JP2019097240A - Cooling structure of dynamo-electric generator - Google Patents

Abstract

To provide a cooling structure of a dynamo-electric generator, capable of performing an efficient cooling with a simple structure.SOLUTION: A cooling structure cooling a dynamo-electric generator (30) that includes: a rotor (31) provided into a dynamo-electric generator chamber (21) covered with a dynamo-electric generator cover (20), fixed to a crank axis (60), and rotated with the crank axis; and a stator (36) fixed to a permanent magnet (35) provided to the rotor while facing a core (38), comprises: a crank case (11) rotatably supporting the crank axis; and an external pipe (40) distributed to an external part of the dynamo-electric generator cover, and supplying an oil into the dynamo-electric generator cover from the crank case. The dynamo-electric generator cover comprises an oil injection port (43) injecting the oil passing through the external pipe to the dynamo-electric generator, and the oil injection port is arranged toward an outer peripheral part of the dynamo-electric generator.SELECTED DRAWING: Figure 5

Description

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

  A vehicle such as a motorcycle includes a generator that generates power using the power of an engine. A generator of this type has a rotor (rotor) that is rotated when a force is transmitted from a rotating shaft such as a crankshaft, and a stator (stator) disposed opposite to the rotor.

  The generator generates heat during operation, and if the temperature becomes excessively high, the power generation efficiency decreases. However, in the case of a motorcycle or the like in which the space around the engine or generator is limited, sufficient heat dissipation and cooling performance may not be obtained with only the air flow flowing around the generator. In particular, in the case of using a generator with a large amount of power generation, or in the case of reducing 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 generator cooling structure described in Patent Document 1, a hollow portion is provided in a mounting boss portion of the generator connected to a rotating shaft such as a crankshaft, and a rotor from the hollow portion to the side portion of the generator An oil passage is provided which communicates with the gap with the stator. Oil is supplied from the oil supply source on the crankcase side to the hollow portion, and the oil guided from the hollow portion to the oil passage cools the generator through the gap between the rotor and the stator.

JP-A-63-234856

  In the generator cooling structure in Patent Document 1, a dedicated oil passage for guiding oil to the generator is provided in a cover that covers the generator. Therefore, the formation of the oil passage results in an increase in the size and weight of the cover. In addition, since it is necessary to provide an oil passage in accordance with the shape of the cover, the shape of the oil passage is likely to be complicated, and the number of manufacturing steps is also increased. In addition, depending on the injection location of the oil, a large amount of oil is required to satisfy the necessary cooling performance, which may have an adverse effect such as an insufficient amount of oil in the engine lubrication system or a drop in oil pressure. In addition, by injecting the oil to the rotating rotor, the drag resistance due to the oil viscosity may be increased, and the mechanical operation loss may be increased.

  This invention is made in view of the point which concerns, It aims at providing the cooling structure of the generator which can perform efficient cooling by easy structure.

  According to the present invention, there is provided a rotor provided in a generator chamber covered with a generator cover, fixed to a crankshaft and rotating with the crankshaft, and a stator fixed with a core facing a permanent magnet provided on the rotor. A cooling structure for cooling a generator, comprising: a crankcase for rotatably supporting a crankshaft; and an external pipe provided outside the generator cover and supplying oil from the crankcase into the generator cover; The machine cover includes an oil injection port for injecting oil having passed through the external pipe toward the generator, and the oil injection port is disposed toward the outer peripheral portion of the generator.

  According to the present invention, efficient cooling of the generator can be performed by a simple configuration including the crankcase and the external piping disposed outside the generator cover, and the oil injection port provided on the generator cover. it can.

It is a left side view of an engine concerning this embodiment. It is a front view of an engine concerning this embodiment. It is a left view of a crankcase. It is a right view of a generator cover. FIG. 5 is a left side view of the generator cover in cross section taken along the line VV of FIG. 2; FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. It is a figure which shows the flow of the oil in an engine notionally.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Front, rear, right, left, upper and lower directions in the following description refer to front, rear, left, right, upper and lower of a vehicle (motorcycle) equipped with the engine of the present embodiment. The lateral direction is the width direction of the engine. In addition, the object which mounts the engine provided with the cooling structure of the generator which concerns on this invention is not restricted to a two-wheeled motor vehicle, You may apply this invention to engines, such as a four-wheeled vehicle and a ship.

  1 and 2 show the appearance of the engine 10 according to the present embodiment. The engine 10 is a V-type engine for a motorcycle, and includes 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 configured by left and right division, and has a left case 11 a that configures a left half portion and a right case 11 b that configures a right half portion. By aligning the left case 11a and the right case 11b, the crankshaft 60 (the position in a side view of the engine is shown in FIGS. 3 and 5 and the axial cross section in FIG. 6) is accommodated in the crankcase 11. Space is formed. The crankshaft 60 extends to the left and right, and a bearing 61 (see FIGS. 3 and 7) for rotatably supporting the crankshaft 60 is formed on 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 11 a and the right case 11 b, and supports the crankshaft 60 in a double-held state. In the following description, the direction orthogonal to the axial line (center) of the crankshaft 60 is taken as the radial direction, and the rotational direction about the axial line of the crankshaft 60 is taken as the circumferential direction.

  The front upper portion and the rear upper portion of the crankcase 11 are opened. A cylinder block 13F is attached so as to close the opening on the front upper side of the crankcase 11. A cylinder head 14F and a cylinder head cover 15F are attached to an upper portion of the cylinder block 13F to constitute a front bank 12F. A cylinder block 13R is attached to close an opening at the rear upper portion of the crankcase 11. The cylinder head 14R and the cylinder head cover 15R are attached to the upper portion of the cylinder block 13R to form a rear bank 12R. In each of the cylinder blocks 13F and 13R, pistons (not shown) that move in and out of cylinders (not shown) are disposed. Each piston is connected to the crankshaft 60 via a connecting rod (not shown), and the forward and backward movement of each piston is transmitted via the connecting rod to rotate the crankshaft 60.

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

  The transmission mechanism 62 has a drive shaft 63 and a counter shaft 64 (see FIG. 3) extending in the left-right direction, and the 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 changing the meshing relationship of these gears. A bearing portion 65 and a bearing portion 66 for rotatably supporting the drive shaft 63 and the counter shaft 64 are formed in the crankcase 11 (see FIGS. 3 and 7), and the left side of each bearing portion 65, 66 is covered. A sprocket cover 16 is attached to the side of the left case 11a (see FIG. 1).

  The flow of oil for lubricating the engine 10 is schematically shown in FIG. At the lower part in the crankcase 11, an oil chamber 50 for storing lubricating oil is provided. 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. In FIG. 7, only a part of the plurality of oil passages extending from the main gallery 53 is shown. Oil is supplied to the bearing 61 supporting the crankshaft 60 via the oil passage 54. Oil is supplied to the bearing portion 65 and the bearing portion 66 supporting the drive shaft 63 and the counter shaft 64 of the transmission mechanism 62 via the oil passage 55. Although not shown, in the engine 10, an oil passage for supplying oil to a bearing portion for supporting a 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 has lubricated each part of the engine 10 is finally collected in the oil chamber 50.

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

  In the side portion of the left case 11a of the crankcase 11, an outer surrounding wall 11d protrudes leftward from a side wall 11c (see FIG. 3). As shown in FIG. 3, the outer wall 11 d is formed so as to surround the crankshaft 60 (bearing portion 61), and the end surface of the outer wall 11 d is a mating surface 11 e facing to the left.

  A 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 surrounding wall 11d. The generator cover 20 has a lid 20a facing the side wall 11c of the crankcase 11 and an outer wall 20b protruding rightward from the periphery of the lid 20a (see FIGS. 4 and 6). The outer wall 20b has a shape that is 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 rightward (see FIG. 4).

  When the mating face 11e is brought into contact with the mating face 20c 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 11 c of the crankcase 11 is formed with a penetrating portion 11 f that causes the lowermost portion of the generator chamber 21 to communicate with the inside of the crankcase 11. Can be returned into the crankcase 11 from the through portion 11 f.

  As shown in FIG. 6, one end of a crankshaft 60 protrudes into the generator chamber 21, and a generator 30 that generates electric power by rotation of the crankshaft 60 is accommodated in the generator chamber 21. The generator 30 according to 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 a cylindrical rotor with a bottom as a rotor. 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 11 c side (right direction) of the crankcase 11, and a concentric cylindrical outer cylinder 33 and an inner cylinder 34 protruding leftward 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 extending in the circumferential direction, facing each other in the radial direction. A permanent magnet 35 is attached along the inner circumferential 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, the permanent magnet 35 may be configured by arranging a plurality of magnets in the circumferential direction by alternately arranging the directions of the magnetic poles, or by partially changing the magnetization state of the annular magnet continuous in the circumferential direction. May be configured. One end of a crankshaft 60 projecting into the generator chamber 21 is inserted in the center of the inner cylinder 34 in a press-fit state, and when the engine is driven to rotate the crankshaft 60, the rotor 31 rotates with the crankshaft 60. Do.

  The stator 36 has a plurality of cores 38 radially protruding outward from an annular base 37 surrounding the inner cylinder 34 of the rotor 31 (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 38a made of magnetic metal to form a conducting wire 38b. The stator 36 is fixed relative to the generator cover 20. When the generator cover 20 is attached to the crankcase 11, as shown in FIG. 3 and FIG. 6, the outer periphery of each core 38 of the stator 36 is spaced apart from the inner peripheral surface of the permanent magnet 35 by a predetermined gap in the radial direction. The parts face each other.

  When the rotor 31 rotates with the rotation of the crankshaft 60, the N pole and the S pole of the permanent magnet 35 alternately pass through the outside of the core 38 of the stator 36, so that the magnetic flux density passing through the core 38 changes. Generates a current in the core 38. What is generated by the generator 30 is an alternating current, which is converted to a direct current by a rectifier (not shown) and controlled to a constant voltage or less by a voltage adjustment circuit (not shown). The electric power obtained by using the generator 30 in this manner is supplied to the electrical system of the two-wheeled motor vehicle on which the engine 10 is mounted.

  The generator cover 20 has a mating surface 20 c and is a base portion 22 attached to the left case 11 a of the crankcase 11, and a side view substantially circle that protrudes leftward from the base portion 22 and covers the outside of the generator 30. And an outer cylindrical portion 23 of a shape. In the outer cylinder portion 23, the outer surrounding wall 20 b has a substantially cylindrical shape surrounding the outer cylinder 33 of the rotor 31. A cylindrical attachment portion 24 projecting inward of the generator chamber 21 is formed at substantially the center of the lid portion 20a of the outer cylindrical 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 by 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 protrudes downward and forward with respect to the outer cylindrical portion 23, and a step between the base portion 22 and the outer cylindrical portion 23 Is formed.

  In the present embodiment, oil is injected and cooled with a simple structure to the generator 30 in the generator chamber 21. The details will be described below.

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

  When viewed from the side as shown in FIGS. 1, 3 and 5, the oil pipe 40 is disposed so as to fit within the outer shell of the crankcase 11 and the generator cover 20 (does not project forward or backward or vertically with respect to the engine 10). It is done. More specifically, the oil pipe 40 extends obliquely upward from the start end 40 a, turns upward at the bending portion 40 c, and extends upward along the oil passage 54. The oil pipe 40 extending immediately below the outer cylindrical portion 23 of the generator cover 20 turns forward at the bending portion 40 d, and along the left side surface of the base portion 22 and the outer peripheral surface on the front side of the outer cylindrical portion 23, It extends forward while going upward. Then, the end portion 40 b is connected to the connection portion 25 formed on the front side of the outer cylindrical portion 23.

  When viewed from the front as shown in FIG. 2, the start end 40 a of the oil pipe 40 is located closer to the widthwise center of the engine 10 than the end 40 b, and the oil pipe 40 has the crankcase 11 and the outer surface of 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 start end 40a, and when it reaches just below the base 22 of the generator cover 20, turns to the left at the bending portion 40e. The oil pipe 40 reaching 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 bending portion 40f, and the left outer surface of the base portion 22 and the outer peripheral surface on the front side of the outer cylinder portion 23 It extends along the And it turns to upper left with the bending part 40g, and reaches the terminal part 40b.

  In summary, the oil pipe 40 includes, in order from the side of the start end 40a, a bent portion 40c (S), a bent portion 40e (T), a bent portion 40f (T), a bent portion 40d (S), and a bent portion 40g (T). Have. In addition, (S) represents each bending part which becomes bending shape in the state (FIG. 1, FIG. 3, FIG. 5) seen from the side, (T) is each bending which becomes bending shape in the state (FIG. 2) seen from the front. Represents a department. Each of these bent portions is set to a gently curved shape so that the radius of curvature does not become too small, and oil can flow smoothly throughout the oil pipe 40.

  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 using a union bolt 41 having a hole for oil circulation, and a part of the oil sent to the oil passage 55 It enters into the oil pipe 40 from the start end 40a (see FIG. 7).

  As shown in FIG. 5 and FIG. 6, the connection portion 25 is formed on the front surface side of the outer cylindrical portion 23 of the generator cover 20 at the boundary between the lid portion 20 a and the outer wall 20 b. An oil introducing hole 26 extending in a radial direction centering on the crank shaft 60 is provided in the inside of the connecting portion 25. The oil introduction hole 26 is open at the end 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 40 b of the oil pipe 40 is connected to the shaft portion 42 a of the union bolt 42, and the oil passage hole 42 b formed in the union bolt 42 communicates with the internal space of the oil pipe 40. Therefore, in the state where the end portion 40 b is connected to the connection portion 25 via the union bolt 42, an oil passage continuous from the oil pipe 40 to the oil introduction hole 26 in the connection portion 25 is formed.

  As shown in FIGS. 4 to 6, the generator cover 20 is formed with an oil injection port 43 which extends rightward from the vicinity of the inner end of the oil introduction hole 26 in the connection portion 25 and opens in the generator chamber 21. It is done. As shown in FIG. 5, the oil injection port 43 is located forward of the entire crankshaft 60 and located lower than the center of the crankshaft 60.

  The oil injection port 43 is, for example, a circular cross-sectional hole having a diameter of about 1 mm, and its cross-sectional area is extremely small compared to 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 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 to the right of the oil injection port 43, and oil injected from the oil injection port 43 into the generator chamber 21 (indicated by arrow A1 in FIG. 6). ) Of the generator 30 reach near the inner surface of the permanent magnet 35 and the outer surface of the core 38. Then, the oil is transmitted in the circumferential direction along the inner peripheral surface of the permanent magnet 35 by the rotation of the rotor 31, and the oil attached 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 is apt to generate heat, and in particular, the outer peripheral portion of the core 38 is the portion most required to be cooled. 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 central portion of the stator 36 where the base portion 37 is located has a small amount of heat generation, the need for supplying the cooling oil is low.

  The oil that has entered between the permanent magnet 35 and the core 38 and contributed to the 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 to the left 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 waste oil to the back side of the generator 30 (right side 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 falls naturally, and moves downward in the generator chamber 21 to pass through the through portion 11 f (FIG. 3) formed in the crankcase 11. It is collected to the oil chamber 50 (FIG. 7).

  In the above cooling structure, the oil for cooling can be efficiently supplied to the generator 30 by the structure obtained simply and inexpensively. First, oil is fed from the start end portion 57 of the oil passage 55 constituting the lubricating structure of the engine 10 to the oil injection port 43 formed in the generator cover 20 through the oil pipe 40 which is an external pipe. Therefore, the cooling oil can be guided to the generator 30 without providing any complicated oil passage inside the crankcase 11 and the generator cover 20.

  In the crankcase 11, it is only necessary to connect the start end 40a of the oil pipe 40 to the lower portion of the start end 57 of the oil passage 55. Therefore, the existing lubrication structure can be configured with little change. The generator cover 20 has a space-saving and simple configuration in which the oil injection port 43 is formed in the connection portion 25 provided near the outer periphery of the outer cylinder portion 23. Therefore, while providing the oil-cooling type cooling structure for cooling the generator 30, the enlargement of the crankcase 11 and the generator cover 20 and the complication of the internal structure can be avoided. If the structures of the crankcase 11 and the generator cover 20 are simple, the productivity can be enhanced and the manufacturing cost can be suppressed. In addition, even when based on an existing engine that does not have an oil-cooled cooling function for the generator, the addition of the oil pipe 40 or the replacement of the generator cover 20 (addition of the connection 25 and the oil injection port 43) Oil-cooling type cooling function can be realized with minor changes such as Therefore, it is also excellent in terms of versatility.

  The oil filter 52 is located forward and downward of the crankshaft 60, and the start end 57 of the oil passage 55, which is a branch point from the engine lubrication system to the generator cooling system, Located below (see Figure 3). An oil injection port 43 which is an end of the generator cooling system is located forward of the crankshaft 60 and lower than the center of the crankshaft 60 (see FIG. 5). Therefore, the oil path from the oil filter 52 to the oil injection port 43 is concentratedly arranged in the area from the lower part of the crankshaft 60 to the front, and the generator cooling system can be configured in a space-saving manner. .

  More specifically, as shown in FIG. 1 and FIG. 5, the oil pipe 40 extends upward from the start end 57 of the oil passage 55 to just below the outer cylindrical portion 23 of the generator cover 20. It extends to the connection portion 25 along the outer periphery (through the left side surface of the base portion 22 in a side view). The oil pipe 40 arranged in this manner is accommodated in 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. Therefore, the oil pipe 40 is excellent in the protection of the oil pipe 40 and space efficiency. Further, the oil pipe 40 is connected to the connecting portion 25 in the vicinity of the outer peripheral portion of the generator 30 by turning from the lower side to the front side of the generator 30 in side view. Can be shortened.

  As shown in FIG. 2, of the engine 10, the width in the left-right direction is small in front view near the front lower portion of the crankcase 11 provided with the oil filter 52, and in particular, the position of the left side of the left case 11a It is greatly squeezed to the width direction center side of 10. The start end 40a of the oil pipe 40 is disposed at a position along the left side surface of the lower portion of the left case 11a. The left end surface 40a of the generator cover 20 protrudes leftward relative to the left case 11a in the vicinity of the end 40b of the oil pipe 40 which is the outer end farthest from the center in the width direction of the engine 10 in front view. Aligned with)). 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 to overlap the outer surface of the generator cover 20 in front view. As a result, the oil pipe 40 is disposed space-efficiently without affecting the layout of other components (without increasing the width of the engine 10) not only in side view but also in front view. In addition, since the oil pipe 40 does not protrude in the left-right direction of the engine 10, the oil pipe 40 does not limit the bank angle. Even if the motorcycle falls over to the left, since the generator cover 20 first contacts the ground to protect the oil pipe 40, it is possible to prevent oil leakage and the like due to damage to the oil pipe 40.

  Since the length of the oil pipe 40 is kept short by the space-saving arrangement as described above, the pressure loss of oil in the generator cooling system can be reduced. In addition, since the oil pipe 40 is set to a simple path extending in the vertical direction and then extending along the outer periphery of the outer cylindrical portion 23 of the generator cover 20, oil can be flowed smoothly in the oil pipe 40. Can. Therefore, the burden on the oil pump 51 can be suppressed.

  Further, an oil branch point to the generator cooling system is set at a position (a start end portion 57 of the oil passage 55) in the front (upstream side) toward the transmission mechanism 62 after passing through the oil filter 52. Since branching from the main gallery 53 directly to the oil pipe 40 is not performed (see FIG. 7), it is possible to suppress the hydraulic pressure drop and hydraulic pressure fluctuation of the main gallery 53. Further, since the branching to the oil pipe 40 is performed before proceeding to the transmission mechanism 62, conditions such as oil 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 as to efficiently cool the generator 30 with a small amount of oil. The main heat generation source of the generator 30 is the core 38 (especially the outer peripheral portion), but the oil is not injected only to the core 38, but the permanent magnet 35 and the core provided on the inner periphery of the rotating rotor 31 An oil injection port 43 is provided at a position facing the gap 38. When oil is injected from the oil injection port 43 disposed at the relevant position, the oil easily enters the gap between the permanent magnet 35 and the core 38, and the oil entering 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 to the outer peripheral portion of the core 38 not only at the specific position in the circumferential direction where the oil injection port 43 is provided, but also in the entire circumferential direction. And, since a small amount of oil can provide a high cooling effect of the core 38 over the entire circumference of the generator 30, the amount of oil to the rotating portion (the bottom 32 of the rotor 31, the inner cylinder 34, etc.) is low. The adhesion can be reduced, and drag resistance and agitation resistance due to oil viscosity can be suppressed. That is, mechanical operation loss at the time of operation of generator 30 can be reduced.

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

  The generator 30 does not have a change such as providing a cooling oil passage to the rotor 31 and the stator 36, and a generator having a general configuration can be used, so the number of parts increases and the manufacturing cost Not cause an increase in

  The amount of oil supplied to the generator 30 and the strength of oil injection can be changed by the setting of 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 conduit resistance changes. Therefore, it is possible to adjust to an appropriate hydraulic pressure 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 in a state where the engine 10 is assembled, parts replacement and setting change for hydraulic pressure adjustment can be easily performed.

  As described above, according to the cooling structure of the generator according to the present embodiment, the oil pipe 40 disposed outside the crankcase 11 and the generator cover 20 and the oil injection provided on the generator cover 20 The generator 30 can be cooled efficiently by the simple configuration provided with the port 43.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications. In the above embodiment, the size, shape, and the like illustrated in the attached drawings are not limited thereto, and can be appropriately changed within the range in which the effects of the present invention are exhibited. In addition, without departing from the scope of the object of the present invention, it is possible to appropriately change and implement.

  For example, although the connection portion 25 (including the oil injection port 43) is integrally formed with the generator cover 20 in the above embodiment, 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 according to the above-described embodiment is an outer rotor type in which the stator 36 which is located on the outer diameter side and the non-rotating stator 36 is located on the inner diameter side. Unlike the above, the present invention can also be applied as a cooling structure of an inner rotor type generator in which the rotor is disposed on the inner diameter side and the stator is disposed on the outer diameter side.

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

10: engine 11: crankcase 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: clutch cover 20: Generator cover 21: Generator chamber 22: Base portion 23: Outer cylinder portion 24: Mounting portion 25: Connection portion 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 transmission)
58: relay passage 60: crank shaft 61: bearing portion 62: speed change mechanism 63: drive shaft 64: counter shaft 65: bearing portion 66: bearing portion

Claims (6)

In a generator chamber covered by a generator cover, a generator having a rotor fixed to a crankshaft and rotating with the crankshaft, and a stator fixed with the core opposed to a permanent magnet provided on the rotor Equipped
A crankcase rotatably supporting the crankshaft and an external pipe disposed outside the generator cover and supplying oil from the crankcase into the generator cover;
The generator cover includes an oil injection port for injecting oil passing through the external pipe toward the generator, and the oil injection port is disposed toward an outer peripheral portion of the generator. Generator cooling structure. The rotor has a bottomed cylindrical shape whose central portion is fixed to the crankshaft, the permanent magnet is disposed on the inner periphery of the cylindrical portion of the rotor, and the core of the stator is positioned inside the cylindrical portion. ,
2. The generator cooling structure according to claim 1, wherein the oil injection port is disposed to inject oil toward a gap between the permanent magnet and the core.   3. The generator cooling structure according to claim 1, wherein the oil injection port is located forward of the crankshaft and lower than the center of the crankshaft. The generator cover has an outer cylinder portion surrounding the generator,
The outer pipe is attached to a front surface of the outer cylinder portion of the generator cover, and an outer end of the outer pipe is disposed in alignment with an outer surface of the generator cover in a front view. The cooling structure of a generator according to any one of 3.   A transmission oil passage for supplying the oil passing through the oil filter to the transmission mechanism is provided on the side of the crankcase, and the external pipe is attached to the beginning of the transmission oil passage. The cooling structure of a generator according to any one of 1 to 4.   The generator cooling system according to claim 5, wherein the transmission oil passage extends in the vertical direction of the engine, and the external pipe is attached to a lower end of the transmission oil passage.

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