JP4396172B2 - Electromagnetic powder brake / clutch - Google Patents

Description

  The present invention relates to an electromagnetic powder brake / clutch that suppresses rotation of an input shaft by applying a magnetic flux to magnetic powder enclosed therein.

  Conventionally, various types of torque control devices in various industrial fields have been configured to couple the internal magnetic powder with magnetic flux generated when the coil is energized to control the rotation of the input shaft and transmit it to the output shaft. Electromagnetic powder brakes and electromagnetic powder clutches are used (for example, see Patent Document 1). For example, as shown in FIG. 3, a conventional electromagnetic powder brake 100 includes a yoke 102 having a built-in coil 101, and a cylinder 104 disposed inside the yoke 102 and integrally provided at the tip of the input shaft 103. The rotor 105 is provided in a non-rotatable manner in the cylinder 104, and the magnetic powder 107 (powder) such as iron powder enclosed in the gap 106 between the cylinder 104 and the rotor 105.

When the coil 101 in the yoke 102 is energized, a magnetic flux is generated between the yoke 102 and the cylinder 104 as shown by the chain line in FIG. 3, and the magnetic force between the cylinder 104 and the rotor 105 is generated along this magnetic flux. Since the powder 107 is coupled in a chain shape and rotational resistance acts on the cylinder 104, the rotation of the cylinder 104 (input shaft 103) is suppressed.
Incidentally, a seal member 108 is provided between the cylinder 104 and the rotor 105 to seal the gap 106 and prevent the magnetic powder 107 from leaking. Conventionally, this seal member is made of a cloth such as wool felt.

Utility Model Registration Gazette No. 2594840

However, in the conventional electromagnetic powder brake, since the sealing member that seals the gap in which the magnetic powder is enclosed is made of cloth such as wool felt, the sealing member is molded to a predetermined size. It was difficult. However, if the seal member is not manufactured according to the dimensions, the gap portion cannot be completely sealed by the seal member, and the magnetic powder in the gap portion leaks to the outside, so that the brake performance is deteriorated.
An object of the present invention is to configure a sealing member that seals magnetic powder in a gap so that it can be easily molded according to dimensions.

Means for Solving the Problems and Effects of the Invention

An electromagnetic powder brake / clutch according to a first aspect of the present invention includes an annular yoke having a coil built therein, a cylinder disposed inside the yoke and provided at one end of the input shaft, and rotating integrally with the input shaft. In an electromagnetic powder brake / clutch comprising a rotor disposed in the cylinder and magnetic powder sealed in a gap between the cylinder and the rotor, the gap is provided between the cylinder and the rotor. A plate-like seal member is attached to seal the cylinder body, and the cylinder has a cylinder body formed open on the one end side and an annular side plate fixed to one end of the cylinder body. The side plate includes an annular recess formed to be inclined at a substantially central portion in the radial direction, and an annular flat portion that extends to the inner end of the annular recess and extends inward in the radial direction . at least Section and the above-mentioned annular recess and the annular flat portion of the side plate in an elastically deformed state, and said rotor are clamped axially between said sealing member is composed of a heat-resistant aramid fiber, it It is characterized by.

In this electromagnetic powder brake / clutch, when a coil in the yoke is energized, a magnetic flux is generated between the yoke and the rotor. At this time, the magnetic powder sealed in the gap between the cylinder fixed to the input shaft and the rotor in the cylinder is chained and coupled between the cylinder and the rotor along the magnetic flux, and is coupled to the cylinder. Since rotation resistance is generated, rotation of the input shaft is suppressed.
Incidentally, a seal member is provided between the cylinder and the rotor to seal the gap and prevent the magnetic powder from leaking. The seal member is formed in a plate shape. Therefore, this plate-like seal member is easier to be molded to a predetermined size than a conventional seal member made of a soft material such as cloth, so that the gap between the cylinder and the rotor is It becomes possible to securely seal the magnetic powder.
By making the sealing member into a plate shape as described above, the sealing member can be attached simply by sandwiching the sealing member between the side plate and the rotor, and the structure of the portion where the sealing member is attached is simplified. Can do.

Further, the seal member is composed of a heat-resistant aramid fibers. The seal member is mounted between the cylinder and the rotor disposed in the cylinder. However, since the cylinder rotates relative to the rotor, a large frictional force acts on the seal member, and the friction is generated. There is a possibility that the seal member becomes hot due to heat and the seal member is deformed or sag. Therefore, by configuring the seal member with a heat-resistant aramid fiber , it is possible to suppress deformation and sag in the seal member due to frictional heat, and to prevent the seal performance from being reduced as much as possible.

  Next, an embodiment of the present invention will be described. This embodiment is an example in which the present invention is applied to an electromagnetic powder brake that can brake the rotation of an input shaft and control its torque.

  As shown in FIG. 1, the electromagnetic powder brake 1 includes an annular yoke 3 having a coil 2 built therein, brackets 4 and 5 holding the yoke 3 from both left and right sides in FIG. A cylinder 7 disposed with a gap and fixed to the left end of the input shaft 6, a rotor 8 disposed in the cylinder 7 and fixed to the bracket 4 so as not to rotate, and the cylinder 7 and the rotor 8. A magnetic powder 10 enclosed in a gap portion 9 therebetween, and a seal member 11 provided between the cylinder 7 and the rotor 8 for sealing the gap portion 9 are provided. The electromagnetic powder brake 1 couples the magnetic powder 10 in the gap 9 in a chain shape by the magnetic flux generated from the coil 2 when the coil 2 is energized to give a rotational resistance to the cylinder 7 and rotate the input shaft 6. It suppresses.

  Inside the yoke 3, a coil 2 for exciting magnetic flux is disposed between the yoke 3 and the rotor 8. The coil 2 can be energized via a lead wire 2a. The yoke 3 is clamped by a pair of left and right substantially disk-shaped brackets 4 and 5, and the yoke 3 is connected to the brackets 4 and 5 by bolts. The input shaft 6 is rotatably held by the right bracket 5 via bearings 12 and 13.

  A cylinder 7 is rotatably disposed in a space formed inside the annular yoke 3 and the left and right brackets. The cylinder 7 has a cylinder body 14 made of a magnetic material (for example, SS400) having an open left end, and an annular side plate 15 fixed to the left end portion of the cylinder body 14 with a bolt. Here, the side plate 15 includes an annular recess 15a formed in a shape slightly recessed to the right at a substantially central portion in the radial direction, and an annular flat portion 15b that extends inward in the radial direction and continues to the inner end of the annular recess 15a. Have. In the space surrounded by the cylinder body 14 and the side plate 15, a rotor 8 made of a magnetic body having a substantially triangular cross section and an annular shape is provided between the inner surface of the cylinder body 14 and a predetermined gap. 9 is provided. The rotor 8 is fixed to the left bracket 4 via a boss 17 so as not to rotate with bolts.

  A gap 9 between the rotor 8 and the inner surface of the cylinder body 14 is filled with magnetic powder 10 made of iron powder or the like. When the coil 2 is energized, a magnetic flux is generated between the yoke 3 and the rotor 8 as shown by a chain line in FIG. Then, the magnetic powder 10 in the gap portion 9 between the cylinder 7 and the rotor 8 is coupled and chained along the magnetic flux, so that a rotational resistance acts on the cylinder 7 and the input shaft 6 rotates. It is suppressed. A magnetic flux blocking ring 16 made of a non-magnetic material is attached to the center of the cylinder body 14 in the left-right direction. This magnetic flux blocking ring 16 can prevent the magnetic flux from being short-circuited inside the cylinder 7. .

  By the way, a protruding portion 8a protruding outward in the radial direction is formed at the left end portion of the inner portion of the rotor 8. As shown in FIGS. 1 and 2, the left end surface of the protrusion 8 a is formed to extend radially outward in a direction perpendicular to the axial direction (the left-right direction in FIG. 1). An annular and plate-shaped seal member 11 is sandwiched between the left end surface of the protruding portion 8 a and the right end surface of the annular flat portion 15 b of the side plate 15. That is, the seal member 11 is held by being pressed against the left end surface of the protruding portion 8 a of the rotor 8 by the thin plate-like side plate 15. Here, during the operation of the electromagnetic powder brake 1, the cylinder 7 rotates with respect to the rotor 8. Therefore, a large frictional force acts on the seal member 11, and the seal member 11 is bent or deformed by the frictional heat. There is a risk that. Therefore, the seal member 11 is made of a heat-resistant material such as a heat-resistant aramid fiber (for example, Nomex: manufactured by DuPont).

Next, the operation of the electromagnetic powder brake 1 will be described.
When the coil 2 is energized while the input shaft 6 is rotating, a magnetic flux is generated between the yoke 3 and the rotor 8 as indicated by a chain line in FIG. Then, the magnetic powder 10 loaded in the gap portion 9 between the cylinder 7 and the rotor 8 is coupled and chained along this magnetic flux, so that a rotational resistance acts on the cylinder 7 and the input shaft 6 Is suppressed. At this time, the gap 9 is sealed by the plate-shaped sealing member 11 sandwiched between the side plate 15 of the cylinder 7 and the protruding portion 8 a of the rotor 8, and the magnetic powder 10 leaks by the sealing member 11. Is prevented.

  On the other hand, when the energization to the coil 2 is stopped, the magnetic flux between the yoke 3 and the rotor 8 disappears, so that the coupled state of the magnetic powder 10 that has been chained is released, and the magnetic powder 10 is subjected to centrifugal force. It moves to the inner surface side of the cylinder 7. Then, the rotation resistance does not act on the cylinder 7 and the brake state of the input shaft 6 is released.

According to the electromagnetic powder brake 1 described above, the following effects can be obtained.
Since the seal member 11 that seals the gap 9 between the cylinder 7 and the rotor 8 has a plate shape, the seal member 11 is compared with the conventional seal member 11 made of a soft material such as cloth. Thus, it is very easy to mold to a predetermined size. Further, since the plate-like sealing member 11 is pressed against the protruding portion 8a of the rotor 8 by the thin plate-like side plate 15 and is sandwiched between the side plate 15 and the protruding portion 8a, the sealing member 11 can be mounted. The shape and structure of the electromagnetic powder brake 1 can be simplified, and since the seal member 11 can be held by the thin side plate 15, the electromagnetic powder brake 1 can be reduced in weight.
Furthermore, since the seal member 11 is made of a heat resistant material, it is possible to prevent the seal member 11 from being deformed or sag by frictional heat, and to prevent the seal performance from being deteriorated.

  In the above embodiment, the present invention is applied to the electromagnetic powder brake. However, the present invention can also be applied to an electromagnetic powder clutch in which the rotor is connected to the output shaft and the torque of the input shaft can be transmitted to the output shaft. Further, the seal member is not limited to the one constituted by the heat-resistant aramid fiber of the above embodiment, and the seal member may be constituted by another heat-resistant material as long as it can be formed into a plate shape.

It is a half body sectional view of an electromagnetic powder brake concerning an embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of a seal member in FIG. 1. It is half body sectional drawing of the conventional electromagnetic powder brake.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic powder brake 2 Coil 3 Yoke 6 Input shaft 7 Cylinder 8 Rotor 9 Air gap part 10 Magnetic powder 11 Seal member 14 Cylinder main body 15 Side plate

Claims (1)

An annular yoke containing a coil, a cylinder disposed inside the yoke and provided at one end of the input shaft and rotating integrally with the input shaft, a rotor disposed in the cylinder, In an electromagnetic powder brake / clutch comprising magnetic powder sealed in a gap between a cylinder and a rotor,
A plate-shaped sealing member for sealing the gap is mounted between the cylinder and the rotor,
The cylinder has a cylinder body formed open on the one end side, and an annular side plate fixed to one end of the cylinder body,
The side plate has an annular recess formed to be inclined at a substantially central portion in the radial direction, and an annular flat portion that extends inward in the radial direction and continues to the inner end of the annular recess,
The seal member and the annular recess and the annular flat portion of the side plate with at least a portion is elastically deformed, and the rotor, which is sandwiched axially between,
The sealing member is made of heat-resistant aramid fiber,
An electromagnetic powder brake / clutch.

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