JPH0642105Y2 - Electromagnetic coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an electromagnetic coupling device including an armature having a driving surface on one surface and a braking surface on the other surface.

[Conventional technology]

Examples of this type of electromagnetic coupling device include, for example, Shokai 58-14963.
Some are disclosed in Japanese Patent Publication No. 7. In this structure, an armature is made to face between a friction surface of a rotor, which is a driving member, and a friction surface of a fixed member, and the armature is fitted to a spline provided on a driven shaft. Then, by moving the armature along the spline in the axial direction, when the electromagnetic coil is in a non-excited state, the elastic shaft of the compression coil spring presses the armature against the fixed member to brake the driven shaft, and When the coil is in the excited state, the armature is magnetically attracted to the rotor to transmit power.

[Problems to be solved by the invention]

However, in the structure in which the armature is moved by using the spline as described above, some backlash must be provided on the spline in order to smoothly move the armature. As a result, during driving or braking, the driven shaft and the armature may slightly rotate relative to each other and collide with each other, resulting in abnormal noise.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and provides an electromagnetic coupling device capable of preventing generation of abnormal noise. An electromagnetic coupling device according to the present invention includes a rotor rotatably supported, a fixing member having a friction surface opposed to a friction surface of the rotor at an axial interval.
An armature having a driving surface on one side and a braking surface on the other side facing between the friction surfaces, and bearings press-fitted into the central holes of the rotor and the fixing member are rotatably supported by the rotor and the fixing member. A driven shaft, a leaf spring that supports the armature on a hub on the driven shaft, an electromagnetic coil that generates a magnetic flux that magnetically attracts the armature to a rotor, and a field core in which the electromagnetic coil is loaded in an annular groove. A bracket made of a non-magnetic material, in which an outer peripheral surface of the field core is fitted and held in a rear portion and the fixing member is fitted in a front portion so as to be able to move forward and backward, and an outer circumference of the fixing member screwed in the bracket in a radial direction. A hub that is a fixed surface of the leaf spring, and includes a headless screw that abuts a surface and a fixing bolt that penetrates the fixing member in the axial direction and is screwed to the bracket. The front surface is formed in front of the friction surface of the fixing member, and the leaf spring is subjected to an initial deflection so that an elastic force acts in a direction in which the braking surface of the armature is constantly pressed against the friction surface of the fixing member. It is a thing.

[Action]

In the present invention, the armature moves in the axial direction of the driven shaft due to elastic deformation of the leaf spring.

〔Example〕

Hereinafter, the configuration and the like will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 is a half sectional view showing an electromagnetic coupling device according to the present invention, FIG. 2 is a front view showing a leaf spring, and the reference numeral A in FIG. 1 is arranged, for example, between a motor and a speed reducer. 3 shows an electromagnetic coupling device. 1 is a field core formed in an annular shape having a central hole, 2 is this field core 1
Is an annular electromagnetic coil loaded in the annular groove 3 provided on the front surface of the.

4 is a rotor to which power is input. The rotor 4 has a cylindrical boss portion 4a which is inserted from the front side into the center hole of the field core 1 and an outer diameter direction projectingly provided at the front end of the boss portion 4a with a space in front of the field core 1. It is formed in a substantially L-shaped cross section from the facing flange portion 4b, and is rotatably supported coaxially with the field core 1 by a bearing 5 press-fitted into the central hole of the field core 1. Inner teeth 6 into which a pinion provided at the motor shaft tip of a motor (not shown) is inserted and fitted are provided in the inner hole of the boss portion 4a of the rotor 4. On the other hand, an annular friction plate 8 having a friction surface 7 on the front surface is fitted on the front surface of the flange portion 4b.
Reference numeral 11 denotes an arcuate slit provided along the friction plate 8 on the rotor 4 and forms a demagnetization portion that diverts the magnetic flux generated in the electromagnetic coil 2 to an armature described later.

Reference numeral 12 is a bracket formed of a non-magnetic material and formed in a cylindrical shape to cover the outside of the field core 1. Field core 1
Is fitted and held in the rear portion of the bracket 12. At the rear end of the bracket 12, there is provided a recess 13 for fitting a brazing motor (not shown). Further, the front portion is provided with a thin portion 12a into which the annular fixing member 14 is fitted in the field core 1 so as to be able to move forward and backward. 15 is the fixing member 1
A fixing bolt that penetrates 4 in the axial direction and is screwed to the bracket 12, and 16 is a fixing member that is screwed in the thin portion 12a in the radial direction.
These are headless screws that come into contact with the outer peripheral surface of the fixing member 14, and these members move the fixing member 14 in the axial direction to fix it at a desired position. That is, the fixing member 14 includes the fixing bolt 15 and a headless screw.
In the loosened state of the cylindrical bracket 12, the inner peripheral surface of the cylindrical bracket 12 is used as a guide surface so as to be movable back and forth along the axial direction. On the back surface of the fixing member 14, a friction surface that faces the friction surface 7 of the rotor 4 at an axial interval.
An annular friction plate 18 having 17 is fixed. here,
The outer diameter of the fixing member 14 is made equal to the inner diameter of the wax recess 13 to form a solder bump 19 fitted into the solder recess of the speed reducer (not shown).

Reference numeral 21 is a driven shaft that penetrates the central hole of the fixing member 14.
The driven shaft 21 is rotatably supported coaxially with the rotor 4 by a bearing 22 press-fitted in the central hole and a bearing 23 press-fitted in the central hole of the rotor 4. Further, a pinion 24 having the same shape as a pinion that meshes with the input gear of the speed reducer and meshes with the internal teeth 6 is provided at the front end portion,
A hub 26 for supporting a leaf spring, which will be described later, is press-fitted and fixed to the knurled portion 25 between 22 and 23.

Reference numeral 27 is an annular armature arranged so as to face between the friction surfaces 7 and 17. The armature 27 has a drive surface formed at a portion facing the friction surface 7 of one rotor 4 and a braking surface formed at a portion facing the friction surface 17 of the other fixed member 14. Armature 27 thickness and friction surface 7,17
The facing distance is set so that the gap g is provided when the armature 27 is in contact with any friction surface. Reference numeral 28 is a leaf spring that supports the armature 27 on the driven shaft 21. This leaf spring 28, as shown in the front view in FIG.
An annular outer peripheral portion 28a and an inner peripheral portion 28b extending in the circumferential direction.
And a bridging portion 28c that extends in the radial direction and connects these to each other are formed in a substantially disc shape. The bridging portions 28c are arranged at three locations at equal intervals in the circumferential direction. A supporting hole 31 is formed in a portion of the outer peripheral portion 28a where the bridging portion 28c is extended in the outer diameter direction, and a fixing hole 32 is formed in a portion of the inner peripheral portion 28b where the bridging portion 28c is extended in the inner diameter direction. It is set up. That is, the outer peripheral portion 28a of the leaf spring 28 is fixed to the front surface of the armature 27 by the rivet 33 penetrating the supporting hole 31 and the inner peripheral portion 28b.
Is fixed to the front surface of the hub 26 by a fixing screw 34 penetrating the fixing hole 32, and the bridging portion 28c elastically deforms in the axial direction of the driven shaft 21 to move the armature 27. In this embodiment, since the bridging portion 28c of the leaf spring 28 extends in the radial direction, torque can be transmitted in both forward and reverse rotation directions. Moreover, since the bridging portion 28c is fixed to the hub 26 at the portion extending in the radial direction to support the armature 27, the armature 27 and the hub 26 can be firmly connected and high torque can be transmitted.

The fixed position of the hub 26 is such that the front surface thereof is the friction surface of the fixed member 14.
It is positioned in front of 17. For this reason, the leaf spring 28 is given an initial deflection so that the bridging portion 28c moves backward as the bridging portion 28c moves toward the outer diameter direction, and the elastic force always acts in the direction in which the armature 27 is pressed against the fixing member 14. .

The electromagnetic coupling device configured as described above is configured such that the housing 12 is used as a housing and each component is mounted in the housing 12, and the fixing member 14 also serves as a lid that closes the front opening of the housing. It has become. In this electromagnetic coupling device, when the electromagnetic coil 2 is in the excited state, a magnetic flux is generated and the armature 27 can be magnetically attracted to the rotor 4. Therefore, the torque input to the rotor 4 is transmitted to the driven shaft 21. be able to. On the other hand, as shown in FIG. 1, when the electromagnetic coil 2 is in the non-excited state, the armature 27 is pressed against the fixing member 14 by the elastic force of the leaf spring 28, so that the driven shaft 21 is braked.

At this time, in the leaf spring 28, the bridging portion 28c is elastically deformed in the front-rear direction to move the armature 27 in the axial direction of the driven shaft 21. Further, since the leaf spring 28 has a large rigidity in the circumferential direction, the armature 27 and the driven shaft 21 do not rotate so much relative to each other.

Therefore, it is not necessary to provide backlash as in the conventional case, and members do not collide with each other during driving or braking, so that generation of abnormal noise can be prevented.

The setting of the braking force can be adjusted by changing the gap s between the rotor 4 and the hub 26. This adjustment can be performed, for example, by changing the press-fitting amount of the hub 26 into the knurled portion 25 or the thickness of a shim (not shown) interposed between the bearing 22 and the driven shaft 21. Also,
When the friction surfaces 7 and 17 of the rotor 4 and the fixing member 14 and the driving and braking surfaces of the armature 27 are worn and the gap g between the rotor 4 and the armature 27 increases, the fixing bolt 15 and the headless screw 16 is loosened, and the fixing member 14 is moved toward the rotor 4 side by an amount corresponding to the increase of the gap g for adjustment. After adjustment, tighten the headless screw 16 to the outer peripheral surface of the fixing member 14 and fix the fixing bolt 15
The adjustment work is completed by fastening the to the bracket 12.

[Effect of device]

As described above, according to the present invention, a rotor rotatably supported, a fixed member having a friction surface axially opposed to the friction surface of the rotor, and a friction member facing the friction surface. An armature having a driving surface on one side and a braking surface on the other side, a driven shaft rotatably supported by the rotor and the fixing member by bearings press-fitted into the central holes of the rotor and the fixing member, and this driven shaft. A leaf spring that supports the armature on a hub on a shaft, an electromagnetic coil that generates a magnetic flux that magnetically attracts the armature to a rotor, and a field core in which the electromagnetic coil is loaded in an annular groove,
A bracket made of a non-magnetic material, in which the outer peripheral surface of the field core is fitted and held in the rear portion and the fixing member is fitted in the front portion so as to be able to move forward and backward, and the outer peripheral surface of the fixing member screwed in the bracket in the radial direction. A headless screw that abuts against, and a fixing bolt that penetrates the fixing member in the axial direction and is screwed to the bracket, and the front surface of the hub that is the fixing surface of the leaf spring is more than the friction surface of the fixing member. The leaf spring is configured to be forward, and the leaf spring is elastically deformed because an initial deflection is applied to the leaf spring so that an elastic force acts in a direction in which the braking surface of the armature is constantly pressed against the friction surface of the fixing member. The armature can be moved in the axial direction of the driven shaft.

Therefore, it is not necessary to provide backlash as in the conventional case, and members do not collide with each other during driving or braking, so that generation of abnormal noise can be prevented. Further, since the fixing member is fitted in the front portion of the bracket so as to be movable back and forth, the fixing member also serving as the lid of the electromagnetic coupling device is
It is possible to move the bracket in the axial direction using the fitting surface as a guide surface. That is, when the friction surface of the rotor or the fixed member and the driving surface or the braking surface of the armature are worn and the gap between the rotor and the armature increases, loosen the fixing bolt and the headless screw and increase the gap. Adjust the fixed member by moving it to the rotor side. After the adjustment, the headless screw is tightened to the outer surface of the fixing member, and the fixing bolt is tightened to the bracket to complete the adjustment work.

Therefore, since the gap between the rotor and the armature can be adjusted by changing the position of the fixing member that also serves as the lid of the electromagnetic coupling device, the function of forming a friction surface for braking on the fixing member and the electromagnetic coupling device The function as the lid and the function for adjusting the gap between the rotor and the armature can be combined.

Therefore, it is possible to obtain a lightweight and compact electromagnetic coupling device in which the number of parts is reduced. Moreover, since the bracket is a non-magnetic material and the magnetic flux of the electromagnetic coil does not leak from the bracket to the fixed member side, it is possible to provide an electromagnetic coupling device having good operating characteristics.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an electromagnetic coupling device according to the present invention, and FIG. 2 is a front view showing a leaf spring. 1 ... field core, 2 ... electromagnetic coil, 4 ... rotor, 14 ... fixed member, 21 ... driven shaft, 27 ... armature, 28 ... leaf spring.

Claims (1)

[Scope of utility model registration request] 1. A rotor rotatably supported, a fixing member having a friction surface opposed to the friction surface of the rotor at an axial distance, and a drive surface on one side facing between the friction surfaces. On the other hand, an armature having a braking surface on the other side, a driven shaft rotatably supported by the rotor and the fixing member by bearings press-fitted into the central holes of the rotor and the fixing member, and a hub on the driven shaft. A leaf spring that supports the armature, an electromagnetic coil that generates a magnetic flux that magnetically attracts the armature to the rotor, a field core in which the electromagnetic coil is loaded in an annular groove, and an outer peripheral surface of the field core is fitted and held in the rear portion. At the same time, a bracket made of a non-magnetic material, in which the fixing member is fitted in the front portion so as to be movable back and forth, and a bracket that is screwed in the bracket in the radial direction and is in contact with the outer peripheral surface of the fixing member. A screw and a fixing bolt that axially penetrates the fixing member and is screwed to the bracket, and the front surface of the hub that is the fixing surface of the leaf spring is configured in front of the friction surface of the fixing member, The electromagnetic coupling device according to claim 1, wherein the leaf spring is given an initial deflection so that an elastic force acts in a direction in which the braking surface of the armature is constantly in pressure contact with the friction surface of the fixing member.