JP2018048596A - Actuator for linkage mechanism for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator for a linkage mechanism for an internal combustion engine that can shorten an axial dimension.SOLUTION: In an actuator for a linkage mechanism for an internal combustion engine, part of a bearing part 32 for supporting a motor output shaft 28 overlaps on a rotor 30 in an axial direction of the motor output shaft 28.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an actuator for a link mechanism for an internal combustion engine.

  2. Description of the Related Art Conventionally, there is known an actuator for a link mechanism for an internal combustion engine that has a control shaft that drives a control link connected to the link mechanism for an internal combustion engine, and that reduces the rotational speed of the motor output shaft of the electric motor and transmits it to the control shaft (For example, Patent Document 1).

JP-A-2015-145647

  An object of the present invention is to provide an actuator for a link mechanism for an internal combustion engine that can shorten the axial dimension.

  In the actuator of the link mechanism for an internal combustion engine in one embodiment of the present invention, a part or all of the bearing portion that supports the motor output shaft overlaps the rotor in the axial direction of the motor output shaft.

  Therefore, in the present invention, the axial dimension can be shortened.

1 is a schematic view of an internal combustion engine provided with an actuator for a link mechanism for an internal combustion engine of Embodiment 1. FIG. FIG. 3 is a side view of an actuator of the link mechanism for the internal combustion engine according to the first embodiment. FIG. 3 is a cross-sectional view taken along line S3-S3 in FIG. FIG. 2 is an enlarged view of a main part of the electric motor 22 according to the first embodiment. 1 is an exploded perspective sectional view of an electric motor 22 according to a first embodiment. It is a principal part enlarged view of the electric motor 22 of Embodiment 2. FIG. FIG. 6 is an enlarged view of a main part of an electric motor 22 according to a third embodiment. FIG. 6 is an enlarged view of a main part of an electric motor 22 according to a fourth embodiment. FIG. 10 is an enlarged view of a main part of an electric motor 22 according to a fifth embodiment.

Embodiment 1
FIG. 1 is a schematic view of an internal combustion engine provided with an actuator for a link mechanism for an internal combustion engine according to a first embodiment. The basic configuration is the same as that described in FIG. 1 of Japanese Patent Laid-Open No. 2011-169251, and will be described briefly.
The piston 1 reciprocates in a cylinder of a cylinder block in an internal combustion engine (gasoline engine). The upper end of the upper link 3 is rotatably connected to the piston 1 via a piston pin 2. A lower link 5 is rotatably connected to the lower end of the upper link 3 via a connecting pin 6. A crankshaft 4 is rotatably connected to the lower link 5 via a crankpin 4a. An upper end portion of the first control link 7 is rotatably connected to the lower link 5 via a connecting pin 8. A lower end portion of the first control link 7 is connected to a connecting mechanism 9 having a plurality of links. The connection mechanism 9 includes a first control shaft 10, a second control shaft 11, a second control link 12 and an arm link 13. The first control shaft 10 extends in parallel with the crankshaft 4 extending in the cylinder row direction inside the internal combustion engine. The first control shaft 10 includes a first journal portion 10a, a control eccentric shaft portion 10b, an eccentric shaft portion 10c, a first arm portion 10d, and a second arm portion 10e. The first journal portion 10a is rotatably supported by the internal combustion engine body. The control eccentric shaft portion 10b is rotatably connected to the lower end portion of the first control link 7. The eccentric shaft portion 10c is rotatably connected to one end portion 12a of the second control link 12. One end of the first arm portion 10d is connected to the first journal portion 10a. The other end of the first arm portion 10d is connected to the control eccentric shaft portion 10b. The control eccentric shaft portion 10b is located at a position offset by a predetermined amount with respect to the first journal portion 10a. One end of the second arm portion 10e is connected to the first journal portion 10a. The other end of the second arm portion 10e is connected to the eccentric shaft portion 10c. The eccentric shaft portion 10c is at a position that is eccentric by a predetermined amount with respect to the first journal portion 10a. One end of the arm link 13 is rotatably connected to the other end portion 12b of the second control link 12. The other end of the arm link 13 is connected to the second control shaft 11. The arm link 13 and the second control shaft 11 do not move relative to each other. The second control link 12 is a lever-shaped part. One end portion 12a connected to the eccentric shaft portion 10c is a substantially linear component. On the other hand, the other end 12b connected to the arm link 13 is a curved part. The second control shaft 11 is a torque transmitted from an electric motor 22 (see FIG. 3) via a wave gear type speed reducer (reduction gear) 21 (see FIG. 3) which is a part of an actuator of a link mechanism for an internal combustion engine. To change the rotation position. When the rotational position of the second control shaft 11 is changed, the attitude of the second control link 12 is changed, the first control shaft 10 is rotated, and the position of the lower end portion of the first control link 7 is changed. As a result, the posture of the lower link 5 changes, and the stroke position and stroke amount of the piston 1 inside the cylinder change. That is, the internal combustion engine link mechanism of the first embodiment is a variable compression ratio mechanism that changes the stroke amount of the piston 1 by changing the posture.

2 is a side view of the actuator of the link mechanism for the internal combustion engine of the first embodiment, FIG. 3 is a cross-sectional view taken along line S3-S3 in FIG. 2, FIG. 4 is an enlarged view of the main part of the electric motor 22, and FIG. FIG. 22 is an exploded perspective sectional view of FIG. The actuator of the link mechanism for the internal combustion engine includes a housing 20, a wave gear reducer 21, and an electric motor 22. Hereinafter, the x-axis is set in the axial direction of the second control shaft 11, and the direction from the wave gear reducer 21 side to the electric motor 22 side is defined as the positive x-axis direction. Further, the radial direction of the x axis is referred to as a radial direction, and the direction around the x axis is referred to as a circumferential direction.
The housing 20 accommodates the second control shaft 11 and the wave gear type speed reducer 21 therein. The housing 20 rotatably supports the second control shaft 11 via a journal portion (not shown). The housing 20 is attached to the internal combustion engine.
The wave gear type reduction gear 21 is a harmonic drive (registered trademark) type reduction gear. The wave gear reducer 21 includes a flexible external gear 23, an internal gear 24, and a wave generator 26. The flexible external gear 23 is a part of a thin cup-shaped metal elastic body that can be bent and deformed. The flexible external gear 23 has a plurality of external teeth 23a on the outer periphery. The flexible external gear 23 includes a plurality of bolts 25. The bolt 25 fixes the flexible external gear 23 to the coupling 50 by screw coupling with the female thread portion 50a of the coupling 50. The coupling 50 is fixed to the positive end of the second control shaft 11 in the x-axis direction. The coupling 50 has an eccentric absorption function. The internal gear 24 is a rigid ring-shaped part. The internal gear 24 is fastened and fixed to the housing 20 by a plurality of bolts 37 (see FIG. 2). The internal gear 24 has a plurality of internal teeth 24a meshing with the external teeth 23a on the inner periphery. The wave generator 26 is a component in which a thin ball bearing is fitted on the outer periphery of the elliptical cam. The wave generator 26 is fixed to the x-axis negative direction end 28a of the motor output shaft 28 and rotates integrally with the motor output shaft 28. The outer peripheral surface of the wave generator 26 slides along the inner peripheral surface of the flexible external gear 23. The number of teeth of the internal teeth 24a of the internal gear 24 is two more than the number of teeth of the external teeth 23a of the flexible external gear 23. In the wave gear type reduction gear 21, the reduction ratio is determined by the difference in the number of teeth, and an extremely large reduction ratio is obtained.

The electric motor 22 is a brushless motor. The electric motor 22 includes a motor output shaft 28, a motor casing 29, a rotor 30, a stator 31, a bearing portion 32, and a motor controller 33.
The motor output shaft 28 is located on the x-axis positive direction side of the second control shaft 11. The motor output shaft 28 is coaxial with the second control shaft 11.
The motor casing 29 has a motor housing part 34 and a controller housing part 35. The motor accommodating portion 34 accommodates a part of the motor output shaft 28, the rotor 30, the stator 31, and the bearing portion 32 therein. The motor housing part 34 includes a cylindrical part 34a, a bottom part 34b, a bearing support part 34c, and a flange part 34d. The cylinder part 34a is a substantially cylindrical part. A plurality of internally threaded portions 36 protrude radially outward at the end in the positive x-axis direction of the cylindrical portion 34a. The bottom portion 34b closes the end in the negative x-axis direction of the cylindrical portion 34a. The center of the bottom 34b is opened. The motor output shaft 28 passes through the opening of the bottom 34b. The bearing support portion 34c extends in the positive x-axis direction from the inner peripheral edge of the bottom portion 34b. The length of the bearing support portion 34c in the x-axis direction is shorter than the length of the cylindrical portion 34a in the x-axis direction. The flange portion 34b extends radially from a position near the end in the negative x-axis direction of the cylindrical portion 34a. The flange portion 34b has a plurality of bolt holes 34e. Bolts 37 pass through the bolt holes 34e. The bolt 37 fixes the motor casing 29 to the internal gear 24 by screw connection with an internal thread portion (not shown) of the internal gear 24.

  The controller housing part 35 houses the motor controller 33 therein. The motor controller 33 is obtained by mounting a CPU, FET, etc. (not shown) on a substrate 33a and attaching a capacitor, an inductor, and the like. The controller housing portion 35 has a lid portion 38 that closes the inside. The controller accommodating part 35 has a bolt hole and a bolt hole through which the bolt passes. The bolts fix the controller housing portion 35 to the motor housing portion 34 by screw coupling with the female screw portion 36 of the motor housing portion 34. The controller housing part 35 has a connector 39. The motor controller 33 supplies a direct current supplied from a battery (not shown) via the connector 39 to each coil 31b of the stator 31 by switching of the FET. A sensor unit 33b is attached to a position on the x-axis negative direction side of the substrate 33a and facing the x-axis positive direction end 28b of the motor output shaft 28. On the other hand, a resolver rotor 28d is fixed to the x-axis positive direction end 28b of the motor output shaft 28. The sensor unit 33b detects the rotation angle of the motor output shaft 28 by detecting the double-tooth target of the resolver rotor 28d.

The rotor 30 has a cylinder part 40 and a bottom part 41. The cylinder part 40 is a cylindrical part. The cylindrical portion 40 is located on the radially outer side of the motor output shaft 28 and the bearing support portion 34c of the motor housing portion 34. The cylinder part 40 has a plurality of permanent magnets 40a on the outer periphery. A part of the cylinder part 40 overlaps with the bearing support part 34c of the motor housing part 34 in the x-axis direction. In other words, a part of the cylindrical portion 40 is located in the annular space 34f on the radially outer side of the bearing support portion 34c. The bottom portion 41 closes the end in the positive x-axis direction of the cylindrical portion 40. The center of the bottom 41 is open. The motor output shaft 28 passes through the opening of the bottom 41. The bottom 41 is coupled to a position near the x-axis positive direction end 28b of the motor output shaft 28.
The stator 31 faces the outer peripheral surface of the rotor 30, that is, the permanent magnet 40a of the rotor 30 in the radial direction. The stator 31 has a stator core 31a and a coil 31b. The stator core 31a is fixed to the cylindrical portion 34a of the motor accommodating portion 34. The stator core 31a has a plurality of slots 31c extending in the x-axis direction. The coil 31b is inserted into the plurality of slots 31c.

The bearing portion 32 rotatably supports the motor output shaft 28 with respect to the motor housing portion 34. The bearing portion 32 is located on the radially inner side of the bearing support portion 34c. The bearing portion 32 is a double row bearing having balls 42 and rollers 43 as double row rolling elements. A retainer 43a for the roller 43 is provided on the negative side of the roller 43 in the x-axis direction. Although there are cages for the balls 42 on both sides of the balls 42 in the x-axis direction, the illustration is omitted. The ball 42 is located on the negative side of the bearing portion 32 in the x-axis direction. The roller 43 is located on the x axis positive direction side of the bearing portion 32. The center position of the roller 43 in the x-axis direction coincides with the position of the center of gravity of the actuator. The bearing portion 32 has an outer ring 44 and an inner ring 45 that support the ball 42 and the roller 43. The outer ring 44 is fixed inside the bearing support portion 34c in the radial direction. The outer ring 44 has an annular groove 44 a that serves as a rolling surface of the ball 42. The length of the outer ring 44 in the x-axis direction matches the length of the bearing support portion 34c in the x-axis direction. The inner ring 45 is integral with the motor output shaft 28. That is, the outer peripheral surface of the motor output shaft 28 becomes the rolling surface of the ball 42 and the roller 43. The outer peripheral surface of the motor output shaft 28 has an annular groove 28 c that serves as a rolling surface of the ball 42.
The bearing portion 32 has an oil seal 46 and a lip seal 47. The oil seal 46 and the lip seal 47 seal between the motor output shaft 28 and the outer ring 44. The oil seal 46 is located on the x-axis negative direction side of the ball 42 and at the end of the outer ring 44 in the x-axis negative direction. The lip seal 47 is located on the x axis positive direction side of the roller 43 and at the end of the outer ring 44 in the x axis positive direction. Grease 48 is sealed in the space between both seals 46, 47, that is, in the bearing portion 32.

Next, the effect of Embodiment 1 is demonstrated.
A conventional actuator for a link mechanism for an internal combustion engine has bearing portions that support a motor output shaft on both axial sides of the rotor. For this reason, the dimension of an axial direction becomes long and a layout becomes disadvantageous. On the other hand, in the first embodiment, a part of the bearing portion 32 is located on the radially inner side of the cylindrical portion 40 of the rotor 30. In other words, a part of the cylindrical portion 40 is located in the annular space 34f that is radially outward of the bearing portion 32. That is, when a part of the bearing portion 32 overlaps with the rotor 30 in the x-axis direction, the dimension in the x-axis direction can be made shorter than that in the conventional technique by an amount corresponding to the overlap. As a result, the layout of the actuator can be improved.
The bearing portion 32 has double-row rolling elements (balls 42 and rollers 43). By supporting the motor output shaft 28 with the double row rolling elements, the motor output shaft 28 can be held more stably than in the case of the single row rolling elements.
The bearing portion 32 includes an oil seal 46 and a lip seal 47 that seal between the motor casing 29 and the motor output shaft 28. By integrating both seals 46 and 47 with the bearing portion 32, the dimension in the x-axis direction can be shortened by the amount of the seal as compared with the case where both seals are provided outside the bearing portion 32.
Grease 48 was sealed in the space between both seals 46 and 47. Thereby, the temperature rise of the bearing part 32 can be suppressed and durability can be improved.
The outer peripheral surface of the motor output shaft 28 was used as a rolling surface for the ball 42 and the roller 43. That is, the motor output shaft 28 has the inner ring 45 of the bearing portion 32. This eliminates the need for a separate space for placing the inner ring, and the radial dimensions of the rotor 30 and the stator 31 can be increased accordingly. As a result, the output of the electric motor 22 can be increased without increasing the size of the motor casing 29.

Among the rolling elements of the bearing portion 32, the rolling element on the x-axis positive direction side was used as the roller 43. Since the roller (roller bearing) has a larger load capacity than the ball (ball bearing), the support strength of the motor output shaft 28 can be improved as compared with the case where the rolling element on the x-axis positive direction side is a ball. Here, since the actuator according to the first embodiment is attached to the internal combustion engine, the influence of the vibration of the internal combustion engine is large, and there is a concern about the wear and deformation of the bearing portion 32 due to the vibration of the rotor 30. In the motor casing 29, the motor output shaft 28 is cantilevered by the bearing portion 32, and the rotor 30 is on the x-axis positive direction side of the bearing portion 32. For this reason, the moment load of the rotor 30 acting on the plurality of rolling elements is greater in the double-row rolling elements on the x-axis positive direction side than on the x-axis negative direction side. Therefore, by using the rolling element on the x-axis positive direction side as the roller 43 having a larger load capacity than the ball 42, wear and deformation of the bearing portion 32 due to vibration of the rotor 30 can be suppressed.
There is a lip seal 47 on the positive side of the x-axis from the roller 43. Since there is no retainer on the x axis positive direction side of the roller 43, the roller 43 is movable in the x axis positive direction with respect to the outer ring 44. By disposing the lip seal 47 on the positive side of the roller 43 in the x-axis direction, it is possible to prevent the roller 43 from falling off the bearing portion 32.
The position of the center of gravity of the actuator in the x-axis direction is at the center position of the roller 43. As a result, the center of vibration (center of gravity) when the actuator vibrates using the internal combustion engine as a vibration source can be received by the roller 43 having a larger load capacity than the ball 42. As a result, the load resistance of the bearing portion 32 can be improved.
Of the rolling elements of the bearing portion 32, the rolling element on the negative side of the x-axis is the ball 42, so that it can cope with the axial load and improve the support stability of the motor output shaft 28.
The motor output shaft 28 is held by the motor casing 29 only by the bearing portion 32. By using a cantilever structure for the motor output shaft 28, the dimension in the x-axis direction can be shortened compared to the double-support structure.
An annular space 34 f on the radially outer side of the bearing portion 32 is inside the motor casing 29. Thus, the motor casing 29 can be assembled to the housing 20 as a motor assembly in which the motor output shaft 28, the rotor 30, the stator 31, the bearing 32, and the motor controller 33 are attached to the motor casing 29. Therefore, assembly property can be improved.

[Embodiment 2]
Next, Embodiment 2 will be described. Since the basic configuration of the second embodiment is the same as that of the first embodiment, only portions different from the first embodiment will be described.
FIG. 6 is an enlarged view of a main part of the electric motor 22 according to the second embodiment. In the second embodiment, the inner ring 45 of the bearing portion 32 is a separate body from the motor output shaft 28. Further, the two rolling elements in the bearing portion 32 are both balls 42. The outer ring 44 and the inner ring 45 have an annular groove 44 a and a groove 45 a corresponding to the two balls 42. In the second embodiment, since the inner ring 45 of the bearing portion 32 is fixed to the motor output shaft 28, there is no need to process the rolling surface of the ball 42 on the outer peripheral surface of the motor output shaft 28.

[Embodiment 3]
Next, Embodiment 3 will be described. Since the basic configuration of the third embodiment is the same as that of the first embodiment, only portions different from the first embodiment will be described.
FIG. 7 is an enlarged view of a main part of the electric motor 22 according to the third embodiment. In the third embodiment, the lip seal 49 is provided at the positive end of the bearing portion 32 in the x-axis direction. The x-axis negative direction end of the bearing portion 32 opens. In the third embodiment, since the bearing portion 32 can be lubricated using the lubricating oil supplied to the wave gear type speed reducer 21 from an oil pump (not shown), no grease for lubrication is required.

[Embodiment 4]
FIG. 8 is an enlarged view of a main part of the electric motor 22 according to the fourth embodiment. The fourth embodiment is different from the third embodiment in that the inner ring 45 of the bearing portion 32 is separate from the motor output shaft 28. In the fourth embodiment, it is not necessary to process the rolling surface of the ball 42 on the outer peripheral surface of the motor output shaft 28.

[Embodiment 5]
FIG. 9 is an enlarged view of a main part of the electric motor 22 according to the fifth embodiment. The fifth embodiment is different from the third embodiment in that the two rolling elements in the bearing portion 32 are both balls 42.

[Other Embodiments]
Although the embodiment for carrying out the present invention has been described above, the specific configuration of the present invention is not limited to the configuration of the embodiment, and there are design changes and the like within the scope not departing from the gist of the invention. Are also included in the present invention.
For example, the annular space may be in the housing and / or the motor casing.
The center of gravity of the actuator may be within the range between both ends of the bearing portion in the axial direction of the motor output shaft. However, it is preferable to dispose the center of gravity of the actuator on the roller side from the center of the bearing portion.

The technical idea that can be grasped from the embodiment described above will be described below.
In one aspect, the actuator of the link mechanism for an internal combustion engine is positioned on the radially outer side of the motor output shaft that rotates to change the attitude of the link mechanism for the internal combustion engine, and a plurality of outer periphery of the motor output shaft. A rotor having a cylindrical portion having a permanent magnet, a bottom portion closed at one end of the cylindrical portion and fixed to the motor output shaft, a stator facing the outer peripheral surface of the rotor and having a coil, and the stator And a bearing part that is partly or wholly located on the radially inner side of the cylindrical part and supports the motor output shaft rotatably with respect to the motor casing.
In a more preferred aspect, in the above aspect, the bearing portion has double-row rolling elements.
In another preferred aspect, in any one of the above aspects, the bearing portion has a seal that is positioned radially inside the cylindrical portion and seals between the motor casing and the motor output shaft.
In still another preferred aspect, in any one of the above aspects, the seal is on both sides of the plurality of rolling elements in the axial direction of the motor output shaft, and grease is sealed in a space between the seals.
In still another preferred aspect, in any one of the above aspects, the seal is at an end portion of the bearing portion opposite to the internal combustion engine link mechanism in the axial direction of the motor output shaft, and the bearing portion includes: An end of the internal combustion engine link mechanism is opened in the axial direction of the motor output shaft.

In still another preferred aspect, in any one of the above aspects, the outer peripheral surface of the motor output shaft is used as a rolling surface of the rolling element.
In still another preferred aspect, in any of the above aspects, the inner ring of the bearing portion is fixed to the outer periphery of the motor output shaft.
In still another preferred aspect, in any one of the above aspects, of the double row rolling elements, the rolling element opposite to the internal combustion engine link mechanism in the axial direction of the motor output shaft is a roller.
In still another preferred aspect, in any one of the above aspects, the center of gravity of the actuator is in a range between both ends of the bearing portion in the axial direction of the motor output shaft.
In still another preferred aspect, in any one of the above aspects, the center of gravity of the actuator is positioned closer to the roller than the center of the bearing portion in the axial direction of the motor output shaft.
In still another preferred aspect, in any one of the above aspects, the rolling elements on the internal combustion engine link mechanism side in the axial direction of the motor output shaft are balls in the double row rolling elements.
In still another preferred aspect, in any one of the above aspects, the bearing portion has a diameter of the cylindrical portion on a side opposite to the internal combustion engine link mechanism with respect to the plurality of rolling elements in an axial direction of the motor output shaft. An actuator for a link mechanism for an internal combustion engine, having a seal that is located on the inner side in the direction and seals between the motor casing and the motor output shaft.

In still another preferred aspect, in any of the above aspects, the motor output shaft is held in the motor casing only by the bearing portion.
In still another preferred aspect, in any one of the above aspects, the actuator is attached to an internal combustion engine, and the internal combustion engine link mechanism changes a posture to change a stroke amount of a piston of the internal combustion engine. It is a variable compression ratio mechanism.
According to another aspect, the actuator of the link mechanism for an internal combustion engine is an actuator of the link mechanism for the internal combustion engine that rotates a control shaft that changes the attitude of the link mechanism for the internal combustion engine in a certain aspect. A speed reducer that reduces the rotational speed of the output shaft and transmits it to the control shaft, a bearing portion that rotatably supports the motor output shaft, a housing that supports the speed reducer, and a plurality of permanent magnets on the outer periphery A rotor having a cylindrical portion, a bottom portion closed at one end of the cylindrical portion and fixed to the motor output shaft, a motor casing fixed to the housing and surrounding the rotor, and an inner peripheral side of the motor casing And a stator having a coil facing the permanent magnet in a radial direction of the motor output shaft, and having the housing and / or the module Motor casing has an annular space radially outward of the bearing portion, a part or the whole of the cylindrical portion of the rotor is positioned within the annular space.
Preferably, in the above aspect, the annular space is inside the motor casing.

11 Second control axis
21 Wave gear reducer
22 Electric motor
28 Motor output shaft
29 Motor casing
30 rotor
31 Stator
31b coil
32 Bearing
34f annular space
40 Tube
40a permanent magnet
41 Bottom

Claims (16)

A motor output shaft that changes the attitude of the link mechanism for the internal combustion engine by rotating; and
A rotor having a cylindrical portion located on the outer side in the radial direction of the motor output shaft and having a plurality of permanent magnets on the outer periphery; and a bottom portion connecting the cylindrical portion and the motor output shaft;
A stator facing the outer peripheral surface of the rotor and having a coil;
A motor casing for supporting the stator;
A bearing part that is partly or wholly located on the radially inner side of the cylindrical part and supports the motor output shaft rotatably with respect to the motor casing;
An actuator for a link mechanism for an internal combustion engine. An actuator for a link mechanism for an internal combustion engine according to claim 1,
The bearing portion is an actuator of a link mechanism for an internal combustion engine having double row rolling elements. An actuator for a link mechanism for an internal combustion engine according to claim 2,
The bearing is an actuator of a link mechanism for an internal combustion engine having a seal that is located radially inside the cylinder and seals between the motor casing and the motor output shaft. An actuator for a link mechanism for an internal combustion engine according to claim 3,
The seal is on both sides of the rolling elements in the axial direction of the motor output shaft;
An actuator of a link mechanism for an internal combustion engine in which grease is sealed in a space between both the seals. An actuator for a link mechanism for an internal combustion engine according to claim 3,
The seal is at an end of the bearing portion opposite to the internal combustion engine link mechanism in the axial direction of the motor output shaft,
The bearing portion is an actuator of an internal combustion engine link mechanism in which an end portion on the internal combustion engine link mechanism side opens in an axial direction of the motor output shaft. An actuator for a link mechanism for an internal combustion engine according to claim 2,
An actuator of a link mechanism for an internal combustion engine in which an outer peripheral surface of the motor output shaft is a rolling surface of the rolling element. An actuator for a link mechanism for an internal combustion engine according to claim 2,
An actuator of a link mechanism for an internal combustion engine in which an inner ring of the bearing portion is fixed to the outer periphery of the motor output shaft. An actuator for a link mechanism for an internal combustion engine according to claim 2,
The actuator of the internal combustion engine link mechanism in which the rolling element on the opposite side to the internal combustion engine link mechanism in the axial direction of the motor output shaft among the double row rolling elements is a roller. An actuator for a link mechanism for an internal combustion engine according to claim 8,
The actuator of the link mechanism for an internal combustion engine, wherein the center of gravity of the actuator is in a range between both ends of the bearing portion in the axial direction of the motor output shaft. An actuator for a link mechanism for an internal combustion engine according to claim 9,
The center of gravity of the actuator is an actuator of a link mechanism for an internal combustion engine that is positioned on the roller side with respect to the center of the bearing portion in the axial direction of the motor output shaft. An actuator for a link mechanism for an internal combustion engine according to claim 8,
Among the double row rolling elements, an actuator of an internal combustion engine link mechanism in which the rolling element on the internal combustion engine link mechanism side in the axial direction of the motor output shaft is a ball. An actuator for a link mechanism for an internal combustion engine according to claim 11,
The bearing portion is located on the opposite side of the link mechanism for the internal combustion engine from the plurality of rolling elements in the axial direction of the motor output shaft, on the radially inner side of the cylindrical portion, and between the motor casing and the motor output shaft. An actuator for a link mechanism for an internal combustion engine having a seal that seals. An actuator for a link mechanism for an internal combustion engine according to claim 2,
The motor output shaft is an actuator of a link mechanism for an internal combustion engine that is held by the motor casing only by the bearing portion. An actuator for a link mechanism for an internal combustion engine according to claim 1,
The actuator is attached to an internal combustion engine;
The internal combustion engine link mechanism is an actuator of the internal combustion engine link mechanism, which is a variable compression ratio mechanism that changes a stroke amount of a piston of the internal combustion engine by changing a posture. An actuator for a link mechanism for an internal combustion engine that rotates a control shaft that changes the attitude of the link mechanism for the internal combustion engine,
A decelerator that decelerates the rotational speed of the motor output shaft of the electric motor and transmits it to the control shaft;
A bearing that rotatably supports the motor output shaft;
A housing that supports the speed reducer;
A rotor having a cylindrical portion having a plurality of permanent magnets on the outer periphery, and a bottom portion connecting the cylindrical portion and the motor output shaft;
A motor casing fixed to the housing and surrounding the rotor;
A stator fixed to the inner peripheral side of the motor casing, facing the permanent magnet in the radial direction of the motor output shaft, and having a coil;
With
The housing and / or the motor casing has an annular space on the radially outer side of the bearing portion,
An actuator of a link mechanism for an internal combustion engine in which a part or all of the cylindrical portion of the rotor is located in the annular space. An actuator for a link mechanism for an internal combustion engine according to claim 15,
The annular space is an actuator of a link mechanism for an internal combustion engine inside the motor casing.

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