FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
STATOR FOR MOTOR AND COMPRESSOR;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
Technical Field
[0001]
The present disclosure relates to a stator for a motor and a compressor
5 including the stator for a motor.
Background Art
[0002]
A typical stator for a motor includes a stator core around which coils are wound.
The manners of winding coils include a concentrated winding manner and a
10 distributed winding manner. A distributed winding configuration has a higher winding
factor than a concentrated winding configuration, and allows a magnetic flux in a rotor
of a motor to be used more effectively. For example, when a compressor of an airconditioning apparatus is required to have a large capacity, the compressor desirably
incorporates a motor including a stator with coils in a distributed winding
15 configuration.
[0003]
A distributed winding configuration has larger end terns than a concentrated
winding configuration. Incorporating a motor including a stator with coils in a
distributed winding configuration results in an increase in the amount of copper used.
20 This may lead to an increase in material cost and a reduction in efficiency that is due
to an increase in copper loss. To reduce the size of coil end turns, a wave winding
manner or a lap winding manner can be used as a distributed winding manner. Coils
are wound around teeth of a stator core in a wave winding manner or a lap winding
manner, so that two coils of the same phase are received in the same slot of the
25 stator core. The coils of different phases received in the slots are located in a
distributed manner, thus reducing overlaps between the coils. This results in a
reduction in size of coil end turns. Thus, a more compact and more highly efficient
stator can be obtained. For example, Patent Literature 1 describes a lap winding
configuration.
30
3
Citation List
Patent Literature
[0004]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
5 2015-35837
Summary of Invention
Technical Problem
[0005]
To cause a stator to have a lap winding configuration, a winding unit including
10 spirally wound wires is inserted into slots of a stator core. At this time, coils need to
be regularly arranged such that one of two coils received in the same slot is located at
an outer circumference of a stator and the other one of the two coils is located at an
inner circumference of the stator. It is therefore necessary to properly correct the
positions of the coils when the coils are attached to a coil insertion jig. The positions
15 need to be corrected by a manual operation of an operator or by using a highly priced
winding device including a correction mechanism having a complicated structure.
[0006]
Instead of coils in a lap winding configuration, concentrically wound coils can
be used such that two coil groups are received in the same slot, one of coils in the
20 same slot is located at the outer circumference of a stator, and the other one of the
coils is located at the inner circumference of the stator. In this case, the coil located
at the outer circumference of the stator and the coil located at the inner circumference
of the stator have different inductance values. If these coils are connected in parallel
to constitute the coil groups, values of currents flowing through the coil groups may
25 be unbalanced. This results in a reduction in motor efficiency due to an increase in
copper loss. The two coil groups can be circumferentially uniformly arranged in the
slots. In this case, the slots need to have a circumferentially increased width. This
leads to an increase in size of the stator, causing an increase in overall size of a
motor. If the motor is designed to have a size suitable for incorporation into a
30 compressor, the teeth of the stator may fail to have a sufficient width.
4
[0007]
In response to the above issue, the present disclosure aims to provide a
compact, easy-to-manufacture, and electrically efficient stator for a motor and a
compressor including the stator for a motor.
5 Solution to Problem
[0008]
A stator for a motor according to an embodiment of the present disclosure
includes a stator core including a core back having an annular shape and a plurality
of teeth extending inwardly from the core back, the plurality of teeth being
10 circumferentially spaced apart from each other and defining a plurality of slots such
that each of the plurality of slots is defined by ones of the plurality of teeth that are
adjacent to each other, and windings of a plurality of different phases wound around
the plurality of teeth. The windings each include a first coil group and a second coil
group, the first coil group is located at an outer circumference of the stator, and the
15 second coil group is located at an inner circumference of the stator. The first coil
group and the second coil group each include a plurality of coils wound concentrically.
The plurality of coils are connected in series. The plurality of teeth each have an
axis extending along a radius of the stator, and the axis is spanned by the windings of
all of the plurality of different phases.
20 Advantageous Effects of Invention
[0009]
According to an embodiment of the present disclosure, the first coil group is
located at the outer circumference of the stator, and the second coil group is located
at the inner circumference of the stator. Such a configuration of the stator for a
25 motor ensures that the teeth each have a sufficient width, and avoids an increase in
size of the stator. In addition, the series connection of the coils of the first and
second coil groups reduces or eliminates an imbalance between values of currents
flowing through the coil groups. This reduces or eliminates a reduction in motor
efficiency due to electrical characteristics. Since the plurality of coils of the first and
30 second coil groups are wound concentrically, the plurality of coils are readily attached
5
to the stator core. The axis, which extends along the radius of the stator, of each of
the teeth is spanned by the windings of all of the plurality of different phases. The
windings are arranged uniformly. Such an arrangement reduces or eliminates a local
increase in size of coil end turns, resulting in a reduction in the amount of copper
5 used. This leads to a reduction in manufacturing cost of the stator and an increase
in motor efficiency.
Brief Description of Drawings
[0010]
[Fig. 1] Fig. 1 is a schematic sectional view of a hermetic compressor including
10 a motor stator according to Embodiment 1 of the present disclosure.
[Fig. 2] Fig. 2 is a plan view of the motor stator according to Embodiment 1 of
the present disclosure.
[Fig. 3] Fig. 3 is a plan view of the configuration of a winding of the motor stator
according to Embodiment 1 of the present disclosure.
15 [Fig. 4] Fig. 4 is a diagram illustrating a first winding to be inserted into the
motor stator according to Embodiment 1 of the present disclosure.
[Fig. 5] Fig. 5 is a diagram illustrating a second winding to be inserted into the
motor stator according to Embodiment 1 of the present disclosure.
[Fig. 6] Fig. 6 is a plan view of an arrangement of the first winding and the
20 second winding in the stator in Embodiment 1 of the present disclosure.
[Fig. 7] Fig. 7 is a diagram illustrating an ideal arrangement of a lap winding in
a stator of a rotary electric machine.
[Fig. 8] Fig. 8 is a diagram illustrating an arrangement of the lap winding in the
stator of the rotary electric machine before position correction.
25 [Fig. 9] Fig. 9 is a plan view of an arrangement of coils of different phases in the
motor stator according to Embodiment 1 of the present disclosure.
[Fig. 10] Fig. 10 is an electrical circuit diagram of the motor stator according to
Embodiment 1 of the present disclosure.
[Fig. 11] Fig. 11 is a plan view of an arrangement of a winding of a motor stator
30 according to Embodiment 2 of the present disclosure.
6
[Fig. 12] Fig. 12 is a diagram illustrating coils of a coil group to be inserted into
a motor stator according to Embodiment 3 of the present disclosure.
[Fig. 13] Fig. 13 is a plan view of an arrangement of a first coil group and a
second coil group in the stator in Embodiment 3 of the present disclosure.
5 [Fig. 14] Fig. 14 is a plan view of an arrangement of a winding in a motor stator
according to Embodiment 5 of the present disclosure.
[Fig. 15] Fig. 15 is a plan view of an arrangement of a winding in the motor
stator according to Embodiment 5 of the present disclosure.
Description of Embodiments
10 [0011]
A motor stator according to one or more embodiments of the present disclosure
will be described below with reference to the drawings. The present disclosure is not
limited to the following embodiments, and can be variously modified without departing
from the spirit and scope of the present disclosure. The present disclosure
15 encompasses all possible combinations of components in the following embodiments.
A motor stator illustrated in the drawings is an example for a device to which a motor
stator according to an embodiment of the present disclosure is applied, and is not
intended to limit a device to which the present disclosure is applicable. For the sake
of understanding, terms representing directions (e.g., "upper", "lower", "right", "left",
20 "front", and "rear") will be used as appropriate. These terms are used herein only for
the purpose of convenience of description, and are not intended to restrict the present
disclosure. Note that components designated by the same reference signs in the
figures are the same components or equivalents. This note applies to the entire
description herein. The relationship between the relative dimensions, the forms, and
25 other conditions of components in the figures may differ from those of actual ones.
[0012]
Embodiment 1.
Fig. 1 is a schematic sectional view of a hermetic compressor including a motor
stator according to Embodiment 1 of the present disclosure. A hermetic compressor
30 1 includes a hermetic container 2, a compression mechanism 3 held in an upper part
7
of the hermetic container 2, and a rotary electric machine 4 held in a lower part of the
hermetic container 2. The compression mechanism 3 includes a fixed scroll 31, an
orbiting scroll 32, a guide frame 33, a compliant frame 34, and an Oldham ring 35.
The rotary electric machine 4 includes a rotor 40 and a stator 50. The stator 50 is
5 fixed to the hermetic container 2 by, for example, shrink fitting. The stator 50 is
connected to a terminal 13 mounted in the hermetic container 2 by a stator power
supply line 12. The compression mechanism 3 and the rotary electric machine 4 are
coupled to each other by a rotary shaft 10 supported by the guide frame 33 and a
sub-frame 11. The rotary electric machine 4 includes a motor that generates power,
10 which is transmitted to the compression mechanism 3. The hermetic container 2
encloses refrigerating machine oil 21 for lubricating sliding parts of the hermetic
compressor 1.
[0013]
The fixed scroll 31 in the compression mechanism 3 is fixed to the guide frame
15 33 by bolts (not illustrated). The guide frame 33 is fixed to the hermetic container 2
by welding. The orbiting scroll 32 is supported by the compliant frame 34. The
compliant frame 34 is supported by the guide frame 33. The Oldham ring 35
includes a pawl (not illustrated). The pawl is fitted in a groove (not illustrated) in the
guide frame 33 and a groove (not illustrated) in the orbiting scroll 32, thus restricting
20 rotational motion of the orbiting scroll 32 relative to the fixed scroll 31.
[0014]
The fixed scroll 31 has, at its central part, a discharge port 36 through which
refrigerant is discharged out of the compression mechanism 3. The fixed scroll 31
has, at its outer side, a suction port 37 through which the refrigerant is sucked into the
25 compression mechanism 3. The hermetic container 2 has, at its side, a discharge
pipe 22 through which high-pressure refrigerant discharged in the hermetic container
2 flows to a refrigeration circuit.
[0015]
As described above, the hermetic compressor 1 in Embodiment 1 is a scroll
30 compressor of a high-pressure shell type. In the compression mechanism 3, the
8
fixed scroll 31 is combined in face-to-face relationship with the orbiting scroll 32.
The fixed scroll 31 includes an involute spiral wall extending from an end plate. The
orbiting scroll 32 includes a wall having a shape obtained by rotating the shape of the
wall of the fixed scroll 31 by 180 degrees. The orbiting scroll 32 performs orbital
5 motion in response to power obtained from the electric machine via the rotary shaft
10, which is eccentric. The pawl of the Oldham ring 35 performs translational motion
along the grooves arranged at right angles to each other in the guide frame 33 and
the orbiting scroll 32, thus restricting rotational motion of the orbiting scroll 32 relative
to the fixed scroll 31.
10 [0016]
The walls of the fixed scroll 31 and the orbiting scroll 32, which are combined in
face-to-face relationship with each other, are in contact with each other such that
outer parts of the spiral walls define a compression chamber, which is moved inward
to the center of a spiral form defined by the walls and in which refrigerant sucked
15 through the suction port 37 is compressed by the orbital motion of the orbiting scroll
32 and is then discharged to the hermetic container 2 through the discharge port 36
located at the center of the compression mechanism 3. The high-pressure
refrigerant discharged in the hermetic container 2 flows to the refrigeration circuit
through the discharge pipe.
20 [0017]
Fig. 2 is a plan view of the motor stator according to Embodiment 1 of the
present disclosure. Fig. 2 illustrates a conceptual configuration of the stator 50.
The stator 50 includes a stator core 51 and windings 52. The stator core 51 is, for
example, a lamination of magnetic steel sheets. The stator core 51 includes a core
25 back 51A having a ring shape and a plurality of teeth 51B extending radially from the
core back 51A toward the center of the stator core 51. The plurality of teeth 51B are
arranged at a predetermined pitch in a circumferential direction of the stator core 51.
The plurality of teeth 51B define a plurality of slots 51C such that each of the plurality
of slots 51C is defined by ones of the plurality of teeth 51B that are adjacent to each
9
other. The stator core 51 has the plurality of slots 51C. In Embodiment 1, the
stator core 51 has 18 teeth 51B and therefore has 18 slots 51C.
[0018]
The windings 52 include an A-phase winding 53, a B-phase winding 54, and a
5 C-phase winding 55. The windings of a plurality of different phases are wound
around the teeth 51B. In Fig. 2, the A-phase winding 53, the B-phase winding 54,
and the C-phase winding 55 are illustrated with different hatching patterns. As
illustrated in Fig. 2, the A-phase winding 53, the B-phase winding 54, and the Cphase winding 55 each include six elements in the stator 50. The stator 50 has six
10 poles.
[0019]
In other words, the stator 50 satisfies S = 3P where P denotes the number of
poles and S denotes the number of slots.
[0020]
15 Fig. 3 is a plan view of the configuration of a winding of the motor stator
according to Embodiment 1 of the present disclosure. Only the A-phase winding 53
is illustrated in Fig. 3 to avoid complicating the figure. The A-phase winding 53 is a
concentric winding and includes an A-phase first coil group 53A and an A-phase
second coil group 53B. The A-phase first coil group 53A includes an A-phase first
20 coil 531, an A-phase second coil 532, and an A-phase third coil 533. The A-phase
second coil group 53B includes an A-phase fourth coil 534, an A-phase fifth coil 535,
and an A-phase sixth coil 536. In other words, the A-phase first coil group 53A and
the A-phase second coil group 53B each include multiple coils. As will be described
later, the A-phase first coil group 53A is located at an outer circumference of the stator
25 50, whereas the A-phase second coil group 53B is located at an inner circumference
of the stator 50. In other words, the A-phase first coil group 53A is located closer to
the core back 51A than is the A-phase second coil group 53B, whereas the A-phase
second coil group 53B is located closer to the center of the stator 50 than is the Aphase first coil group 53A.
30 [0021]
10
Hereinafter, the A-phase first coil 531, the A-phase second coil 532, and the Aphase third coil 533 may be collectively referred to as coils of the A-phase first coil
group 53A. Similarly, the A-phase fourth coil 534, the A-phase fifth coil 535, and the
A-phase sixth coil 536 may be collectively referred to as coils of the A-phase second
5 coil group 53B.
[0022]
The A-phase first coil 531, the A-phase second coil 532, and the A-phase third
coil 533 of the A-phase first coil group 53A are received in the slots 51C at an equal
slot pitch and are arranged counterclockwise from an A-phase lead-wire extraction
10 position 5 in plan view of the stator 50. In the example of Fig. 3, the A-phase first
coil 531, the A-phase second coil 532, and the A-phase third coil 533 are arranged at
a 4-slot pitch.
[0023]
The A-phase fourth coil 534, the A-phase fifth coil 535, and the A-phase sixth
15 coil 536 of the A-phase second coil group 53B are received in the slots 51C at an
equal pitch and are arranged clockwise from the lead-wire extraction position 5 in
plan view of the stator 50. In the example of Fig. 3, the A-phase fourth coil 534, the
A-phase fifth coil 535, and the A-phase sixth coil 536 are arranged at a 4-slot pitch.
[0024]
20 In other words, in plan view of the stator 50, the coils of the A-phase first coil
group 53A and the coils of the A-phase second coil group 53B are arranged in
opposite directions along the circumference of the stator 50.
[0025]
In the same slot 51C, the coil of the A-phase first coil group 53A is located at
25 the outer circumference, and the coil of the A-phase second coil group 53B is located
at the inner circumference.
[0026]
In Fig. 3, the coils of the A-phase first coil group 53A located at the outer
circumference are arranged counterclockwise in plan view of the stator 50, and the
30 coils of the A-phase second coil group 53B located at the inner circumference are
11
arranged clockwise in plan view of the stator 50. The arrangement of the coils is not
limited to this example. In plan view of the stator 50, the coils of the A-phase first
coil group 53A located at the outer circumference may be arranged counterclockwise,
and the coils of the A-phase second coil group 53B located at the inner circumference
5 may be arranged clockwise. In other words, the coils of the A-phase first coil group
53A located at the outer circumference and the coils of the A-phase second coil group
53B located at the inner circumference may simply be arranged in opposite directions
along the circumference of the stator 50 in plan view of the stator 50.
[0027]
10 As will be described later, the B-phase winding 54 and the C-phase winding 55
also have the same configuration as that of the A-phase winding 53.
[0028]
Fig. 4 is a diagram illustrating a first winding to be inserted into the motor stator
according to Embodiment 1 of the present disclosure. Fig. 5 is a diagram illustrating
15 a second winding to be inserted into the motor stator according to Embodiment 1 of
the present disclosure. Fig. 6 is a plan view of an arrangement of the first winding
and the second winding in the stator in Embodiment 1 of the present disclosure. The
arrangement of coils in Embodiment 1 will be described below with reference to Figs.
4 to 6.
20 [0029]
Fig. 4 illustrates a winding-start lead wire 102 of a first winding 101 and a
winding-end lead wire 103 of the first winding 101. The first winding 101 includes a
first-winding first coil 101A, a first-winding second coil 101B, and a first-winding third
coil 101C. The first-winding first coil 101A, the first-winding second coil 101B, and
25 the first-winding third coil 101C are wound uniformly in a winding direction
represented by outlined arrows A in Fig. 4. The first-winding first coil 101A, the firstwinding second coil 101B, and the first-winding third coil 101C are wound
concentrically. The first-winding first coil 101A, the first-winding second coil 101B,
and the first-winding third coil 101C have the same number of turns. Hereinafter, the
30 first-winding first coil 101A located closest to the winding-start lead wire 102 may be
12
referred to as a start coil, and the first-winding third coil 101C located closest to the
winding-end lead wire 103 may be referred to as an end coil.
[0030]
Fig. 5 illustrates a winding-start lead wire 112 of a second winding 111 and a
5 winding-end lead wire 113 of the second winding 111. The second winding 111
includes a second-winding first coil 111A, a second-winding second coil 111B, and a
second-winding third coil 111C. The second-winding first coil 111A, the secondwinding second coil 111B, and the second-winding third coil 111C are wound
uniformly in a winding direction represented by outlined arrows B in Fig. 5. The
10 second-winding first coil 111A, the second-winding second coil 111B, and the secondwinding third coil 111C are wound concentrically. The second-winding first coil 111A,
the second-winding second coil 111B, and the second-winding third coil 111C have
the same number of turns. Hereinafter, the second-winding first coil 111A located
closest to the winding-start lead wire 112 may be referred to as a start coil, and the
15 second-winding third coil 111C located closest to the winding-end lead wire 113 may
be referred to as an end coil.
[0031]
Furthermore, the first-winding first coil 101A, the first-winding second coil 101B,
the first-winding third coil 101C, the second-winding first coil 111A, the second20 winding second coil 111B, and the second-winding third coil 111C have the same
number of turns.
[0032]
The outlined arrows A in Fig. 4 and the outlined arrows B in Fig. 5 point in
opposite directions. In other words, the winding direction of the first winding 101 is
25 opposite to that of the second winding 111.
[0033]
The first winding 101 wound as illustrated in Fig. 4 and the second winding 111
wound as illustrated in Fig. 5 are arranged in the stator core 51, as illustrated in Fig.
6. The coils of the first winding 101 and the coils of the second winding 111 are
30 alternately arranged in the circumferential direction of the stator core 51. For
13
example, the first-winding first coil 101A of the first winding 101 is located between
the second-winding first coil 111A and the second-winding third coil 111C of the
second winding 111 in the circumferential direction of the stator core 51.
[0034]
5 In the example of Fig. 6, the first-winding first coil 101A, the first-winding
second coil 101B, and the first-winding third coil 101C of the first winding 101 are
received in the slots 51C at an equal slot pitch. In Embodiment 1, the first-winding
first coil 101A, the first-winding second coil 101B, and the first-winding third coil 101C
are received in the slots 51C at a 4-slot pitch.
10 [0035]
The first winding 101 is located at the outer circumference of the stator core 51,
whereas the second winding 111 is located at the inner circumference of the stator
core 51.
[0036]
15 In attaching the first winding 101 wound as illustrated in Fig. 4 to a coil insertion
jig, the first winding 101, from the start coil to the end coil, is first attached to the
stator core 51 at an equal pitch of four slots. The second winding 111 wound as
illustrated in Fig. 5, from the start coil to the end coil, is then attached to the stator
core 51 at an equal pitch of four slots. The second winding 111 is located closer to
20 the inner circumference of the stator core 51 than is the first winding 101. Thus, the
coils of the first winding 101 constitute the A-phase first coil group 53A in Fig. 3, and
the coils of the second winding 111 constitute the A-phase second coil group 53B in
Fig. 3.
[0037]
25 To attach a wave winding to a stator core, a ring-shaped coil is first formed, and
an external force is then applied radially inwardly to the ring-shaped coil, thus forming
a star-shaped coil having protrusions and depressions circumferentially alternated
with each other. The star-shaped coil is attached to the stator core. In contrast,
Embodiment 1 eliminates the need for a step of shaping a ring-shaped coil into a star30 shaped coil. In addition, it is unnecessary to apply an external force to a coil. This
14
reduces or eliminates damage to a coil. In other words, Embodiment 1 offers
advantages including lower processing cost, which is achieved by simplifying the
steps of processing coils, and higher winding reliability than those of a wave winding
attached to a stator core.
5 [0038]
Fig. 7 is a diagram illustrating an ideal arrangement of a lap winding in a stator
of a rotary electric machine. Fig. 8 is a diagram illustrating an arrangement of the
lap winding in the stator of the rotary electric machine before position correction. In
attaching a lap winding to a stator core, the winding is inserted into slots of the stator
10 core, and after that, coils need to be arranged as illustrated in Fig. 7. For the coils in
a lap winding configuration of Fig. 7, a first coil 60A is a start coil, and a sixth coil 60F
is an end coil. A second coil 60B, a third coil 60C, a fourth coil 60D, and a fifth coil
60E are arranged in that order between the first coil 60A and the sixth coil 60F.
[0039]
15 In the winding arrangement of Fig. 7, the first to sixth coils 60A, 60B, 60C, 60D,
60E, and 60F are arranged such that the slots receiving two coils are located at an
equal pitch in the circumferential direction of the stator core. Each coil is disposed
such that the coil is located closer to the outer circumference than another coil in one
of the two slots receiving the coil and is located closer to the inner circumference than
20 another coil in the other slot.
[0040]
In a case where the coils sequentially attached from the first coil 60A to a coil
insertion jig and arranged in a lap winding configuration are inserted into the stator
core without being changed, the coils are arranged as illustrated in Fig. 8. In other
25 words, the positional relationship between the first coil 60A and the second coil 60B,
that between the second coil 60B and the third coil 60C, that between the third coil
60C and the fourth coil 60D, that between the fourth coil 60D and the fifth coil 60E,
and that between the fifth coil 60E and the sixth coil 60F are the same as those in the
arrangement of Fig. 7. However, the positional relationship between the first coil
30 60A, which is the start coil, and the sixth coil 60F, which is the end coil, differs from
15
that in Fig. 7. Specifically, the first coil 60A is located at the outer circumference in
both a slot receiving the first coil 60A and the second coil 60B and a slot receiving the
first coil 60A and the sixth coil 60F. Therefore, an operator needs to manually
correct the positional relationship between the first coil 60A and the sixth coil 60F
5 such that the first coil 60A is located at the inner circumference and the sixth coil 60F
is located at the outer circumference, as illustrated in Fig. 7. This results in an
increase in processing cost caused by necessary position correction.
[0041]
In contrast to the case where the coils arranged in a lap winding configuration
10 illustrated in Figs. 7 and 8 are attached to the stator core, Embodiment 1 eliminates
the need for an operator to manually correct the positions. Therefore, Embodiment 1
reduces or eliminates an increase in processing cost.
[0042]
Fig. 9 is a plan view of an arrangement of coils of different phases in the motor
15 stator according to Embodiment 1 of the present disclosure. Fig. 10 is an electrical
circuit diagram of the motor stator according to Embodiment 1 of the present
disclosure. The B-phase winding 54 and the C-phase winding 55 have the same
configuration as that of the above-described A-phase winding 53.
[0043]
20 The B-phase winding 54 is a concentric winding and includes a B-phase first
coil group 54A and a B-phase second coil group 54B. The B-phase first coil group
54A includes a B-phase first coil 541, a B-phase second coil 542, and a B-phase third
coil 543. The B-phase second coil group 54B includes a B-phase fourth coil 544, a
B-phase fifth coil 545, and a B-phase sixth coil 546. The B-phase first coil group 54A
25 is located at the outer circumference of the stator 50, whereas the B-phase second
coil group 54B is located at the inner circumference of the stator 50. In other words,
the B-phase first coil group 54A is located closer to the core back 51A than is the Bphase second coil group 54B, whereas the B-phase second coil group 54B is located
closer to the center of the stator 50 than is the B-phase first coil group 54A.
30 [0044]
16
The B-phase first coil 541, the B-phase second coil 542, and the B-phase third
coil 543 of the B-phase first coil group 54A are received in the slots 51C at an equal
slot pitch and are arranged counterclockwise from the winding start position in plan
view of the stator 50. In the example of Fig. 9, the B-phase first coil 541, the B5 phase second coil 542, and the B-phase third coil 543 are arranged at a 4-slot pitch.
[0045]
The B-phase fourth coil 544, the B-phase fifth coil 545, and the B-phase sixth
coil 546 of the B-phase second coil group 54B are received in the slots 51C at an
equal pitch and are arranged clockwise in plan view of the stator 50. In the example
10 of Fig. 9, the B-phase fourth coil 544, the B-phase fifth coil 545, and the B-phase sixth
coil 546 are arranged at a 4-slot pitch.
[0046]
In other words, in plan view of the stator 50, the coils of the B-phase first coil
group 54A and the coils of the B-phase second coil group 54B are arranged in
15 opposite directions along the circumference of the stator 50.
[0047]
In the same slot 51C, the coil of the B-phase first coil group 54A is located at
the outer circumference, and the coil of the B-phase second coil group 54B is located
at the inner circumference.
20 [0048]
The C-phase winding 55 is a concentric winding and includes a C-phase first
coil group 55A and a C-phase second coil group 55B. The C-phase first coil group
55A includes a C-phase first coil 551, a C-phase second coil 552, and a C-phase third
coil 553. The C-phase second coil group 55B includes a C-phase fourth coil 554, a
25 C-phase fifth coil 555, and a C-phase sixth coil 556. The C-phase first coil group
55A is located at the outer circumference of the stator 50, whereas the C-phase
second coil group 55B is located at the inner circumference of the stator 50. In other
words, the C-phase first coil group 55A is located closer to the core back 51A than is
the C-phase second coil group 55B, whereas the C-phase second coil group 55B is
30 located closer to the center of the stator 50 than is the C-phase first coil group 55A.
17
[0049]
The C-phase first coil 551, the C-phase second coil 552, and the C-phase third
coil 553 of the C-phase first coil group 55A are received in the slots 51C at an equal
slot pitch and are arranged counterclockwise from the winding start position in plan
5 view of the stator 50. In the example of Fig. 9, the C-phase first coil 551, the Cphase second coil 552, and the C-phase third coil 553 are arranged at a 4-slot pitch.
[0050]
The C-phase fourth coil 554, the C-phase fifth coil 555, and the C-phase sixth
coil 556 of the C-phase second coil group 55B are received in the slots 51C at an
10 equal pitch and are arranged clockwise in plan view of the stator 50. In the example
of Fig. 9, the C-phase fourth coil 554, the C-phase fifth coil 555, and the C-phase
sixth coil 556 are arranged at a 4-slot pitch.
[0051]
In other words, in plan view of the stator 50, the coils of the C-phase first coil
15 group 55A and the coils of the C-phase second coil group 55B are arranged in
opposite directions along the circumference of the stator 50.
[0052]
In the same slot 51C, the coil of the C-phase first coil group 55A is located at
the outer circumference, and the coil of the C-phase second coil group 55B is located
20 at the inner circumference.
[0053]
As illustrated in Fig. 9, each of the teeth 51B has the coils of all of the phases
of the stator 50. Specifically, each of the plurality of teeth 51B has an axis 56
extending along the radius of the stator 50, and the axis 56 is spanned by the coils of
25 the A-phase winding 53, the B-phase winding 54, and the C-phase winding 55, which
form coil end turns. The axis 56 of only the tooth 51B spanned by the A-phase sixth
coil 536 of the A-phase second coil group 53B, the B-phase second coil 542 of the Bphase first coil group 54A, and the C-phase second coil 552 of the C-phase first coil
group 55A, which form coil end turns, is illustrated in Fig. 9 to avoid complicating the
18
figure. The other teeth 51B also have the same relationship between the axis 56
and the coil end turns.
[0054]
The A-phase first coil group 53A and the A-phase second coil group 53B are
5 connected in series in a wire-connecting step. Specifically, an A-phase first-coilgroup winding end 132 and an A-phase second-coil-group winding start 133 are
connected in series. An A-phase first-coil-group winding start 131 serves as a
power-supply lead wire. An A-phase second-coil-group winding end 134 serves as a
neutral-point lead wire.
10 [0055]
The B-phase first coil group 54A and the B-phase second coil group 54B are
connected in series in the wire-connecting step. Specifically, a B-phase first-coilgroup winding end 142 and a B-phase second-coil-group winding start 143 are
connected in series. A B-phase first-coil-group winding start 141 serves as a power15 supply lead wire. A B-phase second-coil-group winding end 144 serves as a neutralpoint lead wire.
[0056]
The C-phase first coil group 55A and the C-phase second coil group 55B are
connected in series in the wire-connecting step. Specifically, a C-phase first-coil20 group winding end 152 and a C-phase second-coil-group winding start 153 are
connected in series. A C-phase first-coil-group winding start 151 serves as a powersupply lead wire. A C-phase second-coil-group winding end 154 serves as a neutralpoint lead wire.
[0057]
25 The A-phase first-coil-group winding start 131, which is the power-supply lead
wire of the A-phase winding 53, the B-phase first-coil-group winding start 141, which
is the power-supply lead wire of the B-phase winding 54, and the C-phase first-coilgroup winding start 151, which is the power-supply lead wire of the C-phase winding
55, are each extracted and placed at the outer circumference of the stator 50. This
30 results in a shorter distance between the terminal 13 and each of the A-phase winding
19
53, the B-phase winding 54, and the C-phase winding 55, which are to be connected
to the terminal 13 mounted in the hermetic container 2 by the stator power supply line
12 in Fig. 1. This leads to a reduction in manufacturing cost of the hermetic
compressor 1. In addition, this avoids loosening of the stator power supply line 12
5 caused by a long length of the stator power supply line 12. This reduces or
eliminates contact of the stator power supply line 12 with, for example, the hermetic
container 2.
[0058]
In Embodiment 1, the windings of all of the phases, which are the A phase, the
10 B phase, and the C phase, received in the slots 51C each include two separate,
connected coil groups, which are the first coil group located at the outer
circumference and the second coil group located at the inner circumference. As
described above, each of the teeth 51B has the coils of all of the phases of the stator
50. Therefore, the windings are uniformly arranged, thus reducing or eliminating a
15 local increase in size of the coil end turns. This results in a reduction in the amount
of copper used, leading to a reduction in manufacturing cost of the stator and an
increase in motor efficiency.
[0059]
The wire connection in Fig. 10 is an exemplary wire connection of the stator 50
20 according to Embodiment 1. The wire connection is not limited to the example of
Fig. 10. The stator 50 may have any wire connection that provides an electrical
circuit equivalent to that of Fig. 10.
[0060]
In Embodiment 1, the hermetic compressor 1, which is a scroll compressor, has
25 been described as an example. The hermetic compressor 1 in Embodiment 1 is not
limited to such a scroll compressor. Embodiment 1 is applicable to a motor of any
other type of compressor, such as a rotary compressor.
[0061]
Embodiment 2.
20
Fig. 11 is a plan view of an arrangement of a winding of a motor stator
according to Embodiment 2 of the present disclosure. Only an A-phase winding 70
of a stator 250 is illustrated in Fig. 11 to avoid complicating the figure. In Fig. 11, the
same components as those in Fig. 3 are designated by the same reference signs.
5 The A-phase winding 70 includes an A-phase first coil group 70A and an A-phase
second coil group 70B. The A-phase first coil group 70A is located at an outer
circumference of the stator 50, whereas the A-phase second coil group 70B is located
at an inner circumference of the stator 50. The A-phase first coil group 70A has a
winding start 71 and a winding end 72. The A-phase second coil group 70B has a
10 winding start 73 and a winding end 74.
[0062]
The A-phase first coil group 70A includes an A-phase first coil 711, an A-phase
second coil 712, and an A-phase third coil 713. The A-phase second coil group 70B
includes an A-phase fourth coil 714, an A-phase fifth coil 715, and an A-phase sixth
15 coil 716.
[0063]
In Embodiment 2, the wound form of each of the coils of the A-phase first coil
group 70A and the A-phase second coil group 70B to be inserted into the stator 50 is
the same as that illustrated in Fig. 4. Specifically, the winding direction of the A20 phase first coil group 50A is opposite to the winding direction of the A-phase second
coil group 50B in Embodiment 1 described above, whereas the A-phase first coil
group 70A is equal in winding direction to the A-phase second coil group 70B in
Embodiment 2.
[0064]
25 In Embodiment 2, the winding end 72 of the A-phase first coil group 70A is
connected in series with the winding end 74 of the A-phase second coil group 70B.
The winding start 71 of the A-phase first coil group 70A serves as a power-supply
lead wire. The winding start 73 of the A-phase second coil group 70B serves as a
neutral-point lead wire. A B-phase winding and a C-phase winding are arranged in
21
the same manner as that in Fig. 11. Such a configuration allows the stator 50 to
have windings equivalent to those in Embodiment 1.
[0065]
In Embodiment 2, the coils are wound in one direction, the coils of the A-phase
5 first coil group 70A are arranged counterclockwise, and the coils of the A-phase
second coil group 70B are arranged counterclockwise in the stator 50. This
arrangement allows simplification of a winding step, resulting in improved cycle time.
The coils wound in one direction eliminates a confusion of a winding for the A-phase
first coil group 70A with a winding for the A-phase second coil group 70B.
10 [0066]
The wound form of each of the coils of the A-phase first coil group 70A and the
A-phase second coil group 70B to be inserted into the stator 50 may be the same as
that in Fig. 5.
[0067]
15 The winding in Fig. 11 has an exemplary wire connection for the stator 50
according to Embodiment 2. The wire connection is not limited to the example of
Fig. 11. The stator may have any wire connection that provides an electrical circuit
equivalent to that in Fig. 11.
[0068]
20 Fig. 12 is a diagram illustrating coils of a coil group to be inserted into a motor
stator according to Embodiment 3 of the present disclosure. Fig. 13 is a plan view of
an arrangement of a winding in the motor stator according to Embodiment 3 of the
present disclosure. Only a winding of one phase is illustrated in Fig. 13 to avoid
complicating the figure. Fig. 12 illustrates a winding-start lead wire 81 of a coil and a
25 winding-end lead wire 82 of a coil. A coil group 80 includes a first coil 80A, a second
coil 80B, a third coil 80C, a fourth coil 80D, a fifth coil 80E, and a sixth coil 80F. The
first coil 80A is continuous with the second coil 80B, the second coil 80B is continuous
with the third coil 80C, the third coil 80C is continuous with the fourth coil 80D, the
fourth coil 80D is continuous with the fifth coil 80E, and the fifth coil 80E is continuous
22
with the sixth coil 80F. The first coil 80A, the second coil 80B, the third coil 80C, the
fourth coil 80D, the fifth coil 80E, and the sixth coil 80F are wound concentrically.
[0069]
The coils in Fig. 12 are arranged in a stator 350, as illustrated in Fig. 13. The
5 first coil 80A, the second coil 80B, and the third coil 80C are arranged at an outer
circumference of the stator 350, and constitute a first coil group. The fourth coil 80D,
the fifth coil 80E, and the sixth coil 80F are arranged at an inner circumference of the
stator 350, and constitute a second coil group. The first coil 80A, the second coil
80B, and the third coil 80C are arranged counterclockwise in plan view of the stator
10 350. Similarly, the fourth coil 80D, the fifth coil 80E, and the sixth coil 80F are
arranged counterclockwise in plan view of stator 50.
[0070]
In Embodiment 3, an A-phase winding, a B-phase winding, and a C-phase
winding each including a winding of Fig. 12 are arranged in the stator 350, as
15 illustrated in Fig. 13.
[0071]
In Embodiments 1 and 2 described above, two separate coil groups are
connected in series in the wire-connecting step. In contrast, in Embodiment 3, coils
constituting two coil groups are formed in the winding step. Therefore, the wire20 connecting step can be simplified, thus improving the cycle time and reducing or
eliminating misconnection of wires.
[0072]
In each of the A-phase winding, the B-phase winding, and the C-phase
winding, the winding-start lead wire 81 serves as a power-supply lead wire, and the
25 winding-end lead wire 82 serves as a neutral-point lead wire. Therefore, power
supply extraction from the slots 51C of the stator 50 can be limited to two positions.
This allows the power-supply lead wire and the neutral-point lead wire in the stator 50
to be more easily identified before the wire-connecting step.
[0073]
30 Embodiment 4.
23
In Embodiments 1 to 3 described above, the coils of the first coil group
arranged at the outer circumference of the stator 50 and the coils of the second coil
group arranged at the inner circumference of the stator 50 have the same number of
turns. In contrast, in Embodiment 4, the first coil group is different from the second
5 coil group in number of turns of the coils in the stator 50. In this case, each of the
plurality of slots 51C of the stator 50 receives the same number of wires. For
example, the number of turns of each coil of the first coil group is n (n is a natural
number), and the number of turns of each coil of the second coil group is n+1. Each
of the slots 51C receives 2n+1 wires. The rest of the configuration is the same as
10 those in Embodiments 1 to 3. The coils are connected in series.
[0074]
For the stator core 51 around which the coils of the first coil group and the coils
of the second coil group are wound the same number n of turns, the sum of the turns
of the six coils connected in series is 6n. In this case, a concrete value of the sum
15 of the turns is, for example, 6, 12, or 18. In the case where the number of turns of
each coil of the first coil group is n and the number of turns of each coil of the second
coil group is n+1, the sum of the turns of the six coils connected in series is 6n+3. In
this case, a concrete value of the sum of the turns is, for example, 9, 15, or 21. In
other words, unlike the case where the coils of the first coil group have the same
20 number of turns as that of the coils of the second coil group, the selection of the
number of turns of the coils is not limited in Embodiment 4. This leads to increased
flexibility in design of the number of turns of coils for the stator 50, thus allowing the
stator 50 to have more desirably designed windings.
[0075]
25 In Embodiment 4, the first coil group and the second coil group are connected
in series, as in Embodiments 1 to 3. The coils of the same phase are connected in
series, and each of the slots 50C of the stator 50 receives the same number of wires.
This results in no difference in magnetomotive force between the first coil group and
the second coil group, which differ in the number of turns of each coil from each other.
30 Thus, the stator 50 can be configured without any electrical problem.
24
[0076]
The number of turns of each coil of the second coil group may be n, and the
number of turns of each coil of the first coil group may be n+1.
[0077]
5 Embodiment 5.
Fig. 14 is a plan view of an arrangement of a winding in a motor stator
according to Embodiment 5 of the present disclosure. Only the A-phase winding 53,
which is the same as that in Embodiment 1, is illustrated in Fig. 14 to avoid
complicating the figure. In Fig. 14, the same components as those in Fig. 9 are
10 designated by the same reference signs. As described above, the A-phase first-coilgroup winding end 132 is connected in series with the A-phase second-coil-group
winding start 133. The A-phase first-coil-group winding start 131 is the power-supply
lead wire. The A-phase second-coil-group winding end 134 is the neutral-point lead
wire. As illustrated in Fig. 14, the A-phase first coil group 53A and the A-phase
15 second coil group 53B are arranged in Embodiment 5 such that the A-phase first coil
531 connected to the power supply line is across the center of the stator 50 from the
A-phase sixth coil 536 connected to the neutral point. In other words, the A-phase
first coil group 53A and the A-phase second coil group 53B are arranged such that the
A-phase first coil 531 located closest to the power supply is across the center of the
20 stator 50 from the A-phase sixth coil 536 located farthest from the power supply.
[0078]
Fig. 15 is a plan view of an arrangement of a winding in the motor stator
according to Embodiment 5 of the present disclosure. Only the A-phase winding 70,
which is the same as that in Embodiment 2, is illustrated in Fig. 15 to avoid
25 complicating the figure. In Fig. 15, the same components as those in Fig. 11 are
designated by the same reference signs. As described above, the A-phase first-coilgroup winding end 72 is connected in series with the A-phase second-coil-group
winding end 74. The A-phase first-coil-group winding start 71 is the power-supply
lead wire. The A-phase second-coil-group winding start 73 is the neutral-point lead
30 wire. As illustrated in Fig. 15, the A-phase first coil group 70A and the A-phase
25
second coil group 70B are arranged in Embodiment 5 such that the A-phase first coil
711 connected to the power supply line is across the center of the stator 250 from the
A-phase fourth coil 714 connected to the neutral point. In other words, the A-phase
first coil group 70A and the A-phase second coil group 70B are arranged such that the
5 A-phase first coil 711 located closest to the power supply is across the center of the
stator 50 from the A-phase fourth coil 714 located farthest from the power supply.
[0079]
A coil located farthest from a power supply and connected to a neutral point
has the largest potential difference relative to a coil located closest to the power
10 supply. In Embodiment 5, the coil that is included in the first coil group located at the
outer circumference of the stator and that is located closest to the power supply is
across the center of the stator from the coil that is included in the second coil group
located at the inner circumference of the stator and that is located farthest from the
power supply. Such a configuration avoids insertion of coils having the largest
15 potential difference into the same slot, leading to improved reliability of the stator.
Reference Signs List
[0080]
1: hermetic compressor, 2: hermetic container, 3: compression mechanism, 4:
rotary electric machine, 5: lead-wire extraction position, 10: rotary shaft, 11: sub20 frame, 12: stator power supply line, 13: terminal, 21: refrigerating machine oil, 22:
discharge pipe, 31: fixed scroll, 32: orbiting scroll, 33: guide frame, 34: compliant
frame, 35: Oldham ring, 36: discharge port, 37: suction port, 40: rotor, 50: stator, 50A:
A-phase first coil group, 50B: A-phase second coil group, 50C: slot, 51: stator core,
51A: core back, 51B: tooth, 51C: slot, 52: winding, 53: A-phase winding, 53A: A25 phase first coil group, 53B: A-phase second coil group, 54: B-phase winding, 54A: Bphase first coil group, 54B: B-phase second coil group, 55: C-phase winding, 55A: Cphase first coil group, 55B: C-phase second coil group, 56: axis, 60F: sixth coil, 70: Aphase winding, 70A: A-phase first coil group, 70B: A-phase second coil group, 80: coil
group, 80A: first coil, 80B: second coil, 80C: third coil, 80D: fourth coil, 80E: fifth coil,
30 80F: sixth coil, 101: first winding, 101A: first-winding first coil, 101B: first-winding
26
second coil, 101C: first-winding third coil, 102: lead wire, 103: lead wire, 111: second
winding, 111A: second-winding first coil, 111B: second-winding second coil, 111C:
second-winding third coil, 112: lead wire, 113: lead wire, 250: stator, 350: stator, 531:
A-phase first coil, 532: A-phase second coil, 533: A-phase third coil, 534: A-phase
5 fourth coil, 535: A-phase fifth coil, 536: A-phase sixth coil, 541: B-phase first coil, 542:
B-phase second coil, 543: B-phase third coil, 544: B-phase fourth coil, 545: B-phase
fifth coil, 546: B-phase sixth coil, 551: C-phase first coil, 552: C-phase second coil,
553: C-phase third coil, 554: C-phase fourth coil, 555: C-phase fifth coil, 556: C-phase
sixth coil, 711: A-phase first coil, 712: A-phase second coil, 713: A-phase third coil,
10 714: A-phase fourth coil, 715: A-phase fifth coil, 716: A-phase sixth coil, n: the number
of turns

WE CLAIM:
[Claim 1]
A stator for a motor, the stator comprising:
a stator core including a core back having an annular shape and a plurality of
5 teeth extending inwardly from the core back, the plurality of teeth being
circumferentially spaced apart from each other and defining a plurality of slots such
that each of the plurality of slots is defined by ones of the plurality of teeth that are
adjacent to each other; and
windings of a plurality of different phases wound around the plurality of teeth,
10 the windings each including a first coil group and a second coil group, the first
coil group being located at an outer circumference of the stator, the second coil group
being located at an inner circumference of the stator,
the first coil group and the second coil group each including a plurality of coils
wound concentrically,
15 the plurality of coils being connected in series,
the plurality of teeth each having an axis extending along a radius of the stator,
the axis being spanned by the windings of all of the plurality of different phases.
[Claim 2]
The stator for a motor of claim 1, wherein the plurality of coils constituting the
20 first coil group are connected in series, the plurality of coils constituting the second
coil group are connected in series, and the first coil group and the second coil group
are connected in series.
[Claim 3]
The stator for a motor of claim 2, wherein the plurality of coils of the first coil
25 group and the plurality of coils of the second coil group are wound in opposite
directions.
[Claim 4]
The stator for a motor of claim 3,
wherein the first coil group has a winding end connected in series with a
30 winding start of the second coil group,
28
wherein the first coil group has a winding start serving as a power-supply lead
wire, and
wherein the second coil group has a winding end serving as a neutral-point
lead wire.
5 [Claim 5]
The stator for a motor of claim 3,
wherein the first coil group has a winding end connected in series with a
winding end of the second coil group,
wherein the first coil group has a winding start serving as a power-supply lead
10 wire, and
wherein the second coil group has a winding start serving as a neutral-point
lead wire.
[Claim 6]
The stator for a motor of claim 2, wherein the plurality of coils of the first coil
15 group and the plurality of coils of the second coil group are equal in winding direction,
and the first coil group including the plurality of coils is continuous with the second coil
group including the plurality of coils.
[Claim 7]
The stator for a motor of any one of claims 1 to 6, wherein the first coil group is
20 connected to a power supply line, and the second coil group is connected to a neutral
point.
[Claim 8]
The stator for a motor of any one of claims 1 to 7, wherein each of the plurality
of coils of the first coil group is different from each of the plurality of coils of the
25 second coil group in number of turns.
[Claim 9]
The stator for a motor of claim 1, wherein the first coil group and the second
coil group are arranged such that a coil of the plurality of coils of the first coil group
that is located closest to a power supply is across a center of the stator from a coil of
29
the plurality of coils of the second coil group that is located farthest from the power
supply.
[Claim 10]
A compressor comprising:
5 a rotary electric machine including the stator for a motor of any one of claims 1
to 9;
a compression mechanism configured to be driven by the rotary electric
machine to compress refrigerant sucked from outside; and
a hermetic container containing the rotary electric machine and the
10 compression mechanism.