JP2007113652A - Actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To open up new possibilities for generating sufficient lubrication without keeping a lubrication mechanism large toward a mechanism arranged inside an actuator 2 and for easily discharging foreign bodies and starting drive. <P>SOLUTION: A second vent 8d has a discharge capacity which is lower than a supply capacity of a supply port 8b. A first vent 8c can sufficiently discharge an oil feed volume Vo from the supply port 8b so that an oil level reaches an up-and-down width region W inside which is predetermined to become stable at the time of feeding lubrication oil. Consequently, even one supply port 8b can feed a sufficient lubrication without upsizing the lubrication mechanism. Further, when the lube oil supply is suspended, almost all the lube oils are emitted from the second vent 8d to the outside due to oils'own weight. Accordingly, there is no need to inflow the lube oil at a speed of flow to wash out foreign materials from plural supply ports to every hole and corner, and foreign matters are discharged without upsizing the lubrication mechanism. As almost no lube oil exists at the time of the actuator 2 starting drive and excessive friction is not caused even in cold temperature, starting drive is easily done. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to lubrication of an actuator, and more particularly to lubrication of a mechanical motion mechanism provided inside the actuator.

  As a rotation-linear motion conversion mechanism used for various actuators, a planetary differential screw type rotation-linear motion conversion mechanism in which a sun shaft, a planetary shaft, and a nut are combined is known (see, for example, Patent Document 1).

In order to lubricate such a mechanical motion mechanism, lubricant is supplied to the actuator from the outside. When the mechanical motion mechanism has a complicated shape, such as a planetary differential screw type rotation-linear motion conversion mechanism, it is necessary to distribute the lubricant to every corner and circulate at a sufficient flow rate. Therefore, a function to discharge the foreign matter inside is required.
JP-A-10-196757 (3rd page, FIG. 1)

  However, when lubricating oil is circulated through a mechanical motion mechanism with a complex shape at a sufficient flow rate, it is not necessary to inject lubricating oil at a sufficient flow rate from many locations in the housing that houses the mechanical motion mechanism. In other words, the number of lubricating oil paths becomes large and the actuator itself becomes large.

  In addition, when a large amount of lubricating oil is injected into the housing in this way, when the actuator starts driving, especially when the temperature of the lubricating oil is low, the presence of a large amount of lubricating oil in the actuator is conversely mechanical. This may cause excessive friction in the motion mechanism and make it difficult to start driving. This may make it difficult to start the internal combustion engine when the actuator is applied to an internal combustion engine, particularly a valve drive important for the operation of the internal combustion engine.

  It is an object of the present invention to enable sufficient lubrication of a mechanical motion mechanism disposed in an actuator without increasing the size of the lubrication mechanism, and to facilitate foreign matter discharge and drive start. It is.

In the following, means for achieving the above object and its effects are described.
The actuator according to claim 1 is configured such that an external mechanism is generated by an output of a driving force generated by a mechanical motion mechanism disposed in a lubrication space that is in an oil-tight state except for a supply port and a plurality of discharge ports of the lubricant. An actuator for driving, wherein the discharge port is present at the lowest position in the lubrication space, and when no lubrication oil is supplied from the supply port, almost all the lubrication oil in the lubrication space is removed. It is possible to discharge, and the lowest position discharge port whose discharge capability is lower than the supply capability from the supply port, and lubricating oil is supplied from the supply port, so that the mechanical motion mechanism is provided in the lubrication space. In the state where the lubricating oil level exists at the set lubricating oil level, the lubricating oil equal to the supply amount by the supply port is discharged together with the lowest position discharge port, and the lubricating oil level is set to the lubricating oil level setting level. Arrived In a state where the lubricating oil is not supplied by the supply port together with the lowest position discharge port, the lubricant is discharged by the supply port. When the lubricating oil level exceeds the lubricating oil level setting level, the supply port is used together with the lowest position discharge port. And a lubricating oil supply outlet for discharging lubricating oil exceeding the supply amount.

  Since the lowest position discharge port has a lower discharge capacity than the supply capacity from the supply port, when lubricating oil is supplied from the supply port, the lubricating oil rises beyond the height of the lowest position discharge port and the lubricating oil level rises . However, due to the presence of the lubricant supply outlet, after reaching the lubricant level setting level set for the mechanical motion mechanism, the lubricant level does not rise any further, It will be stable at the lubricant level setting level.

  In this way, when the lubricating oil is supplied from the supply port, the lubricating oil in the lubricating space is at the lubricating oil level setting level set for the mechanical motion mechanism. For this reason, even with a small number of supply ports, for example, one supply port, sufficient lubrication can be achieved without increasing the size of the lubrication mechanism with respect to the mechanical motion mechanism disposed in the lubrication space.

  Further, when the supply of the lubricating oil from the supply port is stopped, almost all the lubricating oil in the lubricating space is discharged out of the lubricating space from its lowest position discharge port existing at the lowest position in the lubricating space by its own weight. For this reason, even if the mechanical motion mechanism has a complicated shape, a downward flow can be formed in the entire lubricating oil due to its own weight, whereby foreign matter can be pushed downward and discharged out of the lubricating space.

  Therefore, it is not necessary to allow the lubricating oil to flow in at such a flow rate that the foreign matter flows away from the many supply ports, and the foreign matter can be easily discharged from the mechanical motion mechanism without increasing the size of the lubricating mechanism.

  Further, when the lubricant is not yet supplied from the supply port at the start of driving the actuator, the lubricating space is only the lubricating oil film that wets the surface of the mechanical motion mechanism, and almost no lubricating oil is contained in the lubricating space. not exist. For this reason, excessive friction is not generated in the mechanical motion mechanism even at low temperatures. This makes it easy to start driving the actuator.

  According to a second aspect of the present invention, in the actuator according to the first aspect, the discharge port at the time of supplying the lubricating oil is disposed at a position higher than the discharge port at the lowest position, and the vertical width region of the discharge port at the time of supplying the lubricating oil is The lubricating oil level setting level is set, and the lubricating oil supply discharge port discharges the lubricating oil amount equal to the supply amount together with the lowest position discharging port in a state where the lubricating oil surface is in any of the vertical width regions. The channel area is set.

  Thus, by setting the flow passage area of the outlet when supplying the lubricating oil, the vertical width region of the outlet when supplying the lubricating oil itself can be set to the lubricating oil level setting level. This makes it possible to adjust the lubricating oil level set for the mechanical motion mechanism when supplying the lubricating oil from the supply port by adjusting the vertical position when forming the lubricating oil supply discharge port having the corresponding channel area. It is easy to make the lubricant level come to the level.

  The actuator according to a third aspect is characterized in that, in the first or second aspect, the mechanism provided in the internal combustion engine is driven as the external mechanism by being fixed to the internal combustion engine.

  Thus, when driving a mechanism provided in an internal combustion engine as an actuator for the internal combustion engine, the lubricating oil supplied from the oil pump on the internal combustion engine side through the supply port is not lubricated in the lubricating space during operation of the internal combustion engine. Can sufficiently lubricate the mechanical movement mechanism. For this reason, the lubrication mechanism may be small and the internal combustion engine will not be enlarged.

  Further, when the internal combustion engine and the actuator are stopped and the supply of the lubricating oil is stopped, almost all the lubricating oil in the lubricating space is removed from the lowest position discharge port at the lowest position in the lubricating space by its own weight. To be discharged. For this reason, even if the mechanical motion mechanism has a complicated shape, a downward flow is formed in the lubricating oil by its own weight, and the foreign matter can be pushed downward and discharged out of the lubricating space from the lowest position discharge port.

  Therefore, it is not necessary to allow the lubricating oil to flow in at such a flow rate that the foreign matter flows away from the many supply ports, and the foreign matter can be easily discharged from the mechanical motion mechanism without increasing the size of the lubricating mechanism. This also contributes to suppressing the increase in size of the internal combustion engine.

  Furthermore, when starting the actuator when starting the internal combustion engine, only the lubricating oil film wets the surface of the mechanical motion mechanism, and there is almost no lubricating oil in the lubricating space, so even at low temperatures. However, excessive friction is not generated in the mechanical motion mechanism. For this reason, the driving of the actuator can be easily started, and the internal combustion engine can be easily started.

According to a fourth aspect of the present invention, in the third aspect, the external mechanism is a mechanism that changes the valve cam lift amount of the internal combustion engine steplessly.
When the actuator drives a mechanism that changes the valve cam lift amount of the internal combustion engine steplessly, the startability of the internal combustion engine can be effectively improved.

  According to a fifth aspect of the present invention, in the actuator according to the fourth aspect, the external mechanism is a mechanism that changes the valve cam lift amount of the internal combustion engine in a stepless manner by the axial movement of a control shaft spanned across a plurality of cylinders. It is characterized by.

  An example of the mechanical motion mechanism of the actuator is a mechanism that drives the control shaft in the axial direction. The lubrication mechanism can be sufficiently lubricated without increasing the size of the lubrication mechanism. Emission and start of internal combustion engine start can be facilitated.

  The actuator according to claim 6 is the actuator according to any one of claims 1 to 5, wherein the mechanical motion mechanism is a planetary differential screw type rotation-linear motion conversion mechanism having a sun shaft, a planetary shaft, and a nut. Features.

When the mechanical motion mechanism is a planetary differential screw type rotation-linear motion conversion mechanism, the shape of the mechanical motion mechanism is complicated, and thus the effect of the present invention is particularly remarkable.
According to a seventh aspect of the present invention, in the sixth aspect, the sun shaft, the planetary shaft, and the nut are engaged with each other by a screw and a gear.

  In the case where the planetary differential screw type rotation-linear motion conversion mechanism is configured to mesh with a screw and a gear, the shape is further complicated, and the effect of the present invention becomes more remarkable.

[Embodiment 1]
FIG. 1 is a longitudinal sectional view of an essential part of an actuator 2 to which the above-described invention is applied, cut along a vertical plane. The actuator 2 adjusts the valve lift amount of the intake valve of the internal combustion engine. A cylinder head or a cam carrier (explained here as cam carrier 4) of an internal combustion engine is provided with a variable valve mechanism that can change the valve lift amount of the intake valve steplessly by the axial movement of the control shaft. By connecting the control shaft of this variable valve mechanism to the tip of a sun shaft 6 provided in the actuator 2 and driving it in the axial direction, the valve lift amount of the intake valve is adjusted. By adjusting the valve lift, the intake air amount to each cylinder of the internal combustion engine can be adjusted to control the output of the internal combustion engine.

  A casing 8 constituting the outer shape of the actuator 2 is fixed to the outer peripheral surface of the cam carrier 4. The sun shaft 6 protruding in the axial direction from the casing 8 is inserted into the cam carrier 4, and as described above, the tip of the sun shaft 6 is located in each cylinder in the internal space surrounded by the cam carrier 4 (right side of the cam carrier 4 in the drawing). It is connected to the control shaft of the variable valve mechanism arranged above.

  Inside the casing 8, a planetary differential screw type rotation-linear motion conversion mechanism 12 (corresponding to a mechanical motion mechanism) is attached via a bearing 10. The planetary differential screw type rotation-linear motion conversion mechanism 12 includes the sun shaft 6, a cylindrical nut 14 that forms the outside, and a planetary shaft 16 disposed around the sun shaft 6.

  The sun shaft 6 includes a spur gear portion 6 a, a screw portion 6 b, and a straight spline portion 6 c at a portion disposed in the internal space of the nut 14. A core 18 for detecting the amount of axial movement of the sun shaft 6 is attached to the end face of the spur gear 6a, and constitutes a displacement sensor together with the coil 20 attached to one end of the nut 14. .

The nut 14 includes a first spur gear portion 14a, a screw portion 14b, and a second spur gear portion 14c on the inner peripheral surface.
A plurality of, for example, nine planetary shafts 16 are arranged between the nut 14 and the sunshaft 6 at this phase interval. Each planetary shaft 16 includes a spur gear portion 16a, a screw portion 16b, and a spur gear-screw portion 16c. The spur gear-thread portion 16c is a portion where both a spur gear and a screw are formed, and is formed so as to mesh with the spur gear and with the screw.

  The planetary shaft 16 and the nut 14 are engaged with each other as follows: the spur gear 16a of the planetary shaft 16 is connected to the first spur gear 14a on the nut 14 side, the screw portion 16b is connected to the screw portion 14b, and the spur gear-screw portion. 16c is meshed with the second spur gear portion 14c. The two screw portions 14b and 16b have the same pitch circle diameter ratio and screw thread ratio, and even if the planetary shaft 16 rolls on the inner peripheral surface of the nut 14, the nut 14 and the planetary shaft. There is no relative movement in the axial direction with respect to 16.

  When the planetary shaft 16 and the sunshaft 6 are engaged, the spur gear portion 16a of the planetary shaft 16 is connected to the spur gear portion 6a on the sun shaft 6 side, and the screw portion 16b and the spur gear-screw portion 16c are both screwed. It is meshed with the part 6b. In addition, although the straight spline part 6c of the sun shaft 6 is meshed with the straight spline part 8a formed in the opening part of the casing 8, the axial movement of the sun shaft 6 is possible. Rotation is regulated.

  Here, the threaded part 16b and the spur gear-threaded part 16c of the planetary shaft 16 and the threaded part 6b of the sun shaft 6 are different in the ratio of the pitch circle diameter and the ratio of the number of screw threads. For this reason, when the planetary shaft 16 rolls around the sun shaft 6 due to the rotation of the nut 14, the sun shaft 6 whose axial rotation is restricted is in the axial direction with respect to the nut 14 and the planetary shaft 16. Causes relative movement. That is, a differential is generated.

  A rotor 22 of an electric motor is attached to the outer periphery of the nut 14, and the nut 14 can be rotated in the casing 8 by energization control on the coil 24 disposed facing the rotor 22 inside the casing 8. it can.

  Since the planetary differential screw type rotation-linear motion conversion mechanism 12 is constructed as described above, when the nut 14 is rotated via the rotor 22 by energization control to the coil 24 by an electric circuit, the planetary differential screw type rotation is performed. -Differential motion occurs in the linear motion conversion mechanism 12 as described above, and the sun shaft 6 moves in the axial direction. Therefore, by adjusting the rotation amount of the nut 14 so that the displacement of the sun shaft 6 detected from the coil 20 of the displacement sensor indicates the target position, the axial position of the control shaft on the variable valve mechanism side can be controlled, and the intake air The valve lift amount of the valve can be controlled to a desired state. FIG. 2 shows a state in which the sunshaft 6 is moved to the right side of the figure from the state of FIG. 1 by such control.

  Here, in the planetary differential screw type rotation-linear motion conversion mechanism 12, in order to perform lubrication between the sun shaft 6, the nut 14, and the planetary shaft 16, lubricating oil is supplied to the inner space of the nut 14. . The base end side of the nut 14 on which the coil 20 is disposed is covered with a lid member 26 so that the lubricating oil does not enter the coil 24 side. Further, a ring-shaped seal member 28 is disposed between the front end side of the nut 14 and the casing 8.

  Lubricating oil is supplied from the oil passage 4 a side of the cam carrier 4 through the supply port 8 b formed in the casing 8 to the lubricating space 30 that is in an oil-tight state in this way. Here, engine oil is supplied as lubricating oil from an oil pump that functions as an output of the internal combustion engine.

  Lubricating oil supplied to the casing 8 includes a first discharge port 8c (corresponding to a discharge port at the time of lubricating oil supply: in FIG. And corresponding to the position discharge port) and discharged into the internal space of the cam carrier 4 via the discharge oil passages 4b and 4c on the cam carrier 4 side.

  Here, the positional relationship among the supply port 8b, the first discharge port 8c, and the second discharge port 8d formed in the casing 8 is shown in the right side view of FIG. Since the central axis of the casing 8 is arranged horizontally, the supply port 8b is present at the highest position, the first discharge port 8c is at an intermediate height position, and the second discharge port 8d is at the lowest position. Is provided.

  Here, when the oil level of the lubricating oil is at the level La, the relationship between the supply oil amount Vo from the supply port 8b, the discharge oil amount Va of the first discharge port 8c, and the discharge oil amount Vb of the second discharge port 8d is When the internal combustion engine is in operation, the equation 1 is satisfied. The level La exists in the vertical width region W of the first discharge port 8c.

[Formula 1]
Vo = Va + Vb
Va> 0
The second discharge port 8d has a small flow path area, and the supply oil amount Vo from the supply port 8b cannot be discharged only by the discharge oil amount Vb of the second discharge port 8d. Therefore, when lubricating oil is supplied from the supply port 8b in a state where there is no lubricating oil in the lubricating space 30, until the oil level reaches the level La between the upper end and the lower end of the first discharge port 8c. Vo> Va + Vb, and the oil level rises in the lubrication space 30.

  And until it reaches the level La from the lower end of the first discharge port 8c, the discharged oil amount Va of the first discharge port 8c is generated and increased. When the level La is reached, the relationship of Equation 1 is established. That is, the sum of the discharged oil amount Va from the first discharge port 8c and the discharged oil amount Vb from the second discharge port 8d is equal to the supply oil amount Vo from the supply port 8b. For this reason, oil level rise stops. Since the flow path area of the first discharge port 8c is set sufficiently large, when the oil level exceeds the level La, the discharged oil amount Va of the first discharge port 8c is further increased, and Vo < Va + Vb. Therefore, the oil level does not exceed the level La and is stabilized at the level La.

  Here, the vertical width region W (corresponding to the lubricating oil level setting level) where the level La is present is an oil level that is necessary and appropriate for lubrication inside the planetary differential screw type rotation-linear motion conversion mechanism 12. The height position of the first discharge port 8c is set. Therefore, during operation of the internal combustion engine, the amount of lubricating oil in the lubricating space 30 is always maintained in an appropriate and sufficient state.

  When the oil pump is stopped due to the stop of the internal combustion engine, the supply oil amount Vo from the supply port 8b becomes zero. Therefore, the lubricating oil in the lubricating space 30 is discharged from both the first discharge port 8c and the second discharge port 8d at first, and then only from the second discharge port 8d. Since air enters the lubricating space 30 from the first discharge port 8c, the discharge of the lubricating oil from the second discharge port 8d is promoted.

  As a result, the lubricating oil in the lubricating space 30 is finally discharged to the lower end level Lb of the second discharge port 8d. Since the lower end level Lb of the second discharge port 8d is the lowest position in the lubrication space 30, it is almost in the lubrication space 30 except for a slight amount of lubricating oil such as the surface of the planetary differential screw type rotation-linear motion conversion mechanism 12. All the lubricating oil will be discharged.

  When the internal combustion engine is started, the actuator 2 is started in a state where there is almost no lubricating oil in the lubricating space 30. Furthermore, since the lubricating oil is supplied into the lubricating space 30 through the supply port 8b when the oil pump starts rotating, the lubricating oil is filled in the lubricating space 30 until the oil level rises to the level La.

According to the first embodiment described above, the following effects can be obtained.
(I). The second discharge port 8d which is the lowest position discharge port has a discharge capacity lower than the supply capacity from the supply port 8b. Furthermore, the 1st discharge port 8c is formed in the flow-path area which can fully discharge | release the supply oil amount Vo supplied from the supply port 8b.

  For this reason, when lubricating oil is supplied from the supply port 8b during operation of the internal combustion engine, the lubricating oil exceeds the second discharge port 8d, and the oil level is a planetary differential screw type rotation-linear motion conversion mechanism which is a mechanical motion mechanism. The upper and lower width region W, which is the set level of the lubricating oil level set for 12, reaches the level La therein, and stabilizes.

  Thus, the lubricating oil surface in the lubricating space 30 exists in the vertical width region W set for the planetary differential screw type rotation-linear motion conversion mechanism 12. Therefore, even if there is a small number of supply ports, here, one supply port 8b, the lubrication mechanism is different from the planetary differential screw type rotation-linear motion conversion mechanism 12 arranged in the lubrication space 30 of the actuator 2. For example, sufficient lubrication can be achieved without increasing the size of the oil pump or the oil passage configuration.

  Further, when the actuator 2 that is not supplied with the lubricating oil is not driven (when the internal combustion engine is stopped), almost all the lubricating oil in the lubricating space 30 is present at the lowest position in the lubricating space 30 due to its own weight. 2 is discharged to the outside of the actuator 2 from the discharge port 8d. For this reason, even if the planetary differential screw type rotation-linear motion conversion mechanism 12 has a complicated shape, a downward flow is formed in the lubricating oil due to its own weight, and the downward flow is accompanied by foreign matter, and the second discharge port 8d. Is discharged to the outside. At this time, the flow of the lubricating oil by its own weight can be accelerated by the air entering the lubricating space 30 from the first discharge port 8c.

  Therefore, it is not necessary to allow the lubricating oil to flow in at such a flow rate that foreign matter flows away from many supply ports, and the planetary differential screw type rotation-linear motion conversion mechanism 12 is not required without increasing the size of the oil pump or the oil passage. The whole foreign matter discharge becomes easy.

  Further, when the actuator 2 starts to be driven, there is only a lubricating oil film that wets the surface of the planetary differential screw type rotation-linear motion converting mechanism 12, and there is almost no lubricating oil in the lubricating space 30. However, excessive friction is not generated in the planetary differential screw type rotation-linear motion conversion mechanism 12. For this reason, the driving of the actuator 2 can be easily started, and further, the internal combustion engine can be easily started.

  (B). In particular, the actuator 2 drives a variable valve mechanism that continuously adjusts the valve cam lift amount of the internal combustion engine, particularly the valve lift amount of the intake valve. Accordingly, since the variable valve mechanism that plays an important role in the stable operation of the internal combustion engine does not generate excessive friction when driven at the time of start, the startability of the internal combustion engine can be effectively improved.

  (C). The planetary differential screw type rotation-linear motion conversion mechanism 12 includes a sun shaft 6, a nut 14, and a planetary shaft 16, and further includes a configuration in which a screw and a gear mesh with each other. Thus, although the shape of the planetary differential screw type rotation-linear motion converting mechanism 12 is complicated, the supply port 8b, the first discharge port 8c, and the second discharge port 8d are formed as described above. ) And (b) are remarkably effective.

[Embodiment 2]
In the present embodiment, the supply port 107 is provided in the sun shaft 106 as shown in the longitudinal sectional view of the main part in FIG. 4 and the right side view in FIG. For this reason, the casing 108 of the actuator 102 is provided with a first discharge port 108c (in FIG. 4, it is on the front side of the cross-section but the height position is indicated by a broken line) and a second discharge port 108d, and there is no supply port.

  The lubricating oil is supplied to the supply port 107 from a control shaft of a variable valve mechanism that is attached to the tip of the sun shaft 106. This control shaft is supplied with engine oil from an oil pump as lubricating oil through an oil passage that opens to a cam bearing 104 or a journal bearing provided in the cylinder head.

Here, the supply oil amount Vo, the discharged oil amounts Va and Vb, the vertical width region W, and the levels La and Lb are the same as those in the first embodiment.
According to the second embodiment described above, the following effects can be obtained.

  (I). The same effect as in the first embodiment is produced. Further, since the lubricating oil outlet 107a of the supply port 107 can be disposed near the meshing portion of the sun shaft 106, the nut 114, and the planetary shaft 116, the lubricating oil can be supplied to the meshing portion at an early stage even at the time of starting. This is more effective for improving the startability of the engine.

[Other embodiments]
(A). In the first embodiment, the supply port is set at a position higher than the first discharge port and the second discharge port, but it is not necessary to arrange in this manner. For example, as shown in FIG. 6A, in the casing 208, the supply port 208b may have the same height as the first discharge port 208c, and as shown in FIG. 6B, the first discharge port 208c and the second discharge port 208c. You may arrange | position in the middle height position with the exit 208d. Furthermore, the supply port 208b may be disposed at the same height as the second discharge port 208d, that is, at the lowest position in the lubrication space so as not to overlap.

  (B). In each of the embodiments described above, the vertical width region W and the level La determined by the first discharge port are set at approximately the center position in the height direction in the lubrication space, but correspond to the oil level required in the lubrication space. By adjusting the height of the first discharge port, the height of the vertical width region W and the level La can be set. For example, as shown in FIG. 7A, when the oil level of the lubricating space in the casing 308 during operation of the internal combustion engine is desired to be higher than the center height, the first discharge port 308c is set to a higher position, The vertical width region W and the level La are increased. Also in this case, the second discharge port 308d is set at the lowest position. The supply port 308b is disposed at a position higher than the first discharge port 308c, but may be lower than the first discharge port 308c.

  As shown in FIG. 7 (B), when it is desired to maximize the oil level in the lubricating space in the casing 408 during operation of the internal combustion engine, the vertical width region W and the first discharge port 408c are set to the maximum position. Increase level La to the maximum. Also in this case, the second discharge port 408d is set at the lowest position. The supply port 408b is disposed at a position lower than the first discharge port 408c in order to avoid the first discharge port 408c. Both the first discharge port 408c and the supply port 408b may be arranged at the highest position in the lubrication space so that they do not overlap.

  (C). The supply port, the first discharge port, and the second discharge port in each of the above embodiments are formed as circular holes or passages, but may be formed in other shapes. Further, a plurality of first discharge ports and second discharge ports may be provided. In particular, the flow path area as a whole may be adjusted by providing a plurality of first discharge ports.

  (D). In each embodiment, an example of a mechanism using a sun shaft, a nut, and a planetary shaft is given as an example of a mechanical motion mechanism inside the actuator. However, other mechanical motion mechanisms such as a ball screw mechanism, a screw mechanism using a bolt and a nut, etc. In addition, the lubricating configuration in the actuator described above can be applied.

  The external mechanism driven by the actuator is a variable valve mechanism that can adjust the valve lift amount of the intake valve of the internal combustion engine steplessly. However, the valve lift amount of the exhaust valve of the internal combustion engine can be adjusted steplessly. A variable valve mechanism may be used. The external mechanism is not limited to a variable valve mechanism.

FIG. 3 is a longitudinal sectional view of a main part of the actuator according to the first embodiment. FIG. 3 is a longitudinal sectional view of a main part showing the operation of the actuator according to the first embodiment. The right view of the casing which shows the positional relationship of the supply port in the actuator of Embodiment 1, and the discharge port. FIG. 6 is a longitudinal sectional view of a main part of an actuator according to a second embodiment. The right view of the casing which shows the positional relationship of the supply port in the actuator of Embodiment 2, and the discharge port. Explanatory drawing of the positional relationship of the supply port and discharge port in the actuator of other embodiment. Explanatory drawing of the positional relationship of the supply port and discharge port in the actuator of other embodiment.

Explanation of symbols

  2 ... Actuator, 4 ... Cam carrier, 4a ... Oil passage, 4b, 4c ... Discharge oil passage, 6 ... Sunshaft, 6a ... Spur gear portion, 6b ... Screw portion, 6c ... Straight spline portion, 8 ... Casing, 8a ... straight spline part, 8b ... supply port, 8c ... first discharge port, 8d ... second discharge port, 10 ... bearing, 12 ... planetary differential screw type rotation-linear motion conversion mechanism, 14 ... nut, 14a ... first Spur gear portion, 14b ... screw portion, 14c ... second spur gear portion, 16 ... planetary shaft, 16a ... spur gear portion, 16b ... screw portion, 16c ... spur gear-screw portion, 18 ... core, 20 ... Coil, 22 ... Rotor, 24 ... Coil, 26 ... Lid member, 28 ... Seal member, 30 ... Lubrication space, 102 ... Actuator, 104 ... Cam carrier, 106 ... Sunshaft, 107 ... Supply port, 107a Lubricating oil outlet, 108 ... casing, 108 c ... first outlet, 108 d ... second outlet, 114 ... nut, 116 ... planetary shaft, 208 ... casing, 208 b ... supply port, 208 c ... first outlet, 208 d ... 2nd discharge port, 308 ... casing, 308b ... supply port, 308c ... 1st discharge port, 308d ... 2nd discharge port, 408 ... casing, 408b ... supply port, 408c ... 1st discharge port, 408d ... 2nd discharge port , La, Lb ... level, Va, Vb ... discharged oil amount, Vo ... supplied oil amount, W ... vertical width region.

Claims (7)

An actuator that drives an external mechanism with an output of a driving force generated by a mechanical motion mechanism disposed in a lubrication space that is oil-tight except for a supply port and a plurality of discharge ports of the lubricant,
The outlet is
By being present at the lowest position in the lubrication space, when no lubrication oil is supplied from the supply port, almost all the lubrication oil in the lubrication space can be discharged, and the discharge capacity is the supply port. The lowest outlet, which is lower than the supply capacity from
When the lubricating oil is supplied from the supply port, the lowest position discharge port in a state where the lubricating oil surface exists at the lubricating oil surface setting level set for the mechanical motion mechanism in the lubricating space. In addition, the lubricating oil equal to the amount supplied by the supply port is discharged, and when the lubricating oil level does not reach the lubricating oil level setting level, the lubricating oil less than the supply amount by the supplying port is discharged together with the lowest position discharging port. A lubricating oil supply outlet for discharging the lubricating oil exceeding the supply amount by the supply port together with the lowest position outlet in a state where the lubricating oil level exceeds the lubricating oil level setting level;
An actuator characterized by comprising: In Claim 1, the discharge port at the time of lubricating oil supply is disposed at a position higher than the discharge port at the lowest position, and the vertical width region of the discharge port at the time of supply of the lubricating oil is the lubricating oil surface setting level,
The discharge port at the time of supplying the lubricating oil is set to a flow passage area that discharges a lubricating oil amount equal to the supply amount together with the lowest position discharge port in a state where the lubricating oil surface is in any of the upper and lower width regions. An actuator characterized by comprising: 3. The actuator according to claim 1, wherein a mechanism provided in the internal combustion engine is driven as the external mechanism by being fixed to the internal combustion engine. 4. The actuator according to claim 3, wherein the external mechanism is a mechanism that continuously changes a valve cam lift amount of the internal combustion engine. 5. The actuator according to claim 4, wherein the external mechanism is a mechanism that changes a valve cam lift amount of the internal combustion engine in a stepless manner by an axial movement of a control shaft spanned across a plurality of cylinders. 6. The actuator according to claim 1, wherein the mechanical motion mechanism is a planetary differential screw type rotation-linear motion conversion mechanism having a sun shaft, a planetary shaft, and a nut. The actuator according to claim 6, wherein the sun shaft, the planetary shaft, and the nut are engaged with each other by a screw and a gear.

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