JP6477028B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device.

  As a power transmission device that transmits a rotational driving force from a driving source such as an internal combustion engine, a planetary gear may be used as in Patent Document 1, for example. In this power transmission device, the speed is increased according to the gear ratio of the planetary gear unit. The power transmission device is provided with a damper unit for suppressing torsional vibration. The damper unit is configured to rotate with the sun gear, and a damping spring is provided between the input side connected to the sun gear and the output side connected to the load side.

JP 2013-96573 A

  By the way, if an elastic body such as a damping spring is included in the rotating system, the size of the elastic body may be restricted. For example, when the spring becomes larger, the rotational inertia increases due to the weight of the spring. As a result, the spring may be deformed or buckled by centrifugal force. Then, an object of this invention is to provide the power transmission device which can remove an elastic body from a rotating system and can respond to the enlargement of an elastic body.

  The present invention relates to a power transmission device including a planetary gear mechanism. One of the sun gear, carrier, and ring gear of the planetary gear mechanism is connected to an input shaft, and the other one of the sun gear, carrier, and ring gear is connected to an output shaft, and yet another one of the sun gear, carrier, and ring gear. One end is connected to the other end of the elastic body having one end fixed. When elastic energy is accumulated in the elastic body, the gear or carrier that is the connection destination of the input shaft is fixed, so that the gear or carrier that is the connection destination of the elastic body and the output shaft are connected. Elastic energy is transmitted from the elastic body to the output shaft through a gear or carrier.

  Moreover, in the said invention, it is suitable for the brake mechanism which fixes the gear or carrier used as the connection destination of the said input shaft to be provided.

  Further, in the above invention, a connection mechanism for connecting and releasing the input shaft and a gear or carrier as a connection destination is provided, and the connection mechanism includes a connection between the input shaft and a gear or a carrier as a connection destination. It is preferable to provide a clutch mechanism provided therebetween.

  In the above invention, a connection mechanism for connecting and releasing the input shaft and a gear or carrier to which the input shaft is connected is provided, and the connection mechanism includes a planetary gear mechanism for connection and a brake mechanism for connection. One of the sun gear, carrier, and ring gear of the planetary gear mechanism for use is connected to the input shaft, and the other one of the sun gear, carrier, and ring gear of the connecting planetary gear mechanism is the gear to which the input shaft is connected or It is preferably connected to a carrier, and the connecting brake mechanism can fix another one of the sun gear, the carrier, and the ring gear of the connecting planetary gear mechanism.

  In the above invention, when the input shaft and a gear or carrier to which the input shaft is connected are connected by the connecting mechanism, the elastic body is biased based on a rotational difference between the input shaft and the output shaft. Elastic energy is accumulated, and when the input shaft and the gear or carrier to which the input shaft is connected are released by the connection mechanism, the gear or carrier connected to the elastic body expands and contracts the elastic body. Accordingly, the input shaft connected to the input shaft is reciprocated around the rotation shaft, and the input shaft connected to the input shaft or the carrier is reciprocated in the opposite direction to the reciprocation. When the speed of the previous gear or carrier is included in the brake region including 0, the gear or carrier to which the input shaft is connected is fixed by the brake mechanism, A gear or carrier to become a consolidated destination of the elastic body, via a gear or carrier to be connected destination of the output shaft, it is preferable that the elastic energy to the output shaft from the elastic body is transmitted.

  In the above invention, it is preferable that a lock mechanism for stopping the rotation of the pinion relative to the carrier is provided.

  According to the present invention, it is possible to provide a power transmission device in which an elastic body is removed from a rotating system.

It is a mimetic diagram (front view) explaining the structure of the power transmission device concerning this embodiment. It is a mimetic diagram (side view) explaining the structure of the power transmission device concerning this embodiment. It is a figure explaining operation | movement (elastic energy storage process) of the power transmission device which concerns on this embodiment. It is a figure explaining operation | movement of a power transmission device when a sun gear and an input shaft are connected by the clutch mechanism. It is a figure explaining operation | movement (elastic energy discharge | release process) of the power transmission device which concerns on this embodiment. It is a figure explaining operation | movement of a power transmission device when a sun gear is fixed by the brake mechanism. It is a figure explaining operation | movement of a power transmission device when accumulation | storage and discharge | release of elastic energy are combined. It is a figure which shows another example of the power transmission device which concerns on this embodiment. It is a figure which shows the further another example of the power transmission device which concerns on this embodiment.

<Overall configuration>
FIG. 1 illustrates a power transmission device 10 according to this embodiment. The power transmission device 10 includes a planetary gear mechanism 12, an elastic body 14, a clutch mechanism 16, a brake mechanism 18, and a control unit 20.

  One of the sun gear 22, the carrier 24, and the ring gear 26 of the planetary gear mechanism 12 is connected to the input shaft 28, and the other one of the sun gear 22, the carrier 24, and the ring gear 26 is connected to the output shaft (not shown). In addition, another one of the sun gear 22, the carrier 24, and the ring gear 26 is connected to one end of the elastic body 14. The other end of the elastic body 14 is connected to a fixing member such as the casing 30.

  In the following description, the sun gear 22 is used as the gear or carrier to which the input shaft 28 is connected, the carrier 24 is used as the gear or carrier to which the output shaft is connected, and the ring gear 26 is used as the gear or carrier to which the elastic body 14 is connected. The power transmission device 10 according to the present embodiment will be described based on an example in which each is assigned.

  The clutch mechanism 16 connects and releases the input shaft 28 and the sun gear 22. The brake mechanism 18 fixes and releases the sun gear 22.

  When the input shaft 28 and the sun gear 22 are connected by the clutch mechanism 16, the torque of the input shaft 28 is transmitted to the sun gear 22. Further, the ring gear 26 is rotated based on the rotation difference between the input shaft 28 and the output shaft, and the elastic body 14 supporting the ring gear 26 is urged to accumulate elastic energy.

  Thereafter, when the clutch mechanism 16 is turned off and the input shaft and the sun gear 22 are released, the ring gear 26 is reciprocated around the rotation shaft of the power transmission device 10 according to the expansion and contraction of the elastic body 14. In response to this, the released sun gear 22 is reciprocated in the opposite direction to the ring gear 26.

  When the rotational speed of the sun gear 22 is included in a brake region described later, the sun gear 22 is fixed by the brake mechanism 18. At this time, the elastic energy of the elastic body 14 is transmitted to the output shaft via the carrier 24 and the ring gear 26.

<Details of each configuration>
The elastic body 14 is made of, for example, a metal spring and supports the planetary gear mechanism 12. Although two elastic bodies 14 are shown in FIG. 1, the present invention is not limited to this, and three or more elastic bodies 14 may be provided. Further, a means for supporting the planetary gear mechanism 12 other than the elastic body 14 may be provided by providing a bearing between the planetary gear mechanism 12 and the casing 30.

  The elastic body 14 according to the present embodiment has a structure in which one end is fixed to the casing 30 and the other end is fixed to the ring gear 26, and is provided at a position away from the rotation system from the input shaft 28 to the output shaft. ing. That is, the input shaft 28 and the output shaft are not rotated. Therefore, it is not necessary to consider buckling or deformation due to rotational inertia when selecting the elastic body 14, and the size (weight) restriction on the elastic body 14 is relaxed.

  The brake mechanism 18 is a member for stopping the rotation of the sun gear 22. As shown in FIG. 2, for example, the brake mechanism 18 includes a disk-shaped disc rotor 34 fixed to an intermediate transmission shaft 32 extending from the center of the sun gear 22, and a brake pad that presses the disc rotor 34 from both the front and back sides. 36.

  The clutch mechanism 16 is a connecting mechanism that is provided between the input shaft 28 and the sun gear 22 and connects / releases them. The clutch mechanism 16 includes a friction disk 38 and a clutch pad 40 as shown in FIG. The friction disk 38 is provided at the end of the input shaft 28, and the clutch pad 40 is provided at the end of the intermediate transmission shaft 32 that faces the connecting end with the sun gear 22. The clutch pad 40 presses the friction disk 38 from both the front surface side and the back surface side so that both are connected (frictionally engaged).

  Returning to FIG. 1, the control unit 20 controls the torque transmission operation of the power transmission device 10 described in detail below by controlling the fixing / releasing operation of the brake mechanism 18 and the clutch mechanism 16 that is the coupling mechanism. To do. The control unit 20 may be a computer, and the computer may be a computer in which operation control programs for the brake mechanism 18 and the clutch mechanism 16 are stored, or an embedded computer. Further, the control unit 20 receives the rotational speeds of the gears from speed sensors (not shown) that detect the rotational speeds of the sun gear 22, the carrier 24, and the ring gear 26, respectively.

<Description of operation of power transmission device according to this embodiment>
FIG. 3 shows changes in the rotational speeds of the sun gear 22 and the ring gear 26 in the operation description of the power transmission device 10 according to the present embodiment. For simplicity of explanation, it is assumed that the input shaft 28 is driven to rotate at a constant speed by a driving source such as an internal combustion engine unless otherwise specified. The rotation speed of the carrier 24 (= output shaft) is also constant. Further, the input shaft rotation speed is assumed to be faster than the average rotation speed of the sun gear 22 (more precisely, the output shaft rotation speed / planet gear reduction ratio).

  The upper graph in FIG. 3 shows changes in the rotational speed of the sun gear 22, and the lower graph shows changes in the rotational speed of the ring gear 26. In both graphs, the vertical axis indicates the rotation speed and the horizontal axis indicates time. Furthermore, the horizontal axis (time) is synchronized in both graphs.

  In the graph of FIG. 3, it is assumed that elastic energy is given to the elastic body 14 in advance as an initial condition. Further, it is assumed that the sun gear 22 is released from the brake mechanism 18 and the clutch mechanism 16 (free). At this time, the ring gear 26 is reciprocated around the rotation axis of the planetary gear mechanism 12 according to the expansion and contraction of the elastic body 14. In response to this, the released sun gear 22 reciprocates in accordance with the reciprocating movement of the ring gear 26. If the rotation of the carrier 24 is constant, the sun gear 22 reciprocates in the opposite direction to the ring gear 26 as shown in the graph of FIG.

  At time t1 when the rotational speed of the sun gear 22 becomes equal to the rotational speed of the input shaft 28, the sun gear 22 is connected to the input shaft 28 by the clutch mechanism 16 (clutch). By this connection, torque is transmitted from the input shaft 28 to the sun gear 22. At this time, as shown in FIG. 4, the ring gear 26 is based on the rotational difference between the input shaft 28 and the output shaft (more precisely, the difference between the input shaft rotational speed and the output shaft rotational speed / planetary gear reduction ratio). Is rotated, and the elastic body 14 supporting the ring gear 26 is urged to accumulate elastic energy.

  By connecting (engaging) the sun gear 22 and the input shaft 28 when the rotational speeds are equal, it is possible to reduce the slip loss at the time of connection (theoretically 0). Instead of setting the connection timing only when the rotational speed difference between the sun gear 22 and the input shaft 28 becomes 0, a clutch region including the time when the rotational speed difference is 0 is set, and an arbitrary timing of the clutch region is set. Thus, the sun gear 22 and the input shaft 28 may be coupled. The clutch region may be set in consideration of slip loss. For example, a region where the difference in rotational speed is 0% or more and 10% or less of the rotational speed of the input shaft 28 may be determined as the clutch region.

  Returning to FIG. 3, when the clutch mechanism 16 releases the connection between the sun gear 22 and the input shaft 28 (free) at time t <b> 2, the ring gear 26 is again rotated according to the expansion and contraction of the elastic body 14. Move back and forth around. At this time, due to the accumulation of elastic energy, the reciprocating amplitude of the ring gear 26 (and therefore also the sun gear 22) becomes greater after time t2 than before time t1. If the rotation of the carrier 24 is constant, the sun gear 22 reciprocates in the direction opposite to the ring gear 26.

  FIG. 5 shows a state in which the elastic energy accumulated in the elastic body 14 is transmitted to the carrier 24. Similarly to FIG. 3, the graph of FIG. 5 shows the change in the rotational speed of the sun gear 22 in the upper part, and the change in the rotational speed of the ring gear 26 in the lower part. In both graphs, the vertical axis represents the rotation speed and the horizontal axis represents time. Furthermore, the horizontal axis (time) is synchronized in both graphs.

  When the rotational speed of the sun gear 22 becomes zero at time t3, the sun gear 22 is connected to the casing 30 by the brake mechanism 18 as shown in FIG. That is, the sun gear 22 is fixed. At this time, the elastic energy of the elastic body 14 is transmitted to the output shaft via the carrier 24 and the ring gear 26.

  By fixing the sun gear 22 aiming at the time when the rotational speed of the sun gear 22 becomes zero, it becomes possible to reduce the slip loss at the time of fixing (when connected) (theoretically 0). Instead of setting the fixed (connected) timing only when the rotation speed of the sun gear 22 becomes zero, a brake region including the time when the rotation speed of the sun gear 22 is zero is set, and an arbitrary timing of the brake region is set. Then, the sun gear 22 may be fixed. The brake region may be set in consideration of slip loss. For example, a region where the rotational speed of the sun gear 22 is 0% to 10% of the maximum value (maximum value) may be determined as the brake region.

  Returning to FIG. 5, when the connection between the sun gear 22 and the casing 30 is released by the brake mechanism 18 at time t <b> 4 (free), the ring gear 26 and the sun gear 22 reciprocate around the rotation axis of the planetary gear mechanism 12. At this time, due to the release of elastic energy, the reciprocating amplitude of the ring gear 26 (and therefore also the sun gear 22) becomes smaller after time t4 than before time t3.

  In the power transmission device 10 according to the present embodiment, the elastic energy of the elastic body 14 is intermittently transmitted to the output shaft by alternately executing the operations of FIGS. 3 and 5. In other words, torque is transmitted from the input shaft 28 to the output shaft by converting the torque of the input shaft 28 into elastic energy of the elastic body 14 and further converting it into torque to the output shaft.

  FIG. 7 shows a graph combining the operations of FIGS. 3 and 5. 7 shows the rotational speed (vibration speed) of the sun gear 22, and the middle stage shows the rotational speed (vibration speed) of the ring gear 26.

  The lower row shows the rotation angle of the ring gear 26. As the rotation angle of the ring gear 26 increases, the elastic body 14 is stretched (or contracted), so the lower graph reflects the amount of deflection (the amount of expansion / contraction) of the elastic body 14. . In this graph, the elastic body 14 is set to have a natural length when the rotation angle of the ring gear 26 is 40 °, and the positive direction of the rotation angle corresponds to the rotation direction of the output shaft.

  In each graph, the horizontal axis represents time, and all graphs are synchronized.

  The periods indicated by f, c, and b are allocated at the top of FIG. f indicates a release period in which the sun gear 22 is not connected to the input shaft 28 or the casing 30 (free), and c indicates a period in which the sun gear 22 is connected to the input shaft 28 by the clutch mechanism 16 (clutch). In the figure, b shows a period during which the sun gear 22 is connected to the casing 30 by the brake mechanism 18. As shown in this figure, the elastic energy of the elastic body 14 is transmitted to the output shaft by alternately switching the release period, the clutch connection period, and the brake connection period.

  Specifically, when the release period is switched to the clutch engagement period at 0.030 seconds, the elastic body 14 is urged in the direction opposite to the rotation direction of the output shaft (negative side). At about 0.035 seconds, the clutch engagement period is switched to the disengagement period. During this disengagement period, the ring gear 26 rotates forward (forward rotation with the output shaft), and the rotation speed of the sun gear 22 becomes approximately 0.038 seconds. At this point, the release period is switched to the brake connection period.

  In the brake connection period, as shown in the lower part of FIG. 7, it is understood that the bending of the elastic body 14 is reduced (approaching the natural length), and the elastic energy of the elastic body 14 is released. Furthermore, at about 0.051 seconds, the brake connection period is switched to the release period, and the above switching pattern is repeated thereafter.

<Other embodiment regarding a connection mechanism>
In the above-described embodiment, the clutch mechanism 16 is provided as a coupling mechanism for coupling / releasing the input shaft 28 and the sun gear 22, but the present invention is not limited to this configuration. Specifically, instead of the clutch mechanism 16, a connection mechanism including a planetary gear mechanism 42 for connection and a brake mechanism 44 as shown in FIG. 8 may be provided.

  In this connection mechanism, one of the sun gear 46, the carrier 48, and the ring gear 50 of the connection planetary gear mechanism 42 is connected to the input shaft 28. The other one of the sun gear 46, the carrier 48, and the ring gear 50 of the connecting planetary gear mechanism 42 is connected to the gear or carrier (the sun gear 22 in FIG. 8) of the planetary gear mechanism 12 to which the input shaft 28 is connected. . Further, another one of the sun gear 46, the carrier 48, and the ring gear 50 of the connecting planetary gear mechanism 42 is connected to the connecting brake mechanism 44.

  In the example shown in FIG. 8, the sun gear 46 of the connecting planetary gear mechanism 42 is connected to the input shaft 28, and the carrier 48 of the connecting planetary gear mechanism 42 is connected to the intermediate transmission shaft 32 connected to the sun gear 22 of the planetary gear mechanism 12. It is connected. Further, the ring gear 50 of the connecting planetary gear mechanism 42 is connected to the connecting brake mechanism 44.

  The connecting brake mechanism 44 fixes and releases the ring gear 50. Since the ring gear 50 idles at the time of release, torque transmission from the input shaft 28 to the intermediate transmission shaft 32 is not performed. That is, it becomes equal to the state where the clutch is disengaged. When the coupling brake mechanism 44 fixes the ring gear 50, torque is transmitted from the input shaft 28 to the intermediate transmission shaft 32 via the sun gear 46 and the carrier 48 of the coupling planetary gear mechanism 42. That is, it becomes equal to the state where the clutch is engaged. The control unit 20 controls torque transmission between the input shaft 28 and the intermediate transmission shaft 32 by controlling fixation / release of the coupling brake mechanism 44.

<Still another embodiment relating to coupling mechanism>
In the above-described embodiment, torque transmission from the input shaft 28 to the output shaft is performed by the brake mechanism 18 and the combination of the coupling planetary gear mechanism 42 and the coupling brake mechanism 44 or the coupling mechanism such as the clutch mechanism 16. However, instead of or in addition to this, a lock mechanism 52 as shown in FIG. 9 may be provided.

  The lock mechanism 52 is a means for stopping (locking) the rotation of the pinion 54 provided on the carrier 24 with respect to the carrier 24. The lock mechanism 52 may be provided in all the pinions 54 on the carrier 24, or may be provided in any pinion 54.

  When the pinion 54 is locked to the carrier 24, the rotation speeds of the sun gear 22, the carrier 24, and the ring gear 26 are the same. When the sun gear 22 is connected to the input shaft 28 and elastic energy is accumulated in the elastic body 14, the input shaft torque from the sun gear 22 and the elastic energy from the ring gear 26 are superimposed on the carrier 24, that is, the output shaft. Communicated.

  DESCRIPTION OF SYMBOLS 10 Power transmission device, 12 Planetary gear mechanism, 14 Elastic body, 16 Clutch mechanism, 18 Brake mechanism, 20 Control part, 22 Sun gear, 24 Carrier, 26 Ring gear, 28 Input shaft, 30 Casing, 32 Intermediate transmission shaft, 34 Disc rotor 36 brake pads, 38 friction discs, 40 clutch pads, 42 planetary gear mechanism for connection, 44 brake mechanism for connection, 52 lock mechanism, 54 pinion.

Claims (6)

A power transmission device having a planetary gear mechanism,
One of the sun gear, carrier and ring gear of the planetary gear mechanism is connected to the input shaft,
The other one of the sun gear, the carrier, and the ring gear is connected to the output shaft,
Still another one of the sun gear, the carrier, and the ring gear is connected to the other end of the elastic body having one end fixed thereto,
When elastic energy is accumulated in the elastic body, the gear or carrier that is the connection destination of the input shaft is fixed, so that the gear or carrier that is the connection destination of the elastic body and the output shaft are connected. A power transmission device, wherein elastic energy is transmitted from the elastic body to the output shaft via a gear or a carrier which is a tip. The power transmission device according to claim 1,
A power transmission device comprising a brake mechanism for fixing a gear or a carrier to which the input shaft is connected. A power transmission device according to claim 1 or 2,
A connection mechanism for connecting and releasing the input shaft and the gear or carrier to which the input shaft is connected;
The power transmission device according to claim 1, wherein the coupling mechanism includes a clutch mechanism provided between the input shaft and a gear or carrier as a coupling destination. A power transmission device according to claim 1 or 2,
A connection mechanism for connecting and releasing the input shaft and the gear or carrier to which the input shaft is connected;
The connecting mechanism includes a connecting planetary gear mechanism and a connecting brake mechanism,
One of the sun gear, carrier and ring gear of the planetary gear mechanism for connection is connected to the input shaft,
The other one of the sun gear, the carrier, and the ring gear of the planetary gear mechanism for connection is connected to a gear or carrier to which the input shaft is connected,
The power transmission device, wherein the connecting brake mechanism can fix another one of the sun gear, the carrier, and the ring gear of the connecting planetary gear mechanism. A power transmission device according to claim 3 subordinate to claim 2 or claim 4 subordinate to claim 2 ,
When the input shaft and the gear or carrier to which the input shaft is connected are connected by the connecting mechanism, the elastic body is biased based on the rotational difference between the input shaft and the output shaft, and elastic energy is accumulated. And
When the input shaft and the gear or carrier to which the input shaft is connected are released by the connection mechanism, the gear or carrier connected to the elastic body reciprocates around the rotation shaft according to the expansion and contraction of the elastic body. In response, the gear or carrier to which the input shaft is connected in the released state is reciprocated in the opposite direction to the reciprocating movement,
When the speed of the gear or carrier connected to the input shaft is included in a brake region including 0, the gear or carrier connected to the input shaft is fixed by the brake mechanism,
Elastic energy is transmitted from the elastic body to the output shaft via a gear or carrier that is a connection destination of the elastic body and a gear or carrier that is a connection destination of the output shaft during the fixing. A power transmission device. A power transmission device according to any one of claims 1 to 5,
A power transmission device, wherein a lock mechanism for stopping rotation of the pinion with respect to the carrier is provided.

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