JP4331852B2 - Electric compressor and electric motor assembling method of electric compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor (compressor) driven by an electric motor.
[0002]
[Prior art]
As a means for obtaining compressed air, a reciprocating electric compressor is often used. The reciprocating electric compressor includes a reciprocating compression mechanism that compresses air introduced into a cylinder by a reciprocating operation of a piston provided with a valve mechanism and discharges it from a discharge port, and a hollow portion. A main frame that supports a compression mechanism at the upper part of the hollow part, an electric motor supported by the main frame, and a rotational movement / reciprocating movement conversion mechanism that converts the rotation of the electric motor into a reciprocating movement in the hollow part of the main frame and transmits it to the piston. The air in the cylinder is compressed and discharged by reciprocating the piston as the electric motor rotates.
[0003]
FIG. 3 shows an example of the configuration of a conventional compressor of this type. In FIG. 3, reference numeral 1 is a molded or cast product such as aluminum, and a main frame having a hollow portion 1a. It is the compression mechanism supported by the upper part of the hollow part.
[0004]
The compression mechanism 2 is attached so as to close the cylinder 201 fixed to the upper portion of the main frame 1 with the axis line oriented in the vertical direction and the lower end opened in the hollow portion 2, and the upper end opening of the cylinder 201. A cylinder head 202, a piston 203 fitted in the cylinder 201, a suction valve mechanism 204 attached to the piston 203, and a discharge valve mechanism 205 provided between the cylinder 201 and the cylinder head 202. The air introduced into the cylinder 201 through the suction valve mechanism 204 when the piston 203 descends is compressed when the piston 203 rises, and the discharge valve mechanism 205 and the discharge port 206 provided in the cylinder head 202 Through.
[0005]
A cylindrical first cover half 101 is integrally formed on the back side of the main frame 1, and the first cover half 101 and a cylindrical second cover half formed separately. An electric motor cover 4 'is constituted by 3'.
[0006]
The first cover half 101 is provided with its axis orthogonal to the axis of the cylinder 201 of the compression mechanism, and its one end 101 a is opened on the opposite side of the compression mechanism 2. The first cover half 101 and the hollow portion 1a of the main frame are partitioned by a partition wall 102, and a boss-shaped bearing holding portion 103 is integrally formed at the center of the partition wall 102.
[0007]
An axial contact surface 101b1 for contacting another member from the axial direction of the cover half 101 and an other member on the inner periphery of the substantially intermediate portion in the axial direction of the first cover half 101 An inlay portion (positioning fitting portion) 101b having a radial contact surface 101b2 to be contacted from the radial direction of the half portion is formed.
[0008]
The second cover half 3 ′ is composed of a substantially cylindrical peripheral wall 3a ′ that is open at one end 3a1 ′ in the axial direction and an end wall 3b ′ that closes the other end of the peripheral wall 3a ′. A boss portion 3c ′ is formed at the center of the end wall 3b ′, and a bearing holding portion 3e ′ is formed inside the boss portion 3c ′ via a plurality of radial ribs 3d ′. An inlay portion 3f ′ having an axial contact surface 3f1 ′ and a radial contact surface 3f2 ′ is formed on the inner peripheral portion of one end of the second cover half 3 ′.
[0009]
The second cover half 3 ′ is arranged with its axis lined up with the first cover half 101 and with its opening directed toward the first cover half 101, Fastened to the first cover half 101.
[0010]
A first bearing 6 and a second bearing 7 made of ball bearings are respectively provided on a bearing holding portion 103 provided on the partition wall 102 of the main frame and a bearing holding portion 3e ′ provided on the second cover half 3 ′. The rotating shaft 8 that is attached and extends in the axial direction of the motor cover 4 ′ is supported by these bearings.
[0011]
The rotor 11 and the stator 12 of the electric motor 10 are accommodated in the electric motor cover 4 ′. In this example, a capacitor-type single-phase induction motor is used as the motor 10, and the rotor 11 is attached to the rotating shaft 8. The stator 12 of the electric motor is formed by winding an armature coil 14 composed of a main winding and a starting winding around a slot of an annular armature core 13, and the armature core 13 is one end in the axial direction thereof. Is fitted to the inner spigot part 101b of the first cover half 101 and the other end is fitted to the spigot part 3f 'of the second cover half 3' so that the axial direction of the motor cover 4 ' And are positioned in the radial direction.
[0012]
A capacitor 15 connected in series to the starting winding of the electric motor 10 is attached to the upper part of the second cover half 3 ′.
[0013]
One end of the rotating shaft 8 is led out through the hollow portion 1 a of the main frame 1, and a blower fan 16 for supplying cooling air to the compression mechanism 2 is attached to one end of the rotating shaft 8.
[0014]
In the hollow portion of the main frame 1, there is provided a rotational motion / reciprocating motion conversion mechanism 17 that converts the rotation of the electric motor into a reciprocating motion and transmits it to the piston 203 of the compression mechanism 2. The illustrated conversion mechanism 17 includes a rotating body 18 coupled to a rotating shaft 8 and a connecting rod 20 having a leading end coupled to a piston 203 of a compression mechanism and a rear end coupled to the rotating body 18 via a ball bearing 19. It is made up of.
[0015]
The rotating body 18 includes a main wheel portion 18a having a cylindrical outer peripheral surface, and a balance wheel portion 18b integrally formed at one end in the axial direction of the main wheel portion 18a in order to balance weight. The rotary shaft 8 is fixed to the rotary shaft 8 by a key 21 and a bolt 22 in a state in which the rotary shaft 8 is fitted in a shaft fitting hole provided at a position eccentric with respect to the central axis of the outer peripheral surface of the main wheel portion 18a. .
[0016]
An annular portion 20a concentrically surrounding the outer periphery of the main wheel portion 18a of the rotating body 18 is formed at the rear end portion of the connecting rod 20, and the inner periphery of the annular portion 20a and the main wheel portion 18a of the rotating body 18 are formed. The outer ring and the inner ring of the ball bearing 19 are fitted to the outer periphery of each.
[0017]
A fan cover 23 is attached to cover the compression mechanism 2, the rotary motion / reciprocating motion converter 17, and the blower fan 16, and a capacitor cover 24 is attached to cover the capacitor 15.
[0018]
In the electric compressor shown in FIG. 3, the rotating body 18 performs an eccentric rotating motion as the electric motor 10 rotates, and the connecting rod 20 connected to the rotating body 18 via a bearing 19 performs a reciprocating motion. Along with the reciprocating motion of the connecting rod, the piston 203 moves up and down in the cylinder 201 and discharges compressed air from the discharge port 206.
[0019]
[Problems to be solved by the invention]
The electric compressor is often installed in an unattended installation site and operated for a long time. For example, the electric compressor shown in FIG. 3 is installed in a fish and shellfish farm and is used for supplying air into seawater. The electric compressor used in fish and shellfish farms is installed with an air tank, and its discharge port is connected to the air tank via a pressure regulator and a check valve, so that the pressure in the air tank exceeds the set value. It is operated intermittently so as to keep.
[0020]
In this type of compressor, it is desirable to make the maintenance and inspection cycle as long as possible. Therefore, it is necessary to increase the durability of the compression mechanism 2 and the conversion mechanism 17, and the electric motor 10 also has a long service life. It is necessary to use a long one. In the example shown in FIG. 3, the life of the motor 10 is increased by using an AC motor having no brush.
[0021]
In this way, when an electric compressor using an AC motor is operated in a farm or the like, an engine generator that generates an AC voltage as a power source is required. When an electric compressor is operated using an engine generator, it is necessary to start the engine every time the pressure in the air tank drops below a set value. There was a problem that the amount of gas exhausted from the engine per day increased, and air pollution caused by exhaust gas from the engine could not be ignored. Further, when the engine is operated frequently, noise generated by the engine may deteriorate the surrounding environment. Therefore, recently, it has been studied to drive this type of electric compressor using a battery.
[0022]
Further, in the compressor as described above, the temperature of the cylinder 201 of the compression mechanism 2 and the valve mechanism disposed in the compressor rises during operation. Therefore, the operation is stopped to extend the life of the valve mechanism and the like. It is desirable to cool the compression mechanism 2 by making the time for the blower fan 16 to rotate by inertia as long as possible. However, since the conventional electric compressor uses an inner rotor type electric motor with small inertia as the electric motor 10, the blower fan 16 stops almost simultaneously with the power off, and the compression mechanism 2 is cooled quickly. There was no problem.
[0023]
In addition, since the conventional electric compressor uses a capacitor-type single-phase induction motor, a large capacitor 15 is required, and a large cover 24 is required to cover the capacitor 15. Therefore, there is a problem that the whole compressor becomes large.
[0024]
An object of the present invention is to enable operation with a battery and to increase the inertia of the motor so that the blower fan can continue to rotate for a relatively long time when the operation of the motor is stopped. The object is to provide an electric compressor.
[0025]
Another object of the present invention is to provide an electric compressor that can be miniaturized without the need to use a large capacitor.
[0026]
Still another object of the present invention is to provide a method for assembling an electric motor of an electric compressor that can facilitate the assembly of the electric motor portion.
[0027]
[Means for Solving the Problems]
The present invention includes a reciprocating compression mechanism that compresses air introduced into a cylinder by a reciprocating operation of a piston provided with a valve mechanism and discharges the air from a discharge port, and has a hollow portion at an upper portion of the hollow portion. A main frame that supports a compression mechanism, an electric motor supported by the main frame, and a rotary motion / reciprocating motion conversion mechanism that converts the rotation of the motor into a reciprocating motion in the hollow portion of the main frame and transmits the reciprocating motion to the piston. For electric compressors.
[0028]
In the electric compressor targeted by the present invention, a first cover half formed integrally with the main frame and having one end opened to the side opposite to the compression mechanism, and one end opened to the first cover half An electric motor cover is constituted by the second cover half portion that is attached so as to close the opening of the first cover half portion, and the components of the electric motor are arranged in the electric motor cover. In addition, an inlay portion is formed on the inner periphery of the first cover half portion for positioning in the axial direction and the radial direction by fitting another member.
In the present invention, there is provided a boss that protrudes from the end wall that closes the other end of the second cover half and extends in the axial direction inside the peripheral wall of the second cover half. The second cover half is fixed to the first cover half in a state where one end of the second cover half is fitted into the inlay portion of the first cover half and positioned in the axial direction and the radial direction.
[0029]
The motor includes a rotor in which a permanent magnet is attached to the inner periphery of a cup-shaped rotor yoke, and a stator in which an armature coil is wound around a slot of an annular armature core disposed inside the rotor. An outer rotor type brushless DC motor is used.
[0030]
The rotating shaft of the electric motor is provided so as to extend in the axial direction in the electric motor cover through the boss portion of the second cover half, and is attached to the partition that partitions the first cover half and the hollow portion of the main frame. The first bearing and the second bearing attached to the end wall of the second cover half are supported.
[0031]
The rotor of the electric motor is attached to the rotating shaft with the opening of the yoke facing the second cover half. The stator is attached in a state where the annular armature core is fitted to the outer periphery of the boss portion provided in the second cover half.
[0032]
As described above, when a DC motor having no brush is used as an electric motor for driving the compression mechanism, the life of the electric motor can be extended as in the case of the electric compressor shown in FIG.
[0033]
If a brushless DC motor is used as described above, the compressor can be driven by a battery. When the electric motor is driven by a battery, it is conceivable to charge the battery with the output of the engine generator. However, if a battery is interposed between the engine generator and the compressor, the engine is turned on each time the compressor is operated. Since the engine can be operated less frequently than when the engine is started, the amount of gas discharged from the engine into the atmosphere during one day can be reduced to reduce air pollution.
[0034]
Further, as described above, when an outer rotor type brushless DC motor is used as an electric motor for driving the compression mechanism, the inertia can be increased. Therefore, when the operation of the compressor is stopped, the time required for the electric motor to rotate by inertia The compression mechanism can be cooled in the meantime. Therefore, when stopping the operation of the compressor, it is possible to cool the compression mechanism while keeping the blower fan rotated for a longer time than before.
[0035]
Furthermore, as described above, when a brushless DC motor is used as the motor, it is not necessary to provide a large capacitor, so that the compressor can be miniaturized.
[0036]
In addition, as described above, when the structure is such that one end of the second cover half is fitted and positioned in the inlay part formed on the inner periphery of the first cover half formed integrally with the main frame, In the conventional electric compressor as shown in FIG. 3, in order to position the stator of the electric motor, the second cover half is positioned by using the spigot portion formed on the inner periphery of the first cover half as it is. You can decide. Therefore, as the main frame 1, the same one as used in the conventional compressor can be used as it is, and a mold conventionally used for molding the main frame can be used as it is. Therefore, the electric motor can be changed from a capacitor-type single-phase induction motor to a brushless DC motor without remaking an expensive mold.
Since the rotor of a brushless DC motor has a permanent magnet on its inner periphery and the permanent magnet is opposed to the armature core of the stator, when the rotor is assembled, the permanent magnet of the rotor Care must be taken not to be absorbed by the core. If the permanent magnet is attracted to the armature core when the rotor is assembled, the magnet is cracked or the magnet is broken, resulting in poor product yield.
[0037]
Therefore, in the assembling method of the present invention, the rotor attaching step for attaching the rotor to the rotating shaft in a state where the opening of the rotor yoke faces the end wall side of the second cover half, and the rotating shaft to which the rotor is attached is the first. A rotating shaft mounting step for press-fitting into the inner ring of the bearing and supporting by the first bearing, and by fitting the boss portion of the second cover half to the inner periphery of the annular armature core A cylindrical shape formed so as to be fitted in a state of sliding contact with the rotating shaft and in a state of sliding contact with the inner periphery of the boss portion of the second cover half. By interposing a (tubular) spacer between the rotating shaft and the inner periphery of the boss part of the second cover half part, the second cover half part is held in a state where the stator and the axis are shared. Move to the cover half side of the 1st cover A stator assembling step for fitting one end of the half part to the inner spigot part of the first cover half part, and a cover for assembling the motor cover by fastening the second cover half part to the first cover half part with bolts After the assembly process and after removing the spacer, the inner ring of the second bearing is press-fitted to the other end of the rotating shaft disposed inside the boss part, and the outer ring of the second bearing is attached to the second half of the cover A motor is assembled by performing a second bearing mounting step in which the second bearing is attached to the second cover half by being press-fitted into a bearing holding hole provided in the end wall of the motor.
[0038]
When the motor part is assembled as described above, a cylindrical (tubular) spacer that can be easily manufactured without using a large jig is interposed between the boss part of the second cover half and the rotating shaft. As a result, the rotor can be incorporated while maintaining the concentric positional relationship between the rotor and the stator, so that the assembly of the motor portion can be facilitated.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
A configuration example in which the present invention is applied to a compressor similar to the compressor shown in FIG. 3 is shown in FIGS. 1 is a longitudinal sectional view similar to FIG. 3, and FIG. 2 is a right side view of an electric motor portion of the compressor of FIG. 1, parts that are the same as the parts in FIG. 3 are given the same reference numerals as those in the parts in FIG.
[0040]
In the present invention, an outer rotor type brushless DC motor including a rotor 31 and a stator 32 disposed inside the rotor is used as the motor 30, and the second cover is used to enable the mounting. The structure of the half 3 is changed.
[0041]
The second cover half 3 includes a substantially cylindrical peripheral wall 3a whose one end 3a1 is open to the first cover half, an end wall 3b that closes the other end of the peripheral wall 3a, and an end wall 3b. It has a boss part 3c that protrudes from the center part and extends in the axial direction inside the peripheral wall part 3a. The outer diameter of one end on the opening side is an inlay part 101b formed on the inner periphery of the first cover half part 101 It is formed in a size that can be fitted to the radial contact surface 101b2 without any gap. Inside the end of the boss 3c of the second cover half 3 on the end wall 3b side, a bearing holding hole 3e having an enlarged inner diameter so as to hold the second bearing 7 is formed outward. It is formed in an open state. The second bearing 7 is composed of a ball bearing, and is attached in a state where the outer ring is pressure-fitted to the inner periphery of the bearing holding hole 3e.
[0042]
The second cover half 3 is arranged in a state in which most of the second cover half 3 is inserted inside the first cover half 101, and one end 3 a 1 thereof is connected to the inlay portion 101 b on the inner periphery of the first cover half 101. The outer peripheral surface and the axial end surface of the one end 3a1 are brought into contact with the radial contact surface 101b2 and the axial contact surface 101b1 of the spigot part 101b, respectively, and are positioned in the radial direction and the axial direction. The second cover half 3 is fastened to the first cover half 101 by the bolt 5 (see FIG. 2) in the state of being positioned in this way.
[0043]
The illustrated rotor 31 includes a rotor yoke 31A formed in a cup shape with a ferromagnetic material such as iron, and a permanent magnet 31B attached to the inner periphery of the yoke. The rotor 31 has an opening in the yoke 31A. The rotary shaft 8 is attached to the second cover half 3 side. In the illustrated example, a boss portion 31 a is riveted to the center of the bottom wall portion of the yoke 31 </ b> A, and the boss portion 31 a is fitted to the rotary shaft 8.
[0044]
The stator 32 includes an annular armature core 32A and an armature winding 32B wound around a slot of the armature core 32A, and the boss of the second cover half 3 is formed on the inner periphery of the core 32A. The second cover half 3 is supported by fitting the portion 3c. With the stator 32 attached in this manner, the iron core 32A and the rotor 31 are arranged concentrically, and the magnetic pole portion formed on the outer periphery of the iron core 32A is opposed to the magnetic pole of the rotor 31 through a predetermined gap. It is like that.
[0045]
The electric motor 30 also includes a printed circuit board 33 on which components of a control circuit that controls the current flowing through the armature coil 32B according to the rotational angle position of the rotor are mounted. The printed circuit board 33 has a hole aligned with the hole on the inner side of the iron core 32A at the center, and the end face of the iron core 32 facing the end wall 3b of the second half of the cover is interposed via a spacer 34. Screwed. The printed circuit board 33 is disposed between the stator 32 and the end wall 3b of the second cover half when the iron core 32A is fitted and held on the outer periphery of the boss 3c of the second cover half. The
[0046]
The end wall 3b of the second cover half 3 is also provided with a vent hole 3h and a cord lead-out hole 3i, and a cover plate 35 covering the cord lead-out hole 3i and the second bearing 7 is secured by a screw 36. It is fixed to the outer surface of the part wall 3b. A grommet 37 is attached to a window portion provided at a position corresponding to the cord drawing hole 3 i of the cover plate 35, and a cord 38 connected to the printed circuit board 33 is led out through the grommet 37. The other points are the same as those of the compressor shown in FIG.
[0047]
As described above, one end of the second cover half 3 is attached to the inlay portion 101b of the first cover half provided integrally with the main frame 1 in order to position the iron core of the stator of the inner rotor type electric motor. The second cover half 3 is fitted and positioned with respect to the first cover half 101, and the stator core 32A is fitted to the boss 3c provided on the end wall of the second cover half. When the positioning is performed together, the outer rotor type electric motor can be attached using the main frame used in the conventional compressor as it is.
[0048]
Further, when the outer rotor type electric motor is used as described above, the inertia of the rotor is large. Therefore, when the operation of the compressor is stopped, the time required for the electric motor to rotate by inertia can be lengthened. Therefore, when the operation of the compressor is stopped, it is possible to lengthen the time that the wind hits the cylinder 201 of the compression mechanism, thereby preventing the temperature of the valve mechanism in the cylinder from rising and deteriorating its components. it can.
[0049]
When assembling the above-described electric compressor, first, a rotor attaching step for attaching the rotor 31 to the rotary shaft 8 with the opening of the rotor yoke facing the end wall 3b side of the second cover half 3 is performed, Then, a rotating shaft mounting step is performed in which the rotating shaft 8 to which the rotor 31 is mounted is press-fitted into the inner ring of the first bearing 6 and supported by the first bearing 6.
[0050]
After the rotating shaft 8 to which the rotor is attached is supported by the first bearing 6, the boss portion 3c of the second cover half 3 is fitted to the inner periphery of the annular armature core 32A. A stator mounting step for supporting the boss 3c is performed.
[0051]
Next, a cylindrical shape (tubular) formed so as to be fitted in a state of sliding contact with the rotating shaft 8 and to be fitted in a state of sliding contact with the inner periphery of the boss portion 3 c of the second cover half 3. The spacer 32 (not shown) is fitted to the outer periphery of the rotary shaft 8, and then the boss 3 c of the second cover half is fitted to the outer periphery of the spacer, so that the stator 32 shares the axis with the rotor 31. The boss 3c of the second cover half 3 is moved to the main frame 1 side while holding in a state where the end of the second cover half 3 is connected to the inner portion 101b of the first cover half 101. A stator assembling step for fitting to is performed.
[0052]
As described above, when the second cover half 3 is moved to the main frame 1 side with a spacer interposed between the rotating shaft 8 and the boss 3c of the second cover half 3, By using a longer spacer as the spacer and projecting the spacer from the end of the rotating shaft 8, the stator 32 is moved toward the main frame 1 while maintaining the stator 32 and the rotor 31 in a concentric positional relationship. It can be moved to incorporate the stator. Therefore, the stator can be incorporated without bringing the iron core 32A of the stator 32 into contact with the magnet 31B of the rotor, and the magnet 31B can be prevented from being damaged when the electric motor is assembled.
[0053]
After the stator 32 is arranged inside the rotor 31 as described above, a cover assembly process is performed in which the second cover half 3 is fastened to the first cover half 101 with the bolt 5 to assemble the motor cover.
[0054]
After the first cover half 3 is attached to the first cover half 101 as described above, the spacer protruding from the outer end of the boss 3c is removed, and the rotation shaft arranged inside the boss 3c. 8, the inner ring of the second bearing 7 is press-fitted to the other end, and the outer ring of the second bearing 7 is press-fitted inside the bearing holding hole 3 e provided in the end wall of the second cover half 3. Then, a second bearing attaching step for attaching the second bearing 7 to the second cover half 3 is performed.
[0055]
Next, the cover plate 35 is attached, and the cord 38 is pulled out through the grommet 37 attached to the cover plate 35 to complete the assembly of the motor part.
[0056]
【The invention's effect】
As described above, according to the present invention, since a DC motor having no brush is used as an electric motor for driving a compression mechanism, the life of the electric motor can be extended as in a conventional compressor.
[0057]
In the present invention, since the outer rotor type brushless DC motor is used as the motor for driving the compression mechanism, the inertia can be increased to extend the time for the motor to rotate by inertia when the operation of the compressor is stopped. it can. Therefore, when stopping the operation of the compressor, it is possible to cool the compression mechanism while keeping the blower fan rotated for a longer time than before, and to prevent the temperature of the components of the compression mechanism from rising. can do.
[0058]
Furthermore, in the present invention, since it is not necessary to provide a large capacitor for rotating the electric motor, it is possible to reduce the size of the compressor.
[0059]
In the present invention, since the second cover half is determined by the position using the inner spigot portion of the first cover half integrally formed with the main frame, the conventional compressor is used. The motor cover for the brushless DC motor can be configured by using the main frame used as it is. Therefore, the electric motor can be changed to a brushless DC motor without remaking an expensive mold.
[0060]
Further, according to the assembling method of the present invention, a cylindrical (tubular) spacer that can be easily manufactured without using a large jig is merely interposed between the boss portion of the second cover half and the rotating shaft. Thus, since the rotor can be incorporated while keeping the rotor and the stator in a concentric positional relationship, there is an advantage that the assembly of the electric motor part can be facilitated.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a configuration of an electric compressor according to the present invention.
FIG. 2 is a right side view of an electric motor portion of the compressor of FIG.
FIG. 3 is a longitudinal sectional view showing a configuration of a conventional electric compressor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main frame, 101 ... 1st cover half part, 2 ... Compression mechanism, 201 ... Cylinder, 203 ... Piston, 204 ... Suction valve mechanism, 205 ... Discharge valve mechanism, 3 ... 2nd cover half part, 4 ... Motor cover, 6 ... first bearing, 7 ... second bearing, 8 ... rotating shaft, 30 ... brushless DC motor, 31 ... rotor, 31A ... rotor yoke, 31B ... permanent magnet, 32 ... stator, 32A ... annular electric machine Child core, 32B ... armature coil, 33 ... printed circuit board.

Claims (2)

A reciprocating compression mechanism that compresses and discharges air introduced into the cylinder by a reciprocating motion of a piston provided with a valve mechanism; and a main body that has a hollow portion and supports the compression mechanism on the upper portion of the hollow portion. Driven by the motor, a frame, an electric motor supported by the main frame, a rotary motion / reciprocating motion conversion mechanism for converting the rotation of the electric motor into a reciprocating motion in the hollow portion of the main frame and transmitting it to the piston A first blower fan that supplies cooling air to the compression mechanism, and is formed integrally with the main frame and has one end opened to the opposite side of the compression mechanism, and one end is the first cover. An electric motor cover is formed by the second cover half portion that is opened to the cover half portion side of the first cover and is attached so as to close the opening portion of the first cover half portion. Machine components are disposed, in the electric compressor wherein the fitting portions on the inner periphery of the first cover half for positioning by fitting the other member in the axial direction and the radial direction is provided,
The second cover half portion has a boss portion that protrudes from an end wall that closes the other end side and extends in the axial direction inside the peripheral wall portion, and one end of the second cover half portion is fitted to the inlay portion to be axial. Fixed to the first cover half in a state of being positioned in the direction and radial direction,
The electric motor is provided so as to extend in the axial direction in the electric motor cover through the boss portion of the second cover half, and partitions the first cover half and the hollow portion of the main frame. A rotating shaft supported by a first bearing attached to the portion and a second bearing attached to an end wall of the second cover half, and an opening on the second cover half side A rotor in which a permanent magnet is attached to the inner periphery of a cup-shaped rotor yoke attached to the rotary shaft in a state of being directed, and an armature coil is wound around a slot of an annular armature core disposed inside the rotor Consisting of an outer rotor type brushless DC motor equipped with a stator,
The electric compressor according to claim 1, wherein the stator is attached in a state in which the annular armature core is fitted to an outer periphery of a boss portion provided in the second cover half. A reciprocating compression mechanism that compresses air introduced into the cylinder by a reciprocating operation of a piston provided with a valve mechanism and discharges the compressed air from a discharge port; and a compression mechanism disposed above the hollow portion. A main frame to be supported, and an inlay portion that is formed integrally with the main frame in a state opened to the opposite side of the hollow portion, and is positioned in the axial direction and the radial direction by fitting another member to the inner peripheral portion. And a second cover half that is attached so that one end is opened toward the first cover half and the opening of the first cover half is closed. An electric motor cover, a first bearing attached to a partition wall partitioning the first cover half and the hollow portion of the main frame, and an end for closing the other end of the second cover half A second bearing mounted on the wall, A motor and a stator disposed in the motor cover, and a rotary shaft rotatably supported by the first bearing and the second bearing, and a rotary motion of the rotary shaft within the hollow portion of the main frame. In the method of assembling the electric motor part of the electric compressor provided with a rotary motion / reciprocating motion conversion mechanism that converts it into a reciprocating motion and transmits it to the piston,
The second cover half is formed with a boss projecting from the end wall closing the other end side and extending in the axial direction inside the peripheral wall, and one end of the second cover half in the axial direction. In a shape that can be fitted into the inlay part,
As the electric motor, the rotor includes a cup-shaped rotor yoke and a permanent magnet attached to the inner periphery of the rotor yoke, and an annular armature core disposed on the inner side of the rotor and the armature core Using an outer rotor type brushless DC motor with an armature coil wound around a slot,
A rotor attachment step of attaching the rotor to the rotary shaft in a state where the opening of the rotor yoke faces the end wall side of the second cover half,
A rotating shaft mounting step in which the rotating shaft to which the rotor is mounted is press-fitted into the inner ring of the first bearing and supported by the first bearing;
A stator attachment step of supporting the stator on the boss portion by fitting the boss portion of the second cover half portion to the inner periphery of the annular armature core;
A cylindrical spacer formed so as to be fitted in a state of sliding contact with the rotary shaft and to be fitted in a state of sliding contact with the inner periphery of the boss portion of the second cover half. And the inner periphery of the boss portion of the second cover half portion so that the boss portion of the second cover half portion is held in the first position while holding the stator in a state of sharing the axis with the rotor. A stator assembling step in which one end of the second cover half is fitted to the inner spigot portion of the first cover half by being moved to the one cover half side;
A cover assembling step of assembling the electric motor cover by fastening the second cover half to the first cover half with a bolt;
After extracting the spacer, the inner ring of the second bearing is press-fitted to the other end of the rotating shaft disposed inside the boss part, and the outer ring of the second bearing is fitted to the second cover half part. The motor part is assembled by performing a second bearing mounting step in which the second bearing is mounted on the second cover half by being press-fitted into a bearing holding hole provided in the end wall. Assembling method of electric motor of compressor.

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