Coaxial variable-frequency motor

Abstract

The utility model discloses a coaxial variable-frequency motor, which comprises a motor main body, a frequency converter and fan blades, wherein the motor main body comprises a motor shell, a front end cover mounted at the power output end of the motor shell, a rear end cover mounted on the motor shell on the opposite side of the front end cover, a motor shaft mounted on the front end cover and the rear end cover, and a rotor mounted on the motor shaft, and is characterized in that a frequency converter shell is mounted on the rear end cover, and the motor shaft extends out of the frequency converter shell; an air duct is arranged at the outer end of the frequency converter shell; fan blades are coaxially mounted on the motor shaft on the outer side of the frequency converter shell, a protective cover is fixedly mounted on the outer circumference of the fan blades, an air inlet window is arranged on the outer end face of the protective cover, and the protective cover is fixedly mounted on the frequency converter shell or the rear end cover. The design not only enhances the heat dissipation effect of the frequency converter, but also improves the compactness of equipment, maintains the same installation space as the original motor, and reduces the space occupation and line change of a control box. The method can be realized and is not limited to the original size space and the original line replacement of the AC asynchronous motor.

Description

Technical Field

[0001] The utility model belongs to a variable frequency motor, in particular to a coaxial variable frequency motor. Background Art

[0002] With the rapid development of industrial automation, the combination of frequency converter and motor is becoming more and more widely used. This integrated design aims to improve the compactness and convenience of the equipment. There are two main combination methods on the market, namely placing the frequency converter in the motor's junction box and installing the frequency converter on the rear end cover of the motor.

[0003] Analysis of defects in existing technologies:

[0004] 1. Inverter in the junction box:

[0005] Heat dissipation problem: Since the inverter generates a lot of heat when working, an effective heat dissipation system is required to ensure its normal operation. However, this method places the inverter in the junction box of the motor, and heat dissipation requires an independent cooling fan, which adds additional maintenance costs and complexity. At the same time, this may also lead to low heat dissipation efficiency, affecting the stability and life of the inverter.

[0006] Low protection level: Placing the inverter in the motor's junction box may expose it to more environmental factors, such as dust, moisture, etc. This may reduce the inverter's protection level and affect its reliability and stability.

[0007] Space occupied: Due to the large size of the junction box, this method may increase the overall size of the equipment, which is not conducive to space-constrained application environments.

[0008] 2. The inverter installed on the rear cover of the motor:

[0009] Natural cooling: In this mode, the inverter does not have a dedicated heat dissipation system, but relies on natural cooling. When working at a continuous high load, the inverter temperature may rise, affecting its performance and life.

[0010] Energy consumption: Without an effective heat dissipation system, the inverter may overheat, which in turn increases its energy consumption. This may increase operating costs for equipment that runs for a long time or under high load.

[0011] Limited application environment: Due to the lack of specific protective measures, this method may make the inverter more susceptible to certain environmental factors, such as moisture, dust, etc. This limits its application in certain environments.

[0012] Summary: Although the existing integrated design of the inverter and motor combination has achieved compactness of the equipment to a certain extent, there are still obvious problems in heat dissipation, protection and energy consumption. For manufacturers and users, how to solve these problems while ensuring the compactness of the equipment and improve the stability and energy efficiency of the equipment will be an important direction for future research and development. Utility Model Content

[0013] In view of the problems existing in the prior art, the utility model provides a coaxial variable frequency motor.

[0014] The utility model is implemented as follows: a coaxial variable-frequency motor comprises a motor body, a frequency converter and fan blades; wherein the motor body comprises a motor housing, a front end cover installed at the power output end of the motor housing, a rear end cover installed on the motor housing on the opposite side of the front end cover, a motor shaft installed on the front end cover and the rear end cover, and a rotor installed on the motor shaft, characterized in that a frequency converter housing is installed on the rear end cover, the motor shaft extends out of the frequency converter housing, and an air duct is provided at the outer end portion of the frequency converter housing; fan blades are coaxially installed on the motor shaft on the outer side of the frequency converter housing, a shield is fixedly installed on the outer circumference of the fan blade, an air inlet window is provided on the outer end surface of the shield, and the shield is fixedly installed on the frequency converter housing or the rear end cover.

[0015] Further preferably, a shaft sleeve is provided between the inverter housings.

[0016] Further preferably, the protective cover is fixedly connected to the outer end surface of the inverter housing.

[0017] Further preferably, the shield is fixedly mounted on the inverter housing, and a relief notch for evading the wiring port is provided on the shield.

[0018] The utility model has the advantages and technical effects: the utility model provides a coaxial variable frequency motor, including a motor body, a frequency converter and a fan blade. The innovation is that the frequency converter is integrated on the rear end cover of the motor, and an air duct is provided on the outer end of the frequency converter housing to enhance the heat dissipation effect of the frequency converter. This design not only improves the compactness of the equipment, but also maintains the same installation space as the original motor, reducing the space occupied by the control box and the line changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 It is a half-section view of the utility model.

[0021] In the figure, 1, motor body; 1-1, motor shaft; 2, front cover; 3, fan blades; 4, motor housing; 5, rear cover; 6, inverter housing; 6-1, air duct; 7, fan blades; 8, rotor; 9, shield; 9-1, air inlet window; 9-2, avoidance gap; 10, bushing; 11, wiring port. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0023] See also Figure 1 and Figure 2 A coaxial variable frequency motor comprises a motor body 1, a frequency converter and fan blades 3; wherein the motor body comprises a motor housing 4, a front end cover 2 installed at the power output end of the motor housing, a rear end cover 5 installed on the motor housing on the opposite side of the front end cover, a motor shaft 1-1 installed on the front end cover and the rear end cover, a rotor 8 installed on the motor shaft, a frequency converter housing installed on the rear end cover, the motor shaft extends out of the frequency converter housing 6, and an air duct 6-1 is provided at the outer end of the frequency converter housing; fan blades 7 are coaxially installed on the motor shaft on the outside of the frequency converter housing, a shield 9 is fixedly installed on the outer circumference of the fan blade, an air inlet window 9-1 is provided on the outer end surface of the shield, and the shield is fixedly installed on the frequency converter housing or the rear end cover.

[0024] Further preferably, a shaft sleeve 10 is provided between the inverter housings.

[0025] Further preferably, the protective cover is fixedly connected to the outer end surface of the inverter housing.

[0026] Further preferably, the shield is fixedly mounted on the inverter housing, and a relief notch 9 - 2 for evading the wiring port 11 is provided on the shield.

[0027] The following are specific creative advantages and technical effects:

[0028] Efficient heat dissipation design: The inverter housing installed on the rear cover is equipped with an air duct, which enhances the heat dissipation effect of the inverter and improves the stability and life of the equipment.

[0029] Space saving: Since the inverter is integrated inside the motor, the overall installation space remains unchanged or changes little, which makes the design more applicable in space-constrained environments.

[0030] Simplified wiring: Since the space occupied by the control box is reduced, the wiring layout is simpler, reducing maintenance costs and complexity.

[0031] Enhanced protection: A shaft sleeve is provided between the inverter housing and the fan blades, and the shield is fixedly mounted on the inverter housing, which enhances the overall protection level of the equipment and enables it to adapt to a wider range of environmental conditions.

[0032] Convenient Wiring: The shroud is equipped with a clearance notch for access to the wiring port, which facilitates external wiring while maintaining the compactness of the device.

[0033] Stable operation: Due to improved heat dissipation and protection design, the equipment operates more stably and reduces failures caused by environmental factors.

[0034] Easy to integrate: This design has a simple structure and is easy to integrate into the existing production line motor installation position, reducing production costs and complexity, and greatly improving the energy efficiency of the electric drive system.

[0035] In summary, the utility model provides a coaxial variable frequency motor with high heat dissipation performance, space saving, high protection level, convenient wiring and easy integration, which has broad application prospects and commercial value.

[0036] The utility model has the advantages and technical effects: the utility model creates that the frequency converter is integrated on the rear end cover of the motor, and at the same time, an air duct is provided at the outer end of the frequency converter housing to enhance the heat dissipation effect of the frequency converter. This design not only improves the compactness of the equipment, but also maintains the same installation space as the original motor, reduces the space occupied by the control box and the line change; it can be realized, and is not limited to, the original size space and original line replacement of the AC asynchronous motor.

[0037] On-site commissioning test:

[0038] Ambient temperature and load conditions: Ambient temperature is about 50℃, slow load, motor works continuously, inverter driven, and variable frequency speed control is required.

[0039] The original motor is an asynchronous motor, which is difficult to start. Due to the large load inertia, the motor cannot be started at one time and can only be started by jogging. Otherwise, the starting current is large, the motor heats up seriously, and the control switch trips due to the large current. The jogging start causes very serious wear, low efficiency and power factor, and high energy consumption.

[0040] The inverter and fan blades of the utility model are installed coaxially, and there is no need to change the original control system circuit, and the interchangeability is very good. Through variable frequency starting, the startup can be completed in one go, and the starting current is low. The motor efficiency and power factor are high, which reduces the current of the system. When working continuously for a long time, the energy saving effect is obvious, and it is not easy to be damaged. The original motor is T--7.5kW, the motor efficiency is 84%, the efficiency of the utility model is 94%, and the theoretical energy saving rate is 10%. The test results of the power analyzer on site in December 2023 are: the power input power of the original motor is 6.23kW, the power input power of this product is 5.4kW, the energy saving rate is (6.23-5.4) ÷ 6.23 = 13.3%, and the actual energy saving rate reaches 13-16%.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A coaxial variable frequency motor, comprising a motor body, a frequency converter and a fan blade; wherein the motor body comprises a motor housing, a front end cover mounted on the power output end of the motor housing, a rear end cover mounted on the motor housing on the opposite side of the front end cover, a motor shaft mounted on the front end cover and the rear end cover, and a rotor mounted on the motor shaft, characterized in that: The inverter housing is installed on the rear end cover, the motor shaft extends out of the inverter housing, and an air duct is provided at the outer end of the inverter housing; fan blades are coaxially installed on the motor shaft outside the inverter housing, a protective cover is fixedly installed on the outer circumference of the fan blade, an air inlet window is provided on the outer end surface of the protective cover, and the protective cover is fixedly installed on the inverter housing or the rear end cover.

2. The coaxial variable frequency motor according to claim 1, characterized in that: A shaft sleeve is arranged between the frequency converter housings.

3. The coaxial variable frequency motor according to claim 1, characterized in that: The protective cover is fixedly connected to the outer end surface of the inverter housing.

4. The coaxial variable frequency motor according to claim 1, characterized in that: The protective cover is fixedly sleeved on the inverter housing, and a relief notch for evading the wiring port is provided on the protective cover.

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