JP2020112178A - Actuator - Google Patents

Abstract

To provide an actuator for making a great impulsive load received from a valve hardly transmissive to a gear on the upstream side (the motor side).SOLUTION: An actuator 10 for driving a valve 19 to control exhaust gas produced by combustion in an internal combustion engine 11 includes a motor 36, an output shaft 26, and a slowdown part 37 for slowing down the rotation of the motor and transmitting it to the output shaft, the slowdown part having an intermediate gear 53 provided between a rotary shaft 55 of the motor and the output shaft and having a large-diameter metal gear 62 and a small-diameter resin gear 63, an intermediate shaft 61 to be the rotation center of the intermediate gear, and a metal bearing 90 for holding the large-diameter gear rotatably relative to the intermediate shaft at the large-diameter gear side of the intermediate gear.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to actuators.

Patent Document 1 discloses an actuator used to drive a valve for supercharging pressure control of a turbocharger. The actuator decelerates the rotation of the motor with a speed reducer to rotate the output shaft with a desired torque. The rotation angle of the output shaft is detected by a non-contact rotation angle sensor having a magnetic circuit section and a detection section. The final gear of the speed reducer is a resin member integrally fixed to the output shaft, and the magnetic circuit section is molded in the final gear. Patent Document 2 discloses an actuator used for an intake valve device. The actuator of this intake valve device includes a rolling bearing between the gear and the shaft or between the shaft and the housing.

JP, 2017-8757, A JP2012-197885A

The actuator that drives the boost pressure control valve is stressed by the engine pulsation through the boost pressure control valve. Since a high-cycle impact load associated with the pulsating cycle is applied to the output shaft, wear resistance and strength of the speed reducer are required. Therefore, for example, when mounted on an engine with large exhaust pulsation or a supercharger with large wastegate port diameter, it is necessary to improve wear resistance and strength against impact load. Such a problem was a problem common to many other actuators.

According to one aspect of the present disclosure, an actuator (10) is provided according to one aspect of the present disclosure. The actuator includes a motor (36), an output shaft (26), and a reduction unit (37) that reduces the rotation of the motor and transmits the rotation to the output shaft, the reduction unit rotating the motor. An intermediate gear (53) provided between the shaft (55) and the output shaft, the intermediate gear (53) having a large-diameter metal gear (62) and a small-diameter resin gear (63), and an intermediate serving as a rotation center of the intermediate gear. A shaft (61) and a metal bearing (90) for rotatably holding the large-diameter gear with respect to the intermediate shaft are provided on the large-diameter gear side of the intermediate gear. According to this aspect, since the metal bearing is provided between the large-diameter metal gear and the intermediate shaft, the rattling in the radial direction can be suppressed, and the inter-axis fluctuation of the intermediate gear can be reduced. As a result, the movement of the intermediate gear when receiving an input load can be reduced, and the stress on the intermediate gear can be reduced. As a result, the wear resistance of the intermediate gear and the shaft can be improved, and the strength against impact load can be improved.

It is a schematic diagram of an intake and exhaust part of an engine to which the actuator of the first embodiment is applied. It is explanatory drawing of a supercharger. It is a top view of an actuator. It is explanatory drawing which shows each gear of a reduction part. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is sectional drawing of a 2nd intermediate gear and a 2nd metal shaft. It is the perspective view which looked at the 2nd intermediate gear and the 2nd metal shaft from the 2nd large diameter external tooth part side. It is the perspective view which looked at the 2nd intermediate gear and the 2nd metal shaft from the 2nd small diameter external tooth part side. It is the perspective view which looked at the 2nd large diameter external tooth part from the 2nd large diameter external tooth part side. It is the perspective view which looked at the 2nd intermediate gear from the 2nd large diameter external tooth part side. It is sectional drawing of a 2nd intermediate gear. It is sectional drawing of a 2nd intermediate gear. It is explanatory drawing which shows the gate at the time of molding a 2nd intermediate gear. It is sectional drawing which shows typically the 2nd intermediate gear, 2nd metal shaft, and bearing of 2nd Embodiment.

First embodiment:
As shown in FIG. 1, the actuator 10 according to the first embodiment is applied to an engine 11 which is a power source for driving a vehicle.

The engine 11 is provided with an intake passage 12 that guides intake air into a cylinder of the engine 11, and an exhaust passage 13 that exhausts exhaust gas generated in the cylinder into the atmosphere. A compressor wheel 14 a of the intake compressor 14 of the supercharger 24 and a throttle valve 15 are provided in the intake passage 12. The compressor wheel 14a supercharges intake air to the engine 11. The throttle valve 15 adjusts the amount of intake air supplied to the engine 11 according to the amount of depression of an accelerator pedal (not shown) of the vehicle.

A turbine wheel 16 a of the exhaust turbine 16 of the supercharger 24 and a catalyst 17 for purifying exhaust gas are provided in the middle of the exhaust passage 13. The turbine wheel 16a is connected to the compressor wheel 14a by a rotating shaft 30. That is, the turbine wheel 16a is rotated by the exhaust energy of the engine 11, and the compressor wheel 14a is rotated. The catalyst 17 is a well-known three-way catalyst adopting a monolith structure, and is heated to an activation temperature by exhaust gas to purify harmful substances contained in the exhaust gas by an oxidizing action and a reducing action.

A bypass passage 18 is provided in the exhaust passage 13 in parallel with the turbine wheel 16a to bypass the turbine wheel 16a and allow the exhaust gas to flow. The bypass passage 18 is provided with a waste gate valve 19 which is a supercharging pressure control valve. When the wastegate valve 19 opens, a part of the exhaust gas from the engine 11 is directly guided to the catalyst 17 through the bypass passage 18. The wastegate valve 19 opens when the pressure of the exhaust gas from the engine 11 exceeds the valve opening pressure of the wastegate valve 19. The opening/closing of the waste gate valve 19 is also controlled by an ECU (engine control unit) 22. That is, the ECU 22 drives the actuator 10 and opens and closes the waste gate valve 19 by the link mechanism 25 provided between the actuator 10 and the waste gate valve 19.

As shown in FIG. 2, the supercharger 24 includes an exhaust turbine 16, an intake compressor 14, and an actuator 10. The exhaust turbine 16 includes a turbine wheel 16a (FIG. 1) that is rotationally driven by the exhaust gas discharged from the engine 11, and a spiral turbine housing 16b that houses the turbine wheel 16a. The intake compressor 14 includes a compressor wheel 14a (FIG. 1) that rotates by receiving the rotational force of the turbine wheel 16a, and a spiral compressor housing 14b that houses the compressor wheel 14a. The turbine wheel 16a and the compressor wheel 14a are connected by the rotating shaft 30 (FIG. 1).

The turbine housing 16b is provided with a bypass passage 18 in addition to the turbine wheel 16a. The bypass passage 18 directly guides the exhaust gas flowing into the turbine housing 16b to the exhaust outlet of the turbine housing 16b without supplying it to the turbine wheel 16a. This bypass passage 18 is opened and closed by a waste gate valve 19. The wastegate valve 19 is a swing valve that is rotatably supported by a valve shaft 20 inside the turbine housing 16b. The wastegate valve 19 opens when the exhaust gas pressure exceeds the valve opening pressure of the wastegate valve 19, but is also driven by the actuator 10 to open and close.

The housing 35 that houses the actuator 10 is attached to the intake compressor 14 side of the supercharger 24, which is separated from the exhaust turbine 16. By doing so, the influence of the heat of the exhaust gas can be avoided. The supercharger 24 is provided with a link mechanism 25 (FIG. 1) for transmitting the output of the actuator 10 to the wastegate valve 19. In the present embodiment, as the link mechanism 25, a four-joint link mechanism including an actuator lever 27, a rod 28, and a valve lever 29 is adopted. The actuator lever 27 is connected to the output shaft 26 of the actuator 10 and is rotated by the actuator 10. The valve lever 29 is connected to the valve shaft 20. The rod 28 transmits the turning torque applied to the actuator lever 27 to the valve lever 29.

The operation of the actuator 10 is controlled by the ECU 22 equipped with a microcomputer. Specifically, the ECU 22 controls the actuator 10 so as to adjust the opening degree of the waste gate valve 19 when the engine 11 is rotating at high speed, and controls the supercharging pressure by the supercharger 24. Further, the ECU 22 warms up the catalyst 17 by controlling the actuator 10 so that the waste gate valve 19 is fully opened when the temperature of the catalyst 17 has not reached the activation temperature immediately after a cold start, for example. As a result, the high-temperature exhaust gas that has not been deprived of heat by the turbine wheel 16a can be directly guided to the catalyst 17, and the catalyst 17 can be warmed up in a short time.

Next, the actuator 10 will be described with reference to FIGS. The actuator 10 is housed in a housing 35 attached to the intake compressor 14. As shown in FIG. 3, the housing 35 has a first housing part 41 and a second housing part 42. The second housing part 42 is also referred to as a “case 42”. The first housing part 41 and the second housing part 42 are formed of a metal material such as aluminum, aluminum alloy, or steel. The first housing part 41 and the second housing part 42 may be made of resin. Further, the first housing part 41 and the second housing part 42 may be formed by any of the manufacturing methods such as die casting, gravity casting, injection molding and pressing. The second housing part 42 is fastened to the first housing part 41 by a fastening member 43. The output shaft 26 projects from the second housing portion 42 and is connected to the actuator lever 27.

As shown in FIGS. 4 and 5, the first housing part 41 forms a housing space 44 together with the second housing part 42. The motor 36 is housed in the housing space 44. Specifically, the motor 36 is inserted into a motor insertion hole 46 formed in the first housing portion 41, and is fixed to the first housing portion 41 by a screw 47. A wave washer 45 is installed between the motor 36 and the bottom surface of the motor insertion hole 46. The wave washer 45 may not be provided. The motor 36 may be, for example, a known DC motor, a known stepping motor, or the like regardless of the type.

As shown in FIGS. 4 and 6, the actuator 10 has a speed reducer 37. The speed reducer 37 is a parallel shaft type speed reducer that reduces the rotation of the motor 36 and transmits it to the output shaft 26, and has a plurality of gears. In the present embodiment, the plurality of gears includes a pinion gear 51, a first intermediate gear 52, a second intermediate gear 53, and an output gear 54.

The pinion gear 51 is fixed to the motor shaft 55 of the motor 36. The pinion gear 51 is a metal gear made of metal. As the metal, for example, iron-based sintered metal is used.

The first intermediate gear 52 is a compound gear having a first large diameter outer tooth portion 57 and a first small diameter outer tooth portion 58, and is rotatably supported by the first metal shaft 56. The first large-diameter outer tooth portion 57 is a large-diameter gear, and meshes with the pinion gear 51 fixed to the motor shaft 55 of the motor 36. The first small-diameter outer tooth portion 58 is a small-diameter gear having a smaller diameter than the first large-diameter outer tooth portion 57. The first large-diameter outer tooth portion 57 and the first small-diameter outer tooth portion 58 are both metal gears made of metal. Similarly, for example, an iron-based sintered metal is used as the metal. The first large-diameter outer tooth portion 57 has a plurality of openings 57o in order to reduce inertia.

The second intermediate gear 53 is a compound gear having a second large-diameter outer tooth portion 62 and a second small-diameter outer tooth portion 63, and is rotatably supported by the second metal shaft 61 which is the center of rotation. The second large-diameter outer tooth portion 62 is a large-diameter gear and meshes with the first small-diameter outer tooth portion 58 of the first intermediate gear 52. The second large diameter outer tooth portion 62 is a metal gear made of metal. Similarly, for example, an iron-based sintered metal is used as the metal. The second small-diameter outer tooth portion 63 is a small-diameter gear having a smaller diameter than the second large-diameter outer tooth portion 62, and is a resin gear formed of resin. As the resin, for example, a polyamide resin, a nylon resin, or a polyacetal resin can be used. Resin gears have smaller inertia than metal gears. Therefore, when a large impact load is applied to the second intermediate gear 53 via the waste gate valve 19, the valve lever 29, the rod 28, the actuator lever 27, the output shaft 26, and the output gear 54 from the pulsation of the exhaust pressure of the engine 11, The impact can be less likely to be transmitted to gears on the upstream side (motor side) including the second intermediate gear 53, for example, the first intermediate gear 52 and the pinion gear 51. Furthermore, since the output gear 54 is a resin gear, when a large impact load is applied to the output gear 54, gears on the upstream side (motor side) including the output gear, for example, the second intermediate gear 53 and the first intermediate gear 52. The impact can be made less likely to be transmitted to the pinion gear 51.

The output gear 54 meshes with the second small-diameter outer tooth portion 63, and the output shaft 26 is connected and fixed along the central axis AX3 of the output gear 54. The output gear 54 is a resin gear made of resin. Therefore, in the first embodiment, the upstream pinion gear 51 to the second large-diameter outer tooth portion 62 are metal gears, and the downstream second small-diameter outer tooth portion 63 to the output gear 54 are resin gears. .. In other words, the gears included in the reduction gear unit 37 are metal gears except for the output gear 54 and the second small-diameter outer tooth portion 63 of the second intermediate gear 53 that is a compound gear that meshes with the output gear 54. Therefore, the meshes of the gears are meshes between the resin gears and the metal gears, and there is no meshing between the resin gears and the metal gears. As a result, abrasion of the resin gear can be suppressed.

As shown in FIGS. 5 and 6, the actuator 10 includes a first housing portion 41 that houses the motor 36, the output shaft 26, and the speed reducing portion 37, and a second housing that is a case that covers the first housing portion 41. The second metal shaft 61 has one end fixed to the first housing part 41 and the other end supported by the second housing part 42. Therefore, as compared with the case where one end of the second metal shaft 61 is fixed to the first housing part 41 and the other end is not supported, the motor 36 is driven and the pulsation from the waste gate valve 19 is caused. The deformation of the second metal shaft 61 due to vibration and torque can be reduced.

The output gear 54 is provided with magnets 66 and 67 that are magnetic flux generating portions and yokes 68 and 69 that are magnetic flux transmitting portions. The magnets 66 and 67 and the yokes 68 and 69 form a magnetic circuit portion 64 that forms an arc-shaped closed magnetic circuit when viewed in the axial direction of the output shaft 26. The magnetic circuit portion 64 rotates integrally with the output gear 54 and the output shaft 26.

Inside the closed magnetic circuit of the magnetic circuit section 64 of the output gear 54, a magnetic flux detecting section 65 that detects the magnetic flux of the magnets 66 and 67 is arranged. The magnetic flux detection unit 65 is configured using, for example, a Hall IC. The magnetic circuit unit 64 and the magnetic flux detection unit 65 function as a rotation angle sensor 39 that detects the rotation angle of the output shaft 26. Basic applications and functions of the magnetic circuit unit 64 and the magnetic flux detection unit 65 are the same as those disclosed in JP-A-2014-126548. The rotation angle of the output shaft 26 detected by the rotation angle sensor 39 is output to the ECU 22 (see FIG. 1). The configurations of the magnetic circuit unit 64 and the magnetic flux detection unit 65 shown in FIG. 6 are examples, and other configurations may be used.

As shown in FIG. 6, the output shaft 26 is rotatably supported by a bearing 48 provided in the first housing portion 41 and a bearing 49 provided in the second housing portion 42. One end of the output shaft 26 extends out from the second housing portion 42 of the housing 35. The actuator lever 27 is fixed to the output shaft 26 outside the second housing portion 42.

As shown in FIGS. 7, 8 and 9, the second intermediate gear 53 includes a second large diameter outer tooth portion 62 which is a metal gear and a second small diameter outer tooth portion 63 which is a resin gear. There is. The second large-diameter outer tooth portion 62 has an opening 62o centered on the axis AX2. The second metal shaft 61 is inserted into the opening 62o along the axis AX2, and the metal bearing 90 is inserted between the opening 62o and the metal shaft 61.

The second intermediate gear 53 uses, as the metal bearing 90, a ball bearing which is a rolling bearing having an inner ring 90i, an outer ring 90o, and a bearing ball 90b. The inner diameter of the opening 62o is slightly smaller than the outer diameter of the outer ring 90o of the bearing 90, and the outer diameter of the second metal shaft 61 is slightly larger than the inner diameter of the inner ring 90i of the bearing 90. The inner ring 90i and the outer ring 90o of the bearing 90 are press-fitted between the second large-diameter outer tooth portion 62 and the second metal shaft 61.

Since the metal bearing 90 is provided between the second large-diameter outer tooth portion 62, which is a large-diameter metal gear, and the second metal shaft 61, rattling in the radial direction can be suppressed, and the second intermediate gear 53 can be prevented. The variation between axes can be reduced. As a result, the movement of the second intermediate gear 53 when receiving an input load can be reduced, and the stress of the second intermediate gear 53 can be reduced. As a result, the wear resistance of the second intermediate gear 53 and the second metal shaft 61 can be improved, and the strength against an impact load can be improved.

Since a ball bearing, which is a rolling bearing, is used as the metal bearing 90, rolling resistance can be reduced and load bearing capacity can be improved.

A resin bearing 95 is formed between the second metal shaft 61 and the end of the second small-diameter outer tooth portion 63 on the opposite side of the second large-diameter outer tooth portion 62.

As shown in FIG. 10, the second large-diameter outer tooth portion 62 includes large teeth 62t, an opening 62o, a through hole 62k, and a positioning hole 62h. The large tooth 62t, which is a tooth of the second large diameter outer tooth portion 62, is formed on the outer periphery of the second large diameter outer tooth portion 62. As described above, the opening 62o is formed at a position centered on the axis AX2 of the second large diameter outer tooth portion 62, that is, substantially at the center of the second large diameter outer tooth portion 62. The through holes 62k are formed at equal intervals in the circumferential direction between the large teeth 62t and the opening 62o. The positioning hole 62h is provided between the large tooth 62t and the opening 62o.

11 is a perspective view of the second intermediate gear, FIG. 12 is a sectional view taken along line XII-XII passing through the through hole 62k, and FIG. 13 is line XIII-XIII not passing through the through hole 62k. It is the sectional view cut. As shown in FIGS. 11, 12, and 13, the resin forming the second small-diameter outer tooth portion 63, which is a small-diameter resin gear, includes the first resin portion 63a, the second resin portion 63b, and the third resin portion. 63c and a small tooth resin portion 63d. The small tooth resin portion 63d is a portion that forms a small diameter gear, and the small tooth 63t that is the tooth of the second small diameter outer tooth portion 63 is formed on the outer periphery of the small tooth resin portion 63d. The first resin portion 63a is formed on the surface of the second large-diameter outer tooth portion 62 opposite to the small tooth resin portion 63d. The first resin portion 63a has a substantially disc shape and covers a region inside the root circle of the large tooth 62t of the second large diameter outer tooth portion 62. In addition, it is preferable that the first resin portion 63a does not extend outside the end surface 62e1 of the large tooth 62t of the second large-diameter outer tooth portion 62 opposite to the small tooth resin portion 63d. By doing so, it is possible to avoid interference between the first resin portion 63a and other members.

The second resin portion 63b is formed on the surface of the second large-diameter outer tooth portion 62 on the small tooth resin portion 63d side. The second resin portion 63b has a substantially disc shape and covers a region inside the root circle of the large tooth 62t of the second large diameter outer tooth portion 62. It is preferable that the second resin portion 63b does not extend outside the end surface 62e2 of the large tooth 62t of the second large-diameter outer tooth portion 62 on the small tooth resin portion 63d side. By doing so, it is possible to avoid interference between the second resin portion 63b and other members. The third resin portion 63c is formed in the through hole 62k, and connects the first resin portion 63a and the second resin portion 63b to be integrated. The first resin portion 63a, the second resin portion 63b, the third resin portion 63c, and the small-tooth resin portion 63d are the second large outer diameter which is a metal gear by insert molding when molding the second intermediate gear. It is integrally molded with the tooth portion 62.

As shown in FIG. 14, the gate 80g serving as a resin filling port when the second intermediate gear 53 is formed is present at a position corresponding to the through hole 62k on the first resin portion 63a side. Therefore, by providing the gate 80g at a position corresponding to the through hole 62k, the resin injected from the gate 80g can be easily flowed to the opposite side of the second large-diameter outer tooth portion 62 from the gate 80g. A gate trace 63g is formed at a position corresponding to the through hole 62k of the first resin portion 63a. Since the surface of the resin molding die does not exist at the gate 80g, a trace remains on the resin. This trace is the gate trace 63g. Therefore, the position of the gate 80g at the time of integral molding can be known from the position of the gate mark 63g. It should be noted that even if the trace is erased with a file etc., it is still the gate trace.

According to the first embodiment, since the metal bearing 90 is provided between the second large-diameter outer tooth portion 62, which is a large-diameter metal gear, and the second metal shaft 61, rattling in the radial direction can be suppressed. Therefore, the variation of the second intermediate gear 53 between the axes can be reduced. As a result, the movement of the second intermediate gear 53 when receiving an input load can be reduced, and the stress of the second intermediate gear 53 can be reduced. Further, the wear resistance of the second intermediate gear 53 and the second metal shaft 61 can be improved, and the strength against an impact load can be improved.

According to the first embodiment, since the bearing 90 is a ball bearing and a rolling bearing, the rolling resistance can be reduced and the withstand load can be improved. Therefore, for example, the load generated by the exhaust force can be opposed. In the present embodiment, when the ball bearing of the rolling bearing is used, any other rolling bearing, for example, a roller bearing, a needle bearing, a tapered roller bearing, a spherical roller bearing, or a thrust bearing may be used. .. A bearing other than the rolling bearing, for example, a sliding bearing may be used.

According to the first embodiment, the second intermediate gear 53 includes the opening 62o and the bearing 90 on the side of the second large-diameter outer tooth portion 62, which is a large-diameter metal gear. Therefore, since the larger opening 62o can be opened on the side of the second large-diameter outer tooth portion 62, a larger-diameter bearing can be used. Further, since the bearing 90 is press-fitted into both the inner ring 90i and the outer ring 90o, the position of the bearing in the thrust direction can be regulated. Further, it is possible to reduce wear of the second metal shaft 61 and the second intermediate gear 53. The bearing 90 may be provided on the second small-diameter outer tooth portion 63 side. Further, in the bearing 90, one or both of the inner ring 90i and the outer ring 90o may not be press-fitted.

According to the first embodiment, the second large-diameter outer tooth portion 62 is sandwiched by the first resin portion 63a and the second resin portion 63b, and the first resin portion 63a and the second resin portion 63b are Since it is integrally formed by the three resin portions 63c, it is hard to come off in the thrust direction. Further, the force can be transmitted between the second large-diameter outer tooth portion 62 and the second small-diameter outer tooth portion 63 via the third resin portion 63c. In addition, only one of the first resin portion 63a and the second resin portion 63b is provided, and the second large-diameter outer tooth portion 62 is not sandwiched between the first resin portion 63a and the second resin portion 63b. It may be. Further, the first resin portion 63a and the second resin portion 63b may not have a disc shape as long as they have a shape that covers the opening 62k and the periphery of the opening 62k.

According to the first embodiment, the second large-diameter outer tooth portion 62 is provided with the through holes 62k formed at equal intervals in the circumferential direction, so that the third large resin portion 63c inside the through hole 62k allows the second large outer tooth portion 62 to have the second large diameter. The force between the radially outer tooth portion 62 and the second small diameter outer tooth portion 63 can be evenly transmitted. Further, the warp of the second intermediate gear 53 after molding the resin can be suppressed. The through holes 62k do not necessarily have to be formed at equal intervals in the circumferential direction.

According to the first embodiment, the gate mark 63g is provided at a position corresponding to the through hole 62k. When the second small-diameter outer tooth portion 63, which is a resin gear, is molded by insert molding, it is easy to evenly flow the resin from the first resin portion 63a side to the second resin portion 63b side. Note that the gate trace 63g may not be provided at the position corresponding to the through hole 62k as long as the second small-diameter outer tooth portion 63, which is the resin gear, can be molded by insert molding.

-Second embodiment:
In the second embodiment shown in FIG. 15, the shape of the second metal shaft 61a is different from the shape of the second metal shaft 61 of the first embodiment. Note that, in FIG. 15, for convenience of illustration, the second housing portion 42 is not shown. Also, illustration of large teeth and small teeth is omitted. In the second metal shaft 61a, the first portion 61a1 of the large-diameter second large-diameter outer tooth portion 62 side is thin, and the end of the second small-diameter outer tooth portion 63 opposite to the second large-diameter outer tooth portion 62 is The second portion 61a2 in contact with the second small-diameter outer tooth portion 63 is thick. That is, the second metal shaft 61a is different from the first embodiment in that the second portion 61a2 has a stepped shape thicker than the first portion 61a1, but is the same as the other portions. A bearing 90 in which both the outer ring 90o and the inner ring 90i are press-fitted is provided between the second large-diameter outer tooth portion 62 and the first portion 61a1 of the second metal shaft 61a. On the other hand, a resin bearing 95a is provided at a portion where the end portion of the second small-diameter outer tooth portion 63 and the second portion 61a2 of the second metal shaft 61a are in contact with each other. The resin bearing 95a and the bearing 90 are separated from each other.

The second embodiment has the following effects in addition to the effects of the first embodiment. That is, since the second portion 61a2 is thicker than the first portion 61a1, as compared with the case where the second portion 61a2 has the same thickness as the first portion 61a1, the second metal shaft 61a in the second portion 61a2 and the resin gear The contact area between the resin and the second small-diameter outer tooth portion 63 and the shaft increases, and the surface pressure applied to the resin in the portion decreases. As a result, it is possible to reduce the abrasion of the resin in that portion. The second portion 61a2 may have the same thickness as the first portion 61a1. This is because at least the effects of the first embodiment are obtained.

According to the second embodiment, since the resin bearing 95a and the bearing 90 are separated from each other, it is easy to suppress the relative inclination between the second metal shaft 61a and the second intermediate gear 53. As a result, it is possible to suppress stress on the resin forming the second small-diameter outer tooth portion 63 and uneven wear of the resin due to the inclination. In the bearing 90, at least one of the outer ring 90o and the inner ring 90i may not be press-fitted.

In each of the above embodiments, the second intermediate gear 53 is described as an example, but other gears can be applied as long as they are compound gears in which a large diameter gear is made of metal and a small diameter gear is made of resin. For example, the first large-diameter outer tooth portion 57 of the first intermediate gear 52 is a metal gear, the first small-diameter outer tooth portion 58 is a resin gear, and the second large-diameter outer tooth portion 62 of the second intermediate gear 53 is a second small-diameter portion. The outer tooth portions 63 may be resin gears, and the configuration described in each of the above embodiments may be applied to the first intermediate gear 52.

In each of the above-described embodiments, the actuator that drives the waste gate valve 19 of the supercharger 24 has been described as an example, but the actuator described in each of the embodiments drives the nozzle that changes the direction of the exhaust gas that hits the turbine of the supercharger 24. As an actuator for driving a valve for controlling supercharging pressure in a supercharger, such as an actuator for switching, a twin turbo equipped with two turbines, an actuator for switching a turbine of a two-stage turbo, an actuator for switching a turbine of a variable capacity turbo, and the like. Is also available.

The present disclosure is not limited to the above-described embodiments, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features of the embodiment corresponding to the technical features in each mode described in the column of the outline of the invention are to solve some or all of the above problems, or some of the above effects. Alternatively, in order to achieve all, it is possible to appropriately replace or combine. If the technical features are not described as essential in this specification, they can be deleted as appropriate.

The present disclosure can be realized as the following modes.

(1) According to one aspect of the present disclosure, an actuator (10) is provided. The actuator includes a motor (36), an output shaft (26), and a reduction unit (37) that reduces the rotation of the motor and transmits the rotation to the output shaft, the reduction unit rotating the motor. An intermediate gear (53) provided between the shaft (55) and the output shaft, the intermediate gear (53) having a large-diameter metal gear (62) and a small-diameter resin gear (63), and an intermediate serving as a rotation center of the intermediate gear. A shaft (61) and a metal bearing (90) for rotatably holding the large-diameter gear with respect to the intermediate shaft are provided on the large-diameter gear side of the intermediate gear.

(2) In the above-mentioned form, the bearing may be a rolling bearing. According to this aspect, the rolling resistance can be reduced and the withstand load can be improved, so that the load generated by the exhaust force can be countered.

(3) In the above-described embodiment, the intermediate gear has a resin bearing between the intermediate gear and the intermediate shaft on the side of the small-diameter resin gear, and the metal bearing includes both the inner ring (90i) and the outer ring (90o). It may be press-fitted. According to this aspect, since the bearing is provided on the large-diameter metal gear side, a larger-diameter bearing can be used. Further, since the inner ring and the outer ring of the bearing are press-fitted, the position of the bearing in the thrust direction can be regulated and wear of the shaft and the intermediate gear can be reduced.

(4) In the above aspect, the large-diameter metal gear is formed between large teeth (62t), an opening (62o) into which the intermediate shaft and the bearing are inserted, and the large teeth and the opening. The resin forming the small-diameter resin gear includes a small-tooth resin portion (63d) and a first resin portion (31d) sandwiching the large-diameter metal gear from a direction along the intermediate shaft. 63a) and a second resin portion (63b), and a third resin portion (63c) connecting the first resin portion and the second resin portion via the through hole. According to this aspect, since the large-diameter metal gear is sandwiched by the first resin portion and the second resin portion, the large-diameter metal gear is unlikely to come off in the thrust direction. Further, the force can be transmitted between the large-diameter metal gear and the small-diameter resin gear via the third resin portion.

(5) In the above aspect, the large-diameter metal gear may have the through holes at equal intervals in the circumferential direction of the large-diameter metal gear. According to this aspect, the force between the large-diameter metal gear and the small-diameter resin gear can be evenly transmitted by the third resin portions of the through holes formed at equal intervals. Further, it is possible to suppress warpage after resin molding.

(6) In the above embodiment, the resin forming the small-diameter resin gear may have a gate mark at a position corresponding to the through hole. According to this aspect, when the resin forming the resin gear is molded, it is easy to flow the resin through the through hole to the side opposite to the large-diameter gear.

(7) In the above embodiment, the intermediate shaft has a stepped shape in which a first portion in contact with the bearing has a narrower stepped shape than a second portion in contact with the resin gear with the small diameter, and the resin gear with the small diameter has the second portion. A resin bearing may be provided in a portion contacting the portion, and the resin bearing may be separated from the bearing. According to this aspect, the contact area between the resin of the small-diameter resin gear and the shaft in the second portion increases, and the surface pressure applied to the resin decreases, so that the abrasion of the resin can be reduced.

(8) In the above aspect, the actuator may drive a device that utilizes or controls exhaust gas generated by combustion of the internal combustion engine (11).

It should be noted that the present disclosure can be implemented in various forms. For example, in addition to an actuator used for opening and closing a wastegate valve of a turbocharger, switching of a twin turbo equipped with two turbines or a turbine of a two-stage turbo is provided. It can also be realized as an actuator for controlling the supercharging pressure in a supercharger, such as an actuator for a turbocharger or an actuator for switching a turbine of a variable capacity turbo.

10 actuator 11 engine 12 intake passage 13 exhaust passage 14 intake compressor 14a compressor wheel 14b compressor housing 15 throttle valve 16 exhaust turbine 16a turbine wheel 16b turbine housing 17 catalyst 18 bypass passage 19 wastegate valve 20 valve shaft 22 engine control unit ( ECU) 24 supercharger 25 link mechanism 26 output shaft 27 actuator lever 28 rod 29 valve lever 30 rotary shaft 35 housing 36 motor 37 speed reducer 39 rotation angle sensor 41 first housing part 42 second housing part (case) 43 fastening member 44 Housing Space 45 Wave Washer 46 Motor Insertion Hole 47 Screw 48, 49 Bearing 51 Pinion Gear 52 First Intermediate Gear 53 Second Intermediate Gear 54 Output Gear 55 Motor Shaft 56 First Metal Shaft 57 First Large Diameter Outer Teeth 57o Opening 58 1st small diameter outer tooth part 61 2nd metal shaft 61a 2nd metal shaft 61a1 1st part 61a2 2nd part 62 2nd large diameter outer tooth part 62e1, 62e2 end face 62h hole 62k through hole 62o opening 62t large tooth 63 2nd small diameter External tooth portion 63a First resin portion 63b Second resin portion 63c Third resin portion 63d Small tooth resin portion 63g Gate mark 63t Small tooth 64 Magnetic circuit portion 65 Magnetic flux detecting portion 66, 67 Magnet 68, 69 Yoke 80g Gate 90 Bearing 90b Bearing ball 90i Inner ring 90o Outer ring AX1, AX2, AX3 Central axis (axis )

Claims (9)

An actuator (10),
A motor (36),
An output shaft (26),
A deceleration part (37) for decelerating the rotation of the motor and transmitting it to the output shaft;
Equipped with
The speed reducer is
An intermediate gear (53) provided between the rotary shaft (55) of the motor and the output shaft, the intermediate gear (53) having a large-diameter metal gear (62) and a small-diameter resin gear (63);
An intermediate shaft (61) serving as a rotation center of the intermediate gear,
A metal bearing (90) for holding the large-diameter gear rotatably with respect to the intermediate shaft on the large-diameter gear side of the intermediate gear;
An actuator. The actuator according to claim 1, wherein
The bearing is a rolling bearing,
Actuator. The actuator according to claim 1 or 2, wherein
The intermediate gear is
On the small-diameter resin gear side, a resin bearing is provided between the intermediate shaft and the intermediate shaft,
The metal bearing is press-fitted into the inner ring (90i) and the outer ring (90o),
Actuator. The actuator according to any one of claims 1 to 3,
The large-diameter metal gear has large teeth (62t), an opening (62o) into which the intermediate shaft and the bearing are inserted, and a through hole (62k) formed between the large tooth and the opening. ,,
The resin forming the small diameter resin gear includes a small tooth resin portion (63d), a first resin portion (63a) and a second resin portion (63b) that sandwich the large diameter metal gear from a direction along the intermediate shaft. ) And a third resin portion (63c) connecting the first resin portion and the second resin portion via the through hole,
Actuator. The actuator according to claim 4, wherein
The large-diameter metal gear has the through holes at equal intervals in the circumferential direction of the large-diameter metal gear,
Actuator. The actuator according to claim 5, wherein
An actuator in which the resin forming the small-diameter resin gear has a gate mark at a position corresponding to the through hole. The actuator according to any one of claims 1 to 6, wherein
The intermediate shaft has a stepped shape in which a first portion in contact with the bearing is thinner than a second portion in contact with the small-diameter resin gear,
The small-diameter resin gear has a resin bearing in a portion in contact with the second portion,
The resin bearing is separated from the bearing,
Actuator. The actuator according to any one of claims 1 to 7, wherein
The actuator drives a device that utilizes or controls exhaust gas generated by combustion of an internal combustion engine (11),
Actuator. The actuator according to claim 8, wherein
The actuator is
An actuator that drives the waste gate valve of the supercharger,
An actuator that drives a nozzle that changes the direction of the exhaust that hits the turbine of the supercharger,
An actuator for switching turbines of a twin turbo or a two-stage turbo equipped with two turbines,
An actuator for switching the turbine of the variable capacity turbo,
One of the actuators for controlling the supercharging pressure in the supercharger,
Actuator.

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