JP4316867B2 - Electromagnetic power transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic power transmission device that is disposed on a propeller shaft on a front wheel side or a rear wheel side that is separated when a two-wheel drive is performed in a four-wheel drive vehicle and is housed in a protective casing.
[0002]
[Prior art]
FIG. 4 shows a conventional driving force transmission device 501 (see Patent Document 1).
[0003]
The driving force transmission device 501 includes a rotating case 503, an inner shaft 505, a multi-plate main clutch 507, a ball cam 509, a pressure plate 511, a cam ring 513, a multi-plate pilot clutch 515, an armature 517, an electromagnet 519, and the like. Yes.
[0004]
In a four-wheel drive vehicle, the driving force transmission device 501 is disposed in a rear wheel side drive system that connects a rear wheel that is cut off during two-wheel drive traveling and a transfer, and a rotating case 503 is connected to a propeller shaft. 505 is connected to a drive pinion shaft of the rear differential.
[0005]
When the electromagnet 519 is excited, a magnetic flux loop is formed, the armature 517 is attracted, and the pilot clutch 515 is pressed and fastened. When the pilot clutch 515 is engaged, pilot torque is generated, and the driving force of the engine is applied to the ball cam 509. The main clutch 507 is pressed by the generated cam thrust force, and the driving force transmission device 501 (main clutch 507) is connected. Driving force is transmitted to the rear wheel side, and the vehicle enters a four-wheel drive state.
[0006]
Further, when the excitation current of the electromagnet 519 is controlled, the slip rate of the pilot clutch 515 is changed, the cam thrust force of the ball cam 509 is changed, and the pressing force of the main clutch 507 is changed so that the driving force sent to the rear wheels is large. Changes, the driving force distribution ratio between the front and rear wheels can be controlled.
[0007]
When the excitation of the electromagnet 519 is stopped, the pilot clutch 515 is released, the cam thrust force of the ball cam 509 disappears, the main clutch 507 is released, the connection of the driving force transmission device 501 is released, and the rear wheel side is disconnected. The vehicle is in a two-wheel drive state.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-153157 (page 9, FIG. 1)
[0009]
[Problems to be solved by the invention]
By the way, like the driving force transmission device 501, the power transmission device arranged on the back surface of the chassis together with the propeller shaft is to protect against flying objects such as flying stones and stepped portions that may collide during traveling. The outer casing (rotating case 503) of the power transmission device is supported on the protective casing 521 by a bearing 523.
[0010]
In addition, an opening 525 for connecting the power transmission device and the propeller shaft is provided in the axial direction of the protective casing 521. Usually, the opening 525 is provided between the protective casing and the rotating case 503. In addition, a seal (dust seal) for preventing entry of foreign matter or dust is disposed. This dust seal is fixed to the protective casing 521 side and arranged to slide with the rotating case 503.
[0011]
On the other hand, in the electromagnetic power transmission device, the outer casing (rotating case 503) is made of a non-magnetic material in order to prevent leakage of the magnetic flux of the electromagnet, and to reduce the weight and reduce the moment of inertia and improve the fuel efficiency of the engine. Made of lightweight aluminum alloy.
[0012]
However, since aluminum alloy is relatively soft, it is difficult to avoid wear due to sliding with the seal.
[0013]
When the rotating case 503 is worn, the generated wear powder may invade the bearings 523 arranged close to each other and wear the bearings 523. When the bearings 523 are worn, the centering function is lowered and the power is reduced. Since vibration is generated in the transmission device, propeller shaft, etc., the torque transmission function becomes unstable, and the maneuverability and stability of the vehicle deteriorates. In addition, it is impossible for the power transmission device, the propeller shaft, and the joints around them. May cause a decrease in durability.
[0014]
However, even if the bearing 523 is arranged away from the dust seal in order to reduce the invasion of wear powder, the fine wear powder diffuses over a wide range due to vibration and the like, so that the wear powder cannot be prevented from entering.
[0015]
Further, if the bearing 523 is disposed away from the opening 525, the support function and the centering function of the power transmission device may be reduced accordingly, and vibration may occur in the power transmission device.
[0016]
Further, in the power transmission device, the electromagnet may be supported by a protective casing or the like depending on the layout. In this case, when vibration occurs in the power transmission device, the driving force transmission device 501 and the counterpart member 527 of the magnetic path The gap of the air gap 529 provided between the electromagnet 519 cannot be maintained at a predetermined value.
[0017]
When the air gap 529 fluctuates, the magnetic flux loop (magnetic force) also fluctuates, the pilot torque of the pilot clutch 515 and the transmission torque of the main clutch 507 become unstable, and the controllability and stability of the vehicle are reduced as described above. Furthermore, when the mating member 527 and the electromagnet 519 come into contact with each other in the air gap 529, both may be worn out and the durability may be reduced.
[0018]
However, if the rotating case 503 is made of austenitic stainless steel, which is a nonmagnetic material, in order to prevent leakage and wear of magnetic flux, the cost is greatly increased due to the difficulty in processing and the expensive material. .
[0019]
Therefore, the present invention is housed in a casing, and while maintaining high sealing performance of the seal and supportability of the bearing with respect to the rotating case, the rotating case can be made of a light non-magnetic material and is configured at low cost. An object of the present invention is to provide an electromagnetic power transmission device that stabilizes the torque transmission function and the maneuverability and running performance of the vehicle.
[0020]
[Means for Solving the Problems]
  The electromagnetic power transmission device according to claim 1 has a rotating case, is housed in a casing having an opening at least on one side in the axial direction, and the rotating case is exposed to the outside through the opening. Type power transmission device,The rotating case is formed of a non-magnetic aluminum alloy, and has an opening for fixing a rotor through which a stud bolt having a bottom in the axial direction is implanted and fixed and a magnetic flux of an electromagnet is transmitted through the other side in the axial direction. Of the casing,On the opening side, a bearing for supporting a first outer peripheral surface formed on the rotating case on a first inner peripheral surface formed on the casing, and a second inner peripheral surface formed on the casing And a seal having a seal portion that slides and seals against a second outer peripheral surface side formed on the rotating case, and the second inner peripheral surface is the first inner peripheral surface The axial position is located closer to the end of the opening, and the first outer peripheral surface is formed to have a smaller diameter. The second outer peripheral surface is positioned closer to the opening than the first outer peripheral surface. Is located on the end side of the portion and is formed with a smaller diameter than the first outer peripheral surface,
  The second outer peripheral surface side that is sealed by the seal portion of the seal on the outer diameter side of the stud bolt comprises a hardened surface portion or ring that is harder than the rotating case.Wear reduction means for reducing wear due to sliding with the seal portion is provided.
[0021]
As described above, in the electromagnetic power transmission device according to the first aspect, the wear reduction means is provided in the sliding portion of the rotating case that comes into contact with the seal portion of the seal, thereby reducing wear and greatly increasing the amount of wear powder. It is reduced.
[0022]
Therefore, even if the seal and the bearing are arranged close to each other, the wear powder is substantially prevented from entering the bearing. This prevents the support function and the centering function from being deteriorated due to wear, vibrations of the electromagnetic power transmission device and the propeller shafts and joints connected to the electromagnetic power transmission device, and the deterioration of durability caused by excessive force applied to them.
[0023]
In addition, since it is no longer necessary to place the bearing away from the seal to reduce the invasion of wear powder, the support function and centering function of the electromagnetic power transmission device are reduced, and the occurrence of vibrations is also prevented. Is done.
[0024]
Further, when the vibration of the electromagnetic power transmission device is prevented, the air gap between the electromagnet supported by the casing and the counterpart member of the magnetic path is maintained at a predetermined value. The deterioration of the performance of the electromagnetic power transmission device due to the fluctuation and the fluctuation of the magnetic force is prevented, and further, the contact between the electromagnet and the counterpart member in the air gap, the wear of both, and the deterioration of the durability are also prevented.
[0025]
For these reasons, the torque transmission function of the electromagnetic power transmission device is stabilized, and the maneuverability and stability of the vehicle are kept high.
[0026]
In addition, since wear due to sliding with the seal does not occur, it is possible to make a rotating case with a light non-magnetic material such as aluminum alloy, for example. The performance of the device is improved and stabilized, and the electromagnetic power transmission device is reduced in weight, the moment of inertia is reduced, and the fuel consumption of the engine (prime mover) is improved.
[0027]
Also, since aluminum alloy prevents wear, it is not necessary to make the rotating case from expensive and difficult-to-process materials such as austenitic stainless steel to prevent wear, avoiding an increase in material costs and processing costs. It is done.
[0029]
Moreover, if this surface hardening part is given only to the sliding part of a rotation case, this invention can be implemented at a very low cost.
[0030]
  Claim2The invention of claim1The electromagnetic power transmission device described in,in frontThe surface hardened portion is an alumite film that is applied to the rotating case and has high wear resistance with respect to the seal portion of the seal,1The same operation and effect as the configuration of can be obtained.
[0031]
Further, as described in claim 1, since the rotating case is made of an aluminum alloy, the magnetic force loss of the electromagnet is prevented, the performance of the electromagnetic power transmission device is improved and stabilized, and the electromagnetic power transmission device. The weight is reduced and the moment of inertia is reduced, improving the fuel efficiency of the engine.
[0032]
Further, since the alumite treatment can be performed only on the sliding portion of the rotating case, this configuration can be implemented at an extremely low cost.
[0033]
  Claim3The invention of claim1The electromagnetic power transmission device according to claim 1, wherein the hardened surface portion is a plated layer that is applied to the rotating case and has high wear resistance with respect to a seal portion of the seal. Term1The same operation and effect as the configuration of can be obtained.
[0034]
In addition, for example, a plating layer such as chromium (Cr) or nickel (Ni) has a low surface treatment cost and extremely high wear resistance.
[0037]
  Claim4The invention of claim 1 to claim 1Any one of 3The electromagnetic power transmission device according to claim 1, wherein the electromagnetic power transmission device is attached to one of the casing and the rotating case so as to cover the opening, and over the air gap between the casing and the other rotating case. A cover that forms a wrap portion is disposed, and the seal is provided with a seal portion that comes into contact with the cover. The seal portion receives air pressure from an air gap of the overlap portion and receives the air pressure from the cover. Claims 1 to claim characterized in that an inclination in the direction of pressing is given.3The same operation and effect as the configuration of can be obtained.
[0038]
In addition, in this configuration, the cover function of the cover disposed between the casing and the rotating case protects the seal from obstacles such as pebbles that fly during traveling and enter from the opening of the casing, and the seal function is maintained. The
[0041]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
The electromagnetic coupling 1 (electromagnetic power transmission device) of the first embodiment will be described with reference to FIG.
[0042]
The electromagnetic coupling 1 is disposed in a power transmission system on the rear wheel side that is disconnected when driving a two-wheel vehicle in a four-wheel drive vehicle, and the left side in FIG. 1 corresponds to the front side (engine side) of the vehicle.
[0043]
The electromagnetic coupling 1 includes a rotating case 3 (one side torque transmission member), an inner shaft 5 (other side torque transmission member), a multi-plate main clutch 7, a ball cam 9 (cam mechanism), and a multi-plate pilot clutch. 11, an electromagnet 13, a protective casing (casing) 15, a double-side sealed ball bearing 17 (bearing), a dust seal (seal) 19, a dust cover (cover) 21, a controller, and the like.
[0044]
The electromagnetic coupling 1 is disposed between the transfer side propeller shaft and the rear differential side drive pinion shaft.
[0045]
The protective casing 15 is bolted to an opening provided on the front side of the rear differential carrier and is supported on the vehicle body side.
[0046]
Each of the protective casing 15 and the differential carrier is made of an iron-based alloy, and after being aligned by a stud pin, is connected to each other with a bolt as described above.
[0047]
The electromagnetic coupling 1 is housed in a protective casing 15 and is protected from collisions with foreign objects such as stones flying during traveling, and stepped portions and convex portions encountered during traveling.
[0048]
The rotating case 3 includes a bottomed cylindrical member 25 made of an aluminum alloy (nonmagnetic material), a rotor 27 made of an iron-based alloy (magnetic material), and the like.
[0049]
The rotor 27 is screwed into the rear side opening of the cylindrical member 25 and is fixed by the double nut function of the nut 28.
[0050]
The front end of the cylindrical member 25 is supported on the protective casing 15 via a ball bearing 17, and the rotor 27 is supported on a differential carrier via a both-side sealed ball bearing 29 and a core 31 of the electromagnet 13. .
[0051]
A companion flange is fixed to the front end of the cylindrical member 25 by a stud bolt 33, and a joint fork of a joint is integrally formed on the companion flange.
[0052]
The cylindrical member 25 is connected to the transfer-side propeller shaft through this joint, and the driving force of the engine is transmitted to the cylindrical member 25 (the rotating case 3) through these power transmission members.
[0053]
The inner shaft 5 penetrates the rotary case 3 from the rear, and a front end portion is supported on the cylindrical member 25 by a ball bearing 35 and a rear portion side is supported on the rotor 27 by a needle bearing 37. The inner shaft 5 is positioned in the axial direction with respect to the rotating case 3 by the snap rings 39 and 41 and the ball bearing 35.
[0054]
A drive pinion shaft is splined to the inner shaft 5, and the rotation of the inner shaft 5 is transmitted to the rear differential.
[0055]
An O-ring 43 is disposed between the cylindrical member 25 of the rotating case 3 and the rotor 27. Further, an X ring 45, which is a seal having an X-shaped cross section, is disposed behind the needle bearing 37 between the rotor 27 and the inner shaft 5. The electromagnetic coupling 1 (rotating case 3) is sealed by the O-ring 43 and the X-ring 45.
[0056]
Oil is injected into the sealed rotating case 3 from an oil hole 47 provided in the cylindrical member 25. After the oil is injected, the oil hole 47 is sealed by press-fitting a check ball 49. The cylindrical member 25 is provided with a space 51 serving as an oil passage at a position corresponding to the oil hole 47.
[0057]
The main clutch 7 is disposed between the rotating case 3 and the inner shaft 5, and the outer plate 53 is connected to a spline portion 55 formed on the inner periphery of the rotating case 3 (cylindrical member 25). 57 is connected to a spline portion 59 formed on the outer periphery of the inner shaft 5.
[0058]
The ball cam 9 is disposed between the pressure plate 61 and the cam ring 63 (intermediate member).
[0059]
The pressure plate 61 has an inner periphery coupled to the spline portion 59 of the inner shaft 5 and presses the main clutch 7 against the rotating case 3 by the cam thrust force of the ball cam 9 as described below to fasten it.
[0060]
The cam ring 63 is disposed on the outer periphery of the inner shaft 5 so as to be relatively rotatable. A thrust bearing 65 and a washer 67 for receiving the cam reaction force of the ball cam 9 are disposed between the cam ring 63 and the rotor 27.
[0061]
The pilot clutch 11 is disposed between the rotating case 3 and the cam ring 63, and the outer plate 69 is connected to the spline portion 55 of the rotating case 3, and the inner plate 71 is a spline portion formed on the outer periphery of the cam ring 63. 73.
[0062]
An armature 75 is disposed between the pilot clutch 11 and the pressure plate 61, and the outer periphery is coupled to the spline portion 55 of the rotating case 3 so as to be axially movable.
[0063]
The core 31 of the electromagnet 13 is supported by a cylindrical hole formed in the differential carrier, and supports the rotor 27 via the ball bearing 29 as described above. The core 31 penetrates into a recess 77 formed in the rotor 27 via an air gap with a predetermined interval, and is positioned in the axial direction between the rotor 27 via the snap rings 79 and 81 and the ball bearing 29. Yes.
[0064]
Further, the core 31 is prevented from rotating around the protective casing 15 via a connecting member.
[0065]
The lead wire of the electromagnet 13 is clipped to the connecting member, drawn out to the outside of the protective casing 15 through the grommet, and connected to the vehicle battery via the controller.
[0066]
The core 31, the rotor 27, the pilot clutch 11, and the armature 75 constitute a magnetic path of the electromagnet 13.
[0067]
The rotor 27 is divided into a radially outer side and an inner side by a ring 83 of austenitic stainless steel which is a nonmagnetic material. Further, each plate 69, 71 of the pilot clutch 11 is provided with a notch 85 provided at equal intervals in the circumferential direction at a radial position corresponding to the ring 83, and a bridge portion for connecting these notches 85. ing. These rings 83 and notches 85 prevent magnetic flux from being short-circuited on the magnetic path.
[0068]
The controller performs excitation of the electromagnet 13, control of excitation current, excitation stop, and the like.
[0069]
When the electromagnet 13 is excited, a magnetic flux loop 87 is generated in the magnetic path and the armature 75 is attracted, and the pilot clutch 11 is pressed and fastened to generate a pilot torque.
[0070]
When the pilot torque is generated, the driving force of the engine is applied from the rotating case 3 to the ball cam 9 via the pilot clutch 11 and the cam ring 63 according to the magnitude of the pilot torque, and the generated cam thrust force is applied to the ball cam 9 via the pressure plate 61. The main clutch 7 is pressed and fastened, and the electromagnetic coupling 1 is connected.
[0071]
Further, as described above, the cylindrical member 25 of the rotating case 3 is made of a non-magnetic aluminum alloy, so that the magnetic flux is prevented from leaking from the magnetic flux loop 87 to the cylindrical member 25, and the magnetic flux is applied to the armature 75. Since the pilot clutch 11 is guided efficiently, a predetermined pilot torque can be obtained, and the electromagnetic coupling 1 can obtain a predetermined coupling torque (transmission torque).
[0072]
When the electromagnetic coupling 1 is connected, the driving force of the engine is transmitted from the inner shaft 5 to the rear differential via the drive pinion shaft, and is distributed from the rear differential to the left and right rear wheels so that the vehicle is in a four-wheel drive state. It improves driving performance on rough roads and the stability of the vehicle body.
[0073]
At this time, if the controller adjusts the exciting current of the electromagnet 13 to control the magnetic force, the slip ratio of the pilot clutch 11 changes, the pilot torque changes, the cam thrust force of the ball cam 9 changes, and the coupling force (electromagnetic force) of the main clutch 7 changes. The magnitude of the transmission torque sent to the rear wheel side via the type coupling 1) can be adjusted.
[0074]
By adjusting the coupling force, the driving force distribution ratio between the front and rear wheels can be arbitrarily controlled. For example, when such control is performed during turning, the controllability and stability of the vehicle are improved. .
[0075]
When the excitation of the electromagnet 13 is stopped, the pilot clutch 11 is released and the cam thrust force of the ball cam 9 disappears, the main clutch 7 is released, and the connection of the electromagnetic coupling 1 is released.
[0076]
When the coupling of the electromagnetic coupling 1 is released, the inner shaft 5 and the rear wheels are disconnected, and the vehicle enters the two-wheel drive state of front wheel drive, and the fuel efficiency of the engine is improved.
[0077]
The hollow inner shaft 5 is partitioned forward and backward by a wall portion 89 to form a capacity increasing space portion 91 that increases the amount of oil enclosed. In the capacity increasing space portion 91, the injected oil and air are accommodated in the same manner as other portions inside the rotary case 3.
[0078]
When the electromagnetic coupling 1 (inner shaft 5) rotates, the oil in the capacity increasing space portion 91 passes through the ball bearing 35 and radial flow paths provided in a plurality of locations of the inner shaft 5 by centrifugal force, and the bearing 35, The main clutch 7, the ball cam 9, the pilot clutch 11, the thrust bearing 65, the washer 67, and the like are lubricated and cooled.
[0079]
Each inner plate 57 of the main clutch 7 is provided with an oil hole 93 to promote the movement of oil toward the ball cam 9, the pilot clutch 11 and the bearing 65, thereby improving the lubrication / cooling effect. Yes.
[0080]
A through hole 95 is formed in the pressure plate 61. The through hole 95 reduces the resistance of the pressure plate 61 to be moved by oil to improve the operation response of the main clutch 7 and also serves as an oil flow path, facilitating the movement of oil toward the ball cam 9 and pilot clutch 11 side. In addition, these lubricating and cooling effects are improved.
[0081]
As shown in FIG. 2 in an enlarged manner, the dust seal 19 is composed of a seal portion 97, an outer peripheral portion 99 integral with the seal portion 97, and a holding member 101 having a cross-sectional shape. Are provided with inner lips 103 and 105 and a front lip 107.
[0082]
  The dust seal 19As shown in FIG.Inner circumference of the opening 109 provided at the front end of the protective casing 15(Second inner peripheral surface)Further, the outer peripheral portion 99 is brought into contact with the holding member 101, and the inner peripheral lips 103 and 105 are attached to the outer peripheral sliding portion of the rotating case 3.(Second outer peripheral surface)111 is contacted to form a seal portion. This sliding part(Second outer peripheral surface)111 is formed smaller in diameter than the inner diameter (bearing inner diameter) of the inner race 113 (inner ring) of the ball bearing 17.As is apparent from FIG. 2, the diameter is smaller than the support surface (first outer peripheral surface) of the rotating case 3 that supports the inner race 113. The second inner peripheral surface is formed with a smaller diameter than the support surface (first inner peripheral surface) that supports the outer race of the ball bearing 17.
[0083]
The dust cover 21 is made of an iron-based alloy, and includes a radial portion 115 and axial portions 117 and 119 provided on the outer peripheral side and the inner peripheral side, respectively. 3 is press-fitted into the outer periphery of the small-diameter portion 121 provided at the front end. The small diameter portion 121 is formed to have a smaller diameter than the sliding portion 111.
[0084]
In addition, the axial direction portion 117 on the outer peripheral side and the front end portion of the protective casing 15 form an overlap portion 123 where the projections in the radial direction overlap each other. In this overlap portion 123, the axial direction portion 117 and the protection portion 15 are protected. An air gap 125 is formed between the casing 15 and the casing 15.
[0085]
When the dust cover 21 is attached to the rotating case 3, the lip 107 in front of the dust seal 19 comes into contact with the radial portion 115 of the dust cover 21 to form a seal portion.
[0086]
The lip 107 and the lips 103 and 105 of the dust seal 19 are in contact with the radial portion 115 of the dust cover 21 when an intrusion such as dust entering from the air gap 125 contacts the lip 107 (each arrow in FIG. 2). The pressing force of the contact portion with the lip 107 is increased and the sealing function is improved.
[0087]
Also, an alumite film 127 (surface hardened portion: wear reducing means) having a hardness higher than that of the lips 103 and 105 of the dust seal 19 is formed on the sliding portion 111 of the rotating case 3 that slides with the lips 103 and 105 of the dust seal 19. As the electromagnetic coupling 1 (rotating case 3) rotates, wear due to sliding between the sliding portion 111 and the stationary lip 103, 105 is reduced, and the generation of wear powder is greatly reduced. Has been reduced.
[0088]
Since the sliding portion 111 of the rotating case 3 is smaller in diameter than the inner diameter of the ball bearing 17 (inner race 113) and the small diameter portion 121 of the rotating case 3 is smaller in diameter than the sliding portion 111 as described above, the ball bearing After the rotating case 3 is assembled to the protective casing 15 via 17, the dust seal 19 is attached to the protective casing 15, the lips 103, 105 are brought into contact with the anodized film 127, and the dust cover 21 is attached to the small diameter portion 121 of the rotating case 3. To make contact with the lip 107.
[0089]
The air gap 125 has a sealing function, and the air gap 125, the dust cover 21, and the dust seal 19 prevent foreign matters such as dust and moisture from entering through the opening 109 of the protective casing 15. .
[0090]
As described above, since generation of wear powder and entry of water, dust, and the like are prevented, the ball bearing 17 prevents dust biting, wear, moisture freezing, generation of rust, rotation lock, and the like.
[0091]
For the same reason, water and dust are prevented from entering the air gap between the core 31 of the electromagnet 13 and the rotor 27, and the rotor 27 (rotating case) due to dust biting, moisture freezing, rusting, etc. 3) Locking is prevented.
[0092]
A large number of cooling fins 129 are provided on the outer periphery of the protective casing 15 to enhance the cooling effect of the space inside the protective casing 15 and the electromagnetic coupling 1 arranged in this space.
[0093]
Thus, the electromagnetic coupling 1 is configured.
[0094]
In the electromagnetic coupling 1, as described above, the alumite film 127 having higher hardness than the lips 103 and 105 is provided on the sliding portion 111 of the rotating case 3 that slides with the lips 103 and 105 of the dust seal 19. And the amount of wear powder is greatly reduced.
[0095]
Therefore, even if the ball bearing 17 is disposed close to the dust seal 19, the wear powder is substantially prevented from entering the ball bearing 17, and wear and rotation lock of the ball bearing 17 due to the biting of the wear powder can be avoided. From the above, the support function and centering function of the electromagnetic coupling 1 (rotating case 3) are deteriorated due to wear of the ball bearing 17, the vibration generated in the electromagnetic coupling 1, the propeller shaft, the joint, etc. It is possible to prevent a decrease in durability caused by hanging.
[0096]
Further, it is not necessary to dispose the ball bearing 17 away from the dust seal 19 in order to reduce the intrusion of wear powder, and accordingly, the support function and the centering function of the electromagnetic coupling 1 by the ball bearing 17 are lowered. Generation of vibration is also prevented.
[0097]
Further, when the vibration of the electromagnetic coupling 1 is prevented, the air gap between the electromagnet 13 supported by the differential carrier and the rotor 27 is maintained at a predetermined value, so that the magnetic force fluctuation due to the air gap fluctuation, The performance of the electromagnetic coupling 1 is prevented from being deteriorated due to the fluctuation of the magnetic force, and further, both wear due to the contact between the rotor 27 and the electromagnet 13 in the air gap, and the deterioration of durability are also prevented.
[0098]
For these reasons, the torque transmission function of the electromagnetic coupling 1 is stabilized, and the maneuverability and stability of the vehicle are kept high.
[0099]
Further, since the rotating case 3 can be made of a lightweight and non-magnetic aluminum alloy as described above by being freed from wear due to sliding with the dust seal 19 (lip 103, 105), the electromagnetic coupling 1 The magnetic force loss of the electromagnet 13 is prevented and the performance is improved and stabilized, and the weight is reduced and the moment of inertia is reduced, so that the fuel efficiency of the engine is improved.
[0100]
Further, since the wear is prevented even with the aluminum alloy in this way, it is not necessary to make the rotating case 3 with an expensive and difficult-to-work material such as austenitic stainless steel in order to prevent the wear. And an increase in processing costs can be avoided.
[0101]
Further, since the alumite film 127 can be applied only to the sliding portion 111 which is a narrow required range of the rotating case 3, the necessary surface treatment cost can be suppressed extremely inexpensively.
[0102]
Further, the cover function of the dust cover 21 disposed in the opening 109 of the protective casing 15 protects the dust seal 19 from obstacles such as pebbles flying during traveling, and the sealing function is maintained.
[0103]
Further, when the lip 107 that contacts the dust cover 21 is provided in the dust seal 19 and receives air pressure from an air gap 125 formed between the lip 107 and the rotary case 3, the lip 107 is pressed by the dust cover 19 and has a sealing property. Since the lip 107 blocks dust and the like that has entered with the outside air, the burden on the inner lips 103 and 105 is greatly reduced, and durability is improved.
[0104]
In addition, as in the invention of claim 4, even if the sliding portion 111 of the rotating case 3 is provided with a plating layer (surface hardened portion: wear reducing means) such as chromium (Cr) or nickel (Ni), for example. Good.
[0105]
These plated layers have a low surface treatment cost and an extremely high wear resistance.
[0106]
Further, since generation of wear powder and entry of water, dust, and the like are prevented, it is possible to use a non-seal type bearing instead of the double-side seal type ball bearing 17, thereby reducing the cost accordingly. .
[0107]
[Second Embodiment]
An electromagnetic coupling 201 (electromagnetic power transmission device) according to the second embodiment of the present invention will be described with reference to FIG.
[0108]
The electromagnetic coupling 201 is used in place of the electromagnetic coupling 1 in the four-wheel drive vehicle using the electromagnetic coupling 1 of the first embodiment. Further, the left side of FIG. 3 corresponds to the front side (engine side) of the vehicle, and members without reference numerals are not shown.
[0109]
Hereinafter, the difference will be described while giving the same reference numerals to members having the same functions as those of the electromagnetic coupling 1.
[0110]
In the electromagnetic coupling 201, a small-diameter portion 203 is provided on the outer periphery of the rotating case 3 facing the lips 103 and 105 of the dust seal 19, and the small-diameter portion 203 is harder than the lips 103 and 105 of the dust seal 19. A high carbon steel ring 205 (wear reduction means) is press-fitted and positioned in the axial direction at the step 207.
[0111]
The arrangement of the ring 205 reduces wear caused by sliding of the lip 103, 105 on the stationary side and the rotating case 3 side with the rotation of the electromagnetic coupling 201 (the rotating case 3). The occurrence is greatly reduced.
[0112]
  Further, the small diameter portion of the rotating case 3(Second outer peripheral surface)Reference numeral 203 denotes a diameter smaller than the inner diameter of the ball bearing 17 (inner race 113), and the smaller diameter portion 121 is smaller in diameter than the smaller diameter portion 203.
  As is apparent from FIG. 3 with reference to FIG. 2, the outer peripheral surface of the ring 205 that slides with the lips 103 and 105 on the stationary side is the support surface (first outer peripheral surface of the rotating case 3 that supports the inner race 113. ) Smaller diameter.
[0113]
Accordingly, after the ring 205 is pressed against the small diameter portion 203 of the rotating case 3, the rotating case 3 is assembled to the protective casing 15 via the ball bearing 17, the dust seal 19 is attached to the protective casing 15, and the lips 103 and 105 are attached to the ring 205. Further, the dust cover 21 is pressed into the small diameter portion 121 of the rotating case 3 and brought into contact with the lip 107.
[0114]
Thus, the electromagnetic coupling 201 is configured.
[0115]
In the electromagnetic coupling 201, as described above, the ring 205 having higher hardness than the lips 103, 105 is disposed on the rotating case 3 that slides with the lips 103, 105 of the dust seal 19, thereby reducing wear and reducing wear powder. The amount of is greatly reduced.
[0116]
Therefore, the electromagnetic coupling 201 can obtain the same effects as the electromagnetic coupling 1 except that the wear reducing means is an alumite film 127 or a plated layer.
[0117]
Further, since the rotating case 3 and the ring 205 (wear reduction means) are separated, the material of the ring 205 can be freely selected and high wear resistance can be obtained. Even if it is relatively expensive, since the amount used is small, it does not give a large burden to the cost.
[0118]
The electromagnetic power transmission device of the present invention can also be used for a differential limiting mechanism if it is disposed between the differential rotating members of the differential device.
[0119]
【The invention's effect】
In the electromagnetic power transmission device according to the first aspect, the wear reduction means is provided on the rotating case side that slides with the seal portion of the seal to reduce the wear, and the amount of wear powder is greatly reduced.
[0120]
Therefore, even if the seal and the bearing are arranged close to each other, the wear and rotation of the bearing due to the intrusion and biting of wear powder, the bearing support function and the centering function are deteriorated, the electromagnetic power transmission device and the connected propeller shaft It is possible to prevent a decrease in durability caused by excessive vibrations and vibrations.
[0121]
Further, it is not necessary to dispose the bearing away from the seal, and accordingly, the support function and the centering function of the electromagnetic power transmission device are reduced, and the occurrence of vibration is prevented.
[0122]
In addition, the vibration of the electromagnetic power transmission device is prevented, and the air gap between the electromagnet on the casing side and the counterpart member of the magnetic path is maintained at a predetermined value. The performance degradation of the power transmission device is prevented, and further, the contact between the electromagnet and the counterpart member in the air gap, the wear of both, and the degradation of durability are also prevented.
[0123]
For these reasons, the torque transmission function of the electromagnetic power transmission device is stabilized, and the maneuverability and stability of the vehicle are kept high.
[0124]
In addition, since wear due to sliding with the seal does not occur, it is possible to make a rotating case with a lightweight non-magnetic material such as aluminum alloy, which prevents the magnetic force loss of the electromagnet and reduces the electromagnetic power transmission device. The performance is improved and stabilized, and the electromagnetic power transmission device is reduced in weight to reduce the moment of inertia, thereby improving the fuel efficiency of the engine.
[0125]
In addition, since the wear is prevented even with the aluminum alloy, it is not necessary to make the rotating case with austenitic stainless steel in order to prevent the wear, and the accompanying increase in material cost and processing cost can be avoided.
[0127]
Further, if the surface hardened portion is provided only on the sliding portion of the rotating case, the present invention can be implemented at a very low cost.
[0128]
  Claim2The electromagnetic power transmission device of claim1An effect equivalent to that of the configuration can be obtained.
[0129]
Further, the alumite treatment can be performed only on the sliding portion of the rotating case, and can be carried out at an extremely low cost.
[0130]
  Claim3The electromagnetic power transmission device of claim1An effect equivalent to that of the configuration can be obtained.
[0131]
In addition, a plating layer such as chromium (Cr) or nickel (Ni) has a low surface treatment cost and an extremely high wear resistance.
[0133]
In addition, since the rotating case and the wear reducing means (ring) are separated, the ring can be freely selected and high wear resistance can be obtained. For example, this ring is relatively expensive. However, since the amount used is small, it does not give a large burden to the cost.
[0134]
  Claim4The electromagnetic power transmission apparatus of claim 1 to claim 1.3An effect equivalent to that of the configuration can be obtained.
[0135]
In addition, the cover disposed at the opening of the casing protects the seal from obstacles such as pebbles flying during traveling, and the sealing function is maintained.
[0136]
Also, when receiving air pressure from the air gap formed between the cover and the rotating case, the seal part is pressed against the cover and the sealing performance is strengthened. The burden is greatly reduced and durability is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing a main part of the first embodiment.
FIG. 3 is a cross-sectional view of a second embodiment.
FIG. 4 is a cross-sectional view of a conventional example.
[Explanation of symbols]
1 Electromagnetic coupling (electromagnetic power transmission device)
3 Rotating case (torque transmission member on one side)
5 Inner shaft (torque transmission member on the other side)
7 Main clutch
9 Ball cam (cam mechanism)
11 Pilot clutch
13 Electromagnet
15 Protective casing (casing)
17 Both sides sealed ball bearing (bearing)
19 Dust seal (seal)
21 Dust cover (cover)
61 Pressure plate
63 Cam ring (intermediate member)
103,105 Lip (seal part of dust seal 19)
107 Lip (seal part of dust seal 19 in contact with dust cover 21)
109 Opening of protective casing 15
111 Sliding part of rotating case 3
123 Overlap part
125 air gap
127 Anodized coating (surface hardened part: means for reducing wear)
201 Electromagnetic coupling (electromagnetic power transmission device)
205 ring (wear reduction means)

Claims (4)

An electromagnetic power transmission device having a rotating case and housed in a casing provided with an opening at least on one side in the axial direction, wherein the rotating case is exposed to the outside from the opening,
The rotating case is formed of a non-magnetic aluminum alloy, and has an opening for fixing a rotor through which a stud bolt having a bottom in the axial direction is implanted and fixed, and a magnetic flux of an electromagnet is transmitted through the other side in the axial direction. Formed into a cylindrical shape,
On the opening side of the casing, a bearing that supports a first outer peripheral surface formed in the rotating case on a first inner peripheral surface formed in the casing;
A seal having a seal portion that is supported by a second inner peripheral surface formed in the casing and that slides and seals against the second outer peripheral surface formed in the rotating case;
The second inner peripheral surface is formed such that the axial position of the second inner peripheral surface is closer to the end of the opening than the first inner peripheral surface, and is smaller in diameter than the first inner peripheral surface.
The second outer peripheral surface has an axial position located closer to the end of the opening than the first outer peripheral surface, and is smaller in diameter than the first outer peripheral surface.
The second outer peripheral surface side that is sealed by the seal portion of the seal on the outer diameter side of the stud bolt is made of a hardened surface or ring that is harder than the rotating case, and reduces wear caused by sliding with the seal portion. An electromagnetic power transmission device, characterized in that wear reduction means is provided. The invention according to claim 1,
The electromagnetic power transmission device , wherein the surface hardened portion is an alumite film that is applied to the rotating case and has high wear resistance with respect to the seal portion of the seal . The invention according to claim 1,
The electromagnetic power transmission device , wherein the surface hardened portion is a plating layer that is applied to the rotating case and has high wear resistance with respect to the seal portion of the seal . It is the invention described in any one of claims 1 to 3,
The axial portion on the inner peripheral side is press-fitted to the outer periphery whose axial position is located on the end side of the opening from the sliding portion on the second outer peripheral surface side of the rotating case, and the axial direction on the outer peripheral side An electromagnetic power transmission device characterized in that a cover that covers the opening and that forms an overlap portion with an air gap is disposed between the cover and the casing .

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