阅读说明：本技术 扭矩限制器、带扭矩限制器的减振装置及动力传递装置 (Torque limiter, vibration damping device with torque limiter, and power transmission device ) 是由 上原宏 萩原祥行 前田昌宏 于 2020-09-24 设计创作，主要内容包括：本发明涉及扭矩限制器、带扭矩限制器的减振装置及动力传递装置,在被容纳于飞轮的容纳部的扭矩限制器中,确保扭矩容量,并防止在进行组装时与飞轮相干扰。在装配有该扭矩限制单元(10)的飞轮(2)中固定有具有主体部(6a)的多个定位销(6)。扭矩限制器(10)具备减振罩(11)、压力环(12)、摩擦盘(13)、锥形弹簧(14)和减振环(15)。减振环(15)与压力环(12)夹持锥形弹簧(14),该减振环(15)在外周部具有供定位销(6)嵌入的多个定位销用孔(15g),安装面安装于飞轮(2)。锥形弹簧(14)的容纳部(5)的内部侧的面与减振环(15)的安装面之间的长度被设定为短于定位销(6)的主体部(6a)的长度。(The present invention relates to a torque limiter, a damper device with a torque limiter, and a power transmission device, which ensure torque capacity in the torque limiter accommodated in an accommodating portion of a flywheel and prevent interference with the flywheel at the time of assembly. A plurality of positioning pins (6) having a main body portion (6a) are fixed to a flywheel (2) to which the torque limiting unit (10) is attached. The torque limiter (10) is provided with a damping cover (11), a pressure ring (12), a friction disc (13), a conical spring (14), and a damping ring (15). A conical spring (14) is sandwiched between a damper ring (15) and a pressure ring (12), the damper ring (15) has a plurality of positioning pin holes (15g) in the outer peripheral portion thereof, into which positioning pins (6) are fitted, and the mounting surface is attached to a flywheel (2). The length between the inner surface of the housing (5) of the conical spring (14) and the mounting surface of the damper ring (15) is set to be shorter than the length of the main body (6a) of the positioning pin (6).)

1. A torque limiter fixed to a flywheel, the flywheel having an annular portion to which a plurality of positioning pins having a main body portion are fixed, and an accommodating portion formed on an inner peripheral side of the annular portion, the torque limiter being disposed inside the accommodating portion except for a portion fixed to the flywheel, the torque limiter comprising:

a first plate to which torque from the flywheel is input;

a second plate arranged axially opposite to the first plate;

a friction disc disposed between the first plate and the second plate;

a pressing member for pressing the second plate against the friction disk; and

a third plate that sandwiches the pressing member with the second plate, the third plate having a plurality of positioning pin holes in an outer peripheral portion into which body portions of the positioning pins are fitted, a mounting surface of the outer peripheral portion being attached to an annular portion of the flywheel,

the length between the inner surface of the accommodating portion of the pressing member and the mounting surface of the third plate is set to be shorter than the length of the body portion of the positioning pin.

2. The torque limiter of claim 1,

the annular portion of the flywheel has a plurality of mounting portions arranged in a circumferential direction, the mounting portions having projecting portions projecting radially inward,

the third plate has:

a support portion that supports the pressing member;

a cylindrical portion provided on an outer peripheral portion of the support portion, covering an outer peripheral surface of the friction disk, and formed to extend in an axial direction so as to face an inner peripheral surface of the annular portion of the flywheel; and

a fixing portion having the positioning pin hole formed therein and fixed to the flywheel,

the cylindrical portion has a plurality of openings arranged in a circumferential direction, and the openings are arranged at positions corresponding to the protruding portions so as to avoid interference between the third plate and the protruding portions.

3. The torque limiter of claim 2,

the outer peripheral surface of the cylindrical portion of the third plate has a diameter larger than the minimum inner diameter of the protruding portion.

4. The torque limiter according to claim 2 or 3,

the pressing member is a conical spring and is disposed inside the cylindrical portion of the third plate.

5. The torque limiter according to any one of claims 2 to 4,

the first plate is fixed to the flywheel together with the fixing portion of the third plate.

6. The torque limiter according to any one of claims 1 to 5,

the first plate and the second plate cannot rotate relatively.

7. A vibration damping device with a torque limiter is provided with:

the torque limiter of any one of claims 1 to 6; and

and a damping unit provided on an output side of the torque limiter, for damping the transmitted rotational fluctuation.

8. A power transmission device is provided with:

a flywheel having an annular portion to which a plurality of positioning pins having a main body portion are fixed, and an accommodating portion formed on an inner peripheral side of the annular portion; and

the torque limiter of any one of claims 1 to 6, transmitting torque from the flywheel to an output side member.

Technical Field

The present invention relates to a torque limiter, and more particularly to a torque limiter which is accommodated in a flywheel having an accommodating portion and is positioned with the flywheel by a positioning pin. The present invention also relates to a power transmission device having a torque limiter.

Background

For example, in a hybrid vehicle including an engine and a motor, a torque fluctuation absorbing device having a torque limiting function as shown in patent document 1 is used in order to prevent excessive torque from being transmitted from an output side to the engine side at the time of engine startup or the like.

The torque fluctuation absorbing apparatus of patent document 1 includes a damper portion having a pair of plates and a plurality of torsion springs, and a torque limiter is provided on an outer peripheral side of the damper portion. The torque limiter and the damper portion are accommodated in an accommodating portion formed on the flywheel. An annular portion is formed on the outer peripheral side of the accommodating portion of the flywheel, and a plate of the torque limiter is fixed to the annular portion by a bolt.

Patent document 1: japanese patent laid-open No. 2008-89017

Since the torque fluctuation absorbing apparatus of patent document 1 is accommodated in the accommodating portion of the flywheel, if the torque limiter is increased to secure the torque capacity, the radial dimension of the entire apparatus becomes large. Therefore, it is considered to provide an opening portion in a member constituting an outer peripheral portion of the torque limiter, to avoid interference with an internal member, and to miniaturize the torque limiter.

However, if the torque limiter is provided with the opening, the internal member is exposed through the opening, and the exposed member may interfere with a part of the flywheel. In particular, when the torque limiter is assembled to the housing portion of the flywheel, since the flywheel and the torque limiter are not positioned in the radial direction, there is a high possibility that the components constituting the torque limiter interfere with a part of the flywheel at the time of assembly.

Disclosure of Invention

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a torque limiter that is accommodated in an accommodating portion of a flywheel, and that suppresses interference between the torque limiter and a part of the flywheel when the torque limiter is assembled to the flywheel while ensuring a torque capacity of the torque limiter.

(1) The torque limiter according to the present invention is fixed to a flywheel having an annular portion and a housing portion, and is disposed inside the housing portion except for a portion fixed to the flywheel. A plurality of positioning pins having a main body are fixed to the annular portion of the flywheel. In addition, the accommodating portion of the flywheel is formed on the inner peripheral side of the annular portion.

The torque limiter includes a first plate, a second plate, a friction disk, a pressing member, and a third plate. Torque from the flywheel is input to the first plate. The second plate is arranged to be axially opposed to the first plate. The friction disk is disposed between the first plate and the second plate. The pressing member presses the second plate against the friction disk. The pressing member is sandwiched between a third plate having a plurality of positioning pin holes in an outer peripheral portion thereof into which the main body portions of the positioning pins are fitted, and a mounting surface of the outer peripheral portion is attached to the annular portion of the flywheel.

Further, the length between the inner surface of the accommodating portion of the pressing member and the mounting surface of the third plate is set to be shorter than the length of the body portion of the positioning pin.

The torque limiter sandwiches the friction disk between the first plate and the second plate by the pressing member. Torque from the flywheel is transmitted to the friction disk via the first plate to be output. When an excessive torque is input from the flywheel, the friction disk sandwiched between the first plate and the second plate slides, preventing the excessive torque from being transmitted to the output side.

Here, the length between the inner side surface of the accommodating portion of the pressing member and the mounting surface of the third plate is set shorter than the length of the body portion of the positioning pin. Therefore, before the pressing member is accommodated in the accommodating portion, the body portion of the positioning pin of the flywheel starts to be inserted into the positioning pin hole of the third plate (corresponding to the mounting surface of the torque limiter to the flywheel). Therefore, in the case where the torque limiter is assembled to the accommodating portion of the flywheel, the flywheel and the third plate (i.e., the torque limiter) are positioned in the radial direction before the pressing member is accommodated in the accommodating portion.

Therefore, even when the opening is provided in the third plate so that a part of the flywheel does not interfere with the third plate and the pressing member is exposed through the opening, the pressing member can be prevented from interfering with the flywheel.

(2) Preferably, the annular portion of the flywheel has a plurality of mounting portions arranged in a circumferential direction, and the mounting portions have protruding portions protruding radially inward. In this case, the third plate preferably has a support portion, a cylindrical portion, and a fixing portion. The support portion supports the pressing member. The cylindrical portion is provided on the outer peripheral portion of the support portion, covers the outer peripheral surface of the friction disk, and is formed to extend in the axial direction so as to face the inner peripheral surface of the annular portion of the flywheel. The fixing portion is formed with a hole for a positioning pin and fixed to the flywheel. In this case, the cylindrical portion has a plurality of openings arranged in a circumferential direction, and the openings are arranged at positions corresponding to the protruding portions so as to avoid interference between the third plate and the protruding portions.

Here, a mounting portion such as a bolt fastening portion is provided in the annular portion of the flywheel. In addition, the mounting portion has a protruding portion that protrudes radially inward in order to reduce the size of the device and to maintain the strength while ensuring the thickness of the mounting portion.

In this structure, the cylindrical portion of the third plate covers the outer peripheral surface of the friction disk. That is, the cylindrical portion is located at the outermost diameter portion of the torque limiter that is housed in the housing portion of the flywheel. Further, a plurality of openings are formed in the cylindrical portion. Further, since the opening is disposed at a position corresponding to the protruding portion of the flywheel, interference between the flywheel and the third plate can be avoided. Therefore, the radial dimension of the entire device can be suppressed while securing the torque capacity of the torque limiter.

(3) Preferably, the outer peripheral surface of the cylindrical portion of the third plate has a diameter larger than the minimum inner diameter of the protruding portion.

Here, since the outer diameter of the cylindrical portion of the third plate is large, the diameter of the friction disk disposed on the inner circumferential side of the cylindrical portion can be increased. Therefore, the torque capacity of the torque limiter can be increased.

(4) Preferably, the pressing member is a conical spring and is disposed inside the cylindrical portion of the third plate.

(5) Preferably, the first plate is fixed to the flywheel together with the fixing portion of the third plate.

(6) Preferably, the first plate and the second plate are not rotatable relative to each other.

(7) The vibration damping device with a torque limiter according to the present invention includes the torque limiter and the vibration damping unit. The damping unit is provided on the output side of the torque limiter and damps the transmitted rotational fluctuation.

(8) A power transmission device according to the present invention includes a flywheel and a torque limiter. The flywheel has an annular portion to which a plurality of positioning pins having a main body portion are fixed, and an accommodating portion formed on an inner peripheral side of the annular portion. The torque limiter has the above-described structure, and transmits torque from the flywheel to the output-side member.

Effects of the invention

In the present invention described above, in the torque limiter accommodated in the accommodating portion of the flywheel, interference between the torque limiter and a part of the flywheel can be suppressed when the torque limiter is assembled to the flywheel while securing the torque capacity of the torque limiter.

Drawings

Fig. 1 is a sectional view of a power transmission device according to an embodiment of the present invention.

Fig. 2 is a front view with the flywheel of fig. 1 removed.

Fig. 3 is a front view of the flywheel.

Fig. 4 is a diagram showing a positional relationship between the positioning pin and the positioning pin engaging hole.

Fig. 5 is a partially enlarged view of fig. 1.

Fig. 6 is a partially enlarged view of fig. 1.

Fig. 7 is a partial front view of the damping ring.

Detailed Description

[ integral Structure ]

Fig. 1 is a sectional view of a power transmission device 1 according to an embodiment of the present invention. The power transmission device 1 includes a flywheel 2 and a damper device 3 with a torque limiter. Fig. 2 is a front view of the power transmission device 1 with the flywheel 2 removed. In fig. 1, an engine is disposed on the left side of the power transmission device 1, and a drive unit including a motor, a transmission, and the like is disposed on the right side.

[ flywheel 2]

The flywheel 2 is fixed to an engine-side member, not shown. As shown in fig. 1 to 3, the flywheel 2 is a disk-shaped member, and includes an annular portion 4 and a housing portion 5. Note that fig. 3 is a front view of the flywheel 2.

The annular portion 4 is provided at the outermost periphery of the flywheel 2. As shown in fig. 2 and 3, a plurality of screw holes 4a are formed in the surface of the annular portion 4 on the drive unit side (right side in fig. 1), and a plurality of positioning pins 6 are fixed thereto. The plurality of screw holes 4a are arranged at predetermined intervals in the circumferential direction and have a predetermined depth. The positioning pins 6 are provided at predetermined intervals in the circumferential direction, and as shown in fig. 4, include a main body portion 6a and a tapered portion 6 b. The body portion 6a has a cylindrical shape and a height H (a length protruding from the surface of the annular portion 4 of the flywheel 2). The tapered portion 6b is formed to extend from the tip of the main body portion 6a so that the outer diameter gradually decreases.

The periphery of the screw hole 4a of the annular portion 4 serves as a bolt fastening portion 4b (an example of an attachment portion). The bolt fastening portion 4b has a protruding portion 4d that protrudes radially inward from the inner peripheral surface 4c of the annular portion 4. Therefore, the periphery of the screw hole 4a has a predetermined thickness, and the bolt fastening portion 4b has sufficient strength.

The annular portion 4 is formed with a plurality of recesses 4 e. The recess 4e is formed in a portion where the bolt fastening portion 4b is not formed so as to be recessed radially outward from the inner peripheral surface 4c of the annular portion 4.

The accommodating portion 5 is formed radially inside the annular portion 4. The receiving portion 5 has a predetermined depth from the mounting surface of the annular portion 4 toward the engine side. As shown in fig. 3, a plurality of holes 5a for fixing the flywheel 2 to an engine-side member are formed in the inner peripheral portion of the housing portion 5.

[ damping device with Torque limiter 3]

The damper device 3 with a torque limiter (hereinafter, also simply referred to as "damper device 3") is a device that is fixed to the annular portion 4 of the flywheel 2, and that limits torque transmitted between the engine and the drive unit and attenuates rotational fluctuation. The damper device 3 has a torque limiting unit 10 and a damper unit 20.

[ Torque limiting Unit 10]

The torque limiting unit 10 limits the torque transmitted between the flywheel 2 and the damping unit 20. As shown in fig. 5 and 6 in an enlarged manner, the torque limiting unit 10 includes a damper cover 11 (an example of a first plate), a pressure ring 12 (an example of a second plate), a friction disk 13, a conical spring 14 (an example of a pressing member), and a damper ring 15 (an example of a third plate).

The damper cap 11 is an annular plate having a friction portion 11a, a fixing portion 11b, and a plurality of engagement holes 11 c.

The friction portion 11a is formed on the inner peripheral portion of the damper cover 11, and the fixing portion 11b is formed on the outer peripheral portion of the friction portion 11 a. The fixing portion 11b is formed with a plurality of fixing holes 11d and a plurality of positioning pin holes 11e (see fig. 4). The damper cover 11 is fixed to the surface of the annular portion 4 of the flywheel 2 by fastening bolts that pass through the fixing holes 11d to the screw holes 4a of the flywheel 2. The positioning pin hole 11e is formed at a position corresponding to the positioning pin 6 of the flywheel 2.

A plurality of engaging holes 11c penetrate in the axial direction, formed between the friction portion 11a and the fixing portion 11b in the radial direction. The plurality of engagement holes 11c are arranged at predetermined intervals in the circumferential direction, and each hole 11c is formed to be long in the circumferential direction.

The pressure ring 12 is an annular plate and is disposed to face the friction portion 11a of the damper cover 11 at a predetermined interval in the axial direction. The pressure ring 12 has a plurality of claws 12 a.

The plurality of claws 12a are arranged at the outer circumferential end of the pressure ring 12 at equal angular intervals in the circumferential direction. The claws 12a extend from the outer peripheral end of the pressure ring 12 toward the axial damper cap 11 side and engage with engagement holes 11c of the damper cap 11. Therefore, the damper cap 11 and the pressure ring 12 cannot rotate relative to each other.

The friction disk 13 is disposed between the friction portion 11a of the damper cover 11 and the pressure ring 12. The friction disk 13 has a core plate 16 and a pair of friction members 17 fixed to both side surfaces of the core plate 16 by rivets. One friction member 17 abuts against the friction portion 11a of the damper cover 11, and the other friction member 17 abuts against the pressure ring 12.

The conical spring 14 is arranged between the pressure ring 12 and the damping ring 15. The conical spring 14 presses the friction disk 13 against the friction portion 11a of the damper cover 11 via the pressure ring 12.

The damping ring 15 is disposed closer to the engine side than the pressure ring 12, and the damping ring 15 supports the conical spring 14 together with the pressure ring 12, and the conical spring 14 is supported in a compressed state between the damping ring 15 and the pressure ring 12. As shown in fig. 5, the damper ring 15 includes a support portion 15a, a cylindrical portion 15b, and a fixing portion 15 c.

The support portion 15a is annular and is formed on the inner peripheral portion of the damper ring 15. The support portion 15a is axially opposed to the pressure ring 12, and the conical spring 14 is held between the support portion 15a and the pressure ring 12.

The cylindrical portion 15b is formed to extend from the outer periphery of the support portion 15a toward the axial damper cover 11 side. The cylindrical portion 15b is disposed so as to cover the outer peripheral surface of the friction disk 13 with a predetermined gap therebetween. As shown in fig. 7, the cylindrical portion 15b has a plurality of first openings 15d and a plurality of second openings 15 e. The first opening 15d and the second opening 15e are arranged at predetermined angular intervals in the circumferential direction.

As shown in fig. 3, the first opening 15d is formed at a position corresponding to the bolt fastening portion 4b of the flywheel 2. Here, as described above, the protruding portion 4d of the bolt fastening portion 4b is formed to protrude radially inward from the inner peripheral surface 4c of the annular portion 4 of the flywheel 2. The outer peripheral surface of the cylindrical portion 15b has a diameter larger than the minimum inner diameter of the protruding portion 4d of the bolt fastening portion 4b of the flywheel 2. Therefore, in order to avoid interference between the protruding portion 4d of the bolt fastening portion 4b and the cylindrical portion 15b, the first opening portion 15d is formed at a position corresponding to the protruding portion 4d of the bolt fastening portion 4b so as to avoid the protruding portion 4 d.

As described above, the plurality of second openings 15e are formed at predetermined angular intervals in the circumferential direction. The claws 12a of the pressure ring 12 pass through the second openings 15 e. Therefore, even if the claws 12a of the pressure ring 12 and the cylindrical portion 15b of the damper ring 15 are arranged at the same positions in the radial direction, mutual interference can be avoided.

The fixing portion 15c extends radially outward from the distal end of the cylindrical portion 15 b. As shown in fig. 7, a plurality of fixing holes 15f and a plurality of positioning pin holes 15g are formed in the fixing portion 15 c. The fixing hole 15f is formed on the outer peripheral side of the first opening 15d, and the damper ring 15 is fixed to the annular portion 4 of the flywheel 2 together with the damper cover 11 by a bolt inserted through the fixing hole 15 f. In more detail, the damper ring 15 is fitted to the annular portion 4 of the flywheel 2, and the damper cap 11 is fitted so as to sandwich the damper ring 15 between it and the flywheel 2. The positioning pin hole 15g is formed at a position corresponding to the positioning pin 6 of the flywheel 2.

[ damping unit 20]

As shown in fig. 1, the damper unit 20 includes clutch plates 21 and a retainer plate 22, a hub flange 23, a plurality of torsion springs 24, and a hysteresis generating mechanism 25.

A friction disk 13 constituting the torque limiter unit 10 is coupled to an outer peripheral portion of the clutch plate 21. The clutch plate 21 is formed in a disk shape and has a plurality of window portions 21 a. The holding plate 22 is disposed to face the clutch plate 21 with a space in the axial direction. The holding plate 22 is formed in a disk shape and has a plurality of window portions 22 a. The clutch plate 21 and the holding plate 22 are fixed to each other by a rivet (not shown) and are not movable relative to each other in the axial direction and the rotational direction.

The hub flange 23 includes a cylindrical hub 26 formed at a center portion thereof, and a flange 28 extending radially outward from an outer peripheral surface of the hub 26. A spline hole 26a is formed in the inner peripheral surface of the hub 26, and the input shaft of the drive unit can be spline-fitted into this spline hole 26 a. The flange 28 is formed in a disk shape and is disposed between the clutch plate 21 and the retaining plate 22 in the axial direction. The flange 28 has a plurality of receiving portions 28 a. The housing portions 28a are formed at positions corresponding to the window portions 21a of the clutch plate 21 and the window portions 22a of the holding plate 22.

The plurality of torsion springs 24 are accommodated in the accommodating portion 28a of the flange 28, and are held in the axial direction and the radial direction by the window portions 21a of the clutch plate 21 and the window portions 22a of the holding plate 22. Further, both circumferential end surfaces of the torsion spring 24 can be brought into contact with the circumferential end surfaces of the window portions 21a and 22a and the housing portion 28a, respectively.

As shown in fig. 1, the hysteresis generating mechanism 25 has a first bush 31, a second bush 32, a friction plate 33, and a conical spring 34.

The first bush 31 is formed annularly and is disposed between the inner peripheral portion of the clutch plate 21 and the inner peripheral portion of the flange 28 of the hub flange 23 in the axial direction. The first bush 31 has a plurality of engaging projections 31a projecting in the axial direction, and the engaging projections 31a are engaged with holes formed in the flange 28 with a predetermined gap therebetween. Therefore, the first bush 31 can rotate relative to the hub flange 23 only within a predetermined angular range.

The second bush 32 and the friction plate 33 are disposed between the retaining plate 22 and the flange 28 of the hub flange 23 in the axial direction. The second bush 32 is formed annularly and has a plurality of engaging projections 32a projecting in the axial direction. The engaging projection 32a engages with a hole formed on the holding plate 22, and therefore, the second bush 32 and the holding plate 22 cannot rotate relatively. The friction plate 33 is disposed between the flange 28 and the second bush 32 so as to be rotatable relative to the flange 28 and the second bush 32.

The conical spring 34 is disposed between the retainer plate 22 and the second bush 32 in the axial direction. The conical spring 34 presses the second bush 32 and the friction plate 33 against the first bush 31, and presses the first bush 31 against the clutch plate 21.

In the hysteresis generating mechanism 25, when the clutch plate 21 and the retainer plate 22 rotate relative to the hub flange 23, frictional resistance (hysteresis torque) is generated between the first bush 31 and the clutch plate 21 and between the second bush 32 and the friction plate 33.

[ relationship between torque limiting unit 10 and positioning pin 6 ]

The torque limiting unit 10 is disposed in the housing portion 5 of the flywheel 2, except for the fixing portions 11b and 15c of the damper cover 11 and the damper ring 15. In order to assemble the power transmission device 1, first, the torque limiting unit 10 and the damper unit 20 are assembled, and the damper device 3 is fixed to the flywheel 2. At this time, the positioning pins 6 of the flywheel 2 are fitted into the positioning pin holes 11e and 15g of the damper cover 11 and the damper ring 15, respectively, so that the flywheel 2 and the damper device 3 are positioned in the radial direction.

Here, the protruding portion 4d of the bolt fastening portion 4b of the flywheel 2 protrudes radially inward through the first opening portion 15d of the damper ring 15. Therefore, when the flywheel 2 and the damper device 3 are not positioned in the radial direction during assembly, the protruding portion 4d of the bolt fastening portion 4b protruding radially inward from the first opening portion 15d may interfere with the conical spring 14.

Therefore, as shown in fig. 4, a length H between the inner side (engine side surface) of the housing portion 5 of the conical spring 14 and the engine side surface of the damper ring 15 (i.e., the mounting surface of the torque limiting unit 10 to the flywheel 2) is set shorter than a main body length H of the positioning pin 6.

Therefore, when the damper device 3 including the torque limiter unit 10 and the damper unit 20 is accommodated in the accommodating portion 5 of the flywheel 2, first, the positioning pins 6 are fitted into the positioning pin holes 11e and 15g of the damper device 3. Thereby, the flywheel 2 and the damper device 3 are positioned in the radial direction, and thereafter, the conical spring 14 enters the housing 5. Therefore, the protruding portion 4d of the bolt fastening portion 4b of the flywheel 2 can be prevented from interfering with the conical spring 14.

[ actions ]

The power transmitted from the engine to the flywheel 2 is input to the damper unit 20 via the torque limiting unit 10. In the damper unit 20, power is input to the clutch plates 21 and the retaining plates 22 of the friction disk 13 to which the torque limiter unit 10 is fixed, and the power is transmitted to the hub flange 23 via the torsion spring 24. Then, power is transmitted from the hub flange 23 to the output-side motor, generator, transmission, and the like.

Further, for example, at the time of engine start, an excessive torque may be transmitted from the output side to the engine because the inertia amount on the output side is large. In this case, the torque transmitted to the engine side is limited to a prescribed value or less by the torque limiting unit 10.

In the damper unit 20, when power is transmitted from the clutch plate 21 and the holding plate 22 to the torsion spring 24, the torsion spring 24 is compressed. Further, the torsion spring 24 repeatedly expands and contracts due to the torque variation. When the torsion spring 24 expands and contracts, torsion occurs between the clutch plate 21 and the retaining plate 22, and the hub flange 23. The hysteresis generating mechanism 25 operates by this torsion, and generates a hysteresis torque. Thereby, the torque variation is attenuated.

[ characteristics ]

(1) In the flywheel 2, the bolt fastening portion 4b is ensured to have a sufficient wall thickness. Therefore, even if the damper device 3 is fixed to the flywheel 2 by bolts, the strength is not insufficient.

On the other hand, the cylindrical portion 15b of the damper ring 15, which is the outermost peripheral portion of the main body portion of the torque limiting unit 10, is provided with a first opening portion 15d to avoid interference of the damper ring 15 with the bolt fastening portion 4b (protruding portion 4d) of the flywheel 2. Therefore, the outer diameter of the cylindrical portion 15b of the damper ring 15 can be increased. Therefore, the friction disk 13 having a large outer diameter can be used, and the device can be downsized without impairing the torque capacity.

(2) In order to avoid interference between the damper ring 15 and the claws 12a of the pressure ring 12, the damper ring 15 is formed with second openings 15 e. Therefore, the claws 12a of the pressure ring 12 are exposed to the outside, and may interfere with the inner peripheral surface 4c of the annular portion 4 of the flywheel 2.

However, since the recessed portions 4e recessed toward the outer peripheral side are provided in the inner peripheral surface 4c of the annular portion 4 of the flywheel 2 at positions facing the second opening portions 15e, the claws 12a of the pressure ring 12 can be prevented from interfering with the annular portion 4 of the flywheel 2.

(3) By providing the first opening portion 15d in the damper ring 15, the projecting portion 4d of the bolt fastening portion 4b of the flywheel 2 projects radially inward through the first opening portion 15d of the damper ring 15. Therefore, when the damper device 3 is assembled to the housing portion 5 of the flywheel 2, the protrusion 4d protruding radially inward from the first opening 15d may interfere with the conical spring 14.

However, in assembly, before the conical spring 14 is accommodated in the accommodating portion 5 of the flywheel 2, the positioning pins 6 of the flywheel 2 are fitted into the positioning pin holes 11e and 15g of the damper device 3, and the flywheel 2 and the damper device 3 are positioned in the radial direction. Therefore, the protruding portion 4d of the flywheel 2 can be prevented from interfering with the conical spring 14.

[ other embodiments ]

The present invention is not limited to the above embodiments, and various changes or modifications may be made without departing from the scope of the present invention.

(a) In the above-described embodiment, the present invention is applied to the damper device 3 provided with the damper unit 20 in addition to the torque limiter unit 10, but the present invention can be similarly applied to a device not provided with the damper unit 20.

(b) In the above embodiment, the damper cover 11 and the damper ring 15 are fixed to the flywheel 2, but the damper cover 11 and the damper ring 15 may be fixed in advance, and either one of the damper cover 11 and the damper ring 15 may be fixed to the flywheel 2.

Description of the reference numerals

1a power transmission device; 2, a flywheel; 3 a damping device with a torque limiter; 4 an annular portion; 4b bolt fastening portions (mounting portions); 4c an inner peripheral surface of the annular portion; 4d a projection; 5 an accommodating part; 6, positioning pins; 6a main body part; 10 a torque limiting unit; 11a damper cover (first plate); 12 pressure ring (second plate); 13 a friction disk; 14 conical springs (pressing members); 15 damping ring (third plate); 15a support portion; 15b a cylindrical portion; 15c a fixing part; 15d a first opening portion; 15g positioning pin holes.