JP7703410B2 - Generators and generator systems for dump trucks - Google Patents

Description

The present invention relates to a generator having a rotor and a stator, and a generator system for a dump truck having this generator.

In recent years, there has been a demand for more efficient generators in order to reduce CO2 emissions. In particular, generators used in vehicles such as automobiles, trains, and construction vehicles are required to be not only more efficient, but also smaller and lighter.

By making generators smaller and lighter, the vehicles themselves can be made smaller and lighter, improving fuel efficiency. This improves the efficiency of automobiles, trains, construction vehicles, and other systems as a whole.

However, in general, there is a trade-off between compactness and weight reduction and high efficiency, so making a generator smaller and lighter reduces the generator's efficiency and increases its losses. In other words, as the generator's output density increases, the generator's heat density also increases. For this reason, when making a generator smaller and lighter, it is extremely important to improve the generator's cooling performance.

In addition, generators used to power construction vehicles have two systems: a main power source (for traction) for driving the vehicle, and an auxiliary power source (for accessories) for driving other accessories.

Since these two systems have different uses, the generators for these two systems have different specifications for electrical capacity and electrical characteristics. For this reason, two generators with different electrical capacity and electrical characteristics are installed inside the generator frame. The two generators then have a tandem structure with rotors arranged on the same shaft.

An example of a tandem-structure generator with a cooling structure that provides such high cooling performance is disclosed in JP 2015-220947 A (Patent Document 1).

This patent document 1 describes a rotating electric machine system having a first rotating electric machine, a second rotating electric machine, an internal fan, a rotating shaft, and a heat exchanger, in which the first rotating electric machine and the second rotating electric machine each have a stator and a rotor, the first rotating electric machine and the second rotating electric machine are connected to the rotating shaft, the outer diameter of the second rotating electric machine is smaller than the outer diameter of the first rotating electric machine, the internal fan is connected to the rotating shaft, internal air is circulated to the first rotating electric machine and the second rotating electric machine, and the heat exchanger is installed on the outer periphery of the second rotating electric machine, external air flows in and the circulating internal air flows in through the internal fan, and the internal air and the external air are heat exchanged to cool the rotating electric machine system.

JP 2015-220947 A

Patent document 1 describes a tandem-structure generator (rotating electric machine system) with a cooling structure.

However, the generator described in Patent Document 1 has a closed type of air (refrigerant) flow rather than an open type, which may result in insufficient cooling of the main generator (first rotating electric machine), which is the largest heat source.

In addition, because the generator described in Patent Document 1 is a closed type, the air flow starts from one end in the axial direction and turns back at the other end in the axial direction. In other words, the air flows through a U-shaped flow path. For this reason, the flow path for the axial air flow has a large pressure loss, the air flow rate is reduced, and there is a risk of insufficient cooling of the main generator.

The present invention provides a tandem-structure generator and a generator system for dump trucks that has an open axial-flow air-cooling cooling structure and, in particular, improves the cooling performance of the main generator.

In order to solve the above-mentioned problems, the generator of the present invention includes a frame having an inlet through which a refrigerant flows in the axial direction, a first generator cooled by the refrigerant flowing in from the inlet, a second generator cooled by the refrigerant that has cooled the first generator, installed coaxially with the first generator and having a radial length longer than the first generator, and a generator in which the refrigerant that has cooled the second generator is discharged in the axial direction to the atmosphere, the diameter of the frame at the location where the first generator is installed is the same as the diameter of the frame at the location where the second generator is installed, a first rear duct through which the refrigerant flows in the axial direction is installed between the first generator and the frame, and a second rear duct through which the refrigerant flows in the axial direction is installed between the second generator and the frame, first coil ends protrude from both axial ends of the first generator, and the first coil end protrudes, the first coil end downstream in the axial direction and the second coil end upstream in the axial direction face each other so as to overlap radially without contacting each other, the refrigerant flowing in from the inlet flows linearly in the axial direction through the first rear duct and then the second rear duct, the installation position of the inlet coincides with the installation position of the first rear duct in the radial direction, a plurality of first fixed parts are installed in the radial direction between the first generator and the frame, the first rear duct through which the refrigerant flows is installed between the first fixed parts, a plurality of second fixed parts are installed in the radial direction between the second generator and the frame, the second rear duct through which the refrigerant flows is installed between the second fixed parts, and the first fixed parts and the second fixed parts are installed so as to have the same circumferential pitch .

The generator system for a dump truck of the present invention also has a generator as described above.

The present invention provides a tandem-structure generator and a generator system for dump trucks that has an open axial-flow air-cooled cooling structure and, in particular, improves the cooling performance of the main generator.

Note that issues, configurations and effects other than those mentioned above will become clear from the explanation of the examples below.

FIG. 2 is an explanatory diagram for explaining the generator 100 described in the first embodiment. FIG. 2 is an explanatory diagram illustrating a partial cross section taken along the line AA′ of FIG. FIG. 2 is an explanatory diagram illustrating a partial cross section taken along the line BB' of FIG. FIG. 2 is an enlarged view of a portion D in FIG. 1 and illustrates a conventional example. FIG. 2 is an enlarged view of a portion D in FIG. 1 and is an explanatory diagram for explaining the first embodiment. 1A and 1B are explanatory diagrams illustrating the relationship between the auxiliary generator 2 and the main generator 3 in the generator 100 described in the first embodiment, in which (a) is a radial cross-sectional view of the auxiliary generator 2, and (b) is an axial cross-sectional view of the main generator 3. 1 is an explanatory diagram illustrating the relationship between the flow path area ratio (aa/bb) of the air 12 and the flow rate of the air 12 in the generator 100 described in the first embodiment. FIG. 1 is an explanatory diagram illustrating the positional relationship between a pillar 20a and a pillar 20b in a generator 100 described in the first embodiment. FIG. 2 is an explanatory diagram for explaining the positional relationship between an inlet 11 for air 12 and a rear duct 21 and a rear duct 31 in the generator 100 described in the first embodiment. FIG. 1. FIG. 4 is an explanatory diagram illustrating an enlarged view of a portion equivalent to portion D in FIG. 1 in a generator 100 according to a second embodiment. FIG. 11 is an explanatory diagram for explaining a generator 100 according to a third embodiment. 11 is an explanatory diagram illustrating a partial cross section taken along the line CC' of FIG. 10. FIG. 11 is an explanatory diagram illustrating a stator axial duct 43 in the generator 100 described in the fourth embodiment. FIG. 1 is an explanatory diagram illustrating a generator system for a dump truck having a generator 100 according to an embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. In each drawing, substantially the same or similar configurations are given the same reference numerals, and when explanations are repeated in each drawing, the repeated explanations may be omitted.

First, we will explain the generator 100 described in Example 1.

Figure 1 is an explanatory diagram illustrating the generator 100 described in Example 1, and is an axial cross-sectional view.

This generator 100 is primarily connected to an engine, has a rotational speed of several thousand revolutions per minute, and is used to supply power to large dump trucks.

The generator 100 is provided with a main generator 3 (second generator) as the main power source (for traction) for driving the vehicle (vehicle body), an auxiliary generator 2 (first generator) as an auxiliary power source (for accessories) for driving other accessories, and a power supply device 8 that supplies excitation current to the rotor 4 of the auxiliary generator 2 and the rotor 6 of the main generator 3, all installed inside the frame 1. The auxiliary generator 2 has a rotor 4 installed on the shaft 10 and a stator 5 installed on the outer periphery of the rotor 4, and the main generator 3 has a rotor 6 installed on the shaft 10 and a stator 7 installed on the outer periphery of the rotor 6.

In other words, this generator 100 is a generator with a tandem structure in which the rotor 4 of the auxiliary generator 2 and the rotor 6 of the main generator 3 are installed so as to be connected to the same shaft 10, i.e., the auxiliary generator 2 and the main generator 3 are installed so as to be coaxial and connected in the axial direction. In this generator 100, the main generator 3 has a larger diameter (longer radial length) and a longer axial length than the auxiliary generator 2. Note that the axial direction is the axial direction of the shaft 10, which is the left-right direction in FIG. 1. In other words, the main generator 3 is larger in size than the auxiliary generator 2.

In the first embodiment, the diameter of the frame 1 at the location where the main generator 3 is installed is the same as the diameter of the frame 1 at the location where the auxiliary generator 2 is installed. Therefore, the radial length of the rear duct 21 installed around the stator 5 of the auxiliary generator 2 is longer than the radial length of the rear duct 31 installed around the stator 7 of the main generator 3. The radial direction is the direction extending radially from the shaft 10 to the outer diameter side, and is the up-down direction in FIG. 1.

In addition, at both axial ends of the stator 5 of the auxiliary generator 2, coil ends 39 (first coil ends) of the auxiliary generator 2 protrude from the stator coil 16 of the auxiliary generator 2, and at both axial ends of the stator 7 of the main generator 3, coil ends 40 (second coil ends) of the main generator 3 protrude from the stator coil 25 of the main generator 3.

In addition, bearings 9 for rotating the shaft 10 are installed on the frame 1. The bearings 9 are installed on one axial end of the shaft 10. No bearing is installed on the other axial end of the shaft 10 because it is connected to the engine 200, and the other axial end of the shaft 10 is supported by a bearing on the engine 200 side. Bearings 9 may be installed on both axial ends of the shaft 10.

The frame 1 is also provided with an inlet 11 through which a refrigerant (e.g., air 12) flows in to cool the auxiliary generator 2 and the main generator 3. The air 12 flowing into the inlet 11 is supplied by an electric blower 301 installed separately from the generator 100. The air 12 flows axially from the inlet 11, that is, from left to right in FIG. 1, and is released into the atmosphere.

The auxiliary generator 2 and the main generator 3 are installed in the order of the inlet 11, that is, the auxiliary generator 2, the main generator 3. In other words, the air 12 flowing into the inlet 11 flows in the axial direction, cooling the auxiliary generator 2, then cooling the main generator 3, and then releasing it into the atmosphere.

In this way, this generator 100 has a simple structure, improves cooling performance, has a structure in which the inside and outside (outside air) are directly connected, and has an axial open-type air-cooled cooling structure in which the air 12 that has cooled the main generator 3 is released into the atmosphere.

The air 12 may be supplied by a self-cooling fan (axial fan) installed on the shaft 10. In particular, an electric blower 301 is preferred that supplies air 12 to the generator 100 even when the generator 100 is stopped, and forcibly flows the air 12 through the generator 100 (forced draft).

Next, we will explain a partial cross section taken along line A-A' in Figure 1.

Figure 2 is an explanatory diagram illustrating a partial cross section taken along line A-A' in Figure 1. Figure 2 is a cross section taken along line A-A' in Figure 1, and shows a 1/8 portion (45° portion) of the auxiliary generator 2.

The auxiliary generator 2 has a rotor 4 and a stator 5. The rotor 4 has a rotor core 13, a field coil 15, and a pole shoe 18. The stator 5 has a stator core 14, a stator coil 16, and a stator wedge 19. The rotor core 13 and the pole shoe 18 are connected by a bolt structure or a dovetail structure.

The rotor 4 and the stator 5 face each other across a gap 17.

Between the stator 5 and the frame 1, pillars 20a (first fixing parts) that fix the frame 1 to the stator 5 are installed at a specified interval in the circumferential direction. Between the pillars 20a and 20a, between the frame 1 and the stator 5 of the auxiliary generator 2, a rear duct 21 (first rear duct) through which air 12 flows in the axial direction is installed. Eight pillars 20a (at 45° intervals) are installed around the stator 5.

Next, we will explain the partial cross section taken along line B-B' in Figure 1.

Figure 3 is an explanatory diagram illustrating a partial cross section taken along line B-B' in Figure 1. Figure 3 is a cross section taken along line B-B' in Figure 1, and shows a 1/10 portion (36° portion) of the main generator 3.

The main generator 3 has a rotor 6 and a stator 7. The rotor 6 has a rotor core 22, a field coil 24, a damper bar 27, and a rotor wedge 28. The stator 7 has a stator core 23, a stator coil 25, and a stator wedge 29. An axial duct 30 through which air 12 flows in the axial direction is installed on the inner diameter side of the rotor core 22 (on the inner diameter side of half the radial length between the shaft 10 (inner diameter side) and the stator 7 (outer diameter side)).

The rotor 6 and the stator 7 face each other across a gap 26.

Between the stator 7 and the frame 1, pillars 20b (second fixing parts) that fix the frame 1 to the stator 7 are installed at a specified interval in the circumferential direction. Between the pillars 20b and 20b, between the frame 1 and the stator 7 of the main generator 3, a rear duct 31 (second rear duct) through which air 12 flows in the axial direction is installed. Eight pillars 20b (at 45° intervals) are installed around the stator 7.

As shown in Figures 1, 2, and 3, air 12 flows in through the inlet 11, flows through the air flow path (ventilation path) of the auxiliary generator 2 (gap 17 and rear duct 21), flows through the air flow path (ventilation path) of the main generator 3 (gap 26, axial duct 30, and rear duct 31), and is released into the atmosphere.

Next, we will explain the enlarged portion D in Figure 1.

Figure 4A is an explanatory diagram showing an enlargement of part D in Figure 1 to explain a conventional example, and Figure 4B is an explanatory diagram showing an enlargement of part D in Figure 1 to explain Example 1.

In the generator 100, the main generator 3 is the largest heat source, and the temperature of the stator coil 25 of the main generator 3 is the highest. In order to reduce the temperature of the stator coil 25, it is effective to increase the air flow rate in the rear duct 31 of the main generator 3.

However, as shown in FIG. 4A, the air 12 flowing through the rear duct 21 of the auxiliary generator 2 is divided in the area between the auxiliary generator 2 and the main generator 3, with one flow flowing to the stator 7 side (outer diameter side) of the main generator 3 and the other flowing to the rotor 6 side (inner diameter side) of the main generator 3. This reduces the air flow rate in the rear duct 31, and there is a risk that the stator coil 25 will not be sufficiently cooled.

4B, in the generator 100 described in the first embodiment, the auxiliary generator 2 and the main generator 3 are installed so that the coil end 39 of the auxiliary generator 2 and the coil end 40 of the main generator 3 are adjacent to each other (but do not contact each other). In other words, the auxiliary generator 2 and the main generator 3 are installed so that the coil end 39 on the downstream side (downstream side in the direction of the flow of the air 12 ) of the auxiliary generator 2 and the coil end 40 on the upstream side (upstream side in the direction of the flow of the air 12: inlet 11 side) of the main generator 3 face each other in the radial direction (overlap so as not to contact each other). Note that the coil end 39 is installed radially inward of the coil end 40, and the coil end 40 is installed radially outward of the coil end 39.

This narrows the radial air flow path in part A of FIG. 4B and the axial air flow path in part B of FIG. 4B, suppressing the air flow rate flowing to the rotor 6 side (inner diameter side). This in turn increases the air flow rate in the rear duct 31, reducing the temperature of the stator coil 25 and improving the cooling effect of the stator coil 25.

In other words, this is synonymous with installing a labyrinth seal structure that increases ventilation resistance in the air flow path on the inner diameter side. Then, of the air flow rate of the air 12 flowing through the rear duct 21 of the auxiliary generator 2, the air flow rate flowing toward the rotor 6 side (inner diameter side) of the main generator 3 is suppressed, and the air flow rate flowing toward the stator 7 side (outer diameter side) of the main generator 3 is increased. This increases the air flow rate of the air 12 flowing through the rear duct 31 of the main generator 3.

Next, the relationship between the auxiliary generator 2 and the main generator 3 in the generator 100 described in the first embodiment will be explained.

Figure 5 is an explanatory diagram illustrating the relationship between the auxiliary generator 2 and the main generator 3 in the generator 100 described in Example 1, where (a) is a radial cross-sectional view of the auxiliary generator 2, and (b) is an axial cross-sectional view of the main generator 3.

As shown in FIG. 5, in the generator 100 described in the first embodiment, the auxiliary generator 2 and the main generator 3 are installed so that the pillars 20a supporting the stator 5 of the auxiliary generator 2 and the pillars 20b supporting the stator 7 of the main generator 3 face each other in the axial direction. This allows the air 12 to flow from the rear duct 21 to the rear duct 31 in a substantially straight line with almost no leakage, improving the straightening effect of the air 12.

As shown in FIG. 5, the generator 100 described in the first embodiment is installed such that the pillar 20a supporting the stator 5 of the auxiliary generator 2 and the coil end 40 of the stator 7 of the main generator 3 face each other in the axial direction.

As shown in FIG. 5, the generator 100 described in the first embodiment is installed such that the pillar 20a supporting the stator 5 of the auxiliary generator 2 and the stator 7 of the main generator 3 face each other in the axial direction.

In this way, according to Example 1, the air flow rate in the rear duct 31 can be increased, the stator coil 25 can be actively cooled, the temperature of the stator coil 25 can be reduced, and the cooling effect of the stator coil 25 can be improved.

Furthermore, according to the first embodiment, the generator 100 does not require the addition of new parts or the change in the shapes of the frame 1, the auxiliary generator 2, and the main generator 3, so the cooling performance of the main generator 3 can be improved without increasing costs or decreasing productivity.

Furthermore, according to the first embodiment, even if the generator 100 has a tandem structure of the auxiliary generator 2 and the main generator 3 and an open axial-flow air-cooled cooling structure, the cooling performance of the main generator 3 can be improved.

In other words, in this tandem-structure generator 100, the air 12 flows in the axial direction. The air 12 cools the auxiliary generator 2 installed upstream of the flow of the air 12, and then cools the main generator 3 installed downstream of the flow of the air 12. The main generator 3 is cooled by the air 12 that has cooled the auxiliary generator 2. According to the first embodiment, even in such a case, the cooling effect of the stator coil 25 is improved, and therefore the cooling performance of the main generator 3 is improved.

In addition, in this tandem-structure generator 100, the auxiliary generator 2 is installed upstream of the flow of air 12, and the main generator 3, which is larger than the auxiliary generator 2, is installed downstream of the flow of air 12. This effectively cools the auxiliary generator 2 and the main generator 3, and improves the cooling effect of the stator coil 25, thereby improving the cooling performance of the main generator 3.

Note that the area aa shown in FIG. 4B is the flow path area through which the air 12 that has flowed through the rear duct 21 of the auxiliary generator 2 flows to the inner diameter side, while the area bb shown in FIG. 4B is the flow path area through which the air 12 that has flowed through the rear duct 21 of the auxiliary generator 2 flows to the rear duct 31 of the main generator 3.

Next, the relationship between the flow area ratio (aa/bb) of the air 12 and the flow rate of the air 12 in the generator 100 described in Example 1 will be explained.

Figure 6 is an explanatory diagram illustrating the relationship between the flow path area ratio (aa/bb) of the air 12 and the flow rate of the air 12 in the generator 100 described in Example 1. In other words, Figure 6 shows the relationship between the ratio (flow path area ratio (aa/bb)) between the part aa and the part bb shown in Figure 4B and the flow rate of the air 12 flowing in the rear duct 31.

In FIG. 6, the horizontal axis is the flow path area ratio (aa/bb) between aa and bb, and the vertical axis is the flow rate of air 12 flowing through the rear duct 31. The flow rate of air 12 is standardized so that the maximum value (5.5) of the flow path area ratio (aa/bb) is 1.0 (P.u.).

In Example 1, the flow path area in the aa area is reduced, the flow rate of air 12 flowing in the aa area is reduced, and the flow rate of air 12 flowing in the bb area is increased.

As shown in FIG. 6, when the flow path area ratio (aa/bb) is 1.5 or less, the flow rate of air 12 flowing through the rear duct 31 increases. Therefore, in Example 1, in order to effectively increase the flow rate of air 12 flowing through the rear duct 31, the flow path area ratio (aa/bb) is set to 1.5 or less.

In the first embodiment, the auxiliary generator 2 has eight poles and the stator 5 has 48 slots, while the main generator 3 has ten poles and the stator 7 has 90 slots, but other numbers of poles and slots may be used.

In addition, the rotor 4 of the auxiliary generator 2 has a salient pole shape, and the rotor 6 of the main generator 3 has a cylindrical shape, but the rotor 4 may be cylindrical and the rotor 6 may be salient pole, or the rotor 4 and the rotor 6 may have the same shape.

Next, we will explain the positional relationship between pillars 20a and 20b in the generator 100 described in Example 1.

Figure 7 is an explanatory diagram illustrating the positional relationship between pillars 20a and 20b in the generator 100 described in Example 1.

As shown in FIG. 7, in the first embodiment, a plurality of pillars (eight in the first embodiment) are installed such that the pillars 20a supporting the stator 5 of the auxiliary generator 2 and the pillars 20b supporting the stator 7 of the main generator 3 are at the same circumferential position (pitch) (so that they overlap in the axial direction). The pillars 20a and 20b are installed at a predetermined interval (45° interval in the first embodiment) in the circumferential direction (at a predetermined pitch).

In the generator 100, the air 12 flows in the axial direction. After flowing through the rear duct 21 of the auxiliary generator 2, the air 12 flows through the rear duct 31 of the main generator 3. In other words, an ideal flow path for the air 12 allows the air 12 flowing in from the inlet 11 to flow in the axial direction and be released into the atmosphere without impeding the flow of the air 12.

In Example 1, columns 20a and 20b are installed so that their circumferential positions are the same, so there is no obstruction to the flow of air 12 in the axial direction.

In this way, according to the first embodiment, the flow of air 12 in the axial direction is not impeded, so the air flow rate in the rear duct 31 can be increased, the stator coil 25 can be actively cooled, the temperature of the stator coil 25 can be reduced, and the cooling effect of the stator coil 25 can be improved.

Next, the positional relationship between the air inlet 11 for the air 12 and the rear duct 21 and rear duct 31 in the generator 100 described in Example 1 will be explained.

Figure 8 is an explanatory diagram illustrating the positional relationship between the air inlet 11 of the air 12 and the rear duct 21 and rear duct 31 in the generator 100 described in the first embodiment.

As shown in FIG. 8, in the first embodiment, the installation position of the inlet 11 is set to be the same as the installation position of the rear duct 21 in the radial direction. In other words, the radial position of the inlet 11 for the air 12 coincides with the radial position of the rear duct 21. The inlet 11 is installed with a predetermined width in the circumferential direction at the upstream tip of the frame 1.

In the generator 100, air 12 flows in the axial direction. After flowing in through the inlet 11 installed at the axial end of the generator 100, the air 12 flows through the rear duct 21 of the auxiliary generator 2 and the rear duct 31 of the main generator 3. In other words, an ideal flow path for the air 12 allows the air 12 flowing in from the inlet 11 to flow in the axial direction and be released into the atmosphere without impeding the flow of the air 12.

In this way, in Example 1, the inlet 11 is installed at a radially equivalent position to the rear duct 21, so that the flow of air 12 in the axial direction is not impeded.

In this way, according to Example 1, the flow of air 12 in the axial direction is not impeded, and the flow of air 12 in the axial direction is linear in the axial direction of the inlet 11, rear duct 21, and rear duct 31, so that the air flow rate in the rear duct 31 can be increased, the stator coil 25 can be actively cooled, the temperature of the stator coil 25 can be reduced, and the cooling effect of the stator coil 25 can be improved.

The generator 100 described in the first embodiment includes a frame 1 having an inlet 11 through which air 12 flows in, an auxiliary generator 2 that is cooled by the air 12 that flows in from the inlet 11, a main generator 3 that is cooled by the air 12 that has cooled the auxiliary generator 2 and is installed coaxially with the auxiliary generator 2 and has a larger diameter than the auxiliary generator 2, and the air 12 that has cooled the main generator 3 is released linearly into the atmosphere.

A number of pillars 20a are installed in the radial direction between the auxiliary generator 2 and the frame 1, and a rear duct 21 through which the air 12 flows is installed between the pillars 20a and 20a. A number of pillars 20b are installed in the radial direction between the main generator 3 and the frame 1, and a rear duct 31 through which the air 12 flows is installed between the pillars 20b and 20b.

Furthermore, coil ends 39 protrude from both axial ends of the auxiliary generator 2, and coil ends 40 protrude from both axial ends of the main generator 3, so that the coil ends 39 of the auxiliary generator 2 and the coil ends 40 of the main generator 3 face each other in the radial direction.

As a result, according to the first embodiment, even if the generator 100 has a tandem structure of the auxiliary generator 2 and the main generator 3 and an open axial-flow air-cooled cooling structure, the cooling performance of the main generator 3 can be improved.

Next, a portion of the generator 100 described in Example 2 that is equivalent to portion D in FIG. 1 will be enlarged and explained.

Figure 9 is an explanatory diagram showing an enlarged view of a portion of the generator 100 described in Example 2 that is equivalent to portion D in Figure 1.

In addition, in Example 2, we will explain the differences from Example 1.

As shown in FIG. 9, the generator 100 described in Example 2 has a jumper 41 that connects the stator coils 25 of the main generator 3 upstream of the coil end 40 of the main generator 3. The jumper 41 connects the stator coils 25 according to the number of three-phase AC or parallel circuits.

The crossover wire 41 is installed in the upstream coil end 40 of the main generator 3 in a space where the downstream side of the column 20a supporting the stator 5 of the auxiliary generator 2 and the upstream side of the coil end 40 of the main generator 3 face each other in the axial direction.

In the second embodiment, the auxiliary generator 2 and the main generator 3 are installed so that at least the downstream coil end 39 of the auxiliary generator 2 and the crossover wire 41 face each other (overlap) in the radial direction. In other words, the auxiliary generator 2 and the main generator 3 may be installed so that the downstream coil end 39 of the auxiliary generator 2 and the upstream coil end 40 of the main generator 3 face each other (overlap) in the radial direction.

In this way, in the second embodiment, the auxiliary generator 2 and the main generator 3 may be installed so that the downstream coil end 39 of the auxiliary generator 2 and the upstream coil end 40 of the main generator 3 face each other (overlap) in the radial direction, and the downstream coil end 39 of the auxiliary generator 2 and the jumper wire 41 face each other (overlap) in the radial direction.

In addition, in the second embodiment, the auxiliary generator 2 and the main generator 3 may be installed so that the downstream coil end 39 of the auxiliary generator 2 and the upstream coil end 40 of the main generator 3 do not face each other (do not overlap) in the radial direction, and the downstream coil end 39 of the auxiliary generator 2 and the jumper wire 41 face each other (overlap) in the radial direction.

This narrows the space between the downstream coil end 39 of the auxiliary generator 2 and the upstream coil end 40 of the main generator 40 (corresponding to the radial air flow path of part A in Figure 4B), and the space between the downstream side of the column 20a supporting the stator 5 of the auxiliary generator 2 and the upstream side of the coil end 40 of the main generator 3 (corresponding to the axial air flow path of part B in Figure 4B).

Then, the air flow rate flowing toward the rotor 6 side (inner diameter side) can be suppressed, and the air flow rate in the rear duct 31 can be increased, reducing the temperature of the stator coil 25 and improving the cooling effect of the stator coil 25.

As a result, according to the second embodiment, even if the generator 100 has a tandem structure of the auxiliary generator 2 and the main generator 3 and an open axial-flow air-cooled cooling structure, the cooling performance of the main generator 3 can be improved.

Furthermore, according to the second embodiment, the generator 100 does not require the addition of new parts or the change in the shapes of the frame 1, the auxiliary generator 2, and the main generator 3 in order to improve the straightening effect of the air 12, and the cooling performance of the main generator 3 can be improved without increasing costs or reducing productivity.

Next, we will explain the generator 100 described in Example 3.

Figure 10 is an explanatory diagram illustrating the generator 100 described in Example 3.

In addition, in Example 3, we will explain the differences from Example 1.

The generator 100 described in Example 3 has a duct (intermediate duct) 42 that flows air 12 radially to the main generator 3.

As shown in FIG. 10, the duct 42 is installed on the rotor 6 and stator 7 of the main generator 3, and is installed at a central position in the axial direction of the main generator 3. The duct 42 is installed between the rotor 6 and stator 7 on the upstream side of the main generator 3 and the rotor 6 and stator 7 on the downstream side of the main generator 3, forming a gap (the axial length of the gap is the height of the partition plate described later) that allows air 12 to flow from the inner diameter side to the outer diameter side (radially).

In the third embodiment, the duct 42 is installed in one stage in the axial direction, but it may be installed in multiple stages in the axial direction.

Next, we will explain the partial cross section taken along line C-C' in Figure 10.

Figure 11 is an explanatory diagram illustrating a partial cross section taken along line CC' in Figure 10.

As shown in FIG. 11, the duct 42 is a space separated by partition plates arranged radially in the circumferential direction. Air 12 flows in from the axial duct 30 installed on the rotor 6, flows from the inner diameter side to the outer diameter side, and flows out into the rear duct 31. This improves the cooling performance of the main generator 3.

The duct 42 of the rotor 6, i.e., the partition plate, bends at one point in the opposite direction (e.g., counterclockwise) to the rotation direction (e.g., clockwise) of the rotor 6. The duct 42 of the stator 7, i.e., the partition plate, also bends at one point in the opposite direction (e.g., counterclockwise) to the rotation direction (e.g., clockwise) of the rotor 6, i.e., in the same direction as the duct 42 of the rotor 6.

As a result, the air 12 flowing from the inner diameter side to the outer diameter side is refracted radially in the circumferential direction at one point in the rotor 6, and is refracted radially in the circumferential direction at one point in the stator 7, further improving the cooling performance of the main generator 3.

As a result, according to the third embodiment, even if the generator 100 has a tandem structure of the auxiliary generator 2 and the main generator 3 and an open axial-flow air-cooled cooling structure, the cooling performance of the main generator 3 can be improved.

In the third embodiment, the duct 42 is installed in the main generator 3, but ducts may be installed in the main generator 3 and the auxiliary generator 2. The duct installed in the auxiliary generator 2 is similar to the duct 42 installed in the main generator 3. This also improves the cooling performance of the auxiliary generator 2.

Next, we will explain the stator axial duct 43 in the generator 100 described in Example 4.

Figure 12 is an explanatory diagram illustrating the stator axial duct 43 in the generator 100 described in Example 4.

The generator 100 described in Example 4 has a stator axial duct 43 in the main generator 3.

As shown in FIG. 12, the stator axial ducts 43 are installed in the axial direction of the stator 7 of the main generator 3. A plurality of stator axial ducts 43 are installed in the circumferential direction on the outer diameter side of the stator 7. This allows air 12 to flow axially through the stator axial ducts 43, improving the cooling performance of the main generator 3.

In addition, by installing the stator axial duct 43, the flow area of the rear duct 31 of the main generator 3 increases by the flow area of the stator axial duct 43. In other words, the flow area of the portion bb shown in FIG. 4B increases. In other words, the cooling performance of the main generator 3 improves.

In addition, because the flow area of the bb portion is increased, even if the flow area of the aa portion is large, a predetermined flow area ratio (aa/bb) of 1.5 or less can be maintained, and the air flow rate of the stator axial duct 43 and the rear duct 31 can be increased.

As a result, according to the fourth embodiment, even if the generator 100 has a tandem structure of the auxiliary generator 2 and the main generator 3 and an open axial-flow air-cooled cooling structure, the cooling performance of the main generator 3 can be improved.

Next, we will explain the generator system for a dump truck that has the generator 100 described in this embodiment.

Figure 13 is an explanatory diagram illustrating a generator system for a dump truck having the generator 100 described in this embodiment.

The generator system for a dump truck (excitation type generator system) described in this embodiment has the generator 100 described in this embodiment, an electric blower 301, an engine 200, a power converter 201a, a power converter 201b, two electric motors 300 (e.g., a front wheel motor and a rear wheel motor), and an electric blower 301.

As shown in FIG. 13, in the generator system for a dump truck, the generator 100 is connected to the engine 200 via a coupling 50. By driving the engine 200, the generator 100 generates electric power. This electric power is supplied to the power converters 201a and 201b.

The power converter 201a supplies power to an electric motor 300 that drives a dump truck (vehicle), and the power converter 201b supplies power to accessories such as an electric blower 301 that generates air 12 to cool the generator 100.

In this way, by using the generator 100 described in this embodiment in a generator system for a dump truck, the cooling performance of the generator 100 can be improved, the generator 100 can be made smaller and lighter, the vehicle itself can be made smaller and lighter, and fuel efficiency can be improved.

The present invention is not limited to the examples described below, and includes various modified examples. For example, the examples described below are specifically described in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all of the configurations described.

It is also possible to replace part of the configuration of one embodiment with part of the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, add part of another configuration, and replace it with part of another configuration.

1. Frame
2. Auxiliary generator
3…Main generator
4, 6…Rotor
5, 7...Stator
8…Power supply device
9...Bearing
10…Shaft
11...Inlet
12. Air
13, 22...Rotor core
14, 23…Stator core
15, 24...Field winding
16, 25…Stator coil
17, 26…Gap
18…Pole shoe
19, 29…Stator wedges
20a, 20b...pillars
21, 31…Rear duct
27…Damper bar
28...Rotor wedge
30...Axial duct
39, 40... Coil end
41...Crossover
42…Duct
43…Stator axial duct
50...Coupling
100…Generator
200…Engine
201a, 201b...Power converter
300...Electric motor
301...Electric blower

Claims (6)

a frame having an inlet through which a refrigerant flows in an axial direction; a first generator cooled by the refrigerant flowing in from the inlet; a second generator cooled by the refrigerant that has cooled the first generator, the second generator being coaxially installed with the first generator and having a radial length longer than that of the first generator; and a generator from which the refrigerant that has cooled the second generator is discharged to the atmosphere in the axial direction,
a diameter of the frame at a portion where the first generator is installed is equal to a diameter of the frame at a portion where the second generator is installed,
a first rear duct through which the refrigerant flows in the axial direction is provided between the first generator and the frame, and a second rear duct through which the refrigerant flows in the axial direction is provided between the second generator and the frame,
a first coil end protruding from each of both ends in the axial direction of the first generator, and a second coil end protruding from each of both ends in the axial direction of the second generator, the first coil end on a downstream side in the axial direction and the second coil end on an upstream side in the axial direction facing each other so as to overlap in the radial direction without contacting each other,
The refrigerant that flows in from the inlet flows linearly in the axial direction through the first rear duct and then the second rear duct,
The installation position of the inlet coincides with the installation position of the first rear duct in the radial direction,
a plurality of first fixed parts are provided in a radial direction between the first generator and the frame, and the first rear duct through which the refrigerant flows is provided between the first fixed parts; a plurality of second fixed parts are provided in a radial direction between the second generator and the frame, and the second rear duct through which the refrigerant flows is provided between the second fixed parts;
A generator characterized in that the first fixed portion and the second fixed portion are installed so as to have the same circumferential pitch . a frame having an inlet through which a refrigerant flows in an axial direction; a first generator cooled by the refrigerant flowing in from the inlet; a second generator cooled by the refrigerant that has cooled the first generator, the second generator being coaxially installed with the first generator and having a radial length longer than that of the first generator; and a generator from which the refrigerant that has cooled the second generator is discharged to the atmosphere in the axial direction,
a diameter of the frame at a portion where the first generator is installed is equal to a diameter of the frame at a portion where the second generator is installed,
a first rear duct through which the refrigerant flows in the axial direction is provided between the first generator and the frame, and a second rear duct through which the refrigerant flows in the axial direction is provided between the second generator and the frame,
a first coil end protruding from each end of the first generator in the axial direction, a second coil end protruding from each end of the second generator in the axial direction, a jumper wire connecting the stator coils of the second generator is installed upstream of the second coil end in the axial direction, and at least the first coil end downstream in the axial direction and the jumper wire face each other so as to overlap in the radial direction without contacting each other,
The refrigerant that flows in from the inlet flows linearly in the axial direction through the first rear duct and then the second rear duct,
The installation position of the inlet coincides with the installation position of the first rear duct in the radial direction,
a plurality of first fixed parts are provided in a radial direction between the first generator and the frame, and the first rear duct through which the refrigerant flows is provided between the first fixed parts; a plurality of second fixed parts are provided in a radial direction between the second generator and the frame, and the second rear duct through which the refrigerant flows is provided between the second fixed parts;
A generator characterized in that the first fixed portion and the second fixed portion are installed so as to have the same circumferential pitch . The generator according to claim 1 or 2,
The second generator has a duct through which the refrigerant flows in a radial direction. 4. The generator according to claim 3 ,
A generator, characterized in that a rotor of the second generator has an axial duct through which the coolant flows in the axial direction. The generator according to claim 1 or 2,
A generator, characterized in that a stator of the second generator has an axial duct through which the refrigerant flows in the axial direction. A generator system for a dump truck, comprising the generator according to claim 1 or 2.

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