RU2788143C1 - Dual mode electromagnetic clutch - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to the field of mechanical engineering, and more specifically to couplings. A dual mode electromagnetic clutch (DMEMC) contains a central axis, a housing, an annular electromagnet with a coil, a magnetic circuit and an armature, three or more twisted return springs. In this case, the DMEMC includes the first and second input shafts with the corresponding gears, the output shaft with the gear and the first mode gear, equipped with a ring gear, rigidly connected to the first input shaft. There is a second mode gear and an output gear kinematically connected to the output shaft by means of the output shaft gear. The slider with the anchor attached to it is provided with toothed rims on both sides, kinematically rigidly connected to the output gear with the possibility of linear coaxial movement relative to it under the action of an electromagnet with the possibility of moving in one direction or under the action of the total force of the return springs in the other direction. The return springs are evenly spaced around the circumference in the output gear and the slider and are made with the possibility of adjusting the force of pressing the slider to the gear of the second mode by means of the corresponding adjusting screws.

EFFECT: reduction in weight and dimensions is achieved.

2 cl, 2 dwg

Description

A dual-mode electromagnetic clutch (EMC) belongs to the field of mechanical engineering and can be used in periodically switched on kinematic chains of various machines for the current selection of one of the two sources of rotation of the output shaft, protection of drive elements from overloads during torque transmission, design of electromagnetic clutches of pulling and holding action.

A safety clutch is known (patent RU 2069282 C1, F16D 7/04, priority dated 11/20/1996) having an inclined operating profile of the cams. The output shaft is turned off when the transmitted torque is limited by axial movement of the driven coupling half due to the inclined working surface of the cams and, when the leaf spring moves to another stable position, the output shaft stops when the cams of the driven coupling half and the fixed disk engage.

In the considered safety clutch, the re-engagement is carried out by forced compression of the driven clutch half to the leading clutch half, and the clutch is turned off only when the protection elements are triggered. The disadvantage of this clutch is the lack of its remote control.

The brake unit (patent RU 2416046 C2, F16D 27/118, priority dated 07/13/2009) is deprived of this disadvantage, having control of its state using a built-in stationary electromagnet.

Braking and fixation of the stop is carried out by means of brake discs of the "tooth - groove" type, the mating surfaces of which are made in the form of radially arranged teeth. The profile of the teeth of one disk corresponds to the profile of the grooves of the other disk. The disadvantage of this device is its purpose for stopping a shaft with a low rotational speed due to the use of brake discs made of friction material.

Known clutch-pulley (patent RU 2272191, F16D 27/02, priority dated 03/04/2004), which allows you to transmit torque due to the axially movable friction disc and having the ability to remote control by repeatedly turning on/off the electromagnet. The clutch-pulley is the closest in technical essence of the claimed utility model and is taken as a prototype.

The transfer of torque in this clutch-pulley when voltage is applied to the electromagnet is carried out by pulling up to the driven half-coupling of the friction disk, which is rigidly fixed on the drive half-coupling, but which has the ability to move coaxially along the drive half-coupling. The return of the clutch-pulley to its original position when the electromagnet is turned off occurs due to a flat annular spring.

The disadvantages of this clutch-pulley can be considered:

• transmission of torque to the pulley from only one source of rotation;

• lack of a brake on the pulley, as a result of which the pulley continues to rotate freely after the clutch is turned off;

• low transmitted torque due to the instability of the friction force, which strongly depends on the size of the air end gap between the armature, fixed on the drive half-coupling, and the magnetic circuit of the electromagnet, located motionless in the housing of the said clutch;

• the absence of a node that protects against unacceptable torques, both the driving and the driven shaft;

• lack of automatic recovery of the transmitted torque when it drops to an acceptable value after the safety unit is triggered.

The task to be solved by the proposed technical solution is the development of a small-sized two-mode electromagnetic clutch of small mass with the transmission of rotation to the output shaft from two independent input shafts at the user's choice and protection of each input shaft from exceeding the permissible torque value.

The proposed technical solution provides the following technical result:

1) alternate operation of the kinematic chains of two modes from one control signal due to the double-sided toothed rim of the slider;

2) the simultaneous activation of the kinematic chains of the first and second modes is completely excluded due to the movement of the slider;

3) after switching on the clutch during the operation of the kinematic chain of the first mode, the source of rotation of the first input shaft is provided with protection against exceeding the permissible torque by slipping the toothed connection due to the special trapezoidal shape of the teeth of the slider ring gear and the ring gear of the first mode gear. When the torque is reduced to an acceptable value, the kinematic chain of the first mode is restored automatically;

4) switching on and off the clutch is allowed at any time, regardless of the presence of a load on the output shaft and the presence of torques on the first and second input shafts;

The specified result of the proposed technical solution is achieved by using in a dual-mode electromagnetic clutch containing a central axis, a housing with an annular bore, an annular electromagnet with a coil, a magnetic circuit and an armature, three or more twisted return springs that perform the function of a flat annular spring used in the prototype.

In addition, the inventive clutch includes the first and second input shafts with the corresponding gears, the output shaft with the gear, the first mode gear, equipped with a ring gear, rigidly connected to the first input shaft, the second mode gear, equipped with a ring gear, kinematically connected to the second input shaft by means of gears of the second input shaft, an output gear kinematically connected to the output shaft by means of the output shaft gear, a slider with an anchor fixed on it, equipped with toothed rims on both sides, kinematically rigidly connected to the output gear with the possibility of linear coaxial movement relative to it under the action of an electromagnet in one side or under the action of the total force of the return springs in the other direction, while the return springs are evenly spaced around the circumference in the output gear and the slider and are made with the possibility of adjusting the force of pressing the slider to the gear of the second mode by means of the corresponding adjusting screws. In a preferred embodiment of a particular design of the coupling, the toothed rims of the slider and gears of the first and second modes are made with trapezoidal teeth.

An additional technical result is the simplicity of the design, the reduction in the weight and dimensions of the DEM, the increase in the manufacturability of its manufacture and the reliability of operation. The specified additional result of the proposed technical solution is achieved by locating the output shaft gear, the first mode gear, the second mode gear and the slider, having rotation independent of each other, on the same axis - the axis of the first input shaft mounted on supports in the housing.

In FIG. 1 and FIG. 2, the following designations are adopted:

1 first input shaft;

2 building;

3 return spring;

4 adjusting screw;

5 output gear;

6 magnetic circuit;

7 electromagnet coil;

8 armature of the electromagnet;

9 gear of the second mode;

10 gear ring of the second mode gear;

11 toothed crown of the slider of the second mode;

12 slider;

13 cover;

14 gear of the first mode;

15 gear ring gear of the first mode;

16 gear rim of the slider of the first mode;

17 second input shaft;

18 output shaft;

19 output shaft gear;

20 gear of the second input shaft.

DEM functions as follows.

Connecting the kinematic circuit of the second mode is shown in Fig. 1.

In the absence of voltage on the coil of the electromagnet 7 (the initial state of the DEM), the return springs 3 with a variable compression force with the adjusting screws 4 press the slider 12 to the gear of the second mode 9, ensuring the engagement of the ring gear of the second mode slider 11 with the ring gear of the second mode gear 10. In this case, the transmission torque of the second mode is carried out according to the following kinematic chain: the torque from the gear of the second mode 9, coming from the second input shaft 17 and the gear of the second input shaft 20 rigidly fixed on it, through the gear rim of the gear of the second mode 10 and the gear rim of the slider 11, forming a clutch of the second mode, is transmitted to the slider 12 and then through the cycloidal engagement to the output gear 5. Then the torque is transmitted to the output shaft 18, using the gear of the output shaft 19 rigidly fixed on it. second gear mode 10 and the ring gear of the slider of the second mode 11, exceeds the total force from the action of each return spring 3, as a result of which the clutch of the second mode opens due to the slipping of these teeth, protecting the kinematic chain from overloads. In a preferred embodiment of a specific design of the clutch, the gear rims of the slider and gears of the first and second modes are made with trapezoidal teeth, which allows you to select the maximum torque value at which the clutch opens due to slipping of these teeth. The specified parameter is adjusted by selecting the angles of the trapezoidal teeth.

Connecting the kinematic circuit of the first mode is shown in Fig. 2.

When voltage is applied to the coil of the electromagnet 7 (on state of the DEM), located in the magnetic circuit 6, which is fixedly installed in the housing 2, a magnetic flux increases in the magnetic circuit 6 and the armature of the electromagnet 8, closing along circuit A and causing an increase in the traction force of the armature of the electromagnet 8. Traction force the armature of the electromagnet 8 overcomes the total force from the action of each return spring 3 and the slider 12, with the armature of the electromagnet 8 attached to it, is attracted to the gear of the first mode 14, ensuring the engagement of the ring gear of the slider of the first mode 16 with the ring gear of the gear of the first mode 15. In this case the transmission of torque is carried out through the following kinematic chain: the torque from the first input shaft 1 through the gear of the first mode 14 and together the ring gear of the gear of the first mode 15 and the ring gear of the slider of the first mode 16, forming the clutch of the first mode, is transmitted to the slider 12 and then through the cycloidal output engagement one gear 5. Then the torque is transmitted to the output shaft 18, using the gear of the output shaft 19 rigidly fixed on it. with a total force from the action of each return spring 3 exceeds the traction force of the armature of the electromagnet 8, as a result of which the clutch of the first mode is opened due to the slipping of these teeth, protecting the kinematic chain from overloads.

Currently, the company has tested experimental samples of the proposed two-mode clutch with a positive result.

Claims (2)

1. A dual-mode electromagnetic clutch containing a central axis, a housing with an annular bore, an annular electromagnet with a coil, a magnetic circuit and an armature, three or more twisted return springs, characterized in that it includes the first and second input shafts with corresponding gears, an output shaft with a gear, a gear of the first mode, equipped with a ring gear, rigidly connected to the first input shaft, a gear of the second mode, equipped with a ring gear, kinematically connected to the second input shaft by means of a gear of the second input shaft, an output gear, kinematically connected to the output shaft by means of a gear of the output shaft, a slider with an anchor fixed on it, equipped with gear rims on both sides, kinematically rigidly connected to the output gear with the possibility of linear coaxial movement relative to it under the action of an electromagnet in one direction or under the action of the total force of the return springs in the other direction, while the return springs are equal to clearly located around the circumference in the output gear and the slider and are made with the possibility of adjusting the force of pressing the slider to the gear of the second mode by means of the corresponding adjusting screws. 2. A dual-mode electromagnetic clutch according to claim 1, characterized in that the toothed rims of the slider and gears of the first and second modes are made with trapezoidal teeth.

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