JPH024255Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a magnetic particle type electromagnetic clutch used in vehicles such as automobiles. More specifically, the present invention relates to a magnetic particle type electromagnetic clutch that prevents foreign matter from entering an annular space in which magnetic particles are accommodated.

[Prior art]

In vehicles such as automobiles, it is known to provide a magnetic particle type electromagnetic clutch in order to transmit engine rotation to the transmission side (for example,
(Special Application No. 106445/1983).

This type of magnetic particle type electromagnetic clutch consists of a cylindrical driving member that is rotated around the centerline, a cylindrical hub part that connects to the driven shaft in the center, and a cylindrical hub part that is located inside the driving member and is concentric with the driven shaft. The drive member includes a driven member having a rotor that is provided to be relatively rotatable, and labyrinth members that are respectively attached to both ends of the drive member and form an annular space for accommodating magnetic particles, and the cylindrical hub. A cylindrical bearing holder extending from the inner periphery of the rotor is disposed at a radially outward position of the rotor, and the inner periphery of one of the labyrinth members is attached to the bearing holder. supported through
The rotational force of the driving member is transmitted to the driven member by magnetically coupling magnetic particles in the gap between the inner circumferential surface of the driving member and the outer circumferential surface of the rotor.

By the way, in the magnetic particle type electromagnetic clutch described above, the outer circumferential part of the cylindrical hub part connected to the driven shaft, and the outer circumferential part of the cylindrical bearing holding part extending from the inner circumferential part of the rotor. There is a gap between them, and through this gap, foreign matter such as muddy water may enter the annular space in which the magnetic particles are accommodated from outside the clutch.

Therefore, the cylindrical bearing holding part is positioned as close to the cylindrical hub part as possible, and the gap therebetween is made small to prevent foreign matter from entering.

However, the axial center on the engine side and the axial center on the transmission side are generally separated to a certain extent (about 0.4 mm).
Since the bearings are assembled with a permissible axis misalignment tolerance, a gap larger than the permissible tolerance inevitably exists between the cylindrical hub portion and the cylindrical bearing holding portion.

Therefore, foreign matter such as muddy water may enter through this gap into the annular space in which the magnetic particles are accommodated, and as a result, there is a risk that the power transmission performance of the magnetic particle type electromagnetic clutch may deteriorate.

[Purpose of invention]

Therefore, the purpose of the present invention is to prevent foreign matter from entering the annular space in which magnetic particles are accommodated by discharging the foreign matter that has entered, thereby preventing deterioration of power transmission performance. There is a particular thing.

[Structure of the idea]

In order to achieve this purpose, in the magnetic particle type electromagnetic clutch of the present invention, a foreign matter discharge guide path such as a groove is provided in the inner cylinder part of the cylindrical bearing holding part in the magnetic particle type electromagnetic clutch of this type described above. The foreign matter discharge guide path is formed to be inclined in a direction in which a component force is generated in the direction opposite to the foreign matter intrusion due to the rotation when the rotation is transmitted from the driving member to the driven member. An annular weir is formed at the end of the pipe.

As a result, if foreign matter such as muddy water enters the gap between the cylindrical hub part and the cylindrical bearing holding part, the foreign matter will adhere to the inner cylinder part of the bearing holding part due to rotational centrifugal force. Through the foreign matter discharge guide path such as a groove provided in the inner cylinder part, the foreign matter is discharged in the opposite direction due to the component force in the opposite direction of the invasion, which occurs with rotation, and the foreign matter is prevented from entering the annular space where the magnetic particles are accommodated. Prevented.

Further, when the rotational speed of the bearing holding portion is reduced, foreign objects may be moved toward the inside of the clutch due to negative rotational angular acceleration. In this case, the annular weir prevents foreign matter from moving toward the inside of the clutch (weir function), thereby preventing foreign matter from entering the clutch.

[Effect of idea]

In the present invention, as described above, foreign matter such as muddy water that enters through the gap between the cylindrical hub part and the cylindrical bearing holding part is reliably discharged in the opposite direction, and magnetic particles are contained. Since the intrusion into the annular space where the magnetic particles are formed is prevented, deterioration of the power transmission performance of the magnetic particle type electromagnetic clutch can be prevented.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

1 to 4 show a first embodiment of the present invention.

Fig. 1 shows a magnetic particle type electromagnetic clutch applied to an automobile, which is built into a clutch housing fixed to an engine (not shown), and which rotates the crankshaft 10 of the engine as a drive shaft (input shaft). The output shaft 12 is the driven shaft.
It is something that can be transmitted or blocked. The output shaft 12 serves as the input shaft of the transmission.

A bottomed cylindrical flywheel 14 is fixed to the end of the crankshaft 10, and a first yoke member 1 is attached to the inner surface of the outer peripheral part of the flywheel 14.
6 and a second yoke member 18, a yoke 20 serving as a driving member is fixed. York 20
has a thick-walled cylindrical shape, and is equipped with an excitation coil 22 inside and an inner circumferential friction surface 24 on the inner circumferential surface. Further, a front labyrinth member 26 and a rear labyrinth member 28 are fixed to the yoke 20, and the rear labyrinth member 28 is integrally provided with a cylindrical bearing case 30 on its inner circumference.

The rotor 34 is provided inside the yoke 20 concentrically and rotatably relative to the yoke 20, and the outer circumferential friction surface 38 of the rotor 34 faces the inner circumferential friction surface 24 with a small gap 40 in between. and,
A substantially closed annular space 4 is formed by the yoke 20, both labyrinth members 26 and 28, and the rotor 34.
2 is formed, and a predetermined amount of magnetic powder 44 is enclosed in this annular space 42. The front labyrinth member 26 and the rear labyrinth member 28 have annular protrusions 46 and 4 that are very close to the rotor 34.
8, and its proximity prevents the magnetic particles 44 from leaking out of the annular space 42.

The rotor 34 is an annular member, and two plates 50 and 52 are fixed to the inside thereof by bolts. The elastic member 54 is held. On the other hand, a clutch hub 56 is attached to the end of the output shaft 12 by spline connection so as to be able to slide in the axial direction and not be able to rotate relative to the shaft.

The clutch hub 56 includes a cylindrical hub portion 58 into which the end of the output shaft 12 is fitted, and a disk portion 60 projecting in the form of a flange in the radial direction from an intermediate portion of the outer peripheral surface of the hub portion 58. A section 60 is disposed between the two plates 50 and 52 and is connected to the rotor 34 via an elastic member 54. The rotation of the rotor 34 is transmitted to the clutch hub 56 via the plates 50 and 52 and the elastic member 54, and the clutch hub 56, the plates 50, 52, and the rotor 34 constitute a driven member.

A pump drive rod 62, one end of which is connected to the crankshaft 10, is inserted into the output shaft 12 so as to be relatively rotatable. and output shaft 12
An oil seal 66 is fitted into the open end from which the rod 64 protrudes, allowing relative rotation between the output shaft 12 and the rod 62 while preventing leakage of lubricating oil between the two. There is.

A slip ring 68 is fixed to the outer peripheral surface of the bearing holding plate 90 that is attached to the bearing case 30 with screws or the like, and this slip ring 68 slides into contact with a brush (not shown) to prevent the conductive member 70 and Power is supplied to the excitation coil 22 via the conductor 72.

At a radially outward position of the circular tubular hub part 58 at a rear position (to the right in FIG. 1), this hub part 5 is located.
8 and the bearing holding part 36 with a slight gap.
is installed. The bearing holding portion 36 is integrally formed extending from the inner peripheral portion of the rotor 34, and has a cylindrical shape. The bearing case 30 on the inner peripheral portion of the rear labyrinth member 28 described above is rotatably supported by the bearing holding portion 36 via a ball bearing 32.

As shown in FIGS. 2 to 4, a groove 80 is formed in the inner cylindrical surface of the cylindrical bearing holding portion 36 as a foreign matter discharge guide path. 2 is a developed view of the inner cylindrical surface of the bearing holding portion 36, FIG. 3 is a cross-sectional view taken along the line -2 in FIG.
A cross section taken along the - line in the figure is shown. The direction of the arrow in FIG. 2 indicates the direction of rotation when rotation is transmitted from the yoke 20, which is a driving member, to the rotor 34, which is a driven member.

The groove 80 is formed to be inclined from the upper left to the lower right when viewed in FIG. Note that, as shown in FIG. 2, the groove 80 is not formed in a predetermined width portion of the left end 80a. This left end 80a corresponds to the inner part in the direction of foreign matter intrusion, and when foreign matter enters, it functions as a dam and prevents the intrusion. Therefore, this leftmost 8
It is preferable that the portion 0a is formed to protrude as shown by the chain line in FIG.

Since the groove 80 is formed to be inclined downward to the right as seen in FIG. 2 as described above, the forces F ₁ , F ₂ , and F ₃ are generated on the foreign object by rotation in the direction of the arrow. F ₁ indicates the force that the foreign object receives from the groove 80 due to rotation, F ₂ indicates the component force along the groove 80 of F ₁ ,
F ₃ indicates the force component of F ₁ that is pressed against the groove 80.
Due to the force F ₂ , the foreign matter is discharged and moved to the right as viewed in FIG. 2 along the groove 80. The direction of this discharge movement is opposite to the direction of intrusion of the foreign matter.

In the magnetic particle type electromagnetic clutch configured as described above, when excitation power is supplied to the excitation coil 22, magnetic particles 44 are generated in the gap 40 between the inner peripheral friction surface 24 of the yoke 20 and the outer peripheral friction surface 38 of the rotor 34. The rotation of the yoke 20 is transmitted to the rotor 34 by its magnetic coupling force and frictional force, and the output shaft 12 is further rotated via the clutch hub 56.

By the way, while a vehicle such as an automobile is running, foreign matter such as muddy water may enter from the rear right side as seen in FIG. The magnetic particles try to enter the annular space 42 in which the magnetic particles are accommodated through the gap between the magnetic particles and the magnetic particles 36 . However, when the foreign matter passes through the gap between the cylindrical hub portion 58 and the cylindrical bearing holding portion 36, it is pressed against the inner cylindrical portion of the bearing holding portion 36 due to the action of rotational centrifugal force, and is formed on the inner cylindrical surface. into the groove 80. Then, as described above, the foreign matter receives the component force of F ₂ as it rotates, and is ejected in the direction opposite to the intrusion direction. Therefore, the annular space 4
Foreign matter is prevented from entering 2.

In most cases, foreign matter that has entered the gap between the cylindrical hub portion 58 and the cylindrical bearing holding portion 36 is discharged as described above.
When the foreign matter attached to the rotor reaches a steady speed (same as the rotational speed), the force _F1 shown in Fig. 2 is no longer generated, so the foreign matter may not be ejected and may remain attached. When deceleration occurs in such a case, an opposing force acts and the object may be moved inward into the clutch.

However, even in such a case, in the case of the above embodiment, as shown in FIGS. 2 and 3, the groove 80 is not formed in the left end 80a portion of the bearing holding portion 36, and the dam Therefore, invading foreign matter is reliably blocked here and prevented from entering the annular space. Note that the foreign matter blocked at the left end 80a is
When the force F ₁ is generated again, it is discharged to the outside of the clutch under the action described above.

In this way, in the first embodiment described above, intrusion of foreign matter into the annular space 42 is reliably prevented, thereby avoiding deterioration of the torque transmission performance of the magnetic particle type electromagnetic clutch due to the intrusion of foreign matter. obtain.

FIG. 5 shows a second embodiment of the invention.

In the first embodiment described above, the groove 80 was formed directly on the inner cylindrical surface of the bearing holding part 36, but it is generally difficult to process the groove 80 directly on the inner cylindrical surface in this way. In this second embodiment, a groove 80 is formed in a member 81 made of resin or the like that is easily molded, and this member 81 is fitted and attached to the inner cylinder surface. By doing so, the groove 80 can be easily processed. In other words, workability is improved.

FIG. 6 shows a third embodiment of the invention.

In this third embodiment, in order to fix the ball bearing 32 in the first embodiment shown in FIG. The shape of the bearing holding plate 90 has been changed, thereby making it possible to discharge foreign matter more effectively.

That is, as shown in FIG. 6, the inner circumferential portion of the bearing holding plate 90 is formed into an inclined surface 92 whose diameter gradually increases in the foreign matter discharge direction (rightward as seen in FIG. 6), and the ball bearing 32 A loophole 91 is provided in the side portion of the holder. In addition, loophole 91
It is preferable to provide as many as possible on the circumference.

In most cases, the foreign matter discharged from the bearing holding part 36 falls on the inclined surface 9, as shown by arrow a.
2 to the outside of the clutch. Note that some of the foreign matter may enter the side of the ball bearing 32 as shown by arrow b, but this foreign material is also discharged to the outside of the clutch through the hole 91 due to centrifugal force. In addition, foreign particles of lubricant such as grease protruding from the ball bearing 32 are also discharged from this hole 91, and the intrusion of these lubricants is also prevented.

Although the present invention has been described above with reference to specific embodiments illustrated, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention.

For example, in each of the above-described embodiments, a case has been described in which the groove 80 constitutes a foreign matter discharge guide path. It is also possible to configure a path.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a sectional view showing the entire magnetic particle type electromagnetic clutch, FIG. 2 is a developed view of the inner cylindrical surface of the bearing holding part, and FIG. 3 is a sectional view taken along the - line in FIG. 2, FIG. 4 is a sectional view taken along the - line in FIG. FIG. 7 is an enlarged sectional view of a main part showing a third embodiment of the invention. Explanation of symbols, 12... Output shaft (driven shaft), 2
0...Yoke (driving member), 24...Inner peripheral friction surface (inner peripheral surface), 26...Front labyrinth member, 2
8... Rear labyrinth member (one labyrinth member), 32... Ball bearing (bearing),
34... Rotor (driven member), 36... Bearing holding part, 38... Outer peripheral friction surface (outer peripheral surface), 4
0... Gap, 42... Annular space, 44... Magnetic powder, 58... Cylindrical hub portion (driven member), 8
0...Groove (foreign matter discharge guide path).

Claims (1)

[Claims for Utility Model Registration] A cylindrical driving member that is rotated around a center line, a cylindrical hub portion that connects to a driven shaft at the center, and a hub portion that is located inside the driving member and is concentric with the driving member. and a rotor that is relatively rotatable, and labyrinth members that are attached to both ends of the drive member to accommodate magnetic particles and form an annular space. A cylindrical bearing holding part extending from the inner peripheral part of the rotor is disposed at a radially outward position of the hub part and is approximately concentric with the driven member. The inner periphery of the labyrinth member is supported via a bearing, and magnetic particles are magnetically coupled in the gap between the inner periphery of the drive member and the outer periphery of the rotor, thereby transferring the rotational force of the drive member to the driven object. In a magnetic particle type electromagnetic clutch of the type in which transmission is transmitted to a member, a foreign matter evacuation guide path such as a groove is provided in the inner cylindrical portion of the cylindrical bearing holding portion, and this foreign matter ejection guide path passes from the driving member to the driven member. It is formed to be inclined in the direction in which the rotation when the rotation is transmitted generates a component force in the direction opposite to the intrusion of foreign matter, and furthermore, an annular weir is formed at the end of the foreign matter discharge guide path. Magnetic powder type electromagnetic clutch.