JP7319211B2 - motor assembly - Google Patents

Description

The present invention relates to motor assemblies.

2. Description of the Related Art A motor assembly is known that integrally includes a motor that drives a rotating machine such as a pump and an inverter that is variable speed means for the motor. Sensors including a vibration sensor are mounted on such an electric motor assembly. By collecting and analyzing the data acquired by such sensors, it is possible to diagnose the state of the motor assembly and notify the time of failure, the time of part replacement, and the like. As a result, it is possible to improve services such as after-sales service.

JP 2017-145830 A JP 2018-129904 A

When a wireless communication device that transmits data acquired by a sensor to the outside is installed outside the housing of the motor assembly, a box-shaped case is required to accommodate the wireless communication device. Therefore, the housing of the electric motor assembly is enlarged.

In general, the housing of the motor and the housing of the inverter are made of metal members. Therefore, if a wireless communication device is installed inside the housing of the motor assembly made of a metal member, the wireless signal will be blocked, making communication with the outside impossible.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an electric motor assembly that can be made compact and can communicate with the outside.

In one aspect, a drive shaft, a motor that rotates the drive shaft, a motor casing that houses the motor, an inverter that is variable speed means for the motor, and an axial direction of the drive shaft that houses the inverter. an inverter case connected in series to the motor casing along a line; a resin shaft cover disposed inside the inverter case and covering the periphery of the drive shaft; and a resin shaft cover disposed inside the inverter case and a wireless communication device. The inverter case includes a cover member to which the shaft cover is connected, and a propagation path for radio waves transmitted from the wireless communication device is formed between the cover member and the drive shaft.

In one aspect, the motor casing includes a bracket arranged adjacent to the inverter case, the inverter case being arranged around the inverter and arranged between the cover member and the bracket. At least a portion of the inverter frame and/or at least a portion of the cover member are made of resin.
In one aspect, the wireless communication device is disposed on the bracket.
In one aspect, the bracket has a saucer shape, and the bracket is filled with resin for dissipating heat from the wireless communication device.

In one aspect, the bracket includes heat radiating fins formed on an inner surface of the bracket.
In one aspect, the electric motor assembly includes a resin cooling fan arranged adjacent to the inverter case and fixed to the drive shaft, and a resin fan cover covering the cooling fan. I have it.
In one aspect, the electric motor assembly includes a resin fan guard that covers the fan cover.
In one aspect, the electric motor assembly includes a resin contact seal attached to the drive shaft, and the contact seal contacts the inverter case on the outside of the inverter case.

The wireless communication device is arranged inside an inverter case provided with a resin-made shaft cover. Therefore, the electric motor assembly can be made compact in overall size, and can be provided with a configuration that allows communication with the outside.

1 is a cross-sectional view showing one embodiment of a motor assembly; FIG. It is a front view of a fan cover. FIG. 11 shows a fan guard attached to the fan cover; FIG. 2 is a diagram showing propagation paths of radio waves transmitted from a wireless communication device; FIG. 11 shows a contact seal mounted on a drive shaft; FIG. 10 is a diagram showing another embodiment of the electric motor assembly; FIG. 11 shows another embodiment of a bracket; FIG. 10 is a diagram showing yet another embodiment of a bracket;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a cross-sectional view showing one embodiment of the electric motor assembly 1. FIG. The electric motor assembly 1 is a mechanical device having an integrated structure in which an inverter 20 is built. As shown in FIG. 1 , the electric motor assembly 1 includes a motor section 2 and an inverter section 3 . The electric motor assembly 1 houses a drive shaft 5 , a motor (rotating element) 8 having a rotor 6 and a stator 7 for rotating the drive shaft 5 , the rotor 6 and the stator 7 . A motor casing 10, an inverter 20 arranged adjacent to the rotor 6 and the stator 7 to control the operation (rotational speed) of the motor 8, and the inverter 20 are housed along the axis CL direction of the drive shaft 5. and an inverter case 21 arranged (connected) in series to the motor casing 10 .

Drive shaft 5 extends through motor casing 10 and inverter case 21 , and motor casing 10 and inverter case 21 are arranged concentrically with drive shaft 5 . In this embodiment, since the motor casing 10 and the inverter case 21 are arranged in series in the direction of the axis CL of the drive shaft 5, the electric motor assembly 1 can have a compact structure. A cooling fan 25 arranged concentrically with the drive shaft 5 is fixed to the end of the drive shaft 5 (that is, the non-load side of the drive shaft 5). Cooling fan 25 is arranged outside inverter case 21 and is adjacent to inverter case 21 . In one embodiment, cooling fan 25 is a centrifugal fan.

A motor 8 that is a heat source is arranged inside the motor casing 10 . The motor 8 includes a rotor 6 fixed to the drive shaft 5 and a stator surrounding the rotor 6. A winding (coil) 7b receives electric power from the outside (not shown) to form a rotating magnetic field. ) 7 and . The stator 7 includes a stator core 7a and a plurality of windings 7b wound around the stator core 7a. Rotor 6 is rotated by a rotating magnetic field formed between rotor 6 and stator 7 , and drive shaft 5 to which rotor 6 is fixed rotates together with rotor 6 .

In FIG. 1, the motor 8 is depicted schematically. The motor 8 is, for example, a permanent magnet type motor using a permanent magnet for the rotor. However, the motor 8 is not limited to a permanent magnet type motor, and may be various types of motors such as an induction motor and an SR motor.

The motor casing 10 includes a motor frame 11 to which the stator 7 is fixed, an end cover 12 which closes one open end of the motor frame 11 and has a through hole 30 through which the drive shaft 5 passes, and the motor frame 11. and a bracket 13 that closes the other open end of the drive shaft 1 and has a through hole 31 through which the drive shaft 5 passes. The end cover 12 and the bracket 13 face each other with the motor 8 interposed therebetween. The drive shaft 5 is rotatably supported by a bearing 27 supported by the bearing support portion 32 of the end cover 12 and a bearing 28 supported by the bearing support portion 33 of the bracket 13 .

The inverter case 21 surrounds the inverter 20 , in other words, includes an inverter frame 22 arranged around the inverter 20 and a cover member 23 that closes an open end of the inverter frame 22 . The inverter frame 22 is arranged adjacent to the bracket 13 and connected to the bracket 13 .

The electric motor assembly 1 includes a fan cover 51 connected to the inverter case 21 , more specifically, the cover member 23 so as to cover the cooling fan 25 . Fan cover 51 is a member for sending cooling air to inverter section 3 and motor section 2 in this order while preventing fingers from touching cooling fan 25 . The fan cover 51 is arranged to cover the cover member 23 and is fixed to the cover member 23 . The fan cover 51 has an opening 51 a formed in the surface of the fan cover 51 facing the cooling fan 25 .

A plurality of fins 36 are formed on the outer surface of the cover member 23 . These fins 36 are adjacent to the cooling fan 25 and extend from the outer surface of the cover member 23 toward the cooling fan 25 . The cover member 23 is arranged concentrically with the drive shaft 5 , and a through hole 40 through which the drive shaft 5 passes is formed in the center of the cover member 23 . The drive shaft 5 extends through the through hole 40 to the outside of the cover member 23 .

FIG. 2 is a front view of the fan cover 51. FIG. The opening 51 a of the fan cover 51 is a plurality of aligned holes, each of which is large enough to prevent the cooling fan 25 from being touched by a human finger. The shape of the opening 51a of the fan cover 51 is not limited to this embodiment. The cooling fan 25 is adjacent to the opening 51 a of the fan cover 51 . When the cooling fan 25 rotates, the air around the opening 51a of the fan cover 51 is sucked into the fan cover 51 through the opening 51a.

FIG. 3 shows the fan guard 55 attached to the fan cover 51. As shown in FIG. As shown in FIG. 3 , the fan guard 55 is attached to the fan cover 51 so as to cover the fan cover 51 . Therefore, when the cooling fan 25 rotates, the air is sucked through the gap between the fan cover 51 and the fan guard 55 and sucked into the fan cover 51 through the opening 51a.

As shown in FIG. 1, the inverter 20 is arranged inside the inverter case 21 . The inverter 20 includes an inverter element 41 including elements such as switching elements and capacitors, and a substrate 42 on which the inverter element 41 is mounted. The substrate 42 is fixed to the inner surface of the cover member 23 via spacers 43 . The inner surface of the cover member 23 is the surface opposite to the outer surface of the cover member 23 on which the fins 36 are formed. The cover member 23 has a saucer shape on which the substrate 42 is placed. With such a structure, the cover member 23 can be filled with resin for heat dissipation and surface protection of the substrate 42 .

The electric motor assembly 1 further includes a shaft cover 50 arranged inside the inverter case 21 and covering the periphery of the drive shaft 5 . The shaft cover 50 is a separating member that separates the drive shaft 5 and the inverter 20 from each other. The shaft cover 50 has a cylindrical shape and is arranged concentrically with the drive shaft 5 . The shape of the shaft cover 50 is not particularly limited. The shaft cover 50 extends in the direction of the axis CL of the drive shaft 5 . Inverter 20 (that is, inverter element 41 and substrate 42 ) and connection lines that electrically connect inverter 20 and windings 7 b of stator 7 are arranged outside shaft cover 50 .

The shaft cover 50 is connected to the cover member 23 . In the embodiment shown in FIG. 1, the cover member 23 has an annular protrusion 23a to which the shaft cover 50 is attached. The shaft cover 50 is connected to the cover member 23 by inserting the annular projection 23 a into the shaft cover 50 .

The substrate 42 has an annular shape through which the drive shaft 5 and the shaft cover 50 pass, and the substrate 42 and the shaft cover 50 are arranged concentrically with the drive shaft 5 . By providing the shaft cover 50 , it is possible to prevent the connection wire from being caught in the drive shaft 5 and the contact of the inverter element 41 with the drive shaft 5 . As a result, failure of inverter 20 can be reliably prevented.

In this embodiment, the motor frame 11 and the inverter frame 22 are configured as separate members, and the bracket 13 is interposed between the motor frame 11 and the inverter frame 22 . Motor frame 11 and bracket 13 are connected to each other, and inverter frame 22 and bracket 13 are connected to each other. As described above, the motor frame 11, the bracket 13, and the inverter frame 22 are formed from separate members, and the motor frame 11 and the inverter frame 22 are connected via the bracket 13. It can be removed from the motor frame 11 . Therefore, the operator can easily replace the bearing 28 without pulling out the rotor 6 . That is, with such a structure, the maintainability of the electric motor assembly 1 can be improved.

As shown in FIG. 1, the electric motor assembly 1 includes a wireless communication device 100 arranged inside the inverter case 21 (that is, the inverter installation space 110). The wireless communication device 100 is a communication module capable of communicating with the outside through a wireless communication method. An example of a wireless communication system is a communication system using Bluetooth (registered trademark). When a wireless communication system is adopted, the influence of electromagnetic noise is not a problem, the emission of electromagnetic noise is suppressed, and large amounts of data can be communicated at high speed.

By arranging wireless communication device 100 inside inverter case 21 , there is no need to provide a case member for housing wireless communication device 100 in the housing of electric motor assembly 1 . Therefore, the electric motor assembly 1 can be made compact in size as a whole, and can be provided with a configuration that allows communication with the outside.

In the embodiment shown in FIG. 1, wireless communication device 100 is arranged on bracket 13 . In one embodiment, the wireless communication device 100 may be arranged on the inner surface of the inverter case 21 (more specifically, the inner surface of the cover member 23 or the inner surface of the inverter frame 22). In one embodiment, wireless communication device 100 may be disposed on substrate 42 .

In one embodiment, wireless communication device 100 may be a combination of a communication module (not shown) and a sensor (not shown) that detects the state of motor assembly 1 . In this case, the communication module and the sensor are arranged in a limited space in inverter installation space 110 . Therefore, it is desirable to use products that are as small as possible for communication modules and sensors.

Wireless communication device 100 including a communication module and a sensor may be arranged in inverter installation space 110 integrally, or divided and arranged in inverter installation space 110 . When the sensor and communication module are separately arranged, the sensor may be arranged on the substrate 42 and the communication module may be arranged on the bracket 13 .

FIG. 4 is a diagram showing propagation paths of radio waves transmitted from the wireless communication device 100. As shown in FIG. As shown in FIG. 4 , wireless communication device 100 placed on bracket 13 is adjacent to shaft cover 50 . In this embodiment, the motor casing 10 and the inverter case 21 are made of strong members such as metal. Such a rigid member blocks the propagation of radio waves, but the shaft cover 50 is made of a material (resin in the embodiment shown in FIG. 4) that does not block the propagation of radio waves. Therefore, as shown in FIG. 4, radio waves transmitted from the wireless communication device 100 pass through the shaft cover 50, and the propagation path of the radio waves is formed between the cover member 23 and the drive shaft 5 (see FIG. 4). arrow).

As shown in FIG. 4, the gap between the cover member 23 and the drive shaft 5 is determined to a size such that the rotating drive shaft 5 does not contact the cover member 23 and the propagation of radio waves is not hindered. Since the drive shaft 5 supports the cooling fan 25 at its end, the cooling fan 25 cannot be supported if the diameter of the drive shaft 5 is too small. Therefore, the drive shaft 5 has a diameter large enough to support the cooling fan 25 . On the other hand, if the size of the through hole 40 is too large with respect to the diameter of the drive shaft 5 , there is a risk that foreign matter, water droplets, or the like will enter the interior of the inverter case 21 . Conversely, if the size of the through-hole 40 is made too small, the propagation of radio waves may be hindered. Therefore, in the present embodiment, the gap between the cover member 23 and the drive shaft 5 is determined to have a size that does not allow the rotating drive shaft 5 to contact the cover member 23 and hinder the propagation of radio waves.

In order not to block the propagation of radio waves more reliably, each of cooling fan 25 and fan cover 51 is preferably made of resin (that is, a material that does not block the propagation of radio waves). As shown in FIG. 4 , the radio wave propagation path is formed along the axis CL direction of the drive shaft 5 . Therefore, if the cooling fan 25 and the fan cover 51 exist in the radio wave propagation path, the radio wave propagation may be hindered. In this embodiment, the cooling fan 25 and the fan cover 51 are made of resin, so that the propagation of radio waves is not hindered by the cooling fan 25 and the fan cover 51 . Therefore, wireless communication device 100 can more reliably communicate with the outside. In one embodiment, if a fan guard 55 is provided, the fan guard 55 may also be constructed from resin. In one embodiment, the drive shaft 5 may be made of resin (that is, a material that does not hinder the propagation of radio waves). In other embodiments, the drive shaft 5 may be made of a material other than resin (for example, metal).

FIG. 5 shows a contact seal mounted on the drive shaft 5. FIG. As shown in FIG. 5 , the motor assembly 1 may include a contact seal 60 mounted on the drive shaft 5 . The contact seal 60 is in contact with the inverter case 21 (more specifically, the cover member 23 ) on the outside of the inverter case 21 . An example of contact seal 60 is a V-ring. Like the cooling fan 25 and the fan cover 51, the contact seal 60 is arranged on the radio wave propagation path. Therefore, the contact seal 60 is also made of a material (for example, resin) that does not hinder the propagation of radio waves.

The contact seal 60 is in contact with the cover member 23 to ensure its waterproofness. The contact area between the contact seal 60 and the cover member 23 has a size that satisfies a certain prescribed value. Therefore, if the size of the through-hole 40 is made too large, the contact area does not satisfy a certain specified value. Conversely, if the size of the through-hole 40 is made too small, the propagation of radio waves may be hindered. Therefore, in the present embodiment, the gap between the cover member 23 and the drive shaft 5 is such that the rotating drive shaft 5 does not come into contact with the cover member 23 and the propagation of radio waves is not hindered, and the contact seal 60 and the cover are separated. The contact area with the member 23 is determined to have a size that satisfies a certain prescribed value.

By providing the shaft cover 50, it is possible to prevent contact between the drive shaft 5 and the inverter element 41, and to prevent entry of foreign substances such as water, humidity, and dust from the outside. By additionally providing the contact seal 60, the intrusion of foreign matter can be prevented more reliably.

FIG. 6 is a diagram showing another embodiment of the electric motor assembly 1. FIG. In the embodiment shown in FIG. 6, an opening 22a is provided in a portion of the inverter frame 22, and the opening 22a is closed by a closing member 101 made of resin. By closing the opening 22a with the closing member 101, it is possible to prevent foreign substances such as water, moisture, and dust from entering.

As described above, the motor casing 10 and the inverter case 21 are made of strong members such as metal. Therefore, in order to further improve the propagation of radio waves, the inverter frame 22 has an opening 22a, which is closed by a closing member 101 made of resin. With such a configuration, the radio wave propagation path is formed not only in the gap between the drive shaft 5 and the cover member 23 (see "first propagation path" in FIG. 6) but also in the opening 22a (see FIG. 6). 6 "Second Propagation Path").

In one embodiment, although not shown, an opening may be formed in the cover member 23 and closed by a closing member. The entire cover member 23 and/or the inverter frame 22 may be made of resin (that is, a material that does not block the propagation of radio waves) if there is no problem with durability or cooling performance. Therefore, at least part of the inverter frame 22 and/or at least part of the cover member 23 may be made of resin.

FIG. 7 is a diagram showing another embodiment of the bracket 13. FIG. As shown in FIG. 7, the bracket 13 has a saucer shape on which the wireless communication device 100 is placed. With such a structure, bracket 13 can be filled with resin 102 for heat radiation and surface protection of wireless communication device 100 .

Since the inverter 20 is a heat source, the inverter installation space 110 becomes hot. When wireless communication device 100 is placed in inverter installation space 110, wireless communication device 100 is affected by heat. If wireless communication device 100 is made of a member that does not have heat resistance, wireless communication device 100 may be affected by the heat of inverter 20 and fail. According to the embodiment shown in FIG. 7, wireless communication device 100 is immersed in resin 102 that fills bracket 13 . Therefore, the radio communication device 100 is not affected by the heat of the inverter 20 and can be prevented from malfunctioning due to the heat.

FIG. 8 is a diagram showing still another embodiment of the bracket 13. As shown in FIG. As shown in FIG. 8 , a plurality of heat radiation fins 103 may be formed on the inner surface 13 a of the bracket 13 . With such a configuration, bracket 13 can dissipate heat, and wireless communication device 100 arranged on bracket 13 can reduce the influence of heat from inverter 20 . As a result, failure of wireless communication device 100 caused by heat can be prevented.

The embodiment shown in FIG. 7 and the embodiment shown in FIG. 8 may be combined. In this case, radiation fins 103 are formed on the inner surface 13a of the bracket 13 having a saucer shape, and the bracket 13 is filled with resin.

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and can of course be embodied in various different forms within the scope of its technical concept.

1 electric motor assembly 2 motor section 3 inverter section 5 drive shaft 6 rotor
7 Stator
7a stator core 7b winding 8 rotating element (motor)
10 Motor casing 11 Motor frame 12 End cover 13 Bracket 13a Inner surface 20 Inverter 21 Inverter case 22 Inverter frame 22a Opening 23 Cover member 23a Annular protrusion 25 Cooling fan 27 Bearing 28 Bearing 30 Through hole 31 Through hole 32 Bearing support 33 Bearing support 36 fin 40 through hole 41 inverter element 42 substrate 43 spacer 50 shaft cover 51 fan cover 51a opening 55 fan guard 60 contact seal 100 wireless communication device 101 closing member 102 resin 110 inverter installation space

Claims (8)

a drive shaft;
a motor that rotates the drive shaft;
a motor casing housing the motor;
an inverter that is variable speed means for the motor;
an inverter case housing the inverter and connected in series to the motor casing along the axial direction of the drive shaft;
a resin shaft cover disposed inside the inverter case and covering the periphery of the drive shaft;
a wireless communication device disposed inside the inverter case,
The inverter case includes a cover member to which the shaft cover is connected,
An electric motor assembly, wherein a propagation path for radio waves transmitted from the wireless communication device is formed between the cover member and the drive shaft. The motor casing includes a bracket arranged adjacent to the inverter case,
The inverter case includes an inverter frame arranged around the inverter and arranged between the cover member and the bracket,
2. The electric motor assembly according to claim 1, wherein at least part of said inverter frame and/or at least part of said cover member are made of resin. 3. The motor assembly of claim 2, wherein said wireless communication device is located on said bracket. The bracket has a saucer shape,
4. The electric motor assembly according to claim 2, wherein said bracket is filled with resin for dissipating heat from said wireless communication device. The electric motor assembly according to any one of claims 2 to 4, wherein the bracket includes heat radiation fins formed on the inner surface of the bracket. The electric motor assembly is
a resin cooling fan disposed adjacent to the inverter case and fixed to the drive shaft;
The electric motor assembly according to any one of claims 1 to 5, further comprising a resin fan cover that covers the cooling fan. 7. The electric motor assembly according to claim 6, further comprising a resin fan guard covering said fan cover. The electric motor assembly includes a resin contact seal attached to the drive shaft,
The electric motor assembly according to any one of claims 1 to 7, wherein the contact seal is in contact with the inverter case on the outside of the inverter case.

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