.

[0071] Figure 3 This is a graph showing the relationship between the addition of cerium and the decrease in the remanent magnetism of a magnet.

[0072] Reference numerals:

[0073] 100: rotor; 110: slot; 120: permanent magnet;

[0074] 200: stator; 210: stator teeth;

[0075] 300: Air gap. DETAILED DESCRIPTION

[0076] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0077] In some embodiments of the present invention, the present invention provides a motor including a rotor 100 and a stator 200 , wherein an air gap 300 is formed between the rotor 100 and the stator 200 .

[0078] refer to Figure 1 and Figure 2 As shown, the rotor 100 includes a rotor core and a plurality of permanent magnets 120 disposed on the rotor core, wherein the permanent magnets 120 contain cerium elements with a mass percentage of x%.

[0079] The stator 200 includes a stator core, which is provided with Q stator teeth 210 along the inner circumference. A stator winding (not shown) is wound around each stator tooth 210, and the number of phases of the stator winding is m.

[0080] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0081] The number Q of the stator teeth 210 and the number m of phases of the stator winding satisfy the relationship: Q / m≤3;

[0082] The width of the magnetic pole of the rotor 100 is b m , b m Satisfaction relationship: b m ≥3040 / (165-x).

[0083] It is understandable that one of the core components of an air conditioner is the compressor, and the compressor is equipped with a motor. The torque of the motor is generated by the interaction between the magnetic field strength of the NdFeB magnet in the motor and the magnetic field strength generated by the stator in the current. In order to meet the demagnetization current requirements of air conditioner manufacturers, the intrinsic coercive force of the NdFeB permanent magnets used in the inverter models of general compressor manufacturers is ≥1830kA / m. The permanent magnets under this intrinsic coercive force contain a large proportion of praseodymium, neodymium and heavy rare earth elements. In order to reduce the dependence on praseodymium, neodymium and heavy rare earth elements, magnets containing cerium can be used, but the use of cerium will lead to a decrease in intrinsic coercive force. The intrinsic coercive force of cerium-containing permanent magnets is in the range of 1500≤H cj The intrinsic coercivity is between 1800kA / m and 1800kA / m, lower than the NdFeB permanent magnets with an intrinsic coercivity of 1830kA / m or higher used in inverter models by typical compressor manufacturers. This reduction in intrinsic coercivity reduces the demagnetization capability of the motor by over 40% under existing motor designs. Using cerium-containing rare earth magnets requires a new motor design.

[0084] To this end, the present invention provides a motor, comprising a rotor 100 and a stator 200. Specifically:

[0085] The rotor 100 in the motor includes a rotor core and a plurality of permanent magnets 120 disposed on the rotor core. The permanent magnets 120 contain cerium in an amount of x% by mass.

[0086] The stator 200 in the motor includes a stator core, which is provided with Q stator teeth 210 along the inner circumference. A stator winding (not shown) is wound around each stator tooth 210, and the number of phases of the stator winding is m.

[0087] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0088] The number Q of the stator teeth 210 and the number m of phases of the stator winding satisfy the relationship: Q / m≤3;

[0089] The width of the magnetic pole of the rotor 100 is b m , b m Satisfaction relationship: b m ≥3040 / (165-x).

[0090] It can also be understood that in the motor of the present invention, the permanent magnet 120 contains x% by mass of cerium, thereby reducing the use of praseodymium, neodymium and heavy rare earth elements, effectively controlling costs. r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which is designed based on the mass percentage x% of the cerium element in the permanent magnet 120, the number Q of the stator teeth 210 and the number m of the phases of the stator winding. When the number Q of the stator teeth 210 and the number m of the phases of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When ≥3040 / (165-x), the efficiency and reliability of the motor can be optimized, while the motor cost is the lowest.

[0091] In order to reduce the dependence on praseodymium, neodymium and heavy rare earth elements, the present invention adopts a permanent magnet containing cerium, corresponding to the mass percentage of cerium in the total weight of the permanent magnet being x%. The addition of cerium will cause the remanence of the magnet to decrease. The remanence decrease is referenced to Figure 3 As shown. Figure 3 It can be seen that different mass percentages of cerium in different permanent magnets correspond to the remanence B of the permanent magnets. r Due to the reduced remanence of the magnets, existing motor designs also reduce the motor's magnetic flux, significantly reducing motor efficiency at comparable costs. To utilize rare earth magnets containing cerium, the present invention redesigns the motor's structural dimensions based on the x% mass percentage of cerium in the permanent magnets.

[0092] In some embodiments of the present invention, the number Q of stator teeth is 9.

[0093] In some other embodiments of the present invention, the number Q of stator teeth is 6.

[0094] In some embodiments of the present invention, the number m of phases of the stator winding is 3.

[0095] It can be understood that since most of the existing motor structures satisfy Q / m≤3, the present invention limits the number of stator teeth Q and the number of phases m of the stator winding to satisfy the relationship Q / m≤3. Without changing the existing motor structure, the utilization of permanent magnets with a cerium content x% of 3% to 10% can be achieved, thereby reducing the use of heavy rare earth resources, broadening the scope of use of the product, and being suitable for popularization and use.

[0096] In some embodiments of the present invention, the number of magnetic pole pairs of the rotor 100 is P, where P≤3.

[0097] The motor of the present invention is a permanent magnet synchronous motor. The main excitation magnetic field is generated by the rotor magnet. Therefore, the number of pairs of magnets determines the number of magnetic poles of the magnetic field. For example, a three-pole pair magnet generates a three-pole pair magnetic field.

[0098] The number of magnetic pole pairs in a permanent magnet motor refers to the number of pairs of north and south poles in the rotor or stator. The number of poles is the total number of north and south poles. The number of magnetic pole pairs = number of poles / 2, so a 6-pole motor has 3 pairs of poles.

[0099] Rotate the permanent magnet rotor once and observe its back EMF. The number of cycles is the number of magnetic pole pairs. Different motor pole pairs have different speeds.

[0100] The torque of the motor is generated by the interaction between the magnetic field strength of the magnets in the motor and the magnetic field strength generated by the stator in the current. The excitation of the motor is provided by the permanent magnets in the rotor. The remanence of the permanent magnets B r The number of magnetic poles of the rotor is P, and the magnetic pole width is b. m , then the magnetic flux that the permanent magnet can provide is 2P×b m ×B r Due to the use of rare earth magnets containing cerium, B r The value decreases accordingly, and the permanent magnet excitation decreases as a whole. In the motor of the present invention, the permanent magnet is a magnet containing cerium element, and with the corresponding number of magnetic poles P, a corresponding B r With H cj When the motor is used, the cost is lower and the motor is more cost-effective.

[0101] In the motor of the present invention, the pole width b is defined m Satisfaction relationship: b m ≥3040 / (165-x).

[0102] Table 1 lists the width b of the rotor pole.m When the value is 20, the corresponding change value of 3040 / (165-x) when the cerium content x% in the permanent magnet changes from 0% to 13% is 20. In fact, when the cerium content x% exceeds 10%, B r The value drops significantly, the motor excitation magnetic field is too small, the motor efficiency is poor, and it cannot meet the compressor energy efficiency requirements.

[0103] It should be noted that the width of the rotor pole is b m , when each pole consists of two permanent magnets, b m It is the sum of the actual widths of the two permanent magnets.

[0104] It should be noted that stator windings are divided into concentrated windings and distributed windings. Concentrated windings refer to windings in which the coil is wound on one stator tooth. Distributed windings refer to windings in which the coil is wound on multiple stator teeth. Specifically, the span of concentrated windings is 1, for example, from slot 1 to slot 2; while the span of distributed windings is not 1, for example, the span is 3, and the winding is from slot 1 to slot 4. The "slot" here refers to the area formed between the stator tooth and the stator tooth. In addition, the end height of concentrated windings is small and the cost is low; the end height of distributed windings is relatively large and the cost is higher, but the motor operation noise is lower.

[0105] It should also be noted that the permanent magnets used in the motor of the present invention can be purchased directly from the market. Specifically, in the permanent magnets shown in Table 1, in addition to the cerium content shown in Table 1, the combined praseodymium and neodymium content is 25wt%, the dysprosium content is 2.25wt%, the cobalt content is 1.5wt%, and the remainder is iron. Commercially available cerium-free permanent magnets typically contain a combined praseodymium and neodymium content of 30wt%, dysprosium content of 2.25wt%, and cobalt content of 1.5wt%. The remainder is primarily iron, with possible trace elements.

[0106] Table 1 Variation of 3040 / (165-x)

[0107] <![CDATA[b m ]]> x 3040 / (165-x) <![CDATA[b m ]]> x 3040 / (165-x) 20.0 0 18.42 20.0 7 19.24 20.0 1 18.54 20.0 8 19.36 20.0 2 18.65 20.0 9 19.49 20.0 3 18.77 20.0 10 19.61 20.0 4 18.88 20.0 11 19.74 20.0 5 19 20.0 12 19.87 20.0 6 19.12 20.0 13 20

[0108] Furthermore, the remanence B of the permanent magnet was compared when the cerium content x% in the permanent magnet changed from 0% to 15%. r , motor efficiency and cost changes. The results are shown in Table 2. According to Table 2, the higher the addition ratio of cerium in the permanent magnet, the higher the remanence B of the permanent magnet. r In the permanent magnet of the motor of the present invention, the mass percentage x% of the cerium element satisfies 3%≤x%≤10%. When the mass percentage x% of the cerium element satisfies 3%≤x%≤10%, the optimal motor efficiency and motor cost performance can be achieved.

[0109] It should be noted that the motor efficiency is the efficiency obtained by testing under rated voltage, frequency and load conditions. Specifically, the voltage is 220V, the speed is 3600r / min, and the torque is 1.75N·m.

[0110] Table 2 Relationship between the mass percentage x% of cerium and the remanence of permanent magnets, motor efficiency and motor cost

[0111] x / ％ <![CDATA[Residual magnetic flux density B of permanent magnet r > Motor efficiency / % Motor cost / yuan 0.0 1.35 92.5 75.0 5.0 1.32 92.4 70.0 10.0 1.28 92.2 65.0 15.0 1.20 91.0 60.0

[0112] As mentioned above, in some embodiments of the present invention, the width of the rotor pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x). Table 3 gives the m When the mass percentage of cerium element x% changes from 0 to 15% when the diameter is 20 mm, the remanence B r Relationship with 3040 / (165-x) and motor efficiency.

[0113] Table 3 Relationship between the change of cerium content and motor efficiency and 3040 / (165-x)

[0114]

[0115]

[0116] As can be seen from Table 3, when the mass percentage x% of cerium is greater than 10% and 3040 / (165-x) is greater than 20, the performance of the magnet is seriously degraded, the motor efficiency is low, and it cannot meet the use requirements. Therefore, the mass percentage x% of cerium in the permanent magnet used in the motor of the present invention satisfies 3%≤x%≤10%. At the same time, for the motor structure, b is limited. m ≥3040 / (165-x).

[0117] It should be noted that the magnet performance B r The data is provided by the magnet manufacturer after production and testing. Since it is a common test method in the industry, it will not be described in detail in this article. r is the residual magnetization, and its unit is T.

[0118] It's also important to note that motor efficiency refers to the ratio of a motor's output power to its input power. For permanent magnet motors, a 0.5% increase in efficiency is considered a significant improvement.

[0119] The test method and steps for motor efficiency are as follows:

[0120] Fix the stator on the stator fixture and the rotor on the corresponding bearing;

[0121] Set the test conditions, including voltage, speed, and torque point, input the corresponding motor controller parameters, start the power supply, and power on the inverter;

[0122] Record the voltage U, current I, input power Pi, speed N, and torque T data under corresponding conditions;

[0123] The motor efficiency = 6.283×N×T / Pi can be automatically calculated by the test equipment.

[0124] As mentioned above, the torque of the motor is generated by the interaction between the magnetic field strength of the magnets in the motor and the magnetic field strength generated by the stator in the current. The excitation of the motor is provided by the permanent magnets in the rotor, and the residual magnetism B r The number of magnetic poles of the rotor is P, and the magnetic pole width is b. m , then the magnetic flux that the permanent magnet can provide is 2P×b m ×B r Due to the use of rare earth magnets containing cerium, B r The value decreases accordingly, and the permanent magnet excitation decreases as a whole. In the motor of the present invention, when the pole width b m Satisfy relationship b m When ≥3040 / (165-x), the magnetic properties of the magnet can meet the efficiency requirements of the motor.

[0125] In some embodiments of the present invention, the coils on the stator teeth in each phase of the stator winding are connected in series.

[0126] It can be understood that at the same power level, using series windings on motors with relatively thicker wire diameters can achieve higher back electromotive force and improve the efficiency of medium and low frequency motors.

[0127] In some embodiments of the present invention, the stator winding and the coils on the stator teeth in each phase are connected in parallel.

[0128] It is also understandable that at the same power level, using parallel windings on motors with relatively thinner wire diameters can appropriately reduce the back electromotive force, which is beneficial to improving the efficiency of high-frequency motors.

[0129] In some embodiments of the present invention, the pole width b m The relationship is satisfied: bm≤3900 / (165-x).

[0130] In some embodiments of the present invention, the efficiency of the motor is ≥ 91.5%.

[0131] The efficiency of the motor of the present invention is ≥91.5%, which is the efficiency obtained by testing under the conditions of rated voltage, frequency and load. Specifically, the voltage is 220V, the speed is 3600r / min, and the torque is 1.75N·m.

[0132] In some embodiments of the present invention, the permanent magnet contains dysprosium, and the content of dysprosium is less than 3 wt %.

[0133] In some embodiments of the present invention, the permanent magnet contains dysprosium, and the content of dysprosium is less than 2.3 wt %.

[0134] In some embodiments of the present invention, the permanent magnet contains dysprosium element, and the content of dysprosium element is about 2.25 wt %.

[0135] Dysprosium is a silvery-white metal that is soft and can be cut with a knife. Besides possessing the chemical activity common to all rare earth elements, allowing it to be used as mixed rare earth metals and compounds, dysprosium also possesses excellent optical, electrical, magnetic, and nuclear properties. Dysprosium is used as an additive in neodymium-iron-boron (NdFeB) permanent magnets. Adding approximately 2% to 3% dysprosium by weight can increase the magnet's coercivity. With the increasing demand for NdFeB magnets, dysprosium has become a necessary additive, and demand is rapidly increasing.

[0136] In some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the total content of praseodymium and neodymium elements is 20 wt % to 32 wt %.

[0137] In some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the total content of the praseodymium and neodymium elements is 25 wt % to 32 wt %.

[0138] In some embodiments of the present invention, the permanent magnet contains praseodymium and neodymium elements, and the total content of the praseodymium and neodymium elements is 25 wt %.

[0139] In some embodiments of the present invention, the permanent magnet contains cobalt element, and the content of cobalt element is 1 wt% to 2 wt%.

[0140] The presence of cobalt in permanent magnets can increase coercive force and magnetic energy product.

[0141] refer to Figure 1 As shown, in some embodiments of the present invention, a plurality of slots 110 are provided on the end surface of the rotor core along the circumference of the rotor core, and each permanent magnet 120 is correspondingly embedded in each slot 110 .

[0142] In some embodiments of the present invention, the slot 110 is V-shaped.

[0143] In some embodiments of the present invention, the V-shaped opening faces the stator 200 .

[0144] Since the intrinsic coercive force of rare earth magnets containing cerium is lower than that of conventional rare earth magnets, directly using rare earth magnets containing cerium will reduce the demagnetization ability of the motor. However, the slot 110 is V-shaped, which can enhance the anti-demagnetization ability of the motor and make the demagnetization ability of the motor not lower than that of conventional rare earth magnets.

[0145] In some other embodiments of the present invention, the present invention provides a compressor comprising the motor of the present invention.

[0146] It can be understood that the compressor of the present invention contains the motor of the present invention, and the motor includes a rotor and a stator.

[0147] in:

[0148] The rotor includes a rotor core and a plurality of permanent magnets arranged on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0149] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference direction, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0150] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0151] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0152] The width of the rotor pole is b m , b m Satisfaction relationship: b m ≥3040 / (165-x).

[0153] In the motor of the compressor of the present invention, the permanent magnet contains x% of cerium by mass, thereby reducing the use of praseodymium, neodymium and heavy rare earth elements, effectively controlling the cost. r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which is designed based on the mass percentage x% of cerium in the permanent magnet, the number of stator teeth Q and the number of phases m of the stator winding are developed. When the number of stator teeth Q and the number of phases m of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When the ratio is ≥3040 / (165-x), the motor efficiency and reliability can be optimized while the motor cost is minimized. Consequently, the compressor efficiency is higher and the cost is lower.

[0154] In some other embodiments of the present invention, a refrigeration device is provided. The refrigeration device includes the compressor of the present invention.

[0155] It can be understood that the refrigeration equipment of the present invention, due to the use of the compressor of the present invention, has all the effects and advantages of the above-mentioned motor and compressor. Specifically:

[0156] The refrigeration device of the present invention comprises a compressor and a motor, wherein the motor comprises a rotor and a stator.

[0157] The rotor includes a rotor core and a plurality of permanent magnets arranged on the rotor core, wherein the permanent magnets contain x% of cerium by mass;

[0158] The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference direction, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m;

[0159] The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%;

[0160] The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3;

[0161] The width of the rotor pole is b m , magnetic pole width b m Satisfaction relationship: b m ≥3040 / (165-x).

[0162] In the motor of the refrigeration equipment of the present invention, the permanent magnet contains x% of cerium by mass, thereby reducing the use of praseodymium, neodymium and heavy rare earth elements, effectively controlling the cost. r In order to ensure that the efficiency of the motor can meet the requirements under the condition of comparable cost, the present invention proposes a motor, which is designed based on the mass percentage x% of cerium in the permanent magnet, the number of stator teeth Q and the number of phases m of the stator winding are developed. When the number of stator teeth Q and the number of phases m of the stator winding meet the relationship Q / m≤3, and the pole width b m Satisfy relationship b m When the ratio is ≥3040 / (165-x), the motor's efficiency and reliability are optimized, while the motor cost is minimized. This, in turn, leads to higher compressor efficiency and lower costs, ultimately improving the performance of the refrigeration equipment.

[0163] In some embodiments of the present invention, the refrigeration device is an air conditioner.

[0164] In some embodiments of the present invention, the air conditioner is a household air conditioner.

[0165] It should also be noted that the cerium-containing permanent magnets involved in the technical solution of the present invention are all products already available on the market. The present invention is based on the cerium content in the cerium-containing permanent magnets, by adjusting the number of stator teeth Q and the number of phases m of the stator winding, as well as the pole width b of the rotor. m Conduct structural design to ultimately improve the performance of permanent magnet motors, compressors, and refrigeration equipment.

[0166] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0167] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0168] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0169] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0170] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A motor, characterized in that: including a rotor and a stator; The rotor includes a rotor core and a plurality of permanent magnets disposed on the rotor core, wherein the permanent magnets contain x% of cerium by mass; The stator comprises a stator core, wherein the stator core is provided with Q stator teeth along the inner circumference, each stator tooth is wound with a stator winding, and the number of phases of the stator winding is m; The mass percentage x% of the cerium element satisfies: 3%≤x%≤10%; The number of stator teeth Q and the number of phases m of the stator winding satisfy the relationship: Q / m≤3; The width of the rotor's magnetic pole is b m , b m Satisfaction relationship: b m ≥3040 / (165-x) mm.

2. The motor according to claim 1, characterized in that The number of magnetic pole pairs of the rotor is P, where P≤3.

3. The motor according to claim 1, characterized in that In the stator winding, the coils on the stator teeth in each phase are connected in series.

4. The motor according to claim 1, characterized in that The stator winding is connected in parallel with the coils on the stator teeth in each phase.

5. The motor according to claim 1, characterized in that Pole width b m Satisfaction relationship: b m ≤3900 / (165-x)mm.

6. The motor according to claim 1, characterized in that The permanent magnet contains dysprosium element, and the content of the dysprosium element is less than 3wt%.

7. The motor according to any one of claims 1 to 6, characterized in that The permanent magnet contains dysprosium element, and the content of the dysprosium element is less than 2.3 wt %.

8. The motor according to any one of claims 1 to 6, characterized in that The permanent magnet contains praseodymium and neodymium elements, and the sum of the praseodymium and neodymium elements is 20 wt % to 32 wt %.

9. The motor according to any one of claims 1 to 6, characterized in that The permanent magnet contains cobalt element, and the content of the cobalt element is 1 wt % to 2 wt %.

10. The motor according to any one of claims 1 to 6, characterized in that A plurality of slots are provided on the end surface of the rotor core along the circumferential direction of the rotor core, and each of the permanent magnets is correspondingly embedded in each of the slots.

11. The motor according to claim 10, characterized in that The slot is V-shaped.

12. The motor according to claim 11, characterized in that The V-shaped opening faces the motor stator.

13. A compressor, characterized in that: The compressor comprises the motor according to any one of claims 1 to 12.

14. A refrigeration device, characterized in that: The refrigeration device includes the compressor according to claim 13.

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