JP2012197891A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device capable of switching constant speed power transmission and deceleration power transmission with a simple constitution at normal rotation and reverse rotation of an input shaft.SOLUTION: In the power transmission device 10, a power transmission unit 20 held in a rotation frame 50 is disposed between chassis 17 and 18. The rotation frame 50 transmits a normal rotation force to the output shaft 12 through one-way clutches 15 and 16 at normal rotation (clockwise rotation) of the input shaft 11 and restricts the rotation at reverse rotation (counterclockwise rotation). Meanwhile, the power transmission unit 20 restricts the rotation by the one-way clutch 25 at normal rotation of the input shaft 11 and decelerates and transmits the reverse force of the input shaft 11 to the output shaft 12 through gears 21 to 24. Thereby, the power transmission device is capable of switching the constant speed power transmission and the deceleration power transmission at normal rotation and reverse rotation of the input shaft 11 without using an outside control device or a power transmission device by the other power.

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 ordinary power transmission device, the transmission ratio between the input shaft and the output shaft and the output characteristics of the transmission torque are constant regardless of the rotation direction of the input shaft. However, there are cases where different output characteristics are required depending on the forward and reverse rotations of the power or the operation of the forward path and the return path of the actuator as the target operation mechanism.

For example, a cargo handling lift requires low speed and high torque when lifted up, and does not require torque when down and requires high speed characteristics. The winch requires low speed and high torque when winding, and does not require torque when pulling out the wire and requires high speed characteristics. The clamp requires a high pressing force at a low speed when tightened, and requires a high-speed characteristic without a pressing force when released. The clutch is required to have low speed and high torque when compressing the spring, and to have low torque and high speed characteristics when escaping along the spring force.
In addition, in a variable compression ratio engine that can change the compression ratio of the engine, when changing from the low compression ratio side to the high compression ratio side, low speed and high torque are required, while on the other hand, the high compression ratio side is changed to the low compression ratio side. In this case, torque is not required and high speed characteristics are required.

In this way, when the required characteristics for forward and reverse rotation or forward and backward paths are different, an actuator with a fixed gear ratio can be dealt with by sacrificing one of the characteristics or increasing the output or physique of the motor or actuator. There must be.
Therefore, conventionally, as an apparatus or method for changing the output characteristics in forward and reverse rotations or forward and backward paths, for example, a transmission using electronic control such as an automatic transmission for automobiles is known. There is also known a method of detecting a rotational direction mechanically or electrically and selecting a power transmission path having a different gear ratio. As an example of this, a forward and reverse two-stage transmission described in Patent Document 1 includes an electromagnetic clutch that can electromagnetically connect and disconnect an output shaft of a driving device and an internal gear of a planetary gear reducer.

Moreover, the following techniques are disclosed as other apparatuses or methods.
The variable compression ratio engine of Patent Document 2 uses two one-way clutches and switches between two power transmission paths. Accordingly, it is described that when a power transmission path with a high reduction ratio is selected, an output with low rotation and high torque is obtained, and when a power transmission path with a reduction speed ratio is selected, an output with high rotation and low torque is obtained.
Similarly to Patent Document 2, the opening / closing body driving device of Patent Document 3 combines two one-way clutches to divide and select power transmission.

The automatic reduction ratio switching device of Patent Document 4 generates a high torque at the displacement end of the forward path of the actuator operating area, and then switches the reduction ratio by moving the lock lever using the abutting force, along the return path. Displace the actuator at high speed.
The reversible rotation transmission device of Patent Document 5 uses a ratchet and selects a power transmission path depending on the rotation direction.
The automatic winding speed change mechanism for a camera described in Patent Document 6 includes a motor and two transmission gears, and the switching gear moves up and down according to the winding load to switch the power transmission path and automatically increase the winding speed. Change.

JP 2006-234062 A Japanese Patent No. 4333129 JP 2009-79408 A JP 2004-239326 A JP-A-7-71558 Japanese Utility Model Publication No. 6-8945

  However, a device using electronic control or a device using a mechanical or electrical detection and power switching mechanism has a complicated mechanism, a large physique, and a high cost. For example, the device of Patent Document 1 increases the number of parts due to the addition of a solenoid and a control device that constitute an electromagnetic clutch, thereby increasing the cost. Further, a circuit for controlling the solenoid in synchronization with the rotation direction of the motor is required. Since sensors and control elements are required, fine operation is difficult and operation may be uncertain.

The devices of Patent Documents 2 and 3 use two one-way clutches that restrain rotations in opposite directions, and each one-way clutch transmits a rotational force to a transmission path having a different gear ratio, so that the rotation direction depends on the rotation direction. The gear ratio is about to be switched. However, as described below, it is considered that forward / reverse operation cannot be realized by this configuration.
For example, referring to FIG. 3 of Patent Document 3, the output shaft (44) is provided with a first one-way clutch (63) and a second one-way clutch (73) that restrain rotation in opposite directions. The first one-way clutch is going to drive the disengagement side drive gear (61), and the second one-way clutch is going to drive the closing side drive gear (71). The open side drive gear and the close side drive gear mesh with an open side driven gear (62) and a closed side driven gear (72) fixed to a common intermediate shaft (90), respectively.

  In such a configuration, it is assumed that the output shaft rotates in the power transmission direction of the first one-way clutch, thereby rotating the common intermediate shaft via the gear. Then, the rotation of the intermediate shaft is transmitted to the closing side drive gear via the closing side driven gear, and the rotational force in the same direction as the rotation of the output shaft acts on the closing side drive gear. Here, when the rotation speed of the closing side drive gear is faster than the rotation speed of the output shaft, this corresponds to a state in which the output shaft rotates in the opposite direction relative to the closing side drive gear. The state in which the output shaft rotates in the opposite direction is the power transmission state of the second one-way clutch, so the first one-way clutch and the second one-way clutch are simultaneously in the power transmission state, and are different from each other in deadlock, that is, different from each other. Each transmission system causes mutual interference due to the power transmission at the gear ratio, and power transmission becomes impossible. Therefore, this mechanism is not established.

  Furthermore, various patterns were verified when two one-way clutches were configured to restrain rotation in the same direction, when the inner ring side of the one-way clutch was driven, or when the outer ring side was driven. As a result, it has been found that in any pattern, deadlock occurs or the two one-way clutches idle together and the output shaft does not rotate. That is, it can be said that a mechanism for switching the gear ratio between forward rotation and reverse rotation cannot be configured by simply combining two one-way clutches.

In addition, the device of Patent Document 4 cannot shift gears when the forward displacement is reversed before returning to the end.
In the device of Patent Document 5, loss torque is generated between the input and output shafts for ratchet switching. In addition, it is necessary to incorporate a ratchet system inside the drive shaft or a portion connected to the drive shaft, and it is difficult to reduce the size of the device and simplify the structure. Furthermore, it is difficult to achieve a rotation balance and is not suitable for high-speed rotation. In addition, since the ratchet fitting portion is limited to a part in the circumferential direction, the power transmission capacity may be insufficient with respect to the size of the entire apparatus.
In the transmission mechanism of Patent Document 6, a period in which power cannot be transmitted to any system occurs while the switching gear 15 moves up and down. Further, since the switching gear moves while rotating, when the switching gear and the transmission gear come into contact with each other, there is a possibility that the teeth do not mesh and the gears repel each other. Therefore, it cannot be applied particularly to a device that rotates at a high speed.

  The present invention was created in view of the above points, and its purpose is (1) not using an external control device, (2) not using a power selection device by other power such as a solenoid, (3) Simple structure, (4) reliable operation and high reliability, (5) can be reduced in size, and (6) one speed is constant at the time of forward rotation and reverse rotation of the input shaft. The other is to provide a power transmission device capable of automatically switching power transmission of constant speed or deceleration or acceleration.

  The power transmission device according to claim 1 transmits the rotational force of the input shaft from the input shaft to the output shaft. Here, when 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”, this power transmission device outputs when the input shaft rotates forward. The shaft is rotated at the same speed as the input shaft. Further, when the input shaft is reversely rotated, the output shaft is rotated at a constant speed, or decelerated or increased with respect to the rotation of the input shaft.

The power transmission device includes a fixed housing, a rotation housing, a power transmission unit, a first one-way rotation restraining member, and a second one-way rotation restraining member.
The rotating housing is rotatably supported by the fixed housing.
The power transmission unit is rotatably supported by the rotary housing, and transmits the rotational force transmitted from the input shaft to the output shaft provided coaxially with the input shaft at a constant speed, or decelerated or increased.

The first one-way rotation restricting member is configured so that the rotating housing can be rotated forward with respect to the fixed housing when the input shaft is rotated forward, and the rotating housing cannot be rotated with respect to the fixed housing when the input shaft is rotated reversely. The reverse rotation of the rotary housing is restrained with respect to the fixed housing. That is, the first one-way rotation restricting member restricts the rotation of the rotating housing in only one direction with respect to the fixed housing.
The second one-way rotation restricting member makes the power transmission unit unable to rotate forward with respect to the rotating housing during normal rotation of the input shaft, and allows the power transmission unit to reverse with respect to the rotating housing when the input shaft reverses. Thus, the normal rotation of the power transmission unit is restricted with respect to the rotating housing. That is, the second one-way rotation restricting member restricts the rotation of the power transmission unit in only one direction with respect to the rotating housing.

Here, when a rotational force is applied to the input shaft in any one direction, which will be referred to as “forward rotation”, the first one-way rotation restricting member is mounted in a direction not restricting the rotation, and the second one-way rotation restricting member. Is mounted in a direction that restrains rotation.
Therefore, when a rotational force is applied to the input shaft in one direction, which is referred to as “reverse rotation”, which is opposite to normal rotation, the first one-way rotation restricting member restricts rotation and the second one-way rotation restricting member rotates. Is not restrained.
With the above configuration, in the power transmission device, when the input shaft rotates in the forward direction, the normal rotation force of the input shaft is transmitted to the output shaft through the rotary housing. Further, when the input shaft rotates in reverse, the reverse rotation force of the input shaft is transmitted to the output shaft through the power transmission unit.

Therefore, it is possible to automatically switch between constant speed power transmission and power transmission based on the gear ratio of the power transmission unit between forward rotation and reverse rotation of the input shaft.
Since this power transmission device has a simple configuration without using an external control device or a power selection device by other power, the physique can be reduced, the number of parts and the cost can be reduced, and the operation is reliable. Reliability can be improved.

According to the second aspect of the invention, the power transmission unit transmits the reverse rotation force transmitted from the input shaft to the output shaft via the plurality of transmission paths.
A power transmission unit is implement | achieved by the gear box etc. which combined the spur gear, for example. In this case, an input-side transmission gear that meshes with an input gear coupled to the input shaft, an output-side transmission gear that meshes with an output gear coupled to the output shaft, and an input-side transmission gear and an output-side transmission gear. The connecting secondary shaft or the like constitutes a transmission path. By providing a plurality of transmission paths, the stress applied to the components of the transmission path can be dispersed. Therefore, it is possible to reduce the size of the system without reducing the transmission torque, and it is possible to increase the transmission torque with a system of the same size.

According to the invention described in claim 3, in the power transmission unit, the plurality of transmission paths are evenly arranged in the circumferential direction around the input shaft and the output shaft. Therefore, the balance at the time of rotation operation can be improved, the center runout of the rotating shaft can be suppressed, and the rotation can be stabilized.
According to the fourth aspect of the present invention, the power transmission unit is arranged such that the plurality of transmission paths coincide with the center of rotation and the center of gravity of the rotary housing. Therefore, the balance at the time of rotation operation can be improved, the center runout of the rotating shaft can be suppressed, and the rotation can be stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS (a): Front view of the power transmission device by 1st Embodiment of this invention, (b): Sectional drawing. 1 is a perspective view of a power transmission device according to a first embodiment of the present invention. 1 is a schematic diagram of a variable compression ratio engine to which a power transmission device of the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS (a): Cross-sectional schematic diagram of the power transmission device by 1st Embodiment of this invention, (b): IVb-IVb sectional drawing of (a). It is explanatory drawing explaining a one-way clutch. It is a schematic diagram which shows the action | operation mechanism at the time of forward rotation 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 reverse rotation of the power transmission device by 1st Embodiment of this invention. (A): Cross-sectional schematic diagram of the power transmission device of 2nd Embodiment of this invention, (b): It is VIIIb-VIIIb sectional drawing of (a). FIG. 2A is a block diagram showing a power transmission device according to the prior art, and FIG.

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. 3 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. 3) 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, 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. 3, 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 configuration of the power transmission device 10 will be described with reference to FIGS. 1, 2, and 4 to 7.
The power transmission device 10 shown in FIGS. 1 and 2 is a device that is manually operated to explain the structure and operation, and the input shaft and the output shaft are not connected to the power and the target operation mechanism.
As shown in FIGS. 1 and 2, in the power transmission device 10, the power transmission unit 20 supported by the rotating frame 50 is disposed between the chassis 17 and 18. The chassis 17 and 18 are fixed to the base 19 substantially in parallel. An input shaft 11 and an output shaft 12 coaxial with the input shaft 11 extend on the chassis 17 side and the chassis 18 side, respectively, and handles 13 and 14 for manual operation are attached to the tip ends thereof.

The one-way clutches 15 and 16 are fixed to the chassis 17 and 18, respectively, and support the rotating frame 50 so as to be rotatable only in the normal rotation direction, as will be described later.
The power transmission unit 20 includes an input gear 21, a first gear 22, a second gear 23, an output gear 24, a countershaft 29, a one-way clutch 25, and the like. In particular, the power transmission unit 20 shown in FIGS. 1 and 2 includes three first gears 22, second gears 23, and countershafts 29. The one-way clutch 25 fixed to the rotary frame 50 supports the power transmission unit 20 so as to be rotatable only in the reverse rotation direction with respect to the rotary frame 50, as will be described later.

Next, detailed configurations of the rotating frame 50 and the power transmission unit 20 will be described with reference to FIGS. Here, in FIGS. 4A, 6, and 7, for convenience of explanation, it is assumed that each of the first gear 22, the second gear 23, and the countershaft 29 is one, unlike FIGS. That is, in FIG. 4B, only the first gear 22a, the corresponding second gear 23a, and the countershaft 29a, whose outlines are indicated by solid lines on the lower side of the first gear 22, are shown in the upper left of the figure. In addition, the first gears 22b and 22c and the corresponding second gears 23b and 23c and the countershafts 29b and 29c whose outlines are indicated by broken lines on the upper right side will be described.
Further, in order to distinguish from the power transmission device 10 shown in FIGS. 1 and 2, the reference numeral of the power transmission device shown in FIGS.

As shown in FIG. 4A, the power transmission unit 20 is supported by the rotating frame 50. The rotating frame 50 is supported by the one-way clutches 15 and 16 fixed to the chassis 17 and 18 so as to be rotatable only in one direction.
The power transmission unit 20 is similar to a gear box. The power transmission unit 20 is connected to an input gear 21 connected to the input shaft 11, an output gear 24 connected to the output shaft 12, and a first shaft 29 connected to the auxiliary shaft 29 provided substantially parallel to the input shaft 11 and the output shaft 12. A gear 22 and a second gear 23, a one-way clutch 25, and bearings 26, 27, and 28 are provided (see the note in FIG. 4). The one-way clutch 25 supports the input shaft 11 so as to be rotatable only in one direction. The bearings 26 and 27 support the auxiliary shaft 29 so as to be rotatable in both directions, and the bearing 28 supports the output shaft 12 so as to be rotatable in both directions.

  The gears 21 to 24 are spur gears, and the input gear 21 and the first gear 22 mesh with each other, and the second gear 23 and the output gear 24 mesh with each other. The number of teeth of the first gear 22 is larger than the number of teeth of the input gear 21, and the pitch circle diameter of the first gear 22 is larger than the pitch circle diameter of the input gear 21. Accordingly, the rotation of the input shaft 11 is transmitted to the auxiliary shaft 29 while being decelerated while being rotated in the opposite direction. Further, the number of teeth of the output gear 24 is larger than the number of teeth of the second gear 23, and the pitch circle diameter of the output gear 24 is larger than the pitch circle diameter of the second gear 23. Accordingly, the rotation of the auxiliary shaft 29 is transmitted to the output shaft 12 while being decelerated and reversed. As a result, the power transmission unit 20 decelerates the rotational force of the input shaft 11 in the same direction and transmits it to the output shaft 12.

Next, the one-way clutches 15, 16, and 25 will be described. One-way clutches 15, 16, and 25 are illustrated with “◯” on one side and “X” on the other side with respect to the shaft. “○” means that the inner ring moves only in the direction from the other side of the page to the front side with respect to the outer ring, and “X” means only in the direction in which the inner ring moves from the front side to the other side of the page with respect to the outer ring. It means moving.
Since the one-way clutches 15 and 16 are “◯” on the upper side of the shaft and “×” on the lower side of the shaft, the one-way clutches 15 and 16 allow rotation (forward rotation) in the CW direction when viewed from the input shaft 11 side. The rotation (reverse rotation) in the CCW direction is restricted. On the other hand, since the upper side of the shaft is “x” and the lower side of the shaft is “◯”, the one-way clutch 25 allows rotation (reverse rotation) in the CCW direction when viewed from the input shaft 11 side, and viewed from the input shaft 11 side. Thus, rotation in the CW direction (forward rotation) is restricted.
That is, the one-way clutches 15 and 16 and the one-way clutch 25 are provided such that the rotational directions to be restrained are opposite to each other.

Here, a specific configuration of the one-way clutch will be described with reference to FIG. In this description, the code of the one-way clutch is “30”.
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. 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. 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.
As shown in FIG. 5B, when the roller 33 is engaged with the wedge portion 31a from the state separated from the wedge portion 31a to switch from the idle state to the power transmission state, or conversely, the idle state from the power transmission state to the idle state. When switching to, rotation of a predetermined switching angle λ1 is required.

  In the configuration of the first embodiment described above, the chassis 17 and 18 correspond to the “fixed housing” described in the claims, and the rotating frame 50 corresponds to the “rotating housing”. The one-way clutches 15 and 16 correspond to “first one-way rotation restricting members”, and the one-way clutch 25 corresponds to “second one-way rotation restricting members”.

Next, the operation of the power transmission device 10 will be described with reference to FIGS.
As shown in FIG. 6, during the normal rotation of the input shaft 11, the power transmission unit 20 is restrained from rotating with respect to the rotating frame 50 by the one-way clutch 25. At this time, the power transmission unit 20 and the rotating frame 50 are like a rigid body. The rotating frame 50 can be rotated forward with respect to the chassis 17 and 18 by the one-way clutches 15 and 16. As a result, the forward rotation force of the input shaft 11 is transmitted to the rotating frame 50 and rotates forward together with the input shaft 11. Therefore, the forward rotation force is transmitted from the input shaft 11 to the output shaft 12 at a constant speed.

  On the other hand, as shown in FIG. 7, when the input shaft 11 is reversely rotated, the rotation frame 50 is restrained from rotating with respect to the chassis 17 and 18 by the one-way clutches 15 and 16. On the other hand, since the power transmission unit 20 is not restrained from rotating with respect to the rotating frame 50 by the one-way clutch 25, the reverse rotation force of the input shaft 11 is transmitted to the input gear 21 and transmitted to the output shaft 12 via the gears 21 to 24. Is done. Thereby, the reverse rotation force is decelerated and transmitted from the input shaft 11 to the output shaft 12.

Next, the power transmission device according to the first embodiment of the present invention will be described in comparison with a conventional power transmission device.
As shown in FIG. 9, a power transmission device 90 according to the prior art is applied to, for example, an automatic transmission for a car, a mechanical clutch transmission, and the like, and includes the following configurations (A) to (E).
(A) A power split mechanism 92 that splits one power P (electric motor, manual handle, etc.) input to the input shaft 91 into two or more systems. For example, a gear, a pulley, etc. are included.
(B) Two or more power transmission paths with different reduction ratios. For example, a constant speed power path 93a and a reduction power path 93b, or a reduced speed ratio gear box 94a and another high reduction ratio gear box 94b are applicable. In addition, friction transmission or the like may be used.

(C) A rotation sensor 95 that detects the rotation direction, speed, or torque direction. Includes mechanical and electronic items.
(D) A clutch control device 96 that controls and drives the selector clutch 97 based on the discrimination of the rotation sensor 95. In the specific example, the power supply 96a includes a control power supply 96a, a clutch controller 96b, and a clutch control actuator 96c. Includes mechanical and electronic items.
(E) A selector clutch 97 that selects the power shifted by the transmission of (B) and transmits it to the output shaft 98 connected to the target operation mechanism 99. Includes mechanical and electronic items.

  The power transmission device 90 having such a configuration requires an externally driven power switching element such as an externally driven clutch or the like because “a sensor or a control element is required, so that it is difficult to finely operate and the operation is not reliable.” Is a large scale, "" the number of parts is large. "," The neutral point may be ambiguous. "

In contrast to the above-described conventional power transmission device 90, the power transmission device 10 according to the first embodiment of the present invention has the following characteristics due to the configuration and operation described above.
(1) Do not use an external control device.
(2) Do not use a power selection device with other power, such as a solenoid.
(3) The configuration is simple.
(4) Reliable operation and high reliability.
(5) The physique can be reduced.
(6) It is possible to automatically switch the power transmission between the normal rotation and the reverse rotation of the input shaft, one of which is constant speed and the other of which is constant speed or deceleration or acceleration.

(Second Embodiment)
Next, the power transmission apparatus of 2nd Embodiment is demonstrated with reference to FIG. The power transmission device 102 of the second embodiment is different from the first embodiment in the configuration of the power transmission unit. In the following description, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
The power transmission unit 40 is supported by the rotating frame 50 as shown in FIG. The power transmission unit 40 is connected to an input gear 41 connected to the input shaft 11, an output gear 44 connected to the output shaft 12, and four auxiliary shafts 49 provided substantially parallel to the input shaft 11 and the output shaft 12. Four first gears 42 and four second gears 43, one-way clutches 46 and 47, and bearings 45 and 48.

The bearing 45 supports the input shaft 11 so as to be rotatable in both directions, and the bearing 48 supports the output shaft 12 so as to be rotatable in both directions.
The one-way clutches 46 and 47 as “second one-way rotation restricting members” support the countershaft 49 so as to be rotatable in the CW direction and restrict the rotation in the CCW direction. Then, since the rotation directions of the auxiliary shaft 49 and the input shaft 11 are opposite, the rotational force of the input shaft 11 is transmitted to the input gear 44 during rotation (reverse rotation) in the CCW direction, and rotation (forward rotation) in the CW direction. Sometimes rotation is constrained to the rotating frame 50. That is, the power transmission unit 40 operates similarly to the power transmission unit 20 of the first embodiment.

  With the above configuration, when the input shaft 11 rotates forward, the power transmission unit 40 is restrained from rotating with respect to the rotating frame 50 by the one-way clutches 46 and 47. Thereby, the power transmission unit 40 and the rotation frame 50 become like a rigid body. The rotating frame 50 can be rotated forward with respect to the chassis 17 and 18 by the one-way clutches 15 and 16. As a result, the forward rotation force of the input shaft 11 is transmitted to the rotating frame 50 and rotates forward together with the input shaft 11. Therefore, the forward rotation force is transmitted from the input shaft 11 to the output shaft 12 at a constant speed.

  On the other hand, when the input shaft 11 rotates in the reverse direction, the rotation of the rotating frame 50 is restricted with respect to the chassis 17 and 18 by the one-way clutches 15 and 16. On the other hand, since the one-way clutches 46 and 47 in the power transmission unit 40 are not restrained, the reverse rotation force of the input shaft 11 is transmitted to the input gear 41 and transmitted to the output shaft 12 via the gears 41 to 44. Thereby, the reverse rotation force is decelerated and transmitted from the input shaft 11 to the output shaft 12.

In the second embodiment, in the power transmission unit 40, the rotational force is transmitted via four transmission paths including the countershaft 49, the first gear 42, and the second gear 43. Therefore, compared to the case of one power transmission path, the stress applied to the gear that is a component of the transmission path is dispersed, and the transmission torque can be improved.
The four transmission paths are equally arranged in the circumferential direction around the input shaft 11 and the output shaft 12. Therefore, the balance of power transmission can be improved. Therefore, the rotation of the rotating shaft can be suppressed and the rotation can be stabilized.

(Other embodiments)
(A) In the above embodiment, the power transmission unit decelerates the reverse force of the input shaft 11 and transmits it to the output shaft 12. However, the power transmission unit increases the reverse force of the input shaft 11 at a constant speed or increases the speed. A combination of gears may be set so as to transmit to the output shaft 12.
(B) The transmission member that constitutes the power transmission unit is not limited to a spur gear, but may be a helical gear, a worm, or a planetary gear. Alternatively, friction transmission, a belt and a pulley, a chain and a sprocket, etc. may rotate. Any format is acceptable as long as it can be communicated.

(C) The “one-way rotation restricting member” is not limited to a one-way clutch, and may be an element that restricts rotation in any one direction and does not restrict reverse rotation, such as a reverse prevention ratchet.
(D) 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) In the above embodiment, the input shaft 11 and the output shaft 12 are clearly defined. However, the present invention can be applied to a device in which the relationship between the input shaft and the output shaft is changed every moment, such as a motor / generator. Is also applicable. That is, even if the internal structure of the apparatus is not changed, the input shaft 11 and the output shaft 12 used in the embodiment can be changed to function as the output shaft and the input shaft. For example, when the input shaft 11 is rotated forward, the output shaft 12 rotates at 1 × speed (constant speed), and when the input shaft 11 is rotated reversely, the output shaft 12 rotates at 4 × speed (acceleration). On the other hand, when a forward rotation force (forward rotation direction force viewed from the input shaft 11) is input from the output shaft 12, the input shaft 11 is rotated at a single speed (constant speed), When a reverse rotation force (reverse direction force as viewed from the input shaft 11) is input to the output shaft 12, the input shaft 11 can be rotated at a quarter speed (deceleration).

(F) In the above-described embodiment, the one-way clutches (first one-way rotation restricting members) 15 and 16 are provided on the chassis (fixed housing) 17 and 18, but may be provided on the rotating frame (rotating housing) 50 side. Alternatively, it may be provided in any way as long as it is provided between the chassis 17 and 18 and the rotating frame 50 so as to exhibit the restraining function.
Similarly, in the above embodiment, the one-way clutches (second one-way rotation restricting members) 25, 46, and 47 are provided on the rotary frame (rotary housing) 50, but are provided on the power transmission units 20 and 40 side. Alternatively, it may be provided in any way as long as it is provided between the power transmission units 20 and 40 and the rotary frame 50 so as to exhibit the restraining function.

(G) The power transmission device of the present invention is not limited to the variable compression ratio engine, but 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, 101, 102, 90 ... power transmission device,
11 ・ ・ ・ Input shaft,
12 ... Output shaft,
15, 16 ... one-way clutch (first one-way rotation restricting member),
17, 18 ... Chassis (fixed housing),
20, 40 ... power transmission unit,
21 ・ ・ ・ Input gear,
24 ... Output gear,
25, 46, 47 ... one-way clutch (second one-way rotation restricting member),
29 ・ ・ ・ Secondary shaft,
50: Rotating frame (rotating housing).

Claims (4)

When the rotational force of the input shaft is transmitted from the input shaft to the output shaft, the rotation of the input shaft in one rotation direction is normal rotation, and the rotation of the input shaft in the other rotation direction is reverse rotation, the input shaft Power that rotates the output shaft at the same speed as the rotation of the input shaft during normal rotation of the input shaft, and rotates the output shaft at a constant speed or reduced or increased speed relative to the rotation of the input shaft during reverse rotation of the input shaft A transmission device,
A fixed housing;
A rotating housing rotatably supported by the fixed housing;
A power transmission unit that is rotatably supported by the rotary housing, and that transmits the rotational force transmitted from the input shaft to the output shaft provided coaxially with the input shaft by decelerating or increasing speed at a constant speed;
In the fixed housing, the rotation housing can be rotated forward with respect to the fixed housing when the input shaft is rotated forward, and the rotation housing cannot be rotated with respect to the fixed housing when the input shaft is rotated reversely. A first one-way rotation restraining member for restraining the reverse rotation of the rotating housing;
The rotation in which the power transmission unit cannot be rotated forward with respect to the rotating housing during normal rotation of the input shaft, and the power transmission unit can be rotated in reverse with respect to the rotating housing during reverse rotation of the input shaft. A second one-way rotation restraining member for restraining forward rotation of the power transmission unit with respect to the housing;
With
During normal rotation of the input shaft, the normal rotation force of the input shaft is transmitted to the output shaft via the rotary housing,
The power transmission device according to claim 1, wherein the reverse rotation force of the input shaft is transmitted to the output shaft via the power transmission unit during the reverse rotation of the input shaft.   The power transmission device according to claim 1, wherein the power transmission unit transmits reverse force transmitted from the input shaft to the output shaft through a plurality of transmission paths.   3. The power transmission device according to claim 2, wherein the power transmission unit is configured such that the plurality of transmission paths are evenly arranged in a circumferential direction around the input shaft and the output shaft.   4. The power transmission device according to claim 2, wherein the power transmission unit is arranged such that the plurality of transmission paths have a rotation center and a center of gravity of the rotary housing coincide with each other.

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