JP6988400B2 - Generator cooling structure - Google Patents

Description

The present invention relates to a cooling structure of a generator.

Vehicles such as motorcycles are equipped with a generator that uses the power of the engine to generate electricity. This type of generator has a rotor (rotor) that rotates by transmitting a force from a rotating shaft such as a crank shaft, and a stator (stator) that is arranged so as to face the rotor.

The generator generates heat during operation, and if the temperature becomes excessively high, the power generation efficiency will decrease. However, in a motorcycle or the like in which the space around the engine or the generator is limited, sufficient heat dissipation and cooling performance may not be obtained only by the air flow flowing around the generator. In particular, when using a generator with a large amount of power generation or when trying to reduce the size and weight of the generator while maintaining the amount of power generation, it is required to enhance the cooling performance of the generator.

For example, in the cooling structure of a generator described in Patent Document 1, a hollow portion is provided in a mounting boss portion of a generator connected to a rotating shaft such as a crank shaft, and a hollow portion is connected to a rotor on the side portion of the generator. An oil passage is provided to communicate with the stator to the gap. Oil is supplied to the hollow portion from the oil supply source on the crankcase side, and the oil guided from the hollow portion to the oil passage passes through the gap between the rotor and the stator to cool the generator.

Japanese Unexamined Patent Publication No. 63-234856

The cooling structure of the generator in Patent Document 1 is provided with a dedicated oil passage for guiding the oil to the generator in the cover covering the generator. Therefore, the formation of the oil passage causes an increase in the size and weight of the cover. Further, since it is necessary to provide an oil passage according to the shape of the cover, the shape of the oil passage tends to be complicated and the manufacturing man-hours increase. Further, depending on the injection location of the oil, a large amount of oil is required to satisfy the required cooling performance, which may have an adverse effect such as an insufficient amount of oil in the engine lubrication system and a decrease in oil pressure. Further, by injecting oil into the rotating rotor, the drag resistance due to the oil viscosity increases, and there is a possibility that the mechanical operation loss increases.

The present invention has been made in view of the above points, and an object of the present invention is to provide a cooling structure for a generator capable of performing efficient cooling with a simple configuration.

The present invention includes a rotor provided in a generator room covered with a generator cover, fixed to a crank shaft and rotating together with the crank shaft, and a stator fixed with a core facing a permanent magnet provided in the rotor. In the cooling structure that cools the generator, it is arranged outside the crank case that rotatably supports the crank shaft and the generator cover, and is equipped with an external pipe that supplies oil from the crank case into the generator cover to generate power. The machine cover is provided with an oil injection port that injects oil that has passed through an external pipe toward the generator, the oil injection port is arranged toward the outer periphery of the generator, and the generator cover is arranged in the crank case. On the side of the side, there is an oil passage for the mission that extends in the vertical direction of the engine and supplies the oil that has passed through the oil filter to the transmission mechanism, and the generator cover has an outer cylinder that surrounds the generator, and the external piping The starting end is attached to the lower end of the oil passage for the mission and is located below the outer cylinder, and the end of the external piping is attached to the front of the outer cylinder of the generator cover. The starting end is located closer to the center of the width of the engine than the ending, and the external piping is arranged along the outer surface of the crank case and generator cover so that the whole can be seen from the front. do.

According to the present invention, the generator can be efficiently cooled by a simple configuration consisting of an external pipe arranged outside the crankcase and the generator cover, and an oil injection port provided on the generator cover. can.

It is a left side view of the engine which concerns on this embodiment. It is a front view of the engine which concerns on this embodiment. It is a left side view of a crankcase. It is a right side view of a generator cover. It is a left side view of the generator cover in cross-sectional view along the VV line of FIG. It is sectional drawing which follows the VI-VI line of FIG. It is a figure which conceptually shows the flow of oil in an engine.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the front-rear, left-right, and up-down directions refer to the front-back, left-right, and up-down directions of the vehicle (motorcycle) equipped with the engine of the present embodiment. The left-right direction is the width direction of the engine. The object to which the engine provided with the cooling structure of the generator according to the present invention is mounted is not limited to the motorcycle, and the present invention may be applied to the engine of a four-wheeled vehicle, a ship, or the like.

1 and 2 show the appearance of the engine 10 of the present embodiment. The engine 10 is a V-type engine for motorcycles, and has a front bank 12F and a rear bank 12R arranged in the front-rear direction on the upper part of the crankcase 11.

As shown in FIG. 2, the crankcase 11 is composed of left and right splits, and has a left case 11a constituting the left half portion and a right case 11b constituting the right half portion. By aligning the left case 11a and the right case 11b, the crankshaft 60 (positions shown in FIGS. 3 and 5 when viewed from the side of the engine and an axial cross section is shown in FIG. 6) and the like are housed in the crankcase 11. A space is formed. The crankshaft 60 extends to the left and right, and a bearing portion 61 (see FIGS. 3 and 7) that rotatably supports the crankshaft 60 is formed in the crankcase 11. Although detailed illustration of the bearing portion 61 is omitted, the bearing portion 61 is formed in each of the left case 11a and the right case 11b, and supports the crank shaft 60 in a double-sided state. In the following description, the direction orthogonal to the axis (center) of the crank shaft 60 is defined as the radial direction, and the rotation direction centered on the axis of the crank shaft 60 is defined as the circumferential direction.

The front upper part and the rear upper part of the crankcase 11 are open. The cylinder block 13F is attached so as to close the opening at the upper front side of the crankcase 11. A cylinder head 14F and a cylinder head cover 15F are attached to the upper part of the cylinder block 13F to form a front bank 12F. The cylinder block 13R is attached so as to close the opening at the upper rear side of the crankcase 11. A cylinder head 14R and a cylinder head cover 15R are attached to the upper part of the cylinder block 13R to form a rear bank 12R. Pistons (not shown) that advance and retreat in the cylinder (not shown) are arranged in the cylinder blocks 13F and 13R, respectively. Each piston is connected to the crank shaft 60 via a connecting rod (not shown), and the forward / backward movement of each piston is transmitted via the connecting rod to rotate the crank shaft 60.

As shown in FIG. 2, a clutch cover 17 is attached to the side portion of the right case 11b of the crankcase 11. A clutch chamber (not shown) for accommodating a clutch mechanism (not shown) is formed between the right case 11b and the clutch cover 17. The rotation of the crankshaft 60 is transmitted to the transmission mechanism 62 (see FIG. 7) arranged in the transmission chamber (not shown) in the crankcase 11 via the clutch mechanism to drive the drive wheels (rear wheels) of the motorcycle. It is taken out as a driving force.

The speed change mechanism 62 has a drive shaft 63 extending in the left-right direction and a counter shaft 64 (see FIG. 3), and rotation is transmitted from the clutch mechanism to the drive shaft 63. A plurality of gears are supported on the drive shaft 63 and the counter shaft 64, respectively, and the gear ratio is changed by rearranging the meshing relationship of these gears. The crankcase 11 is formed with a bearing portion 65 and a bearing portion 66 that rotatably support the drive shaft 63 and the counter shaft 64 (see FIGS. 3 and 7), and covers the left side of the bearing portions 65 and 66. The sprocket cover 16 is attached to the side of the left case 11a (see FIG. 1).

The flow of oil lubricating the engine 10 is schematically shown in FIG. An oil chamber 50 for storing lubricating oil is provided in the lower part of the crankcase 11. The oil in the oil chamber 50 is pumped up by the oil pump 51 and sent to the oil filter 52. The oil filtered by the oil filter 52 is sent from the main gallery 53 to each part of the engine. FIG. 7 shows only a part of the plurality of oil passages extending from the main gallery 53. Oil is supplied to the bearing portion 61 that supports the crank shaft 60 via the oil passage 54. Oil is supplied to the bearing portion 65 and the bearing portion 66 that support the drive shaft 63 and the counter shaft 64 of the speed change mechanism 62 via the oil passage 55. Although not shown, the engine 10 further has an oil passage for supplying oil to the bearing portion supporting the balancer shaft provided in the crankcase 11 and an oil passage for supplying oil to the cylinder heads 14F and 14R. Etc. are arranged. The oil that lubricates each part of the engine 10 is finally collected in the oil chamber 50.

As shown in FIGS. 3 and 5, the oil passage 54 for guiding the oil to the crank shaft 60 and the oil passage 55 for guiding the oil to the transmission mechanism 62 are both provided on the left side surface of the crankcase 11 (left case 11a). There is. The oil filter 52 is provided on the lower front surface of the crankcase 11, and the starting end portion 56 of the oil passage 54 is located behind the oil filter 52. The oil passage 54 extends upward from the start end portion 56 and reaches the bearing portion 61. The start end portion 57 of the oil passage 55 is located behind the start end portion 56, and a relay passage 58 connecting the start end portion 56 to the start end portion 57 is formed. The oil passage 55 extends upward from the start end portion 57 while being inclined slightly rearward, and reaches the bearing portion 66.

An outer wall 11d projects from the side wall 11c (see FIG. 3) to the left on the side of the left case 11a of the crankcase 11. As shown in FIG. 3, the outer wall 11d is formed so as to surround the crank shaft 60 (bearing portion 61), and the end surface of the outer wall 11d is a mating surface 11e facing to the left.

The generator cover 20 is attached to the left side of the crankcase 11 so as to close the opening of the left case 11a surrounded by the outer wall 11d. The generator cover 20 has a lid portion 20a facing the side wall 11c of the crankcase 11 and an outer peripheral wall 20b protruding to the right from the peripheral edge of the lid portion 20a (see FIGS. 4 and 6). The outer wall 20b has a shape continuous with the outer wall 11d of the crankcase 11 in the left-right direction, and the end surface of the outer wall 20b is a mating surface 20c facing to the right (see FIG. 4).

When the mating surface 11e and the mating surface 20c are brought into contact with each other and the generator cover 20 is fastened and fixed to the crankcase 11, a generator chamber 21 (see FIG. 6) surrounded by the crankcase 11 and the generator cover 20 is formed. As shown in FIG. 3, the side wall 11c of the crankcase 11 is formed with a penetrating portion 11f that communicates the lowermost portion of the generator chamber 21 with the inside of the crankcase 11, and the oil that has entered the generator chamber 21 is formed. Can be returned to the inside of the crankcase 11 from the penetrating portion 11f.

As shown in FIG. 6, one end of the crank shaft 60 projects into the generator chamber 21, and the generator 30 that generates power by the rotation of the crank shaft 60 is housed in the generator chamber 21. The generator 30 of the present embodiment is an outer rotor type generator in which a permanent magnet located on the outer diameter side of the core (coil) rotates to generate an electromotive force, and is a bottomed cylindrical rotor as a rotor. It has 31 and has a stator 36 located inside the rotor 31 as a stator.

The rotor 31 has a bottom portion 32 facing the side wall 11c side (right side) of the crankcase 11, and an outer cylinder 33 and an inner cylinder 34 having a concentric cylindrical shape protruding left from the bottom portion 32. The inner peripheral surface of the outer cylinder 33 and the outer peripheral surface of the inner cylinder 34 are cylindrical surfaces that are radially opposed to each other and extend in the circumferential direction. A permanent magnet 35 is attached along the inner peripheral surface of the outer cylinder 33. In the permanent magnet 35, N poles and S poles are alternately arranged in the circumferential direction. For example, a plurality of magnets may be arranged in the circumferential direction by alternating the directions of the magnetic poles to form the permanent magnet 35, or the magnetizing states of the annular magnets continuous in the circumferential direction may be partially different to form the permanent magnet 35. May be configured. One end of the crank shaft 60 protruding into the generator chamber 21 is inserted into the center of the inner cylinder 34 in a press-fitted state, and when the engine is driven and the crank shaft 60 rotates, the rotor 31 rotates together with the crank shaft 60. do.

The stator 36 has a plurality of cores 38 that radiate from the annular base 37 surrounding the inner cylinder 34 of the rotor 31 toward the outer diameter side (see FIGS. 3 and 4). As shown in FIG. 6, each core 38 is a coil in which a conducting wire is wound around a core portion 38a made of a magnetic metal to form a conducting wire portion 38b. The stator 36 is fixed to the generator cover 20. When the generator cover 20 is attached to the crankcase 11, as shown in FIGS. 3 and 6, a predetermined gap is provided in the radial direction with respect to the inner peripheral surface of the permanent magnet 35, and the outer circumference of each core 38 of the stator 36 is formed. The parts face each other.

When the rotor 31 rotates with the rotation of the crank shaft 60, the N pole and the S pole of the permanent magnet 35 alternately pass outside the core 38 of the stator 36, so that the magnetic flux density passing through the core 38 changes and electromagnetic induction occurs. Causes a current to be generated in the core 38. The generator 30 generates alternating current, which is converted to direct current by a rectifier (not shown) and controlled by a voltage adjustment circuit (not shown) to a certain level or less. The electric power thus obtained by using the generator 30 is supplied to the electrical system of the motorcycle equipped with the engine 10.

The generator cover 20 has a base portion 22 having a mating surface 20c and attached to the left case 11a of the crankcase 11, and a side view circle that projects to the left from the base portion 22 and covers the outside of the generator 30. It has an outer cylinder portion 23 having a shape. In the outer cylinder portion 23, the outer peripheral wall 20b has a substantially cylindrical shape that surrounds the outer cylinder 33 of the rotor 31. A cylindrical mounting portion 24 projecting inward of the generator chamber 21 is formed substantially in the center of the lid portion 20a of the outer cylinder portion 23 (see FIGS. 4 and 6). The base portion 37 of the stator 36 is fitted to the mounting portion 24, and the mounting portion 24 and the base portion 37 are fixed with bolts (not shown) or the like. When the generator cover 20 is viewed from the side as shown in FIGS. 1 and 4, the base portion 22 projects downward and forward with respect to the outer cylinder portion 23, and a step is formed between the base portion 22 and the outer cylinder portion 23. Is formed.

In this embodiment, oil is injected into the generator 30 in the generator room 21 with a simple structure to cool the generator, and the details thereof will be described below.

As shown in FIGS. 1 to 3 and 5, the start end portion 40a of the oil pipe 40 is connected to the lower portion of the start end portion 57 of the oil passage 55 that sends oil to the transmission mechanism 62. The end portion 40b of the oil pipe 40 is connected to the connection portion 25 formed in the outer cylinder portion 23 of the generator cover 20. The oil pipe 40 is made of a metal or the like having excellent weather resistance and corrosion resistance.

When viewed from the side as shown in FIGS. 1, 3, and 5, the oil pipe 40 is arranged so as to fit inside the outer shell of the crankcase 11 and the generator cover 20 (do not protrude back and forth or up and down with respect to the engine 10). Has been done. More specifically, the oil pipe 40 extends diagonally upwardly forward from the starting end portion 40a, turns upward at the bent portion 40c, and extends upward along the oil passage 54. The oil pipe 40 extending to just below the outer cylinder portion 23 of the generator cover 20 turns forward at the bent portion 40d, along the left side surface of the base portion 22 and the outer peripheral surface on the front side of the outer cylinder portion 23. It extends forward while heading upward. Then, the terminal portion 40b is connected to the connection portion 25 formed on the front surface side of the outer cylinder portion 23.

When viewed from the front as shown in FIG. 2, the start end portion 40a of the oil pipe 40 is located closer to the center in the width direction of the engine 10 than the end portion 40b, and the oil pipe 40 is the outer surface of the crankcase 11 and the generator cover 20. It is arranged along the shape. More specifically, the oil pipe 40 extends upward while inclining to the left from the starting end portion 40a, and when it reaches directly below the base portion 22 of the generator cover 20, it turns to the left at the bent portion 40e. The oil pipe 40 that has reached the vicinity of the boundary between the base portion 22 and the outer cylinder portion 23 in the left-right direction turns upward at the bent portion 40f, and the left side surface of the base portion 22 and the outer peripheral surface on the front side of the outer cylinder portion 23. Extends along. Then, the bending portion 40g turns to the upper left and reaches the terminal portion 40b.

In summary, the oil pipe 40 includes the bent portion 40c (S), the bent portion 40e (T), the bent portion 40f (T), the bent portion 40d (S), and the bent portion 40 g (T) in order from the starting end portion 40a side. Have. It should be noted that (S) represents each bent portion having a bent shape when viewed from the side (FIGS. 1, 3, and 5), and (T) represents each bent portion having a bent shape when viewed from the front (FIG. 2). Represents a part. Each of these bent portions is set to have a gently curved shape so that the radius of curvature does not become too small, and oil can flow smoothly over the entire oil pipe 40.

The starting end portion 40a of the oil pipe 40 is connected to the lower part of the starting end portion 57 of the oil passage 55 by using a union bolt 41 having a hole for oil flow, and a part of the oil sent to the oil passage 55 is used. Enter the oil pipe 40 from the start end portion 40a (see FIG. 7).

As shown in FIGS. 5 and 6, the connection portion 25 is formed at the boundary portion between the lid portion 20a and the outer peripheral wall 20b on the front surface side of the outer cylinder portion 23 of the generator cover 20. An oil introduction hole 26 extending in the radial direction about the crank shaft 60 is provided inside the connection portion 25. The oil introduction hole 26 has an opening on the outer diameter side, and a union bolt 42 is inserted into the oil introduction hole 26 through the opening. A female screw is formed on the inner surface of the oil introduction hole 26, and a male screw formed on the outer peripheral surface of the shaft portion 42a of the union bolt 42 is screwed into the female screw in the oil introduction hole 26. The end portion 40b of the oil pipe 40 is connected to the shaft portion 42a of the union bolt 42, and the oil flow hole 42b formed in the union bolt 42 and the internal space of the oil pipe 40 communicate with each other. Therefore, in a state where the terminal portion 40b is connected to the connection portion 25 via the union bolt 42, a continuous oil passage is formed from the oil pipe 40 to the oil introduction hole 26 in the connection portion 25.

As shown in FIGS. 4 to 6, the generator cover 20 is formed with an oil injection port 43 extending to the right from the vicinity of the inner end of the oil introduction hole 26 in the connection portion 25 and opening into the generator chamber 21. Has been done. As shown in FIG. 5, the oil injection port 43 is located in front of the entire crank shaft 60 and below the center of the crank shaft 60.

The oil injection port 43 is, for example, a circular cross-sectional hole having a diameter of about 1 mm, and has an extremely small cross-sectional area as compared with the oil pipe 40 and the oil introduction hole 26. Therefore, the oil pressure-fed to the oil introduction hole 26 via the oil pipe 40 is vigorously injected into the generator chamber 21 through the oil injection port 43.

As shown in FIG. 6, the oil injection port 43 is located at a position facing the outer peripheral portion of the generator 30, and oil is injected from the oil injection port 43 toward the outer peripheral portion of the generator 30. More specifically, the gap between the permanent magnet 35 and the core 38 is located on the right side of the oil injection port 43, and the oil injected from the oil injection port 43 into the generator chamber 21 (shown by arrow A1 in FIG. 6). ) Reach the vicinity of the inner surface of the permanent magnet 35 and the outer surface of the core 38 in the generator 30. Then, the rotation of the rotor 31 transmits oil in the circumferential direction along the inner peripheral surface of the permanent magnet 35, and the oil adhering to the inner peripheral surface of the permanent magnet 35 cools the outer peripheral portion of the core 38 in the stator 36. In the generator 30, the core 38 tends to generate heat, and the outer peripheral portion of the core 38 is the portion where cooling is most required. Therefore, efficient cooling can be performed by guiding the cooling oil from the oil injection port 43 toward the outer peripheral portion of the core 38. On the other hand, since the calorific value of the central portion of the stator 36 where the base portion 37 is located is small, the need to supply cooling oil is low.

The oil that has entered between the permanent magnets 35 and the core 38 and contributed to cooling is discharged from the end of the rotor 31 to the outside of the generator 30 by the centrifugal force of the rotating rotor 31. More specifically, since the oil injection port 43 is located on the left side of the generator 30, oil is injected to the left end side of the generator 30. Since the gap between the inner peripheral surface of the permanent magnet 35 and the outer peripheral portion of the core 38 is narrow, it is necessary for cooling without passing wasteful oil to the inner side of the generator 30 (to the right where the bottom 32 of the rotor 31 is located). A moderate amount of oil can be distributed in the gap. Then, the oil that has taken heat from the core 38 and the like is discharged from the gap by the centrifugal force of the rotor 31. The discharged oil travels along the inner surface of the generator cover 20 or naturally falls, moves downward in the generator chamber 21, and passes through the penetration portion 11f (FIG. 3) formed in the crankcase 11. It is collected in the oil chamber 50 (FIG. 7).

With the above cooling structure, cooling oil can be efficiently supplied to the generator 30 by a configuration that can be easily and inexpensively obtained. First, oil is sent from the start end portion 57 of the oil passage 55 constituting the lubrication structure of the engine 10 to the oil injection port 43 formed in the generator cover 20 via the oil pipe 40 which is an external pipe. Therefore, neither the crankcase 11 nor the generator cover 20 can guide the cooling oil to the generator 30 without providing a complicated oil passage inside.

In the crankcase 11, since it is only necessary to connect the start end portion 40a of the oil pipe 40 to the lower portion of the start end portion 57 of the oil passage 55, the existing lubrication structure can be configured with almost no modification. The generator cover 20 has a space-saving and simple structure in which an oil injection port 43 is formed in a connection portion 25 provided near the outer periphery of the outer cylinder portion 23. Therefore, while providing an oil-cooled cooling structure for cooling the generator 30, it is possible to avoid increasing the size of the crankcase 11 and the generator cover 20 and complicating the internal structure. If the structure of the crankcase 11 and the generator cover 20 is simple, the productivity can be increased and the manufacturing cost can be suppressed. In addition, even if an existing engine that does not have an oil-cooled cooling function for the generator is used as a base, an oil pipe 40 can be added or replaced with a generator cover 20 (addition of a connection portion 25 and an oil injection port 43). An oil-cooled cooling function can be realized with small changes such as. Therefore, it is also excellent in terms of high versatility.

The oil filter 52 is located in front of and below the crank shaft 60, and the starting end 57 of the oil passage 55, which is a branch point from the engine lubrication system to the generator cooling system, is behind the crank shaft 60. It is located below (see Fig. 3). The oil injection port 43, which is the end of the generator cooling system, is located in front of the crank shaft 60 and below the center of the crank shaft 60 (see FIG. 5). Therefore, the oil path from passing through the oil filter 52 to the oil injection port 43 is centrally arranged in the region from the lower part to the front side of the crank shaft 60, and the generator cooling system can be configured in a space-saving manner. ..

More specifically, as shown in FIGS. 1 and 5, the oil pipe 40 extends upward from the start end portion 57 of the oil passage 55 to just below the outer cylinder portion 23 of the generator cover 20, and subsequently the outer cylinder portion 23. Along the outer circumference (passing on the left side surface of the base portion 22 in a side view), it extends to the connection portion 25. The oil pipe 40 arranged in this way fits inside the outer shell of the crankcase 11 in a side view and does not protrude in the front-rear direction or the up-down direction, so that the oil pipe 40 is excellent in terms of protection and space efficiency. Further, since the oil pipe 40 rotates from the lower side to the front side of the generator 30 and is connected to the connection portion 25 near the outer peripheral portion of the generator 30, the route does not affect the layout of other parts. Can be shortened.

As shown in FIG. 2, of the engine 10, the vicinity of the lower front portion of the crankcase 11 provided with the oil filter 52 has a small width in the left-right direction when viewed from the front, and the position of the left side surface of the left case 11a is particularly the engine. It is largely squeezed toward the center side in the width direction of 10. The starting end portion 40a of the oil pipe 40 is arranged at a position along the left side surface of the lower portion of the left case 11a. The vicinity of the terminal portion 40b, which is the outermost end of the oil pipe 40 that is farthest from the center in the width direction in the front view, is the left side surface (cover portion 20a) of the generator cover 20 that protrudes to the left of the left case 11a. ) And are arranged. That is, the oil pipe 40 is accommodated within the width of the engine 10 in the left-right direction, and in particular, the outer end of the oil pipe 40 is arranged so as to overlap the outer surface of the generator cover 20 in the front view. As a result, the oil pipe 40 is arranged in a space-efficient manner without affecting the layout of other parts (without widening the width of the engine 10) not only in the side view but also in the front view. Further, since the oil pipe 40 does not protrude in the left-right direction of the engine 10, the bank angle is not limited by the oil pipe 40. Even if the motorcycle falls to the left, the generator cover 20 first comes into contact with the ground to protect the oil pipe 40, so that oil leakage or the like due to damage to the oil pipe 40 can be prevented.

Since the length of the oil pipe 40 is kept short by the space-saving arrangement as described above, it is possible to reduce the pressure loss of the oil in the generator cooling system. Further, since the oil pipe 40 is set to a simple path that extends in the vertical direction and then extends along the outer periphery of the outer cylinder portion 23 of the generator cover 20, the oil can flow smoothly in the oil pipe 40. Can be done. Therefore, the load on the oil pump 51 can be suppressed.

Further, an oil branch point to the generator cooling system is set at a position (starting end portion 57 of the oil passage 55) before (upstream side) toward the speed change mechanism 62 after passing through the oil filter 52. Since the main gallery 53 is not directly branched to the oil pipe 40 (see FIG. 7), it is possible to suppress the hydraulic pressure drop and the hydraulic pressure fluctuation of the main gallery 53. Further, since the branch to the oil pipe 40 is performed before proceeding to the speed change mechanism 62, the conditions such as hydraulic pressure in the generator cooling system are stable, and excellent cooling performance for the generator 30 can be obtained. ..

The oil injection position of the oil injection port 43 is optimized so that the generator 30 can be efficiently cooled with a small amount of oil. The main heat source of the generator 30 is the core 38 (particularly the outer peripheral portion), but instead of simply injecting oil only toward the core 38, the permanent magnet 35 and the core provided on the inner circumference of the rotating rotor 31 are provided. An oil injection port 43 is provided at a position facing the gap of 38. When oil is injected from the oil injection port 43 arranged at the position, the oil easily enters the gap between the permanent magnet 35 and the core 38, and the oil that has entered the gap is transferred to a wide range in the circumferential direction by the rotation of the rotor 31. .. In other words, the rotating rotor 31 is used as part of the cooling structure of the generator 30. As a result, the oil can be distributed not only to the specific position in the circumferential direction in which the oil injection port 43 is provided but also to the outer peripheral portion of the core 38 in the entire circumferential direction. Then, since a high cooling effect of the core 38 can be obtained over the entire circumference of the generator 30 with a small amount of oil, oil is applied to the rotating portion (bottom 32 of the rotor 31, inner cylinder 34, etc.) where cooling is less necessary. It is possible to reduce adhesion and suppress drag resistance and stirring resistance due to oil viscosity. That is, it is possible to reduce the mechanical operation loss during the operation of the generator 30.

Further, if the amount of oil used for cooling the generator 30 is small, the load on the oil pump 51 is reduced, and the amount of oil for lubrication of each part of the engine 10 and fluctuations in oil pressure are suppressed. As a result, it is possible to prevent an adverse effect on the lubrication performance while cooling the generator 30 by using the lubricating oil.

In the generator 30, no changes such as providing a cooling oil passage in the rotor 31 and the stator 36 have been made, and a generator having a general configuration can be used, so that the number of parts increases and the manufacturing cost increases. Does not lead to an increase in.

The amount of oil supplied to the generator 30 and the strength of the oil injection can be changed by setting the oil pipe 40 and the oil injection port 43. For example, when the inner diameter size or the curvature of the bent portion of the oil pipe 40 is changed, the pipeline resistance changes. Therefore, it is possible to adjust the hydraulic pressure to an appropriate level by changing the setting of the oil pipe 40 without providing a special orifice or the like in the oil passage of the crankcase 11 or the generator cover 20. In particular, since the oil pipe 40, which is an external pipe, can be retrofitted with the engine 10 assembled, it is possible to easily replace parts and change settings for the purpose of adjusting the hydraulic pressure.

As described above, according to the cooling structure of the generator according to the present embodiment, the oil pipe 40 arranged outside the crank case 11 and the generator cover 20, and the oil injection provided on the generator cover 20. The generator 30 can be efficiently cooled by a simple configuration including the mouth 43.

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size, shape, and the like shown in the accompanying drawings are not limited to this, and can be appropriately changed within the range in which the effects of the present invention are exhibited. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

For example, in the above embodiment, the connection portion 25 (including the oil injection port 43) is integrally formed with the generator cover 20, but the connection portion 25 is formed as a separate member from the generator cover 20. It is also possible to attach it to the generator cover 20.

The generator 30 of the above embodiment is an outer rotor type in which the rotating rotor 31 is located on the outer diameter side and the non-rotating stator 36 is located on the inner diameter side. Unlike this, the present invention can also be applied as a cooling structure for an inner rotor type generator in which the rotor is arranged on the inner diameter side and the stator is arranged on the outer diameter side.

As described above, the present invention has an effect that the generator can be efficiently cooled with a simple configuration, and is particularly useful for an engine or the like equipped with a small and lightweight generator having a large amount of power generation.

10: Engine 11: Crank case 12F: Front bank 12R: Rear bank 13F: Cylinder block 13R: Cylinder block 14F: Cylinder head 14R: Cylinder head 15F: Cylinder head cover 15R: Cylinder head cover 16: Sprocket cover 17: Clutch cover 20: Generator cover 21: Generator room 22: Base part 23: Outer cylinder part 24: Mounting part 25: Connection part 26: Oil introduction hole 30: Generator 31: Rotor 33: Outer cylinder 34: Inner cylinder 35: Permanent magnet 36: Stator 37: Base 38: Core 40: Oil pipe (external piping)
41: Union bolt 42: Union bolt 43: Oil injection port 50: Oil chamber 51: Oil pump 52: Oil filter 53: Main gallery 54: Oil passage 55: Oil passage (oil passage for mission)
58: Relay passage 60: Crank shaft 61: Bearing part 62: Speed change mechanism 63: Drive shaft 64: Counter shaft 65: Bearing part 66: Bearing part

Claims (6)

In a generator room covered with a generator cover, a generator having a rotor fixed to a crank shaft and rotating together with the crank shaft, and a stator fixed with a core facing a permanent magnet provided in the rotor is provided. Prepare,
A crankcase that rotatably supports the crank shaft and an external pipe that is arranged outside the generator cover and supplies oil from the crankcase into the generator cover are provided.
The generator cover includes an oil injection port that injects oil that has passed through the external pipe toward the generator, and the oil injection port is arranged toward the outer peripheral portion of the generator .
A transmission oil passage that extends in the vertical direction of the engine and supplies oil that has passed through an oil filter to the transmission mechanism is provided on the side surface of the crankcase on the side where the generator cover is arranged.
The generator cover has an outer cylinder portion that surrounds the generator.
The starting end of the external pipe is attached to the lower end of the oil passage for the mission and is located below the outer cylinder.
The end portion of the external pipe is attached to the front surface of the outer cylinder portion of the generator cover.
When viewed from the front, the start end portion of the external pipe is located closer to the center in the width direction of the engine than the end portion.
The external piping is arranged along the outer surface of the crankcase and the generator cover, and is characterized in that the entire structure can be visually recognized from the front view. The rotor has a bottomed cylindrical shape whose central portion is fixed to the crank shaft, the permanent magnet is arranged on the inner circumference of the cylindrical portion of the rotor, and the core of the stator is located inside the cylindrical portion. ,
The cooling structure for a generator according to claim 1, wherein the oil injection port is arranged so as to inject oil toward a gap between the permanent magnet and the core. The cooling structure for a generator according to claim 1 or 2, wherein the oil injection port is located in front of the crank shaft and below the center of the crank shaft. In front plane view, the end portion of the outer pipe, in any one of claims 1, characterized in that it aligns the position and the side surface of the generator cover in the width direction of the engine 3 The cooling structure of the generator described. When viewed from the side, the external pipe is arranged within a range that fits within the outer shell of the crankcase and the generator cover, extends diagonally upward from the starting end portion, and changes its direction upward at the bending portion to the outside. claim extends to just below the cylindrical portion extends forwardly while directed upward along the outer circumferential surface of the front side of the outer cylindrical portion, the end portion on the front surface of the outer cylindrical portion and wherein the connecting 1 The cooling structure of the generator according to any one of 4 to 4. The lower end of the mission oil passage and the start end of the external pipe are located on the side of the oil filter in the front view and behind the oil filter in the side view.
The cooling structure for a generator according to any one of claims 1 to 5, wherein the end portion of the external pipe is located above the oil filter in a side view.

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