JP5459559B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device that transmits a rotational force of an input shaft to an output shaft.

The power transmission device transmits the rotation of the input shaft by a driving force of a motor or the like at a constant speed or by decelerating or increasing the speed to the output shaft, and drives a target operation mechanism connected to the output shaft. In an apparatus provided with such a rotation mechanism, it is required to position the rotation position of the rotation shaft during assembly.
For example, according to the rotational position positioning method disclosed in Patent Document 1, “When rotating and positioning the drive motor in the reverse direction, the rotational shaft is excessively rotated by the amount including the mechanical error amount and then rotated to the normal position. By doing so, it is finally always rotated from the same direction, and positioning is performed with high accuracy without measuring mechanical errors such as backlash.

JP 05-1111827 A

  However, the rotational position positioning method disclosed in Patent Document 1 requires a sensor for measuring the amount of over-rotation, and a calculator that stores the amount of over-rotation and reflects it in motor control, resulting in a complicated configuration and increased cost. Further, a mechanism for holding the positioned rotational position when the apparatus is not energized is necessary.

By the way, the present applicant previously filed a joint application for an invention relating to a power transmission device (Japanese Patent Application No. 2011-0663012). The invention according to this application provides a power transmission device that automatically switches between constant speed power transmission and deceleration power transmission between forward rotation and reverse rotation of an input shaft.
This power transmission device is stored and shipped after manufacture, for example, with a driving means such as a motor connected to the input shaft. Then, the output shaft is connected to the counterpart rotating shaft that is a part of the target operation mechanism at the shipping destination. In addition, there is a case where the output shaft is reconnected to the counterpart rotating shaft at the time of reassembly after the power transmission device is once removed for repair of the target operation mechanism or the like.

At this time, when it is required to make the rotational positions of the output shaft and the counterpart rotational shaft coincide with each other with high accuracy, it is necessary to position the rotational position of the output shaft of the power transmission device. Furthermore, after the positioning, it is necessary to maintain the rotational position so that the output shaft does not rotate irregularly due to its own weight or vibration during storage or transfer.
Therefore, especially in this power transmission device, the solution of the above problem is important.
The present invention has been created in view of such a point, and an object thereof is to provide a power transmission device capable of positioning and holding the rotational position of an output shaft with a simple configuration.

  The power transmission device according to the first aspect transmits the rotational force of the input shaft driven by the driving means to the output shaft. Here, if the rotation of the input shaft in one rotation direction is “forward rotation” and the rotation of the input shaft in the other rotation direction is “reverse rotation”, the power transmission device Is rotated at the same speed as the input shaft. Further, when the input shaft is reversely rotated, the output shaft is decelerated and rotated with respect to the rotation of the input shaft.

The power transmission device includes an input transmission member, a first transmission member, a second transmission member, an output transmission member, a housing, a regulating member, a one-way rotational force transmission member, and a two-way rotational force transmission member.
The input transmission member is fixed to the input shaft and rotates together with the input shaft.
The first transmission member is fixed to an input side auxiliary shaft provided on a shaft different from the input shaft, and the rotation of the input transmission member is transmitted to rotate together with the input side auxiliary shaft.
The second transmission member is fixed to an output side auxiliary shaft provided on a shaft different from the output shaft, and rotates together with the output side auxiliary shaft.
The output transmission member is fixed to the output shaft, and the rotation of the second transmission member is transmitted to rotate together with the output shaft.
Specifically, gears, pulleys, and the like can be used as the transmission members.
The housing rotatably supports the input shaft, the output shaft, the input side auxiliary shaft, and the output side auxiliary shaft. The restricting member is provided on one of the output transmission member and the housing and is provided on the other side of the output transmission member or the housing. It is possible to contact the contact portion.

The unidirectional rotational force transmitting member can transmit the normal rotation force of the input shaft to the output shaft when the input shaft rotates normally, and can cause the output shaft to idle when the input shaft rotates reversely.
The two-way rotational force transmission member can transmit the rotational force of the input side secondary shaft to the output side secondary shaft and cause the input side secondary shaft to idle with respect to the rotational force of the output side secondary shaft.
Specifically, a one-way clutch or the like can be used as the one-way rotational force transmission member. Further, specifically, a two-way clutch or the like can be used as the two-way rotational force transmission member.

  In the power transmission device having the above configuration, when the input shaft is driven by the driving means, the forward rotation force of the input shaft is transmitted to the output shaft via the one-way rotational force transmission member when the input shaft is rotated forward. During reverse rotation of the input shaft, the reverse rotation force of the input shaft passes through the input transmission member, the first transmission member, the input side auxiliary shaft, the two-way rotational force transmission member, the output side auxiliary shaft, the second transmission member, and the output transmission member. It is transmitted to the output shaft.

  Further, when the drive by the driving means is stopped, when the output shaft is reversed, the reverse force of the output shaft is transmitted to the input shaft via the one-way rotational force transmitting member, and when the output shaft is rotated forward, the one direction The output shaft is idled by the rotational force transmitting member and by the two-way rotational force transmitting member. The rotational position of the output shaft with respect to the housing can be positioned by rotating the output shaft forward and bringing the restricting member into contact with the contact portion.

The power transmission device of the present invention uses a one-way rotational force transmission member and a two-way rotational force transmission member, so that when the input shaft is driven by the driving means, “when the input shaft is rotated forward and backward. Thus, a mechanism for automatically switching between constant speed power transmission and deceleration power transmission can be realized.
Further, when driving by the driving means is stopped, the output shaft can be rotated with a small torque in the forward rotation direction. When the output shaft is rotated forward, the regulating member comes into contact with the contact portion, and the output shaft Is positioned. On the other hand, in the reverse rotation direction, since the reverse rotation force of the output shaft is transmitted to the input shaft at a constant speed, the rotation is restricted by the load torque of the driving means connected to the input shaft, and the rotational position of the output shaft once positioned Is retained. Thus, the power transmission device of the present invention can position and hold the rotational position of the output shaft with a simple configuration.

In the invention according to claim 2, the regulating member is provided in the housing, and the output transmission member is formed in a fan-shaped plate centered on the output shaft, and the wall facing the forward rotation direction constitutes the abutting portion. .
Thereby, the structure of a control member and a contact part is shown concretely. For example, by setting the central angle of the sector to an angle corresponding to the required movable range of the output shaft, the size of the output transmission member can be minimized, and the apparatus can be reduced in size and weight. Moreover, a pin etc. can be used for a control member, for example.

According to the invention described in claim 3, the restricting member is fixed to the output transmission member or the housing.
When the required movable range of the output shaft during driving of the power transmission device may be smaller than “an angle obtained by subtracting the angle corresponding to the region occupied by the regulating member from 360 °”, the regulating member is fixed. The mounting structure of the regulating member is simplified.

According to the invention described in claim 4, the regulating member is detachably provided on the output transmission member or the housing.
On the other hand, only when positioning the rotational position of the output shaft, the restricting member is attached or engaged, and when driving, the restricting member is removed or released so that the movable range of the output shaft during driving of the power transmission device is unlimited. It can be.

1 is an overall cross-sectional view of a power transmission device according to a first embodiment of the present invention. It is an arrow view of the II direction of FIG. It is an arrow view of the III direction of FIG. 1 is a schematic diagram of a variable compression ratio engine to which a power transmission device of the present invention is applied. It is explanatory drawing explaining a one-way clutch. It is explanatory drawing explaining a two-way clutch. (A): It is a perspective view of a coupling and a spring. (B): It is a schematic cross section of the coupling when the input shaft is switched from stop to forward rotation. (C): A schematic cross-sectional view of the coupling when the input shaft is switched from forward rotation to stop or reverse rotation. It is a schematic diagram which shows the operation mechanism at the time of (a) input shaft normal rotation of the power transmission device by 1st Embodiment of this invention, and the (b) input shaft reverse rotation. (A): It is a timing chart of the power transmission device of a comparative example. (B): It is a timing chart of the power transmission device by 1st Embodiment of this invention. It is a schematic diagram which shows the operation mechanism at the time of (a) output shaft normal rotation of the power transmission device by 1st Embodiment of this invention, and the (b) output shaft reverse rotation. It is an output side schematic diagram of the power transmission device by 1st Embodiment of this invention. It is an output side schematic diagram of the power transmission device by the modification of 1st Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 2nd Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 3rd Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 4th Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 5th Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 6th Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 7th Embodiment of this invention. It is an output side schematic diagram of the power transmission device by 8th Embodiment of this invention. It is the output side schematic diagram of the power transmission device by 9th Embodiment of this invention.

Embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
In the first embodiment of the present invention, the power transmission device of the present invention is applied to a variable compression ratio engine mounted on an automobile or the like and capable of changing the compression ratio. A variable compression ratio engine 80 shown in FIG. 4 includes a cam cover 81, a cylinder head 82, a cylinder block 83, a lower case 84, and the like. A cylinder 85 is formed in the cylinder block 83, and a piston 86 is accommodated in the cylinder 85 so as to be reciprocally movable. The cylinder head 82 is provided with an intake valve 881 that opens and closes an intake passage and an exhaust valve 882 that opens and closes an exhaust passage. A space surrounded by the inner wall of the cylinder 85, the upper end of the piston 86, the intake valve 881 and the exhaust valve 882 forms a combustion chamber 89. A crankshaft 871, a connecting rod 872 and the like are accommodated in the lower case 84, and the reciprocating motion of the piston 86 is converted into the rotational motion of the crankshaft 871.
Further, the cylinder block 83 is provided with a compression ratio change changing mechanism including the power transmission device 10, the motor 17, the worm 18 and the worm wheel 19.

Hereinafter, the rotation in the clockwise direction (hereinafter referred to as “CW direction”) when viewed from the input shaft side (left side in FIG. 4) of the power transmission device 10 is referred to as “forward rotation”, and the counterclockwise direction (hereinafter referred to as “CCW direction”). )) Is called “reverse”.
During normal rotation of the motor 17 as “driving means”, the power transmission device 10 transmits the normal rotation force of the motor 17 to the worm 18 at a constant speed. Further, when the motor 17 is reversely rotated, the power transmission device 10 decelerates and transmits the reverse rotation force of the motor 17 to the worm 18.

In the state shown in FIG. 4, the cylinder block 83 is at the lowest position with respect to the lower case 84. At this time, the volume of the combustion chamber 89 is the minimum, and it is in a “high compression ratio” state in which the rate of volume change due to the movement of the piston 86 is maximized.
When the forward rotation force of the motor 17 is transmitted to the worm 18, the cam cover 81, the cylinder head 82, and the cylinder block 83 are raised with respect to the lower case 84, and the upper end position of the cam cover 81 is moved to the position indicated by the broken line in the figure. As a result, the volume of the combustion chamber 89 increases, so that the rate of volume change due to the movement of the piston 86 is reduced, resulting in a “low compression ratio” state. In the transition from the high compression ratio side to the low compression ratio side, the force applied to the cylinder block 83 by the combustion pressure in the combustion chamber 89 acts in the same direction, so that a large driving force is not required. Therefore, the power transmission device 10 can transmit the rotation of the motor 17 to the worm 18 at a constant speed, and can raise the cylinder block 83 at a relatively high speed.

  Subsequently, when the reverse rotation force of the motor 17 is transmitted to the worm 18, the cam cover 81, the cylinder head 82 and the cylinder block 83 are lowered with respect to the lower case 84. Thereby, since the volume of the combustion chamber 89 decreases, the volume change rate due to the movement of the piston 86 increases, and a state of “high compression ratio” is obtained. In the transition from the low compression ratio side to the high compression ratio side, it is necessary to lower the cylinder block 83 against the combustion pressure in the combustion chamber 89. Therefore, the power transmission device 10 can decelerate the rotation of the motor 17 and output a high torque.

Next, the structure of the power transmission device 10 is demonstrated based on FIGS. 1-3 and FIGS.
As shown in FIGS. 1 to 3, the power transmission device 10 includes a main support body 60, an input side support plate 61, an output side support plate 62, an input shaft 11, an output shaft 12, an input side auxiliary shaft 51, and an output side auxiliary shaft. 52 and the like. The main support body 60, the input side support plate 61, and the output side support plate 62 constitute a “housing” described in the claims.
The input shaft 11 and the input side auxiliary shaft 51 are rotatably supported by bearings 63 and 64 fixed to the input side support plate 61, and the output shaft 12 and the output side auxiliary shaft 52 are attached to the output side support plate 62. It is rotatably supported by fixed bearings 65 and 66. Further, the output shaft 12 is rotatably supported by a bearing 67 fixed to the main support body 60, and the input side auxiliary shaft 51 is rotatably supported by a bearing 68 fixed to the main support body 60. Yes.

  The input shaft 11 and the output shaft 12 rotate about the rotation axis P. The input side auxiliary shaft 51 and the output side auxiliary shaft 52 rotate around a rotation axis Q substantially parallel to the rotation axis P. The input shaft 11 is connected to power such as a motor, and the output shaft 12 is connected to a target operation mechanism such as an actuator. Instead of the output shaft 12 or in addition to the output shaft 12, the output side auxiliary shaft 52 may be connected to the target operation mechanism.

  The input shaft 11 and the output shaft 12 are connected via a coupling 20 and a one-way clutch 30. The coupling 20 includes an input rotor 21, an intermediate rotor 23, and a spring 29, and generates a rotation time difference between the input shaft 11 and the intermediate shaft 13. The one-way clutch 30 includes an intermediate shaft 13 as an inner ring 32 formed integrally with the intermediate rotor 23, an outer ring 31 formed integrally with the output shaft 12, and the like. The one-way clutch 30 transmits the normal rotation force of the intermediate shaft 13 to the output shaft 12 when the input shaft 11 rotates forward, and causes the output shaft 12 to idle with respect to the intermediate shaft 13 when the input shaft 11 rotates reversely. Further, the input side countershaft 51 and the output side countershaft 52 are connected via a two-way clutch 50. Details of the coupling 20, the one-way clutch 30, and the two-way clutch 50 will be described later.

An input gear 41 is fixed to the input shaft 11, and a first gear 42 is fixed to the input side auxiliary shaft 51. A second gear 43 is fixed to the output side auxiliary shaft 52, and a substantially fan-shaped output gear 44 a is fixed to the output shaft 12.
The gears 41 to 44a are spur gears, and the input gear 41 and the first gear 42 mesh with each other, and the second gear 43 and the output gear 44a mesh with each other. The number of teeth of the first gear 42 is larger than the number of teeth of the input gear 41, and the pitch circle diameter of the first gear 42 is larger than the pitch circle diameter of the input gear 41. Accordingly, the rotation of the input shaft 11 is transmitted to the input-side auxiliary shaft 51 while being decelerated while being rotated in the opposite direction. Further, the number of teeth obtained by converting the number of teeth of the output gear 44 a to the entire circumference is larger than the number of teeth of the second gear 43, and the pitch circle diameter of the output gear 44 a is larger than the pitch circle diameter of the second gear 43. Therefore, the rotation of the output side auxiliary shaft 52 is transmitted to the output shaft 12 after being decelerated while the rotation direction is opposite.

Here, a specific configuration of the one-way clutch will be described with reference to FIG.
The one-way clutch 30 includes an outer ring 31, an inner ring 32, a plurality of rollers 33, and a spring 34. The plurality of rollers 33 are arranged in an annular gap sandwiched between the outer ring 31 and the inner ring 32. A wedge portion 31 a corresponding to each roller 33 is formed on the inner wall of the outer ring 31. The wedge portion 31a is formed in such a shape that the roller 33 is engaged in one side in the circumferential direction (CW direction in the figure) and the roller 33 is free in the other circumferential direction (CCW direction in the figure). The spring 34 is provided between the roller 33 and the roller 33 and presses the roller 33 against the outer ring 31 side.
In the standby state shown in FIG. 5A, the outer ring 31 and the inner ring 32 are stopped, and the roller 33 is pressed against the wedge portion 31a.

  FIG. 5C shows a case where the inner ring 32 that is the drive shaft rotates in the CW direction with respect to the outer ring 31, and FIG. 5D shows the case where the outer ring 31 that is the drive shaft moves in the CCW direction with respect to the inner ring 32. Indicates the case of rotation. In either case, as indicated by the solid line arrow in the figure, the roller 33 is engaged with the wedge portion 31a, and the rotational force of the drive shaft is transmitted to the counterpart shaft via the roller 33. Here, when the rotation number of the inner ring 32 is Rin, the rotation number of the outer ring 31 is Rout, the rotation in the CW direction is positive, and the rotation in the CCW direction is negative, the power transmission state is established when “Rin> Rout”. .

  Next, FIG. 5E shows a case where the inner ring 32 that is the drive shaft rotates in the CCW direction with respect to the outer ring 31, and FIG. 5F shows that the outer ring 31 that is the drive shaft moves relative to the inner ring 32. The case where it rotates in the CW direction is shown. In either case, as indicated by broken line arrows and “x” marks in the figure, the roller 33 slides between the outer ring 31 and the inner ring 32, the rotational force of the drive shaft is not transmitted, and the counterpart shaft rotates idle. That is, when “Rin <Rout”, the idling state is established.

In short, including the case where one of the outer ring 31 and the inner ring 32 is stopped, the direction of “relative rotation between the outer ring 31 and the inner ring 32” determines whether the power transmission state or the idling state occurs.
Further, as shown in FIG. 5 (b), when the roller 33 is engaged with the wedge 31a from the state separated from the wedge 31a to shift from the idling state to the power transmission state, or conversely, from the power transmission state to the idling state. When shifting to, rotation of a predetermined switching angle λ1 is necessary. The switching angle λ1 corresponds to so-called backlash.

Next, a specific configuration of the two-way clutch 50 will be described with reference to FIG.
As shown in FIG. 6A, which is an enlarged view of the VIa portion of FIG. 1, the two-way clutch 50 includes an input side countershaft 51 as an outer ring, an output side countershaft 52 as an inner ring, a roller 53, a cage 54, a slide. It consists of a dynamic spring 55, a case 56, and the like.
The holder 54 holds the roller 53. The sliding spring 55 is stretched by the radially inner end 55 a being hooked on the cage 54 and the radially outer sliding portion 55 b being in contact with the inner wall of the case 56. The case 56 is fixed to the main support 60, holds the radially outer side of the input side countershaft 51, and rotatably supports the output side countershaft 52 via a bearing 57.

  FIG. 6B shows a case where the input side auxiliary shaft (outer ring) 51 rotates as a drive shaft. At this time, since the retainer 54 tries to stay in place due to the sliding resistance between the case 56 and the sliding spring 55, the roller 53 rotates relative to the input side countershaft 51 in the opposite direction. To do. When the roller 53 moves in the opposite direction and engages with the wedge portion 51 a, the rotation of the input side auxiliary shaft 51 is transmitted to the output side auxiliary shaft 52 through the roller 53. Here, assuming that the rotation speed of the input-side countershaft 51 is Sin and the rotation speed of the output-side countershaft 52 is Sout, the input-side countershaft is satisfied when “Sin> Sout” regardless of the rotation direction of the input-side countershaft 51. The rotational force is transmitted from 51 to the output side countershaft 52.

FIG. 6C shows a case where the output side auxiliary shaft (inner ring) 52 rotates as a drive shaft. At this time, the retainer 54 and the input side countershaft 51 do not move. Since the roller 53 is located in the concave portion 51b on the radially inner side of the input side auxiliary shaft 51 and cannot mesh with the input side auxiliary shaft 51 and the output side auxiliary shaft 52, only the output side auxiliary shaft 52 rotates. Therefore, regardless of the rotation direction of the output side auxiliary shaft 52, when “Sin <Sout”, the rotational force is not transmitted from the output side auxiliary shaft 52 to the input side auxiliary shaft 51, and the input side auxiliary shaft 51 idles.
Similarly to the one-way clutch 30, when the two-way clutch 50 shifts from the idling state to the power transmission state, or when the two-way clutch 50 shifts from the power transmission state to the idling state, it is necessary to rotate at a predetermined switching angle λ2 corresponding to backlash. It is.

Next, the configuration of the coupling 20 will be described with reference to FIG.
As shown in FIG. 7A, the coupling 20 includes a columnar input rotor 21, an intermediate rotor 23, and a coiled spring 29. The input rotor 21 is provided coaxially and integrally with the input shaft 11. The intermediate rotor 23 is provided coaxially and integrally with the intermediate shaft 13.
As shown in FIG. 7B, the input rotor 21 is provided with two fan-shaped projecting portions 22 projecting on the end surface on the intermediate rotor 23 side. On the other hand, the intermediate rotor 23 is provided with two fan-shaped stopper portions 24 on the end face on the input rotor 21 side. The protruding portion 22 and the stopper portion 24 are each disposed on the target with respect to the rotation axis P. The protrusion 22 is disposed between the stopper portions 24 in the circumferential direction so as to be relatively rotatable with respect to the stopper portion 24 within a predetermined play angle θ.

  In other words, the protrusion 22 can be relatively rotated by a play angle θ from an “initial position” that contacts the outer wall 25 on the CW side of the stopper 24 to a “limit position” that contacts the outer wall 26 on the CCW side of the stopper 24. is there. When the projection 22 reaches the limit position during normal rotation of the input rotor 21, the projection 22 abuts against the outer wall 26 of the stopper 24 and integrally rotates forward. Thereby, power transmission from the input rotor 21 to the intermediate rotor 23 becomes possible.

  As shown in FIG. 7A, both ends of the spring 29 are locked to claw portions 27 and 28 provided on the outer circumferences of the input rotor 21 and the intermediate rotor 23. The spring 29 is pulled to generate a load when the input rotor 21 rotates forward with respect to the intermediate rotor 23 from the initial position. Therefore, as shown in FIG. 7C, when the input rotor 21 is switched from normal rotation to stop or reverse rotation, the spring 29 is in the initial position where the protrusion 22 secures the play angle θ with respect to the stopper portion 24. The input rotor 21 is urged in the CCW direction with respect to the intermediate rotor 23 so as to return.

  In the configuration of the embodiment described above, the input gear 41, the first gear 42, the second gear 43, and the output gear 44a are respectively “input transmission member” and “first transmission member” described in the claims. , “Second transmission member” and “output transmission member”. The one-way clutch 30 corresponds to a “one-way rotational force transmission member”, and the two-way clutch 50 corresponds to a “two-way rotational force transmission member”.

Next, the operation of the power transmission device 10 when the input shaft 11 is driven by the motor 17 will be described with reference to FIGS. The thick arrow in FIG. 8 indicates the driving force Fd to be transmitted, and the middle thick broken line arrow indicates the non-driving force Fn. The thin line arrow indicates rotation in the CW direction or CCW direction.
As shown in FIG. 8A, when the input shaft 11 rotates forward, the normal rotation force is transmitted to the intermediate shaft 13 via the coupling 20. Then, since the rotational speed Rin of the inner ring 32 is a positive value in the one-way clutch 30, if the rotational speed Rout of the outer ring 31 is regarded as zero, the relationship of “Rin> Rout” is established, and the forward rotation force is applied to the output shaft. 12 is transmitted at a constant speed (see FIG. 5C).

  At this time, due to the meshing of the input gear 41 and the first gear 42, the input side countershaft 51 is decelerated and reversely rotated. On the other hand, the output side countershaft 52 is increased in speed by the meshing of the output gear 44a and the second gear 43 and reversely rotated. Then, in the two-way clutch 50, the rotation speed Sout of the inner ring (output-side countershaft) 52 becomes larger than the rotation speed Sin of the outer ring (input-side countershaft) 51 (Sin <Sout). It idles with respect to the countershaft 51 (refer FIG.6 (c)).

  On the other hand, as shown in FIG. 8B, when the input shaft 11 rotates in the reverse direction, the input side countershaft 51 is decelerated and rotates forward due to the meshing of the input gear 41 and the first gear 42. Then, in the two-way clutch 50, the rotational speed Sin of the outer ring (input-side secondary shaft) 51 is larger than the rotational speed Sout of the inner ring (output-side secondary shaft) 52 that is stopped (Sin> Sout). The forward rotation force 51 is transmitted to the output side auxiliary shaft 52 (see FIG. 6B). The output shaft 12 is decelerated and reversely rotated by meshing between the second gear 43 and the output gear 44a. As a result, the reverse rotation force of the input shaft 11 is decelerated and transmitted to the output shaft 12.

  At this time, the reverse rotation force of the input shaft 11 is transmitted to the intermediate shaft 13 via the coupling 20. However, since the rotational speed Rin of the inner ring 32 in the one-way clutch 30 is a negative value, if the rotational speed Rout of the outer ring 31 is regarded as zero, the relationship “Rin <Rout” is established, and the output shaft 12 rotates idly. (See FIG. 5 (e)).

Next, the behavior when the input shaft 11 switches from reverse rotation to normal rotation will be described with reference to FIG. First, as a comparative example for one embodiment of the present invention, FIG. 9A shows a timing chart when the power transmission device does not include a coupling.
Here, each variable is defined as follows.
n (1 / s): Number of rotations per second of the input shaft 11 (forward rotation is positive and reverse rotation is negative)
λ1 (deg): switching angle of the one-way clutch 30 λ2 (deg): switching angle of the two-way clutch 50 Z (−): input side reduction ratio (= (number of teeth of the first gear 42 / number of teeth of the input gear 41)) (Rotation speed of input shaft 11 and intermediate shaft 13 / rotation speed of input side auxiliary shaft 51))
T1 (s): Time required for the intermediate shaft 13 (= the inner ring 32 of the one-way clutch 30) to rotate by the switching angle λ1 T2 (s): The input side auxiliary shaft 51 (= the outer ring of the two-way clutch 50) rotates for the switching angle λ2 Correspondingly, the time required for the input shaft 11 and the intermediate shaft 13 to rotate by angle Z × λ2

Times T1 and T2 are expressed by the following formulas 1 and 2.
T1 = λ1 / (360 · n) (Formula 1)
T2 = Z × λ2 / (360 · n) (Formula 2)
Therefore, when Z × λ2> λ1, T2> T1 as shown in FIG. Then, if the time at which the input shaft 11 switches from reverse rotation to normal rotation is t0, the one-way clutch 30 shifts from the idling state to the power transmission state after time T1 from time t0, and the two-way clutch 50 is after time T2 from time t0. Transition from the power transmission state to the idling state. Therefore, the one-way clutch 30 and the two-way clutch 50 are simultaneously in a power transmission state within a range indicated by hatching in the figure, and so-called deadlock occurs.
When the input shaft 11 switches from forward rotation to reverse rotation, the one-way clutch 30 shifts from the power transmission state to the idle rotation state, and then the two-way clutch 50 shifts from the idle rotation state to the power transmission state, so that no deadlock occurs.

In order to solve this problem, an embodiment of the present invention includes a coupling 20 having a play angle θ. Here, the play angle θ is set to satisfy the following expression 3.
θ ≧ Z × λ2−λ1 (Formula 3)
When Z × λ2> λ1, θ takes a positive value. Further, the time Tθ is defined as follows.
Tθ (s): time for the input shaft 11 to rotate with respect to the intermediate shaft 13 by a play angle θ

In other words, Tθ is the “following delay time” of the intermediate shaft 13 when the input shaft 11 is switched from reverse rotation to normal rotation. As a result, as shown in the timing chart of FIG. 9B, the one-way clutch 30 shifts from the idling state to the power transmission state after time (T1 + Tθ) from time t0. Therefore, the one-way clutch 30 and the two-way clutch 50 are not in the power transmission state at the same time, and the occurrence of deadlock can be avoided.
When the input shaft 11 is switched from forward rotation to reverse rotation, the projection 22 is returned to the initial position by the spring 29 of the coupling 20, so that the rotation between the input shaft 11 and the intermediate shaft 13 is caused by the play angle θ. There is no time difference. Therefore, it behaves the same as the comparative example shown in FIG.

  As described above, the power transmission device 10 uses the one-way clutch 30 and the two-way clutch 50, so that when the input shaft 11 is driven by the motor 17, “when the input shaft rotates forward and backward. , A mechanism for automatically switching between constant-speed power transmission and deceleration power transmission can be realized.

  Next, with reference to FIGS. 10 and 11, the operation of the power transmission device 10 when the drive by the motor 17 is stopped will be described. In this operation, the output shaft 12 is rotated by rotational power that is manually or temporarily connected during assembly or maintenance of the power transmission device 10. In FIG. 10, as in FIG. 8, the thick arrow indicates the transmitted driving force Fd, and the middle thick broken line arrow indicates the non-driving force Fn. A thin line arrow indicates rotation in the CW direction (forward rotation direction) or the CCW direction (reverse rotation direction) viewed from the input shaft 11 side.

  As shown in FIG. 10A, during the normal rotation of the output shaft 12, the normal rotation force is transmitted to the outer ring 31 of the one-way clutch 30. However, since the rotational speed Rout of the outer ring 31 is a positive value and the rotational speed Rin of the inner ring 32 is zero in the one-way clutch 30, the relationship “Rin <Rout” is established, and the output shaft 12 rotates idly (see FIG. 5 (f)).

Further, in the two-way clutch 50, the rotational speed Sout of the inner ring (output-side secondary shaft) 52 is larger than the rotational speed Sin of the outer ring (input-side secondary shaft) 51 that is stopped (Sin <Sout). 52 idles with respect to the input side countershaft 51 (see FIG. 6C).
Therefore, the forward rotation force of the output shaft 12 is not transmitted to the input shaft 11, and the input shaft 11 remains stopped.

  On the other hand, as shown in FIG. 10B, when the output shaft 12 rotates in the reverse direction, the reverse rotation force is transmitted to the outer ring 31 of the one-way clutch 30. Then, in the one-way clutch 30, the rotational speed Rout of the outer ring 31 is a negative value, and the rotational speed Rin of the inner ring 32 is zero. Therefore, the relationship “Rin> Rout” is established, and the reverse rotation force is applied to the input shaft 11 or the like. It is transmitted at a high speed (see FIG. 5 (d)). As a result, since the stopped motor 17 is rotated by an external force, a load torque (cogging torque) is generated. In other words, in order to reversely rotate the output shaft 12, a reverse torque larger than the load torque is required, and when the reverse torque is equal to or less than the load torque, the output shaft 12 cannot be reversed.

  At this time, due to the meshing of the output gear 44a and the second gear 43, the output side countershaft 52 is accelerated and rotates forward. On the other hand, due to the meshing of the input gear 41 and the first gear 42, the input side countershaft 51 is decelerated and rotates forward. Then, in the two-way clutch 50, the rotation speed Sout of the inner ring (output-side countershaft) 52 becomes larger than the rotation speed Sin of the outer ring (input-side countershaft) 51 (Sin <Sout). It idles with respect to the countershaft 51 (refer FIG.6 (c)).

FIG. 11 is a diagram schematically showing the output side portion of the power transmission device 10 shown in FIGS. 1 and 3, and the output shaft 12 and the output side countershaft 52 are shown thinner than FIG. 11B is a cross-sectional view taken along the line bb in FIG. 11A, that is, a cross-sectional view on the output shaft 12 and the output side auxiliary shaft 52, and FIG. 11A is a view taken in the direction of the arrow a in FIG. That is, it is a view seen from the input shaft 11 side.
12 to 20 showing the following embodiment are schematic views similar to FIG.

As shown in FIG. 11, in the fan-shaped output gear 44a, a wall facing the forward rotation direction constitutes a contact portion 46a. Further, a stopper pin 47 a as a “regulating member” is fixed to the output side support plate 62. As described above, when the motor 17 is not driven, the output shaft 12 can be easily rotated in the forward rotation direction. Therefore, as shown in FIG. 11A, when the substantially sector-shaped output gear 44a rotates in the forward rotation direction, the stopper pin 47a contacts the contact portion 46a. The rotation position of the output shaft 12 at this time is referred to as “rotation limit position”.
On the other hand, since the output shaft 12 is restricted from rotating in the reverse direction shown in FIG. 11B by the load torque of the motor 17, once the stopper pin 47a contacts the contact portion 46a, the output gear 44a Cannot rotate easily. Therefore, the output shaft 12 is held at the “rotation limit position”.

  Therefore, after the power transmission device 10 is manufactured, the output shaft 12 is stored and shipped in a state where the output shaft 12 is held at the “rotation limit position” to prevent the output shaft 12 from rotating irregularly due to its own weight or vibration. can do. And when assembling to the variable compression ratio engine 80 shown in FIG. 4, the rotational position can be matched with high accuracy by connecting the output shaft 12 to the rotational shaft on the engine side which is previously positioned at the predetermined rotational position. .

  In the first embodiment, since the output gear 44a is formed in a substantially sector shape, for example, by setting the central angle of the sector shape to an angle corresponding to the required movable range of the output shaft 12, the size of the output gear 44a is set. Minimizing and lightening the device can be achieved. Further, the first embodiment has a high degree of freedom in the configuration of the “regulating member” and the like. For example, instead of the stopper pin 47a, a stopper key 47j may be employed as the “regulating member” as in the modification shown in FIG.

(Second Embodiment)
The power transmission device of the following embodiment differs from the first embodiment only in the configuration of the output gear and the “regulating member”. In the following description of the embodiments, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 13, in the second embodiment, as in the first embodiment, the substantially fan-shaped output gear 44 b has a contact portion 46 b with a wall facing in the forward rotation direction. The output side support plate 62b is provided with a stopper wall 48b with which the abutting portion 46b of the output gear 44b can abut as a “regulating member”. When the output gear 44b rotates forward, the stopper wall 48b comes into contact with the contact portion 46b, and the rotational position of the output shaft 12 is positioned.
In the second embodiment, the number of parts can be reduced, and the height of the power transmission device 10 can be reduced by devising the shape of the output side support plate 62b.

(Third embodiment)
As shown in FIG. 14, in the third embodiment, a stopper pin 47c as a “regulating member” is fixed to the output gear 44c. The output side support plate 62c is provided with an abutting portion 46c with which the stopper pin 47c can abut. When the output gear 44c rotates forward, the stopper pin 47c comes into contact with the contact portion 46c, and the rotational position of the output shaft 12 is positioned.
In the third embodiment, the number of parts can be reduced, and the movable range of the output shaft 12 can be made relatively large.

(Fourth embodiment)
As shown in FIG. 15, in the fourth embodiment, the output gear 44d has an arcuate hole 45d. The stopper pin 47 d as a “regulating member” has a tip portion fitted in the hole 45 d and a root portion fixed to the output side support plate 62. When the output gear 44d rotates forward, the stopper pin 47d comes into contact with a contact portion 46d formed on the inner wall of the hole 45d, and the rotational position of the output shaft 12 is positioned.
In the fourth embodiment, the processing of the hole 45d of the output gear 44d is relatively easy, and the number of parts can be reduced.

(Fifth embodiment)
As shown in FIG. 16, in the fifth embodiment, the output gear 44e has a plurality of meat steals 45e in the circumferential direction. The stopper pin 47 e as a “regulating member” has a tip portion fitted into one of the plurality of meat thefts 45 e and a root portion fixed to the output side support plate 62. When the output gear 44e rotates forward, the stopper pin 47e comes into contact with the contact portion 46e formed on the rib of the meat steal 45e, and the rotational position of the output shaft 12 is positioned.
In the fifth embodiment, the output gear 44e can be reduced in weight and the number of parts can be reduced.

(Sixth embodiment)
As shown in FIG. 17, in the sixth embodiment, the output gear 44f has an arcuate shape with a relatively large center angle and a bottomed groove 45f. The stopper pin 47 f as the “regulating member” has a tip portion fitted in the groove 45 f and a root portion fixed to the output side support plate 62. When the output gear 44f rotates forward, the stopper pin 47f comes into contact with the contact portion 46f formed on the inner wall of the groove 45f, and the rotational position of the output shaft 12 is positioned.
In the sixth embodiment, since the groove 45f of the output gear 44f has a bottom, the strength of the output gear compared to the fourth and fifth embodiments in which the hole 45d and the meat steal 45e penetrate the plate thickness of the output gear. The impact on is small. Therefore, the angle of the groove 45f can be set to the maximum to nearly 360 °. Therefore, the movable range of the output shaft 12 can be made relatively large.

(Seventh embodiment)
In the first to sixth embodiments, a stopper pin or the like as a “regulating member” is fixed to the output side support plate 62 or the output gear 44c. Therefore, it can be applied only to a power transmission device in which the output shaft 12 rotates within a movable range within the “rotation limit position”. That is, even the sixth embodiment that is most advantageous for maximizing the movable range among the above-described embodiments cannot be applied to an apparatus in which the movable range of the output shaft 12 is 360 ° or more.

  Therefore, as shown in FIG. 18, in the seventh embodiment, the output gear 44g has a spiral groove 45g. The stopper pin 47g as the “regulating member” is fitted with the spiral groove 45g at the tip, and the outer diameter of the base and the flange are guided by the guide groove 49g of the output side support plate 62 and slide in the radial direction. Is possible. As a result, the stopper pin 47g slides in the radial direction along with the rotation of the spiral groove 45g, so that the output gear 44g can rotate 360 ° or more. When the output gear 44g rotates forward, the stopper pin 47g comes into contact with the contact portion 46g formed on the inner wall of the spiral groove 45g, and the rotational position of the output shaft 12 is positioned. Thus, the seventh embodiment can be applied when the movable range of the output shaft 12 is 360 ° or more.

(Eighth embodiment)
Although the seventh embodiment can be applied to an apparatus in which the movable range of the output shaft 12 is 360 ° or more, the allowable movable range is limited. On the other hand, in the eighth embodiment and the next ninth embodiment, the movable member of the output shaft 12 is made unlimited by making the regulating member detachable or switching between the engaged state and the released state. Can do.

  As shown in FIG. 19, in the eighth embodiment, a stopper member 47h as a “regulating member” is provided so as to be switchable between an engaged state and a released state. Before the power transmission device 10 is assembled to the variable compression ratio engine 80, as shown in FIGS. 19 (a) and 19 (b), when the substantially fan-shaped output gear 44h rotates forward, the outer wall 48h of the engaged stopper member 47h. Contacts the contact portion 46h of the output gear 44h, and the rotational position of the output shaft 12 is positioned. On the other hand, at the time of driving after the power transmission device 10 is assembled to the variable compression ratio engine 80, the stopper member 47h is pushed into the output side support plate 62 as shown in FIG. Can rotate indefinitely.

(Ninth embodiment)
As shown in FIG. 20, in the ninth embodiment, the output gear 44i has a plurality of meat thefts 45i in the circumferential direction. The hook-shaped stopper member 47 i as the “regulating member” can be engaged with the rib 46 i of the meat steal 45 i in one of the plurality. Before assembling the power transmission device 10 to the variable compression ratio engine 80, as shown in FIGS. 20A and 20B, when the output gear 44i is rotated forward, the outer wall 48i of the engaged stopper member 47i is stealed. The rotation position of the output shaft 12 is positioned by contacting the contact portion 46i formed on the rib of the portion 45i. On the other hand, at the time of driving after the power transmission device 10 is assembled to the variable compression ratio engine 80, the stopper member 47i is pushed into the output side support plate 62 as shown in FIG. Can rotate indefinitely.

(Other embodiments)
(A) In the above embodiment, due to the relationship between the input gear 41 and the first gear 42, the rotation of the input shaft 11 is decelerated and transmitted to the input side auxiliary shaft 51. Further, due to the relationship between the second gear 43 and the output gear 44 a, the rotation of the output side auxiliary shaft 52 is decelerated and transmitted to the output shaft 12. That is, there is a relationship of “deceleration → deceleration” and “deceleration as a whole”. Here, since the output shaft 12 that is the outer ring of the one-way clutch 30 is idled with respect to the intermediate shaft 13 that is the inner ring when the input shaft 11 is reversely rotated, the rotational speed of the output shaft 12 is smaller than the rotational speed of the input shaft 11. That is, it is an essential requirement that the power transmission device 10 “decelerate as a whole”.

However, the relationship between the rotational speeds of the input shaft 11 and the input-side secondary shaft 51 and the rotational speeds of the output-side secondary shaft 52 and the output shaft 12 are not limited to “deceleration → deceleration” as in the above embodiment. , “Constant speed → deceleration” or “deceleration → constant speed” may be used. Alternatively, “decelerate as a whole” may be performed by “slightly increase → decelerate a lot” or “many decelerate → slightly increase”. Any of the embodiments can be realized by adjusting the number of teeth and the pitch circle diameter of the meshing gears.
Here, in the case of “constant speed → decelerate” or “slightly increase → decelerate a lot”, “Z” in Equation 2 is 1 or a value smaller than 1.

  (A) As described at the beginning of the description of the power transmission device 10, the output side auxiliary shaft 52 may be connected to the target operation mechanism instead of the output shaft 12 or in addition to the output shaft 12 (FIG. 1). reference). Thereby, two kinds of output characteristics can be selected or used together. As described in (a) above, the range of application of the power transmission device 10 can be further expanded by variously selecting the relationship between the rotational speeds of the output side auxiliary shaft 52 and the output shaft 12.

(C) Each “transmission member” that transmits rotational force from the input shaft 11 to the output shaft 12 is not limited to a spur gear, and may be a helical gear, a worm, a planetary gear, or a friction transmission, belt Any type can be used as long as it can transmit rotation, such as a pulley, a chain and a sprocket.
(D) The “one-way rotational force transmitting member” and the “two-way rotational force transmitting member” are not limited to the one-way clutch and the two-way clutch of the above embodiment, but may be of other types. For example, a reverse preventing ratchet may be used instead of the one-way clutch.

  (E) In the above embodiment, the outer ring 31 of the one-way clutch 30 is provided integrally with the output shaft 12, and the inner ring 32 is provided integrally with the intermediate shaft 13. However, the outer ring 31 may be formed separately from the output shaft 12 and may be coupled coaxially. The inner ring 32 may be formed separately from the intermediate shaft 13 and may be coupled coaxially.

(F) The projection 22 and the stopper 24 that constitute the coupling 20 are not limited to the configuration of the above embodiment, and the input rotor 21 and the intermediate rotor 23 can be relatively rotated within a predetermined play angle θ range. Any configuration may be used.
The input rotor 21 constituting the coupling 20 may be formed separately from the input shaft 11 and may be coupled coaxially. The intermediate rotor 23 may be formed separately from the intermediate shaft 13 and coupled coaxially. Good.

  (G) When the relationship between the switching angle λ1 of the one-way clutch 30, the switching angle λ2 of the two-way clutch 50, and the input side reduction ratio Z is “Z × λ2 ≦ λ1,” even if “θ = 0”, Therefore, it is not necessary to provide the play angle θ. Therefore, the coupling may be eliminated and the input shaft 11 and the intermediate shaft 13 may be directly connected. In that case, the input shaft 11 can be the inner ring 32 of the one-way clutch 30.

(H) The configuration of the restricting member and the contact portion for positioning and holding the rotational position of the output shaft 12 is not limited to the above embodiment.
For example, in an embodiment in which the “regulating member is detachable or the engagement state and the release state can be switched” are engaged by pushing the stopper member in the axial direction as in the eighth and ninth embodiments. In addition to the form of releasing the state, the engaged state may be released by pulling the stopper member in the axial direction. Further, the engagement state and the release state may be switched by sliding or rotating along the direction perpendicular to the axial direction, that is, the surface direction of the output-side support plate 62.

(K) In the above embodiment, the CW direction is defined as “forward rotation” when viewed from the input shaft 11 side, and the CCW direction is defined as “reverse rotation” when viewed from the input shaft 11 side.
(E) The power transmission device of the present invention is not limited to the variable compression ratio engine, and can be applied to various devices that change the transmission ratio and the transmission torque between the input shaft and the output shaft by forward and reverse rotation.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

10: Power transmission device,
11 ・ ・ ・ Input shaft,
12 ... Output shaft,
13 ... intermediate shaft,
17 ... Motor (driving means),
20 ・ ・ ・ Coupling,
30 ・ ・ ・ One-way clutch (unidirectional rotational force transmission member),
31 ・ ・ ・ Outer ring,
32 ... inner ring,
41 ・ ・ ・ Input gear (input transmission member),
42 ... 1st gear (1st transmission member),
43 ... 2nd gear (second transmission member),
44a to 44i ... output gear (output transmission member),
46a-46i ... contact part,
47a-47g ... stopper pin (regulating member),
47h, 47i ... stopper member (regulating member),
47j ... Stopper key (regulating member),
50 ... Two-way clutch (two-way rotational force transmission member),
51 ・ ・ ・ Input side countershaft, outer ring,
52 ... Output side countershaft, inner ring,
60 ・ ・ ・ Main support (housing),
62 ・ ・ ・ Output side support plate (housing),
80: Variable compression ratio engine.

Claims (4)

When the rotational force of the input shaft driven by the driving means is transmitted to the output shaft, the rotation of the input shaft in one rotational direction is forward rotation, and the rotation of the input shaft in the other rotational direction is reverse rotation, A power transmission device that rotates the output shaft at a constant speed with the rotation of the input shaft during normal rotation of the input shaft, and rotates the output shaft at a reduced speed relative to the rotation of the input shaft during reverse rotation of the input shaft. ,
An input transmission member fixed to the input shaft and rotating together with the input shaft;
A first transmission member that is fixed to an input-side countershaft provided on a shaft different from the input shaft, is rotated by the rotation of the input transmission member and rotates together with the input-side countershaft;
A second transmission member fixed to an output side auxiliary shaft provided on a shaft different from the output shaft and rotating together with the output side auxiliary shaft;
An output transmission member that is fixed to the output shaft and that rotates with the output shaft by transmitting the rotation of the second transmission member;
A housing that rotatably supports the input shaft, the output shaft, the input side counter shaft, and the output side sub shaft;
A regulating member provided on one of the output transmission member or the housing and capable of contacting a contact portion provided on the other of the output transmission member or the housing;
A one-way rotational force transmitting member capable of transmitting a normal rotation force of the input shaft to the output shaft during normal rotation of the input shaft and allowing the output shaft to idle during reverse rotation of the input shaft;
A two-way rotational force transmission member capable of transmitting the rotational force of the input-side secondary shaft to the output-side secondary shaft and allowing the input-side secondary shaft to idle with respect to the rotational force of the output-side secondary shaft;
With
When the input shaft is driven by the driving means,
During forward rotation of the input shaft, forward rotation force of the input shaft is transmitted to the output shaft via the one-way rotational force transmitting member, and when reverse rotation of the input shaft, the reverse rotation force of the input shaft is the input force. Transmitted to the output shaft via the transmission member, the first transmission member, the input side countershaft, the two-way rotational force transmission member, the output side countershaft, the second transmission member, the output transmission member,
When driving by the driving means is stopped,
When the output shaft is reversed, the reverse force of the output shaft is transmitted to the input shaft via the one-way rotational force transmitting member, and when the output shaft is rotated forward, the one-way rotational force transmitting member and The output shaft is idled by a two-way rotational force transmission member, and the rotational position of the output shaft relative to the housing can be positioned by causing the output shaft to rotate forward and causing the regulating member to abut against the abutting portion. A power transmission device characterized by that. The regulating member is provided in the housing;
2. The power transmission device according to claim 1, wherein the output transmission member is formed in a fan-like plate shape centered on the output shaft, and a wall facing a forward rotation direction constitutes the contact portion.   The power transmission device according to claim 1, wherein the restricting member is fixed to the output transmission member or the housing.   The power transmission device according to claim 1, wherein the restricting member is detachably attached to the output transmission member or the housing, or is switchable between an engaged state and a released state.

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