STATOR

Abstract

The stator according to the present disclosure is inserted into a circular ring element and comprises: a cylindrical stator core; a coil with a coil end projecting axially outward from the end face of the stator core and provided around the stator core; and a cylindrical cover section provided to cover the coil end and projecting axially outward from the end face of the stator core. The cover section has a sealing material attachment section to which a sealing material is attached for sealing the gap between the circular ring element and the cover section. The sealing material attachment section has an annular groove that is radially recessed inward on the outer circumferential surface of the cover section, extends to the end section of the cover section on the axially outward side, and is open.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a stator for an electric motor or the like. TECHNICAL BACKGROUND

[0002] A cast stator, in which the coil ends protruding from both axial ends of a cylindrical stator core are coated with resin, is watertight and dustproof on the machine side where the cast stator is installed. A cylindrical cooling jacket may be provided within the cast stator, covering the outer circumference. If foreign matter penetrates the gap between the cooling jacket and the stator resin, the insulation performance deteriorates. If the insulation performance deteriorates, the cast stator may fail. Therefore, it is conceivable to provide a sealing material between the cooling jacket and the stator resin to seal the gap. Although the reason is different, various proposals have been made for sealing the gap between the cooling jacket and the stator resin with a sealing material. List of references Patent document

[0003] Patent document 1: Unexamined Japanese patent application (translation of the PCT application), publication number 2013-527740 DISCLOSURE OF THE INVENTION Problems to be solved by the invention

[0004] In a conventional setup, removing the sealing material requires removing the cooling jacket from the stator. Therefore, maintenance is time-consuming and labor-intensive. Consequently, a stator that improves serviceability through a simpler configuration is desirable. Means to solve the problems

[0005] One aspect of the present disclosure is a stator inserted into an annular element. The stator comprises a cylindrical stator core, a coil provided within the stator core and having a coil end projecting axially outward from an axial end face of the stator core, and a cylindrical cover provided to cover the coil end, also projecting axially outward from the axial end face of the stator core. The cover has a sealing material attachment to which a sealing material is attached for sealing a gap between the annular element and the cover. The sealing material attachment is in the form of an annular groove formed by a radially inward recess on an outer circumferential surface of the cover. The sealing material attachment extends to an end on an axially outer side of the cover and is open. Effects of the invention

[0006] From this perspective, it is possible to provide a stator that is able to improve serviceability with a simple configuration. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic longitudinal sectional view showing a state of use of a stator according to a first embodiment of the present invention; Fig. Figure 2 is a schematic longitudinal sectional view showing a state of use of a stator according to a second embodiment of the present invention, and part of the stator is shown enlarged in a state before sealing with a sealing material; Fig. Figure 3 is a schematic longitudinal sectional view showing a state of use of the stator according to the second embodiment of the present invention, and a portion of the stator is shown enlarged in a state after sealing with the sealing material; Fig. Figure 4 is a schematic longitudinal sectional view showing a state of use of a modification of the stator according to the second embodiment, and part of the stator is shown in an enlarged manner; Fig. Figure 5 is a schematic longitudinal sectional view showing a state of use of a stator according to a third embodiment of the present invention, and part of the stator is shown enlarged; Fig. Figure 6 is a schematic longitudinal sectional view showing a state of use of a first modification of the stator according to the third embodiment, and part of the stator is shown enlarged; Fig. Figure 7 is a schematic longitudinal sectional view showing a state of use of a second modification of the stator according to the third embodiment, and part of the stator is shown enlarged; Fig. Figure 8 is a schematic longitudinal sectional view showing a state of use of a stator according to a fourth embodiment of the present invention, and part of the stator is shown enlarged; and Fig. Figure 9 is a schematic longitudinal sectional view showing a state of use of a modification of the stator according to the fourth embodiment, and part of the stator is shown enlarged. PREFERRED MODE FOR EXECUTING THE INVENTION

[0007] A stator according to one aspect of the present disclosure is described below with reference to the drawings. Fig. In this document, a stator 1 according to a first embodiment is described. The stator 1 is used together with a rotor (not shown) in an electric motor that supplies current to a rotating device. The stator 1 has a cylindrical stator core 2, a coil 3 provided in the stator core 2, and cylindrical cover parts 4 and 4' provided in the stator core 2. The device in which the stator 1 is used is not limited to an electric motor and can, for example, be a generator.

[0008] The stator core 2 has a cylindrical shape with both ends open in the axial direction J1 and is made of a magnetic material. The stator core 2 has a plurality of toothed segments (not shown) that project radially inwards from the inner circumferential surface. Each of the plurality of toothed segments extends along the axial direction J1 of the stator core 2. The plurality of toothed segments are arranged side by side in the circumferential direction of the stator core 2.

[0009] The coil 3 is attached to each of the multiple tooth segments. In a state where the coil 3 is attached to the stator 1, the coil 3 projects from one end face of the stator core 2 in the axial direction J1 to one side in the axial direction J1, and from the other end face of the stator core 2 in the axial direction J1 to the other side in the axial direction J1. As described above, the coil 3 has coil ends 5 and 5' that project outwards in the axial direction J1 from the end faces of the stator core 2.

[0010] The stator core 2 is provided with cover parts 4 and 4' to cover the coil ends 5 and 5', respectively. Of the cover parts 4 and 4', one cover part 4 is provided on the stator core 2 to cover the coil end 5, which projects from one end face of the stator core 2 in the axial direction J1 to one side in the axial direction J1, and the other cover part 4' is provided to cover the coil end 5', which projects from the other end face of the stator core 2 in the axial direction J1 to the other side in the axial direction J1. One of the cover parts 4 has a cylindrical shape and projects from one end face of the stator core 2 in the axial direction J1 to one side in the axial direction J1 when the coil end 5 is covered.The other cover part 4' has a cylindrical shape and projects from the other end face of the stator core 2 in the axial direction J1 to the other side in the axial direction J1, in a state where the coil end 5' is covered. As described above, the cover parts 4 and 4' are cylindrical and extend in the axial direction J1 and project outwards from the end faces of the stator core 2 in the axial direction J1. The cover parts 4 and 4' are made of resin.

[0011] The stator 1 with this configuration is inserted into a cylindrical annular element 6. The annular element 6 covers the outer circumferential portion of the stator 1, and the stator 1 is attached to the inner circumferential portion of the annular element 6. The annular element 6 is, for example, a cooling jacket for cooling the stator 1. In this case, the annular element 6 has a helical groove 7 on its outer circumferential surface. The groove 7 opens radially outward from the annular element 6. The opening of the groove 7 is closed by a cylindrical frame (not shown) that covers the outer circumference of the annular element 6. This creates a coolant channel between the annular element 6 and the frame, consisting of the groove 7 in which the opening is closed. A coolant is passed through the coolant channel to cool the stator 1.The coolant is fed into the coolant channel from a supply nozzle integrated into the frame. The coolant supplied from the supply nozzle to the coolant channel is guided through the spiral-shaped coolant channel and then discharged to the outside through an outlet nozzle integrated into the frame.

[0012] In a state where the stator 1 is inserted into the annular element 6, ideally there should be no gap between the annular element 6 and one cover part 4, nor between the annular element 6 and the other cover part 4'. In practice, however, tiny gaps 8 and 8' form for the reason described later. Although the shapes and paths of the gaps 8 and 8' vary depending on the accuracy and temperature of the annular element 6 and the cover parts 4 and 4' themselves, the gaps 8 and 8' are in contact with the stator core 2 and the coil 3. For the sake of simplicity, the gaps 8 and 8' are referred to as... Fig. The gap is shown larger than the actual gap. The gap 8 between the annular element 6 and one cover part 4 opens to one side in the axial direction J1, that is, to an outside in the axial direction J1, and the gap 8' between the annular element 6 and the other cover part 4' opens to the other side in the axial direction J1, that is, to an outside in the axial direction J1.

[0013] As described above, the gaps 8 and 8', which open outwards in the axial direction J1, are formed between the annular element 6 and the cover parts 4 and 4'. If the outer diameters of the cover parts 4 and 4' are designed slightly larger than the outer diameter of the stator core 2, so that the gaps 8 and 8' are not formed, the cover parts may crack due to the stress exerted on them when the stator is clamped to the annular element by a shrink fit. Even if no cracks occur in this situation, the cover parts expand due to heat during motor operation, exerting further force on them from the annular element. This force further increases the risk of cracking.Therefore, it is generally unavoidable that the gaps 8 and 8' are formed between the annular element 6 and the cover parts 4 and 4'.

[0014] If gaps 8 and 8' are formed between the annular element 6 and the cover parts 4 and 4', foreign matter such as liquid or dust can penetrate these gaps during operation of the stator 1. If foreign matter enters these gaps, the insulation performance can deteriorate and the stator 1 may fail. Therefore, the openings of gaps 8 and 8' are sealed by sealing materials 9 and 9'. In the example shown, the sealing materials 9 and 9' are elastically deformable O-rings.

[0015] One cover part 4 and the other cover part 4' each have sealing material fastening parts 10 and 10' to which the sealing materials 9 and 9' are attached for sealing the openings of the gaps 8 and 8'. The sealing material fastening part 10 of one cover part 4 has an annular groove shape along the circumferential direction of the cover part 4. More precisely, the sealing material fastening part 10 has an annular groove shape formed by a radially inwardly directed depression on the outer circumferential surface of the cover part 4 and extends to one end of the cover part 4 on the outside in the axial direction J1, which is one side of the cover part 4 in the axial direction J1, and is open. The sealing material fastening part 10 is part of the stepped cylindrical cover part 4 with a small diameter.The sealing material fastening part 10' of the other cover part 4' has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part 10' of the other cover part 4', the outside in the axial direction J1 is the other side in the axial direction J1.

[0016] In the case of the stator 1 according to the first embodiment, the cover parts 4 and 4' have the sealing material mounting parts 10 and 10' to which the sealing materials 9 and 9' are attached for sealing the gap 8 and 8' between the annular element 6 and the cover parts 4 and 4'. The sealing material mounting parts 10 and 10' have the configuration described above. In this configuration, the sealing materials 9 and 9' attached to the sealing material mounting parts 10 and 10' can be easily removed from the sealing material mounting parts 10 and 10' through the openings of the gap 8 and 8'. New sealing material 9 and 9' can then be easily attached to the sealing material mounting parts 10 and 10' through the openings of the gap 8 and 8'.Therefore, according to the stator 1 of the first embodiment, it is not necessary to remove the stator 1 from the annular element 6 when the sealing materials 9 and 9' are replaced, and thus it is possible to improve the ease of maintenance with a simple configuration.

[0017] Next, with reference to the Fig. 2 and Fig. 3. A stator according to a second embodiment of the present invention is described. It is noted that components having the same reference numerals as those used in the first embodiment have the same functions and therefore their description can be omitted below. A stator 1a according to the second embodiment differs from that of the first embodiment in the configuration of the sealing material fastening part 10 of the cover part 4. Here, one cover part 4 is described instead of the other.

[0018] The sealing material mounting part 10 has a sealing material arrangement part 11 located on the inside in the axial direction J1, that is, on the opposite side in the axial direction J1 of the cover part 4, and a sealing material insertion part 12 located on the outside in the axial direction J1, that is, on one side in the axial direction J1 of the cover part 4. The sealing material 9 can be arranged on the sealing material arrangement part 11. The sealing material 9 seals the opening of the gap 8 between the annular element 6 and the cover part 4 when it is arranged on the sealing material arrangement part 11. The sealing material insertion part 12 has an open end portion of the sealing material mounting part 10.The sealing material insertion part 12 allows the sealing material 9 to be inserted into the sealing material arrangement part 11 from the open end part of the sealing material fastening part 10. This means that the sealing material insertion part 12 allows the sealing material 9 to be inserted into the rear of the sealing material fastening part 10 from the opening of the gap 8.

[0019] As in the Fig. 2 and Fig. As shown in Figure 3, an outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 and an outer circumferential surface 14 of the sealing material insertion part 12 of the cover part 4 are continuous. The outer diameter of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 increases from the connecting part with the outer circumferential surface 14 of the sealing material insertion part 12 of the cover part 4 towards the inside in the axial direction J1 of the cover part 4. More precisely, the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 is tapered such that the diameter increases towards the inside in the axial direction J1 of the cover part 4.As described above, the outer diameter of the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4 is smaller than the outer diameter of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4.

[0020] In the case of stator 1a according to the second embodiment, the sealing material 9 is introduced from the opening of the gap 8 onto the sealing material introduction part 12. As in Fig. As shown in Figure 2, the sealing material 9 protrudes outwards in the axial direction J1 of the cover part 4 when it is inserted onto the sealing material insertion part 12. As shown in Fig. As shown in Figure 3, the stator 1a is attached to a counter element 15 in a state where the sealing material 9 is placed onto the sealing material insertion part 12. The stator 1a is attached to the counter element 15 by screwing a screw 17 into a screw hole 16 of the stator 1a via the counter element 15. When the stator 1a is attached to the counter element 15, the sealing material 9, located in the sealing material insertion part 12, is pressed inwards by the counter element 15 in the axial direction J1 of the cover part 4. This forces the sealing material 9 from the sealing material insertion part 12 onto the sealing material arrangement part 11. The sealing material 9 seals the opening of the gap 8 while being pressed onto the sealing material arrangement part 11.

[0021] The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1. The sealing material is attached to the sealing material fastening part of the other cover part in the same way as in the case of the sealing material fastening part 10 of one cover part.

[0022] In the case of stator 1a according to the second embodiment, the sealing material 9 is pushed onto the sealing material arrangement part 11 with a small gap under elastic deformation. Because the sealing material 9 is pushed onto the sealing material arrangement part 11 with a small gap, the contact area with the outer circumferential surface of the cover part 4 and the contact area with the inner circumferential surface of the annular element 6 are increased. Therefore, according to stator 1a of the second embodiment, the opening of the gap 8 can be sealed more tightly.

[0023] Next, with reference to Fig. 4 describes a modification of the stator according to the second embodiment. It is noted that components with the same reference numerals as those used in the first and second embodiments have the same functions and therefore their descriptions can be omitted below. A stator 1b of the present modification differs from that of the second embodiment with respect to the configuration of the sealing material arrangement part 11 and the sealing material fastening part 10. Here, one of the cover parts 4 and the other cover part 4 are described.

[0024] The outer diameter of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 increases from the connecting part with the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4 towards the inside in the axial direction J1, that is, towards the other side in the axial direction J1 of the cover part 4. More precisely, it bulges, as shown in Fig. Figure 4 shows the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4, extending outwards in the radial direction of the cover part 4. The longitudinal section shape of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 is a curved shape that bulges outwards in the radial direction of the cover part 4. For example, the longitudinal section shape of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 is an arc shape that bulges outwards in the radial direction of the cover part 4.

[0025] In the case of stator 1b of the present modification, the sealing material 9 is attached to the sealing material mounting part 10 in the same way as in the case of the second embodiment. Specifically, the sealing material 9 is pressed by the sealing material insertion part 12 and the counter element 15 onto the sealing material arrangement part 11.

[0026] The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1. The sealing material is attached to the sealing material fastening part of the other cover part in the same way as in the case of the sealing material fastening part 10 of one cover part.

[0027] Next, with reference to Fig. 5. A stator according to a third embodiment of the present invention is described. It is noted that components having the same reference numerals as those used in the first embodiment have the same functions and therefore their description can be omitted below. A stator 1c according to the third embodiment differs from that of the first embodiment in the configuration of the sealing material fastening part 10 of the cover part 4. Here, one cover part 4 is described instead of the other.

[0028] The outer diameter of an outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 increases from the end on the outside in the axial direction J1, i.e., one side in the axial direction J1 of the cover element 4, to the end on the inside in the axial direction J1, i.e., the other side in the axial direction J1 of the cover element 4. More precisely, the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 is tapered such that the diameter increases towards the inside in the axial direction J1 of the cover element 4.

[0029] In the case of stator 1c according to the third embodiment, the sealing material 9 is attached to the sealing material mounting part 10 in the same way as in the case of the second embodiment. More precisely, the sealing material 9 is pressed by the counter element 15 from the front of the sealing material mounting part 10 to the rear of the sealing material mounting part 10. This forces the sealing material 9 from a part with a large gap on the outside in the axial direction J1 to a part with a small gap on the inside in the axial direction J1. Therefore, according to stator 1c of the third embodiment, as in the case of the second embodiment, the opening of the gap 8 can be sealed more tightly with a simple configuration.

[0030] The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1. The sealing material is attached to the sealing material fastening part of the other cover part in the same way as in the case of the sealing material fastening part 10 of one cover part.

[0031] Next, with reference to Fig. 6 describes a first modification of the stator according to the third embodiment. It is noted that components with the same reference numerals as those used in the first and third embodiments have the same functions and therefore their descriptions can be omitted below. A stator 1d of the first modification differs from that of the third embodiment in the configuration of the sealing material fastening part 10. Here, one cover part 4 is described instead of the other.

[0032] The outer diameter of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover part 4 increases from the outer end in the axial direction J1 (i.e., one side in the axial direction J1 of the cover part 4) to the inner end in the axial direction J1 (i.e., the other side in the axial direction J1 of the cover part 4). More precisely, the outer circumferential surface 18 of the sealing material fastening element 10 of the cover part 4 bulges outwards in the radial direction of the cover part 4. The longitudinal section shape of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover part 4 is a curved shape that bulges outwards in the radial direction of the cover part 4. For example, the longitudinal section shape of the outer circumferential surface 18 of the sealing material fastening part 10 of the cover part 4 is an elliptical arc shape that curves outwards in the radial direction of the cover part 4.

[0033] In the case of stator 1d of the first modification, the sealing material 9 is pressed by the counter element 15 from the front of the sealing material fastening part 10 to the rear of the sealing material fastening part 10, as in the case of the second embodiment. The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1. The sealing material is attached to the sealing material fastening part of the other cover part in the same way as in the case of the sealing material fastening part 10 of one cover part.

[0034] Next, with reference to Fig. 7 A second modification of the stator according to the third embodiment is described. It is noted that components having the same reference numerals as those used in the first and third embodiments have the same functions and therefore their descriptions can be omitted below. A stator 1e of the second modification differs from that of the third embodiment in the configuration of the sealing material fastening part 10. Here, one cover part 4 is described instead of the other cover part 4.

[0035] The outer diameter of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 increases from the end on the outside in the axial direction J1, which is one side in the axial direction J1 of the cover element 4, to the end on the inside in the axial direction J1, which is the other side in the axial direction J1 of the cover element 4. More precisely, the outside in the axial direction J1 of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 is radially recessed inwards with respect to the cover element 4, and the inside in the axial direction J1 of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 bulges radially outwards with respect to the cover element 4.The longitudinal section of the outer circumferential surface 18 on the outside in the axial direction J1 of the sealing material fastening element 10 of the cover element 4 is a curved shape that is recessed inwards in the radial direction of the cover element 4. The longitudinal section of the outer circumferential surface 18 on the inside in the axial direction J1 of the sealing material fastening element 10 of the cover element 4 is a curved shape that bulges outwards in the radial direction of the cover element 4. The outside in the axial direction J1 of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4 is seamlessly integral with the inside in the axial direction J1 of the outer circumferential surface 18 of the sealing material fastening element 10 of the cover element 4.

[0036] In the case of stator 1e of the second modification, as in the case of the second embodiment, the sealing material 9 is pressed by the counter element 15 from the front of the sealing material fastening part 10 to the rear of the sealing material fastening part 10. According to stator 1e of the second modification, the seating of the sealing material 9 can be improved because the outer surface is recessed in the axial direction J1 of the outer circumferential surface 18 of the sealing material fastening part 10 of the cover part 4.

[0037] The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1. The sealing material is attached to the sealing material fastening part of the other cover part in the same way as in the case of the sealing material fastening part 10 of one cover part.

[0038] Next, with reference to Fig. 8. A stator according to a fourth embodiment of the present invention is described. It is noted that components having the same reference numerals as those used in the first embodiment have the same functions and therefore their description can be omitted below. A stator 1f according to the fourth embodiment differs from that of the first embodiment in the configuration of the sealing material fastening part 10 of the cover part 4. Here, one cover part 4 is described instead of the other.

[0039] The sealing material mounting part 10 has the sealing material arrangement part 11, which is located on the inside in the axial direction J1, that is, on the opposite side in the axial direction J1 of the cover part 4, and the sealing material insertion part 12, which is located on the outside in the axial direction J1, that is, on one side in the axial direction J1 of the cover part 4. The sealing material 9 can be arranged on the sealing material arrangement part 11. The sealing material 9 seals the opening of the gap 8 between the annular element 6 and the cover part 4 when it is arranged in the sealing material arrangement part 11. The sealing material insertion part 12 has an open end portion of the sealing material mounting part 10.The sealing material insertion part 12 allows the sealing material 9 to be inserted into the sealing material arrangement part 11 from the open end of the sealing material fastening part 10. This means that the sealing material 9 can be inserted through the sealing material insertion part 12 from the opening of the gap 8 to the back of the sealing material fastening part 10.

[0040] As in Fig. As shown in Figure 8, the outer diameter d81 of the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4 is larger than the outer diameter d82 of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 and smaller than the outer diameter d83 of the outer circumferential surface of the portion of the cover part 4 on which the sealing material fastening part is not formed. Typically, the sealing material fastening part 10 of the cover part 4 has a stepped column shape and comprises a large-diameter part 19 located on the outside in the axial direction J1 and a small-diameter part 20 located on the inside in the axial direction J1. The outer circumferential surface of the large-diameter part 19 is the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4.The outer circumferential surface of the small-diameter part 20 is the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4.

[0041] In the case of stator 1f according to the fourth embodiment, the sealing material 9 is pressed from the opening of the gap 8 through the sealing material insertion part 12 onto the sealing material mounting part 11. The sealing material 9 seals the opening of the gap 8 in a state in which it is pressed against the sealing material mounting part 11. As described above, the outer diameter of the outer circumferential surface 14 of the sealing material insertion part 12 of the cover part 4 is larger than the outer diameter of the outer circumferential surface 13 of the sealing material mounting part 11 of the cover part 4. Therefore, stator 1f according to the fourth embodiment has a configuration in which it is unlikely that the sealing material 9 will separate from the sealing material mounting part 10.

[0042] The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1.

[0043] Next, with reference to Fig. 9 describes a modification of the stator according to the fourth embodiment. It is noted that components having the same reference numerals as those used in the first and fourth embodiments have the same functions and therefore their descriptions can be omitted below. A stator 1g of the present modification differs from that of the fourth embodiment in the configuration of the sealing material fastening part 10. Here, one cover part 4 is described instead of the other cover part 4.

[0044] As in Fig.As shown in Figure 9, the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 and the outer circumferential surface 14 of the sealing material insertion part 12 of the cover part 4 are continuous. The outer diameter of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 decreases from the connecting part with the outer circumferential surface 14 of the sealing material insertion part 12 of the cover part 4 towards the inside in the axial direction J1, that is, towards the other side in the axial direction J1 of the cover part 4. More precisely, the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4 is tapered such that the diameter decreases towards the inside in the axial direction J1 of the cover part 4.As described above, the outer diameter d91 of the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4 is larger than the smallest part d92 of the outer diameter of the outer circumferential surface 13 of the sealing material arrangement part 11 of the cover part 4. The outer diameter d91 of the outer circumferential surface 14 of the sealing material introduction part 12 of the cover part 4 is smaller than the outer diameter d93 of the outer circumferential surface of the part of the cover part 4 on which the sealing material fastening part 10 is not formed.

[0045] In the case of stator 1g of the present modification, the sealing material 9 is pressed from the opening of the gap 8 through the sealing material insertion part 12 onto the sealing material arrangement part 11. The sealing material fastening part of the other cover part has essentially the same configuration as the sealing material fastening part 10 of one cover part 4. However, in the case of the sealing material fastening part of the other cover part, the outside in the axial direction J1 is the other side in the axial direction J1, and the inside in the axial direction J1 is one side in the axial direction J1.

[0046] It is noted that the present invention is not limited to the embodiments and modifications described above, and that modifications and improvements within the scope of the present invention are included. For example, with respect to the sealing material fastening part 10 of one cover part 4 and the sealing material fastening part 10' of the other cover part 4', the embodiments and modifications described above can be combined where appropriate. REFERENCE MARK LIST 1 Stator 2 Stator core 3 coil 4 Cover part 5 Coil end 6 ring-shaped element 8 gaps 9 Sealing material 10 Sealing material fastening part 11 Sealing material arrangement part 12 Sealing material insertion part

Claims

[1] Stator inserted into an annular element, the stator comprising: a cylindrical stator core; a coil provided in the stator core and having a coil end projecting axially outward from an axial end surface of the stator core; and a cylindrical cover part provided to cover the coil end and protruding axially outward from the axial end surface of the stator core, the cover part having a sealing material fixing part to which a sealing material for sealing a gap between the annular member and the cover part is fixed, and the sealing material fixing part has the shape of an annular groove formed by being recessed radially inward on an outer peripheral surface of the cover part, the sealing material fixing part extending to one end on an axially outer side of the cover part and being opened. [2] The stator according to claim 1, wherein the sealing material fixing member comprises: a sealing material arranging part located on an axially inner side of the cover part and on which the sealing material can be arranged; and a sealing material introduction part located on the axially outer side of the cover part, having an open end part of the sealing material fixing part and allowing the sealing material to be introduced from the open end part of the sealing material fixing part into the sealing material arranging part, and wherein an outer diameter of an outer peripheral surface of the sealing material arranging part of the cover part increases from a connecting part with an outer peripheral surface of the sealing material introducing part of the cover part toward an axially inner side of the cover part. [3] The stator according to claim 1, wherein an outer diameter of an outer peripheral surface of the sealing material fixing part of the cover part increases from the end on the axially outer side of the cover part to an end on an axially inner side of the cover part. [4] The stator according to claim 1, wherein the sealing material fixing member comprises: a sealing material arranging part located on an axially inner side of the cover part and on which the sealing material can be arranged; and a sealing material introduction part located on the axially outer side of the cover part, having an open end part of the sealing material fixing part and allowing the sealing material to be introduced from the open end part of the sealing material fixing part into the sealing material arranging part, and wherein an outer diameter of an outer peripheral surface of the sealing material introduction part of the cover part is larger than an outer diameter of an outer peripheral surface of the sealing material arrangement part of the cover part. [5] The stator according to claim 4, wherein the outer diameter of the outer peripheral surface of the sealing material arranging part of the cover part decreases from a connecting part with the outer peripheral surface of the sealing material introducing part of the cover part toward the axially inner side of the cover part.

Images