JP2009133338A - Spline engagement structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spline engagement structure excellent in durability without being enlarged when an external gear member with an external gear projected in one axial direction on a periphery of an external gear body, and an internal gear member with an internal gear engaging with this external gear are engaged in spline. <P>SOLUTION: A spline engagement structure, equipped with an external gear member 51 and an internal gear member 72 which are mutually engaged in spline, is characterized in that: the external gear member 51 includes an external gear body 61, and an external gear 62a projected to one axial side in a periphery 62 of the external gear body 61; the internal gear member 72 includes an internal gear body 71, and an internal gear 72a formed in an inner periphery 74 of the internal gear body 71 so as to engage with the external gear 62a; and a stress easing hole 75a formed adjacent to an engaging surface in which the internal gear 72a, engages with the external gear 62a or the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spline fitting structure, and more particularly to a spline fitting structure that can reduce stress generated in a tooth root portion of an external tooth member that is spline fitted with an internal tooth member.

In general, in this type of spline fitting structure, the external teeth are spline-fitted to the internal teeth by engaging the external teeth of the external teeth and the internal teeth of the internal teeth. When the inner teeth are pressed against the inner teeth, the stress generated in the root portion of the outer teeth due to the reaction force received by the outer teeth becomes higher than in the other portions. For this purpose, the shape of the tooth root is devised so as to increase the mechanical strength of the tooth root portion, and structural considerations are made so that the stress at the tooth root portion is reduced.
Conventionally, as a typical example of this type of spline fitting structure, there is known a planetary gear device that employs a spline fitting structure in which a carrier having inner teeth and a rotating member having outer teeth are fitted. (For example, refer to Patent Document 1).
In this planetary gear device, high stress is generated in the fitting portion located near the pin connected to the carrier out of the whole fitting portion where the carrier and the rotating member are spline-fitted. The interdental pitch of the external and internal teeth of the mating part is larger than the interdental pitch of other parts, and the tooth base thickness is increased to increase the mechanical strength of the mating part. ing.
JP-A-6-117502

However, in the conventional spline fitting structure as described above, since the inter-tooth pitch between the external teeth and the internal teeth is formed large and the root thickness is increased, the number of teeth of the entire fitting portion is reduced, It is difficult to say that the stress of each fitting portion becomes high and the mechanical strength of each fitting portion is sufficiently secured. In such a fitting part, it is conceivable to increase the tooth width and the arc of the tooth root part to increase the mechanical strength. However, in this case, the fitting part becomes large, and the carrier and the rotating member are There was a problem of becoming large. In particular, when the carrier and the rotating member are arranged in a place where there is no extra space around them, it is difficult to increase the tooth width and the arc of each root part in order to increase the mechanical strength of each root part. Therefore, there is a problem that it is difficult to obtain mechanical strength that can withstand the stress generated at the tooth portion of the fitting portion.
Further, in the case where the carrier is constituted by an external tooth main body and an external tooth formed on the outer peripheral portion of the external tooth main body so as to protrude on one side in the axial direction, the external tooth is only at one end side in the tooth width direction. Since it is supported by the external tooth body, the stress generated in the tooth root portion is unbalanced in the tooth width direction, and a large stress is generated in the tooth root portion on one end side in the tooth width direction. In this case, it is difficult to reinforce the external teeth due to space constraints, and the external teeth may cause metal fatigue at the tooth root portion on one end side in the tooth width direction that receives a large repetitive stress, resulting in a decrease in durability. There was a problem.

  The present invention has been made in order to solve the above-described conventional problems, and an external tooth member having external teeth formed on the outer peripheral portion of the external tooth body so as to protrude on one side in the axial direction, and the external teeth An object of the present invention is to provide a spline fitting structure excellent in durability without being increased in size when an internal tooth member having an inner tooth meshing with the inner tooth member is spline fitted.

  To achieve the above object, the spline fitting structure according to the present invention is (1) a spline fitting structure comprising an external tooth member and an internal tooth member that are spline-fitted with each other, wherein the external tooth member is an external tooth main body. And an external tooth formed on the outer peripheral portion of the external tooth body so as to protrude to one side in the axial direction, and the internal tooth member engages with the internal tooth body and the external tooth. An internal tooth formed on a peripheral portion, and the internal tooth has a recess formed in the vicinity of an engagement surface that engages with the external tooth.

  With this configuration, since the inner teeth have a recess formed in the vicinity of the engaging surface that engages with the outer teeth, the rigidity of the inner teeth is reduced, and the external force is exerted in the direction in which the outer teeth member tries to rotate. When the outer teeth press the inner teeth, the elastic teeth are easily elastically deformed by the pressing force (N), and the reaction force (N) received by the outer teeth from the inner teeth is reduced. As a result, since the stress (MPa) generated at the root of the external tooth is reduced, a simple structure that only forms a recess in the internal tooth of the conventional internal tooth member makes it durable without increasing the structure. An excellent spline fitting structure can be obtained.

  In the spline fitting structure described in (1) above, (2) the outer tooth member constitutes a part of the planetary gear device, and the inner tooth member serves as a part of the case that houses the planetary gear device. You may make it comprise.

  With this configuration, it is possible to obtain a planetary gear device and a case having a spline fitting structure excellent in durability without increasing the size of the planetary gear device and the case housing the planetary gear device.

  In the spline fitting structure according to the above (2), preferably, (3) the internal teeth of the internal gear member have a facing surface facing the planetary gear device, and the concave portion is the internal gear member. Are formed so as to open at the facing surface.

  With this configuration, the rigidity of the opposing surface side of the internal tooth member is reduced, an external force is applied in the direction in which the external tooth member is to rotate, and the external tooth presses the internal tooth by the pressing force (N). The opposing surface side of the inner teeth is easily elastically deformed, and the reaction force (N) received by the outer teeth from the opposing surface side of the inner teeth is reduced.

  In the spline fitting structure described in the above (1) to (3), preferably, (4) the recess is formed in the specified internal tooth.

  With this configuration, since the concave portion is formed only in the specified internal tooth, the processing accuracy for fitting the spline only to the specific internal tooth and the external tooth is increased in the external tooth member and the internal tooth member, and the other external teeth The teeth and internal teeth can be processed with normal accuracy, and the manufacturing process is simplified. Furthermore, it is only necessary to tightly spline-fit specific external teeth and internal teeth, and other spline fittings can be loosely fitted, so that assembly work can be facilitated.

  According to the present invention, an external tooth member having external teeth formed on the outer peripheral portion of the external tooth body so as to protrude in one axial direction and an internal tooth member having internal teeth meshing with the external teeth are spline-fitted. In this case, it is possible to provide a spline fitting structure with excellent durability without increasing the size.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment)
FIG. 1 is a side view of a state in which a carrier mounted with a pinion of a planetary gear device is fitted to a case in a power transmission device 1 according to an embodiment of the present invention, as viewed from the mounting surface side. FIG. 2 is a sectional view taken in the direction of arrows AA in FIG.

First, the configuration will be described.
A spline fitting structure 10 according to an embodiment of the present invention is employed in an outer peripheral support portion of a reduction planetary gear device 5, and the reduction planetary gear device 5 is a part of a power transmission device 1 such as a vehicle transaxle. Is configured. The power transmission device 1 is, for example, of a hybrid type that inputs power from an internal combustion engine such as a multi-cylinder gasoline engine and selectively operates a built-in electric motor.

  As shown in FIGS. 1 and 2, the power transmission device 1 includes a front generator 2 that mainly operates for power generation, a front motor 3 that mainly operates for driving, and a power split that divides power of an engine (not shown). A planetary gear unit 4 and a reduction planetary gear unit 5 for decelerating the front motor 3 are included. The power transmission device 1 connects an input shaft 7 that transmits engine power to the power split planetary gear device 4 via the damper 6, and a ring gear of the power split planetary gear device 4 and a ring gear of the reduction planetary gear device 5. And a counter drive gear 8 having a function of transmitting power as a common ring gear. The power transmission device 1 also includes a counter driven gear 9 that meshes with the counter drive gear 8 and transmits power from the ring gear, a final drive gear 11 that is provided coaxially with the counter driven gear 9, and a final that meshes with the final drive gear 11. It further includes a driven gear 12, a differential 13 connected to the final driven gear 12, a left drive shaft 14 and a right drive shaft 15 connected to the differential 13, and a transaxle case 16 that accommodates these.

  The transaxle case 16 includes a case 17, a cover 18 fixed to the end of the case 17, a housing 19 fixed to the other end of the case 17, and a cover 21 fixed to the end of the housing 19. It is configured to include. The case 17, the cover 18, the housing 19, and the cover 21 define an internal space. Lubricating oil is supplied into the internal space from an oil pump 22 that is attached to the cover 18 and driven by the power of the engine. It is designed to be lubricated. In addition, oil seals are attached to the insertion portion of the left drive shaft 14 of the case 17, the attachment portion of the oil pump 22 of the cover 18, the insertion portion of the right drive shaft 15 of the housing 19, and the insertion portion of the input shaft 7 of the cover 21. Therefore, the lubricating oil does not leak to the outside.

  The front generator 2 has a function of an electric motor for driving a hybrid vehicle and a function of a generator for charging a battery, and is configured to mainly function as a generator. The stator and the rotor are not included. The stator has a core fixed to the inner peripheral portion of the housing 19, and the winding is wound around the outer periphery of the core so as to form a three-phase winding for generating a magnetic field. Further, the rotor has a permanent magnet composed of an N pole and an S pole, and is provided rotatably on the inner peripheral portion of the stator.

  Further, the front generator 2 is connected to an inverter, and is switched to either an electric motor or a generator via an inverter by an electronic control unit (ECU) so as to function with either the electric motor or the generator. Yes. This inverter is composed of switching elements such as a traveling IPM (Intelligent Power Module) and an IGBT (Insulated Gate Bipolar Transistors). In the case of a generator, the rotation of the engine, the front motor 3, the left drive shaft 14, and the right drive shaft 15 is transmitted to the rotor via the power split planetary gear unit 4 and is generated by the rotation of the rotor. The generated AC voltage is converted into a DC voltage and sent to a capacitor or a capacitor, and a battery connected to an inverter is charged.

Like the front generator 2, the front motor 3 has a function of an electric motor for driving a hybrid vehicle and a function of a generator for charging a battery, and is configured to act mainly as an electric motor. The rotor is included. The stator has a core fixed to the inner peripheral portion of the case 17, and the winding is wound around the outer periphery of the core so as to form a three-phase winding for generating a magnetic field. Further, the rotor has a permanent magnet composed of an N pole and an S pole, and is provided rotatably on the inner peripheral portion of the stator.
Similarly to the front generator 2, the front motor 3 is connected to an inverter, and is switched between an electric motor and a generator via the inverter by the electronic control unit, and functions as either the electric motor or the generator. It is like that.

  In the case of an electric motor, when a three-phase alternating current flows from the battery to the three-phase winding of the stator via an inverter based on a command from the electronic control unit, a rotating magnetic field is generated inside the rotating magnetic field. The permanent magnet arranged on the rotor is controlled by the position and speed, and is attracted to the rotating magnetic field to generate torque, which is output to the reduction planetary gear unit 5. The magnitude of the generated torque is controlled by the current, and the magnitude of the rotational speed is controlled by the frequency of the AC power supply.

  The power split planetary gear unit 4 is integrated with the ring gear of the reduction planetary gear unit 5 and has a counter drive gear 8 having a function of transmitting power, and the axis line in the counter drive gear 8 is made to coincide with the axis line of the counter drive gear 8. A sun gear arranged in a row, a carrier inserted between the counter drive gear 8 and the sun gear so as to coincide with the axis of the counter drive gear 8 and the sun gear, and a pinion gear rotatably accommodated in the carrier and meshing with the ring gear and the sun gear It consists of and. The sun gear is connected to the rotating shaft of the rotor and rotates together with the rotor, and the carrier is rotatably supported on the rotating shaft of the rotor. As described above, the power split planetary gear device 4 splits the engine power transmitted to the input shaft 7 via the damper 6 into the front generator 2, the left drive shaft 14, and the right drive shaft 15. That is, the engine power transmitted to the input shaft 7 is transmitted to the rotor of the front generator 2 via the sun gear and to the counter drive gear 8 via the pinion gear, and the counter driven gear 9, final drive gear 11, The power is transmitted to the left drive shaft 14 and the right drive shaft 15 via the final driven gear 12 and the differential 13.

  FIG. 3 is a perspective view of the reduction planetary gear unit 5 according to the embodiment of the present invention, and FIG. 4 is a partially enlarged cross section near the reduction planetary gear unit 5 of the power transmission device 1 according to the embodiment of the present invention. FIG.

  As shown in FIGS. 3 and 4, the reduction planetary gear unit 5 includes a counter drive gear 8, a sun gear 31, a carrier 32, five pinion gears 33 arranged at equal intervals on the circumference, and each pinion gear 33. And a pinion shaft 34 that rotatably supports the carrier 32.

  The counter drive gear 8 is formed of an annular body formed integrally with the ring gear of the power split planetary gear device 4, and an inner tooth is formed at an inner peripheral portion at one end portion to constitute the ring gear of the reduction planetary gear device 5. The internal teeth mesh with the pinion gear 33 of the reduction planetary gear unit 5. Further, an inner tooth is formed on the inner peripheral portion at the other end portion to constitute a ring gear of the power split planetary gear device 4, and this inner tooth meshes with the pinion gear of the power split planetary gear device 4. External teeth are formed on the outer periphery of the counter drive gear 8, and the external teeth mesh with the counter driven gear 9. Further, bearings 41 are mounted at both ends of the outer peripheral portion of the counter drive gear 8 and are rotatably supported by the case 17.

  The sun gear 31 is formed of an annular body in which outer teeth are formed on the outer peripheral portion and spline inner teeth are formed on the inner peripheral portion, and the spline outer teeth and the spline fitting formed on the end portion of the rotor shaft 3a of the front motor 3 And rotate together with the rotor shaft 3a. The rotor shaft 3 a is rotatably supported by the case 17 via a bearing 42. A pipe-shaped oil pump drive shaft 43 that is engaged with the input shaft 7 integrally in the rotational direction is inserted into the rotor shaft 3a. As shown in FIG. 2, a drive rotor 44 located on the back side of the front motor 3 is attached to the oil pump drive shaft 43, and a drive rotor (not shown) that constitutes the oil pump 22 together with the drive rotor 44 covers the oil pump drive shaft 43. 18 is rotatably supported.

  Further, an oil pump cover 46 that houses a relief valve 45 is mounted on the cover 18, and the lubricating oil pumped up from a predetermined location in the cover 18 by the oil pump 22 is limited to a predetermined set pressure by the relief valve 45. While being supplied to the meshing portion of the power split planetary gear unit 4 and the reduction planetary gear unit 5 through a passage in the oil pump drive shaft 43 and a plurality of oil passages formed in the rotor shaft 3 a and the input shaft 7. It has come to be.

The external teeth of the sun gear 31 mesh with the pinion gears 33. Each pinion gear 33 is rotatably supported by a pinion shaft 34 via a bearing 35, and both ends of the pinion shaft 34 are fixed to a carrier 32.
The carrier 32 includes an external tooth member 51 having external teeth formed on the outer periphery thereof, a support member 52 that supports the pinion shaft 34 together with the external tooth member 51, and a support member 52 that is formed integrally with the support member 52. A connecting member 53 that connects the member 52 is included.

  FIG. 5 is a plan view of the external tooth member 51 of the reduction planetary gear device 5 according to the embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along the line BB in FIG. 7 is a plan view of the internal gear member 72 of the case 17 to which the external gear member 51 of the reduction planetary gear device 5 according to the embodiment of the present invention is fitted, and FIG. 8 is a CC arrow in FIG. FIG. 9 is a cross-sectional view showing a cross section taken along the line DD in FIG. 7. FIG. 10 is a partially enlarged plan view of the internal gear member 72 of the reduction planetary gear device 5 according to the embodiment of the present invention.

  As shown in FIG. 5, the external tooth member 51 protrudes from the external tooth main body 61 and one axial side of the external tooth main body 61, and includes ten external teeth 62 a to 62 a that are supported by the outer peripheral portion 62 of the external tooth main body 61. 62j. The external tooth body 61 has a through hole 61a at the center and five through holes 61b to 61f arranged on the side surface at equal intervals on the circumference. The corner portions of the outer peripheral portion 62 and the external teeth 62a to 62j are chamfered 62k so that they can be easily assembled during spline fitting.

As shown in FIG. 6, the external teeth body 61 is formed with a thickness t, to no external teeth 62a 62j is formed with a width W _1. Further, the external teeth body 61 has a width W ₂ protruding from the side surface portion 61g in the axial _direction, the projecting portions 61h of the annular outer diameter D ₁ is formed. In the external tooth member 51, an annular groove 51 a is defined by the outer peripheral portion 62, the side surface portion 61 g, and the protruding portion 61 h, and a part of the case 17 is accommodated in the groove 51 a to reduce the planetary gear unit 5. Space saving is achieved by shortening the overall length of the.

  As shown in FIG. 4, the support member 52 has a stepped through hole having a predetermined depth at the center portion, like the external tooth member 51, and a bearing 47 is mounted in the through hole. The input shaft 7 is rotatably supported at its end. Further, five through holes arranged at equal intervals on the circumference are formed on the side surface of the support member 52, and the end of the pinion shaft 34 is inserted and fixed by caulking. Yes.

  As shown in FIG. 4, the connecting member 53 is integrally formed with the support member 52 so as to connect the external tooth member 51 and the support member 52. The sun gear 31 and the five pinion gears 33 are accommodated in the internal space defined by the external tooth member 51, the support member 52, and the connecting member 53.

The thickness t, the width _W of from the external teeth 62a 62j ₁ of the external teeth body 61 in the reduction planetary gear unit 5, the width _{W 2} of the projecting portion 61h, the dimensions of the outer diameter _{D 1,} the number of the external teeth and the shape, the pinion gear 33 The specifications such as the number of teeth and the number of teeth are appropriately selected according to the design conditions such as the structure, size, and torque transmission characteristics of the reduction planetary gear unit 5. In addition, the external tooth of the external tooth main body 61 should just be formed in at least one place, and many may be formed.

  As shown in FIG. 7, the case 17 has an internal tooth member 72, and the internal tooth member 72 is spline-fitted with the internal tooth main body 71 and the external teeth 62 a to 62 j of the external tooth member 51. It has internal teeth 72 a to 72 j formed on the inner peripheral portion 74. The external teeth 62a of the external tooth member 51 are between the internal teeth 72a and 72b, the external teeth 62b are between the internal teeth 72b and 72c, and so on. Spline fitting is performed between the internal teeth 72a to 72j of the tooth member 72, respectively. Accordingly, the outer teeth member 51 is spline-fitted to the inner teeth member 72, whereby the carrier 32 is fixed to the case 17.

Here, when the external tooth member 51 tries to rotate counterclockwise toward the drawing, the external teeth 62a to 62j of the external tooth member 51 press the internal teeth 72a to 72j of the stationary internal tooth member 72. Therefore, the inner teeth 72a to 72j have engaging surfaces that engage with the outer teeth 62a to 62j, respectively.
In addition, stress relaxation holes 75a to 75j are formed in the vicinity of the engaging surface 72n of the inner tooth member 72, respectively, to relieve stress generated at the roots of the outer teeth 62a to 62j due to the pressing of the outer teeth 62a to 62j. It is supposed to be. As shown in FIG. 9, the internal teeth 72 a to 72 j of the internal tooth member 72 have a facing surface 72 s that faces the reduction planetary gear device 5, and the stress relaxation holes 75 a to 75 j described above are formed on the internal tooth member 72. The inner teeth 72a to 72j are respectively formed so as to open at the opposing surfaces 72s of the inner teeth 72a to 72j.

In the case of the spline fitting shown in FIG. 7, the spline-fitted external tooth member 51 tends to rotate counterclockwise toward the drawing when the hybrid vehicle advances, for example, so that the stress relaxation hole 75a. Or 75j is formed in the vicinity of each engaging surface 72n of the inner teeth 72a to 72j that engage with the rotation direction advance side of the outer teeth 62a to 62j of the outer tooth member 51.
On the other hand, when the hybrid vehicle moves backward, contrary to when moving forward, the external tooth member 51 tries to rotate clockwise toward the drawing. However, as in the case of forward movement, the internal teeth 72a to 72j are connected to the external teeth 62a. In addition, a stress relaxation hole may be formed in the vicinity of another engaging surface 72n that engages with each of 62 to 62j.

In the case of backward movement, when the torque applied to the external tooth member is set to be smaller than that of forward movement, the pressing force applied to the engaging surface 72n is also small, so that the internal teeth engaged with the backward side in the rotational direction. It is not necessary to form a stress relaxation hole in the vicinity of the engagement surface 72n of 72a to 72j.
The stress relaxation holes 75a to 75j of the spline fitting structure 10 according to the present embodiment constitute a recess in the spline fitting structure according to the present invention.

As shown in FIG. 8, in the internal tooth member 72 of the case 17, the internal teeth 72 a to 72 j are formed at a height L ₁ from the bottom surface portion 72 k of the internal tooth member 72. The central portion of the internal gear member 72, annular protrusion 73 that protrudes at a height L ₂ from the bottom portion 72k is formed. The annular projection 73, a through hole 73a is formed at a slightly larger inner diameter D ₂ than the outer diameter D ₁ of the projecting portion 61h which is formed in the external gear member 51, the external gear member in the through hole 73a 51 projecting portions 61h are inserted, and positioning is performed so that the axis of the internal tooth member 72 and the axis of the external tooth member 51 coincide with each other.

The external tooth member 51 is fitted into the internal tooth member 72 so that the protruding side of the external tooth 62 b of the external tooth member 51 faces the bottom surface portion 72 k of the internal tooth member 72, and the side surface portion 61 g of the external tooth member 51 is the internal tooth member 72. By contacting the end surface portion 73b of the annular projecting portion 73, the spline is fitted. Also, since to not the internal teeth 72a of the internal gear member 72 height L ₁ of 72j is larger than the height L ₂ of the annular projection 73, splined and the external gear member 51 and the internal gear member 72 When mating, the spline is smoothly fitted. That is, first, the external teeth 62 a to 62 j of the external tooth member 51 and the internal teeth 72 a to 72 j of the internal tooth member 72 are engaged, and then the protruding portion 61 h of the external tooth member 51 is connected to the through hole of the annular protruding portion 73. Since it is inserted into 73a, the engagement between the external teeth 62a to 62j and the internal teeth 72a to 72j of the internal tooth member 72 serves as a guide, and the protruding portion 61h is easily inserted into the through hole 73a.

As shown in FIGS. 9 and 10, the internal teeth 72c of the internal gear member 72, the engagement surface 72n of the distance from the side surface portion 72m to the center axis p is the external teeth 62c of the _{L 4,} the internal teeth 72c A stress relaxation hole 75c is formed so that the distance to the central axis p is L ₅ , the depth from the opposed surface 72s is L ₃ , and the inner diameter is D ₃ . The depth _{L 3} from opposing surface 72s, to the height _{L 1,} is preferably _{0.5L 1 <L 3 <L 1} . The depth _{L 3} is less than 0.5 L _1, may to no external teeth 62a to no external teeth 62a by the pressing of 62j relaxation of stress generated in the tooth root of 62j decreases, the internal teeth exceeds _{L 1} The rigidity of 72a thru | or 72j may fall, and durability may fall.

The specifications such as the distances L ₃ , L ₄ , L ₅ , and the inner diameter D ₃ in the internal tooth member 72 are appropriately selected according to the design conditions such as the structure, size, torque transmission characteristics of the case 17 and the reduction planetary gear unit 5. The

Next, operation | movement of the power transmission device 1 which concerns on this Embodiment is demonstrated easily.
As shown in FIG. 2, when engine power (not shown) is transmitted to the input shaft 7 via the damper 6, the sun gear of the power split planetary gear device 4 rotates together with the input shaft 7. The power transmitted from the engine is divided into charging and driving by the rotation of the sun gear. That is, when the sun gear rotates, the rotor of the front generator 2 connected to the sun gear rotates and power is generated in the front generator 2. The generated AC voltage is converted into a DC voltage, sent to a capacitor or a capacitor for storage, and sent to a battery connected to an inverter to charge the battery.

  On the other hand, the pinion gear meshing with the sun gear rotates, the counter drive gear 8 meshing with the pinion gear rotates, and via the counter driven gear 9, the final drive gear 11, and the final driven gear 12, the left drive shaft 14 connected to the differential 13 and The right drive shaft 15 is driven.

  When a drive command is issued from the electronic control unit to the front motor 3 in accordance with the operating state, a three-phase alternating current flows from the battery to the three-phase winding of the stator via the inverter, and a rotating magnetic field is generated inside. The permanent magnet disposed in the rotor is attracted by the rotating magnetic field to generate torque, and as shown in FIG. 4, the sun gear 31 of the reduction planetary gear unit 5 rotates as the rotor shaft 3a rotates. Next, the five pinion gears 33 that mesh with the sun gear 31 rotate. At this time, the carrier 32 that supports the pinion gear 33 does not rotate because the outer tooth member 51 is spline-fitted to the inner tooth member 72 of the case 17, and the torque of the sun gear 31 remains unchanged via the pinion gear 33. It is transmitted to the drive gear 8, and the rotation of the front motor 3 is decelerated and transmitted to the counter driven gear 9. Subsequently, as shown in FIG. 2, the left drive shaft 14 and the right drive shaft 15 connected to the differential 13 are driven via the final drive gear 11 and the final driven gear 12.

  Further, depending on the driving state, the front generator 2 may be rotated by a command from the electronic control unit, and the power may be transmitted through the above-described path to drive the left drive shaft 14 and the right drive shaft 15. The front generator 2 may be rotated and charged via the counter driven gear 9 by the rotation of the left drive shaft 14 and the right drive shaft 15. Further, the front motor 3 may be rotated and charged via the counter driven gear 9 by the rotation of the left drive shaft 14 and the right drive shaft 15.

Next, the operation of the spline fitting structure 10 according to the present embodiment will be described.
FIG. 11 is a partially enlarged perspective view of the spline fitting structure 10 according to the embodiment of the present invention, and FIG. 12 is generated at the base of the external teeth of the spline fitting structure 10 according to the embodiment of the present invention. It is a graph of stress.

As shown in FIG. 11, when the external tooth member 51 and the internal tooth member 72 are spline-fitted and the external tooth member 51 tries to rotate in the arrow Y direction, the external tooth 62b presses the internal tooth 72b and the internal tooth A reaction force (N) indicated by an arrow H is received from 72b. At this time, stress (MPa) resisting the reaction force and stress (MPa) resisting the rotational moment (Nm) generated by the reaction force act on the external teeth 62b, and the stress is generated at the root 61i of the external teeth 62b. Maximum. As indicated by the arrow O, the stress generated in the tooth base 61i gradually increases in the tooth width direction from the side surface portion 61j of the external tooth 62b.
The tooth width direction means a direction in the external teeth that is substantially parallel to the axial direction of the external tooth member 51.
Magnitude of stress generated in the tooth base 61i, for example, can be measured by the gauge SP ₁ and SP ₂ strain affixed to the surface of the tooth root 61i. In addition, since a gap is defined between the external teeth 62b and the internal teeth 72c in the tooth base 61i, strain gauges SP ₁ and SP ₂ are provided on the surface portion of the tooth base 61i without any special processing. Can be pasted.

The reason why the stress increases in the strain gauge SP ₂ is that this portion is supported by the external tooth body 61 of the external tooth member 51 and has high rigidity. The portion of the strain gauge SP _1, since not supported by external teeth body 61, because the stress is reduced by the deformation of lower portion thereof than the portion of the gauge SP ₂ strain stiffness.

  In the spline fitting structure 10 according to the present embodiment, since the stress relaxation hole 75b is formed in the internal tooth 72b of the internal tooth member 72, when the external tooth 62b presses the internal tooth 72b, the internal tooth 72b Is deformed, and the reaction force received by the outer teeth 62b from the inner teeth 72b decreases. As a result, the stress generated in the tooth root 61i is also reduced. That is, the stress relaxation hole 75b formed in the inner tooth 72b acts on the outer tooth 62b so as to reduce the stress generated in the tooth base 61i.

The graph shown in FIG. 12 shows the external teeth 62a to 62j when the external teeth 62a to 62j of the external tooth member 51 shown in FIG. 5 are spline-fitted to the internal teeth 72a to 72j of the internal tooth member 72 shown in FIG. The stress generated in each tooth base is measured by strain gauges SP ₁ and SP ₂ , and the position (mm) and stress (MPa) in the tooth width direction of the tooth base 61i of the external tooth with respect to the external tooth having the largest stress. Represents the relationship.

  In the spline fitting structure 10 according to the present embodiment, the engagement degrees of the respective engagement portions in the spline fitting between the inner teeth 72a to 72j and the outer teeth 62a to 62j are not equal, that is, the outer teeth Since the pressing force of the external teeth against the internal teeth when the member 51 is about to rotate is different, the stress of the external teeth at the portion where the maximum pressing force is generated is targeted.

As shown in FIG. 12, in the conventional spline fitting structure in which the stress relaxation holes are not formed in the inner teeth, the stress on the strain portion of the gauge SP ₁ of dedendum 61i as shown by the dotted line A (MPa) occurs, the portion of the strain gauge SP _2, stress B (MPa) occurs. In contrast, in the spline fitting structure 10 of the present embodiment, it occurs stress C (MPa) is the strain part of the gauge SP ₁ of dedendum 61i as shown by the solid line, the portion of the strain gauge SP ₂ is Stress D (MPa) is generated.

Since the stress generated in the tooth width direction from the strain gauge SP ₁ portion to the strain gauge SP ₂ portion is known to change substantially linearly, the stress generated in the intermediate portion by measuring both ends is determined. Can be sought. That is, the stress increases in proportion to the strain gauge SP ₁ portion closer to the strain gauge SP ₂ portion in the tooth width direction. Therefore, in the conventional technique, the stress is represented by AB, and in the present embodiment, CD. It is represented by In this case, by reducing the stress B maximum stress become strain portion of the gauge SP ₂ occurring dedendum 61i, it is possible to achieve the object of the present invention. In this respect, in the portion of the strain gauge SP ₂ , the stress B is generated in the spline fitting structure 10 of the present embodiment compared to the stress B generated in the conventional spline fitting structure, and the stress is reduced by about 10%. Has been. That is, forming the stress relaxation hole has an effect of reducing the root stress of the external tooth by about 10%. Further, in the conventional spline fitting structure, there is a stress difference between the stress A generated in the strain gauge SP ₁ portion and the stress B generated in the strain gauge SP ₂ portion, and a relatively large stress is generated in the tooth width direction. Although an imbalance has occurred, in the spline fitting structure 10 of the present embodiment, the stress difference between the stress C generated in the strain gauge SP ₁ portion and the stress D generated in the strain gauge SP ₂ portion is small. The stress imbalance in the tooth width direction is reduced.

  As described above, the spline fitting structure 10 of the present embodiment includes the external tooth member 51 and the internal tooth member 72 that are spline-fitted with each other, and the external tooth member 51 includes the external tooth body 61 and the external tooth body 61. External teeth 62a to 62j formed on the outer peripheral portion 62 so as to protrude on one side in the axial direction, and the internal tooth member 71 is engaged with the internal tooth body 71 and the external teeth 62a to 62j. Stress relaxation hole 75a formed in the vicinity of engagement surface 72n and the like in which inner teeth 72a to 72j engage outer teeth 62a to 62j. Or 75j. Further, the external tooth member 51 is constituted by a part of the carrier 32 of the reduction planetary gear device 5, and the internal tooth member 72 is constituted by a case 17 that houses the reduction planetary gear device 5.

  In this case, when an external force is applied in the direction in which the external tooth member 51 tries to rotate and the external teeth 62a press the internal teeth 72a, the stress relaxation holes 75a are formed in the vicinity of the pressing portion of the internal teeth 72a. The rigidity of the inner teeth 72a is reduced, the inner teeth 72a are easily deformed by the pressing force (N), and the reaction force (N) received by the outer teeth 62a from the inner teeth 72a is reduced.

  As a result, the stress (MPa) generated in the tooth base 62i of the external tooth 62a is reduced, so that the spline fitting structure 10 can be realized by a simple structure in which the stress relaxation hole 75a is formed in the internal tooth 72a of the conventional internal tooth member. It is possible to obtain a spline fitting structure with excellent durability without increasing the size. The spline fitting structure of the other external teeth 62b to 62j of the external tooth member 51 and the other internal teeth 72b to 72j of the internal tooth member 72 is as simple as the spline fitting structure of the external teeth 62a and the internal teeth 72a. With the structure, a spline fitting structure having excellent durability can be obtained without increasing the size of the spline fitting structure 10.

  Further, the outer tooth member 51 is constituted by a part of the carrier 32 of the reduction planetary gear device 5, and the inner tooth member 72 is constituted by the case 17 that houses the reduction planetary gear device 5. Also in the power transmission device constituted by the device 5 and the case 17, a power transmission device excellent in durability can be obtained with a simple structure without increasing the size of the spline fitting structure 10.

Next, a modified example of the spline fitting structure 10 according to the present embodiment will be described.
FIG. 13 is a partially enlarged perspective view of the internal tooth member 72 in a modification of the spline fitting structure 10 according to the embodiment of the present invention. FIG. 13 (a) is an oval shape of the internal tooth 82 of the internal tooth member 72. FIG. 13B shows a state in which an oval-shaped stress relief hole 85 is formed in the internal tooth 84 of the internal tooth member 72, and FIG. A state in which a plurality of circular stress relaxation holes 87 having different sizes is formed in the inner teeth 86 of the inner tooth member 72 is shown.

  FIG. 14 is a partially enlarged perspective view of the internal tooth member 72 in another modification of the spline fitting structure 10 according to the embodiment of the present invention. FIG. 14 (a) is an internal tooth 88 of the internal tooth member 72. FIG. 14B shows a state in which two elliptical stress relaxation holes 89 and 91 are formed, and FIG. 14B shows a state in which two oval stress relaxation holes 93 and 94 are formed in the internal teeth 92 of the internal tooth member 72. FIG. 14C shows a state where a plurality of circular stress relaxation holes 97 and 98 having different sizes are formed in the inner teeth 96 of the inner tooth member 72.

  FIG. 15 is a partially enlarged perspective view of an internal tooth member 72 in another modification of the spline fitting structure 10 according to the embodiment of the present invention. FIG. 15 (a) is an internal tooth 102 of the internal tooth member 72. FIG. 15B shows a state in which a stress relief hole 103 made of an oval recess is formed, and FIG. 15B shows a state in which a conical stress relief hole 105 is formed in the internal tooth 104 of the internal tooth member 72. (C) shows a state in which a circular stress relaxation hole 107 is formed in the tooth width direction on the inner tooth 106 of the inner tooth member 72.

  In the spline fitting structure 10 according to the present embodiment, the case where the stress relief holes 75a to 75j having a circular cross section are formed in the inner teeth 72a to 72j of the inner tooth member 72 has been described. In the fitting structure, stress relaxation holes having other shapes may be formed in the inner teeth of the inner tooth member.

  For example, as shown in FIG. 13A, an elliptical stress relaxation hole 83 having a predetermined depth may be formed in the vicinity of the engagement surface 72n where the inner teeth 82 engage with the outer teeth. In this case, since the stress relaxation hole 83 is formed in an elliptical shape, the rigidity of the internal teeth can be further reduced.

  Further, as shown in FIG. 13B, an oval stress relaxation hole 85 having a predetermined depth may be formed in the vicinity of the engaging surface 72n where the inner teeth 84 engage with the outer teeth. Also in this case, since the stress relaxation hole 85 is formed in an oval shape, the rigidity of the internal teeth can be further reduced.

  As shown in FIG. 13 (c), circular stress relaxation holes 87 with different sizes of predetermined depths are formed in the tooth width direction in the vicinity of the engaging surface 72n where the inner teeth 86 engage with the outer teeth. You may form in order of the thing from the thing with the largest cross section. In this case, since the stress relaxation holes 87 are formed in a plurality of circles, the rigidity of the internal teeth can be gradually reduced. Further, since the inner teeth 86 are formed in different sizes in the order of radial cross-section from the largest to the smallest, the inner teeth 86 are cross-sectioned at the inner teeth corresponding to the roots of the outer teeth where the greatest stress occurs. By disposing a material having a large diameter, the stress can be reduced and the difference in stress in the tooth width direction can also be reduced.

  Further, when trying to rotate counterclockwise toward the drawing, as shown in FIG. 14A, the vicinity of the engaging surface 72n where the inner teeth 88 engage with the outer teeth and the outer tooth member 51 are reversed. When the inner teeth 88 are to rotate clockwise, the elliptical stress relief holes 89 and 91 having a predetermined depth are formed in both the vicinity of the engaging surface 72n where the inner teeth 88 engage with the outer teeth, respectively. May be. In this case, since the stress relaxation hole 83 is formed in an elliptical shape, the rigidity of the internal teeth can be further reduced, and the external tooth member is about to rotate in the reverse direction, such as when the hybrid vehicle is retracted. In addition, the rigidity of the engaging portion between the outer teeth and the inner teeth 88 can be reduced.

  As shown in FIG. 14B, oval stress relaxation holes 89 and 91 having a predetermined depth may be formed in the vicinity of the engaging surface 72n where the inner teeth 92 engage with the outer teeth, respectively. . In this case as well, since the stress relaxation holes 89 and 91 are formed in an oval shape, the rigidity of the internal teeth can be further reduced, and the external tooth member will rotate in the reverse direction, such as when the hybrid vehicle moves backward. In this case, the rigidity of the engaging portion between the outer teeth and the inner teeth 92 can be reduced.

  As shown in FIG. 14C, different circular stress relaxation holes 97 and 98 having a predetermined depth are formed in the vicinity of the engaging surface 72n where the inner teeth 96 engage with the outer teeth, respectively. Good. Also in this case, since the plurality of circular stress relaxation holes 97 and 98 are formed, the rigidity of the internal teeth can be reduced to the outside, and the external tooth member in the reverse direction, such as when the hybrid vehicle moves backward Even when it is going to rotate, the rigidity of the engaging portion between the external teeth and the internal teeth 92 can be reduced.

  Further, as shown in FIG. 15A, a stress relaxation hole 103 made of a notch having a predetermined depth, width and length is provided in the vicinity of the engaging surface 72n where the inner teeth 102 engage with the outer teeth. It may be formed. Also in this case, since the stress relaxation hole 103 is formed by a notch, the inner tooth portion corresponding to the root portion where the stress generated in the external tooth is maximum is located at the opening portion of the notch. The rigidity of the teeth can be further reduced, and the root stress of the external teeth can be effectively reduced.

  Further, as shown in FIG. 15 (b), a conical stress relaxation in which the opening is formed with a large diameter in the vicinity of the engaging surface 72n where the inner tooth 104 engages with the outer tooth, and its cross section is gradually reduced. The hole 105 may be formed. Also in this case, since the stress relaxation hole 105 is formed so that the opening has a large diameter and the cross-section is gradually reduced, the portion of the internal tooth corresponding to the tooth root portion where the stress generated in the external tooth is maximized However, since it is located in the large-diameter opening, the rigidity of the inner teeth can be further reduced, and the root stress of the outer teeth can be effectively reduced.

  As shown in FIG. 15 (c), a predetermined depth opened at the tip surface 106a of the inner tooth 106 in the vicinity of the engagement surface 72n where the inner tooth 106 engages with the outer tooth, radially outward of the inner tooth 106. A circular stress relaxation hole 107 may be formed. Also in this case, since the stress relaxation hole 107 is formed, the rigidity of the internal teeth can be further reduced.

  In the spline fitting structure 10 according to the present embodiment, ten external teeth are formed on the outer peripheral portion 62 like the external teeth 62a to 62j on the external tooth member 51, and the internal tooth member 72 corresponds to the external teeth. In the spline fitting structure according to the present invention, ten inner teeth are formed on the inner peripheral portion 74 and the respective splines are fitted, as in the inner teeth 72a to 72j. It is only necessary that at least one external tooth is formed on the inner teeth, and it is only necessary that one internal tooth corresponding to the external teeth is formed on the inner peripheral portion of the internal tooth member.

Further, when a plurality of external teeth are formed on the external tooth body of the external tooth member and a plurality of internal teeth of the corresponding internal tooth member are formed on the inner peripheral portion thereof, the splines of all the external teeth and internal teeth The external teeth and the internal teeth need not be formed so that the degree of engagement of the engaging portions to be fitted, that is, the pressing force (N) when the internal teeth are pressed by the external teeth, is all uniform. For example, when a plurality of external teeth and internal teeth are spline-fitted, the degree of engagement of specific external teeth and internal teeth is set high, and a stress relief hole as a recess is formed only in the specific internal teeth You may make it do.
In this case, the processing accuracy for spline fitting is increased only for specific external teeth and internal teeth, and the other external teeth and internal teeth can be processed with normal accuracy, making the manufacture simple. The specific outer teeth and the inner teeth only need to be firmly spline-fitted, and other spline fittings can be loosely fitted, so that the fitting operation can be facilitated.

  Further, in the spline fitting structure 10 according to the present embodiment, the case where the external tooth member 51 constitutes the carrier 32 of the reduction planetary gear device 5 has been described. However, in the spline fitting structure according to the present invention, You may apply to the thing of the structure which carries out the spline fitting of the external tooth member in which the external tooth was simply formed in the outer peripheral part, and the internal tooth member in which the internal tooth was formed in the internal peripheral part. For example, it may be applied to a spline fitting structure of a constant velocity joint, or may be applied to a spline fitting structure of a transmission clutch.

  As described above, according to the present invention, the external tooth member having the external tooth supported on the one end side in the tooth width direction and the internal tooth member having the internal tooth are spline-fitted, The spline fitting structure having excellent durability can be provided without increasing the size, and is useful for the spline fitting structure in general.

It is the side view which looked at the state which fitted the carrier with which the pinion mounting | wearing of the planetary gear apparatus was fitted to the case in the power transmission device which concerns on embodiment of this invention from the attachment surface side. It is the combined sectional view seen in the AA arrow direction of FIG. 1 is a perspective view of a reduction planetary gear device according to an embodiment of the present invention. It is a partial expanded sectional view of the vicinity of the reduction planetary gear apparatus of the power transmission device according to the embodiment of the present invention. It is a top view of the external-tooth member of the reduction planetary gear apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the BB arrow cross section of FIG. It is a top view of the internal gear member of the case which the external gear member of the reduction planetary gear apparatus which concerns on embodiment of this invention fits. It is sectional drawing which shows the CC arrow cross section of FIG. It is sectional drawing which shows the DD arrow cross section of FIG. It is the elements on larger scale of the internal gear member of the reduction planetary gear apparatus which concerns on embodiment of this invention. It is a partial expansion perspective view of the spline fitting structure concerning an embodiment of the invention. It is a graph of the stress which arises in the base of the external tooth of the spline fitting structure concerning an embodiment of the invention. FIG. 13 (a) is a partially enlarged perspective view of an internal gear member in a modification of the spline fitting structure according to the embodiment of the present invention, and FIG. 13 (a) has an elliptical stress relaxation hole formed in the internal tooth of the internal gear member. FIG. 13 (b) shows a state where an oval-shaped stress relaxation hole is formed in the internal teeth of the internal tooth member, and FIG. 13 (c) shows a plurality of different sizes of the internal teeth of the internal tooth member. A state in which a circular stress relaxation hole is formed is shown. FIG. 14 (a) is a partially enlarged perspective view of an internal gear member in another modification of the spline fitting structure according to the embodiment of the present invention, and FIG. 14 (a) shows an elliptical stress relaxation hole in the internal tooth of the internal gear member. FIG. 14 (b) shows a state where two oval stress relief holes are formed in the internal teeth of the internal tooth member, and FIG. 14 (c) shows the internal teeth of the internal tooth member. Shows a state where two circular stress relaxation holes having different sizes are formed. FIG. 15A is a partially enlarged perspective view of an internal gear member in another modified example of the spline fitting structure according to the embodiment of the present invention, and FIG. 15A is a stress relief composed of a rectangular recess in the internal tooth of the internal gear member. FIG. 15B shows a state in which a conical stress relaxation hole is formed in the internal teeth of the internal tooth member, and FIG. 15C shows a state in which the internal teeth of the internal tooth member have teeth. The state which formed the circular stress relaxation hole in the width direction is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission device 2 Front generator 3 Front motor 4 Power split planetary gear device 5 Reduction planetary gear device 7 Input shaft 8 Counter drive gear 9 Counter driven gear 10 Spline fitting structure 11 Final drive gear 12 Final driven gear 13 Differential 16 Transaxle case 17 Case 19 Housing 31 Sun gear 32 Carrier 33 Pinion gear 34 Pinion shaft 51 External tooth member 52 Support member 53 Connection member 61 External tooth body 62 Outer peripheral part 62a, 62b, 62c, 62d, 62e, 62f, 62g, 62h, 62i, 62j External tooth 71 Internal tooth body 72 Internal tooth member 72a, 72b, 72c, 72d, 72e, 72f, 72g, 72h, 72i, 72j, 82, 84, 86 88, 96, 92, 102, 104 Inner teeth 72n Engagement surface 72s Opposing surface 73 Annular protrusion 74 Inner circumference 75a, 75b, 75c, 75d, 75e, 75f, 75g, 75h, 75i, 75j, 83, 85, 87, 89, 91, 93, 94, 97, 98, 103, 105, 107 Stress relaxation hole (concave)

Claims (4)

In the spline fitting structure provided with an external tooth member and an internal tooth member that are spline fitted to each other,
The external tooth member has an external tooth main body, and external teeth formed on the outer peripheral portion of the external tooth main body so as to protrude on one side in the axial direction.
The inner tooth member has an inner tooth body and an inner tooth formed on an inner peripheral portion of the inner tooth body so as to mesh with the outer tooth, and the inner tooth engages with the outer tooth. A spline fitting structure having a recess formed in the vicinity of a surface.   2. The spline according to claim 1, wherein the external tooth member constitutes a part of a planetary gear device, and the internal tooth member constitutes a part of a case that houses the planetary gear device. Mating structure.   The said internal tooth of the said internal gear member has an opposing surface which opposes the said planetary gear apparatus, The said recessed part is opened in the said opposing surface of the said internal gear member, The Claim 2 characterized by the above-mentioned. Spline fitting structure.   The spline fitting structure according to any one of claims 1 to 3, wherein the recess is formed in the specified internal tooth.

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