GB2364556A - A method of controlling a friction coupling so that a warning signal is generated - Google Patents

A method of controlling a friction coupling so that a warning signal is generated Download PDF

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Publication number
GB2364556A
GB2364556A GB0119888A GB0119888A GB2364556A GB 2364556 A GB2364556 A GB 2364556A GB 0119888 A GB0119888 A GB 0119888A GB 0119888 A GB0119888 A GB 0119888A GB 2364556 A GB2364556 A GB 2364556A
Authority
GB
United Kingdom
Prior art keywords
friction
coupling
electromagnet
hub
friction coupling
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB0119888A
Other versions
GB0119888D0 (en
GB2364556B (en
Inventor
Eberhard Wilks
Andreas Lohmueller
Andreas Sarfert
Reinhold Walter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Walterscheid GmbH
Original Assignee
GKN Walterscheid GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19943209A external-priority patent/DE19943209C2/en
Application filed by GKN Walterscheid GmbH filed Critical GKN Walterscheid GmbH
Publication of GB0119888D0 publication Critical patent/GB0119888D0/en
Publication of GB2364556A publication Critical patent/GB2364556A/en
Application granted granted Critical
Publication of GB2364556B publication Critical patent/GB2364556B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
    • F16D27/10—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings
    • F16D27/108—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members
    • F16D27/112—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs
    • F16D27/115—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs with more than two discs, e.g. multiple lamellae
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D48/00—External control of clutches
    • F16D48/06—Control by electric or electronic means, e.g. of fluid pressure
    • F16D48/064—Control of electrically or electromagnetically actuated clutches
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D48/00—External control of clutches
    • F16D48/06—Control by electric or electronic means, e.g. of fluid pressure
    • F16D48/066—Control of fluid pressure, e.g. using an accumulator
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/08—Interaction between the driver and the control system
    • B60W50/14—Means for informing the driver, warning the driver or prompting a driver intervention
    • B60W2050/143—Alarm means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/10—System to be controlled
    • F16D2500/102—Actuator
    • F16D2500/1021—Electrical type
    • F16D2500/1022—Electromagnet
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/10—System to be controlled
    • F16D2500/104—Clutch
    • F16D2500/10443—Clutch type
    • F16D2500/1045—Friction clutch
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/10—System to be controlled
    • F16D2500/11—Application
    • F16D2500/1107—Vehicles
    • F16D2500/111—Agricultural
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/30—Signal inputs
    • F16D2500/316—Other signal inputs not covered by the groups above
    • F16D2500/3166—Detection of an elapsed period of time
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/50—Problem to be solved by the control system
    • F16D2500/51—Relating safety
    • F16D2500/5104—Preventing failures
    • F16D2500/5106—Overheat protection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2500/00—External control of clutches by electric or electronic means
    • F16D2500/70—Details about the implementation of the control system
    • F16D2500/71—Actions
    • F16D2500/7101—Driver alarm

Abstract

A coupling assembly, for an agricultural implement, comprises a friction coupling 1 actuated by an electromagnet 6 controlled by a controller 7. If a predetermine speed difference between housing 2 and hub 3 is exceeded, for a predetermined time, speed sensors 25, 26 cause the electromagnet to be activated, via controller 7, to relieve the load on friction plates 10, thereby partially or fully disengaging the friction coupling 1 and generating a warning signal so that any risk of overheating is reduced. The friction coupling has a plurality of friction plates 10 which are loaded between a pressure plate 14 and hub plates 12, 13 by springs 15, 16 so that, in an engaged state, a nominal torque is transmitted by the assembly. Electromagnet 6 may also be controlled so that torque transmitted during acceleration of a drive line is built up slowly to the nominal torque. If the friction coupling is to be loaded additionally a second electromagnet may be used to increase the load produced by springs 15, 16.

Description

2364556 Title: Control of Friction Coupling for Agricultural Implements
Description of Invention
This invention relates to a method of controlling a coupling assembly for agricultural implement drivelines, and comprising a friction coupling.
Friction couplings are used in agricultural machinery in those cases where large masses, e.g. flywheels, have to be accelerated. During the acceleration phase, the coupling slips and transforms the energy absorbed in the process into heat. The friction coupling in such implements also reacts if a blockage occurs inside the implement, so that the entire friction power, i.e. the driving power is transformed into heat by friction in the coupling. The coupling heats up very quickly. The stored heat can only be dissipated via the surface of the coupling. In consequence, cooling takes a correspondingly long time, and there is a great risk of the friction coupling overheating. This is the reason why friction couplings are used only in those cases where large masses have to be accelerated and where overloading due to blockages occurs only occasionally.
It is the object of the invention to provide a method of controlling a coupling assembly with a friction coupling wherein the risk of overheating can be reduced so that the coupling can have a correspondingly longer service life.
According to the invention, we provide a method of controlling a friction coupling which comprises a housing, a hub and a friction assembly loaded by a pressure plate, wherein the pressure plate is loaded by pressure springs and the pressure applied to the friction assembly is adjustable by an actuating device; wherein the adjustment is effected by control means and wherein during acceleration within a predetermined period of time, the pressure applied to the friction assembly is increased from a starting minimum value to the full value of pressure application; and wherein the speeds of the housing ZD 2 and hub are measured and compared and, if a predetermined speed differential is exceeded over a predetermined period of time, the pressure applied to the friction assembly is caused to be relieved and a warning signal is generated.
The advantage of a method in accordance with the invention is that, during acceleration, the transmitted torque can slowly be built up to the nominal torque, so that, if there exists a high speed differential, the specific surface pressure values at the beginning of the coupling process are low and that, as compared to the conventional solution, there is generated less heat which has to be absorbed by the coupling. The risk of the coupling overheating is reduced accordingly and the service life is increased. When the actuating device no longer applies adjustment pressure to the friction assembly, the coupling is set to the nominal torque.
The pressure applied to the friction assembly may be increased for a predetermined period of time in order to act against a reduction in the friction value when the coupling is used frequently and to free the implement in the case of a blockage.
Overall, the advantage achieved with such a method of operation with controlled starting behaviour consists in that the drivelines connected to and following the coupling assembly can be designed without having to take into account the starting torque peaks. Even when the coupling is warm, it is possible to provide compensation during the starting process in that the pressure applied to the friction coupling may be increased, as a result of which the transmission of torque by the coupling can be increased to such an extent that it corresponds to the normal starting behaviour of the coupling when it is cold.
The invention will now be described with reference to the drawings, wherein:
Figure 1 shows a first embodiment of a coupling assembly with a friction coupling and an electromagnet in half a longitudinal section; and Figure 2 shows a second embodiment wherein, in addition to the friction coupling, a claw coupling is connected in series.
Figure I shows a friction coupling I which can be actuated electromagnetically and comprises a housing 2, a hub 3, a friction assembly 4 and an actuating device 5 with an electromagnet 6 and an anchor plate 19. The electromagnet 6 can be connected to a power source 8 by control means 7.
The housing 2 which is arranged and centred on a longitudinal axis 9 comprises a first friction face 10 disposed perpendicularly relative to the longitudinal axis 9 and a housing plate I I which is connected to the housing 2 so as to be rotationally fast relative to the longitudinal axis 9 and adjustable in the direction of the longitudinal axis 9.
In the housing 2, there is received the hub 3 so as to be centred on the longitudinal axis 9 and so as to be rotatable relative to the housing 2 around the longitudinal axis 9 and displaceable axially relative thereto to a limited extent. A first hub plate 12 is connected to the hub 3 so as to be rotationally fast and axially non-displaceable, with a second hub plate 13 being connected to the hub 3 so as to be rotationally fast relative to the longitudinal axis 9 and displaceable in the direction of the longitudinal axis 9.
A pressure plate 14 adjoins the first hub plate 12 and is loaded by pressure springs 15, 16 which, in turn, bear against a supporting plate 17 connected to the housing 2. The supporting plate is held by a cylindrical sleeve in the open end of the housing, the sleeve being held by, for example, portions pressed into circumferentially extending openings in the housing. Through the centres of the springs there extend setting pins 18 which are parallel to the longitudinal axis 9, being axially fixed to the pressure plate 14 and extending into apertures 20 in an annular anchor plate 19, being axially held in the latter by means of securing rings 3 1.
The setting pins 18 extend through respective circumferentially spaced clearance apertures in the supporting plate 17.
Between the first friction face 10 of the housing 2 and the second hub plate 13 as well as between the latter and the housing plate 11 and also between the housing plate 11 and the first hub plate 12 as well as between the latter and the pressure plate 14, there are arranged friction plates 2 1.
The anchor plate 19 adjoins the electromagnet 6 and, by means of fixing elements as shown at 30, is connected to the supporting plate 17 of the housing 2 in an axially displaceable and rotationally fast way. Even if wear occurs at the friction plates 21, there does not occur any contact between the anchor plate 19 and the electromagnet 6. Furthermore, the fixing elements 30 prevent the setting pins 18 from being bent when the friction coupling 1 starts operating. The fixing element 30 shown in the drawing has been displaced through about 30' about the axis 9 in order to appear in the plane of the drawing.
The electromagnet 6 is annular in shape; it is arranged co-axially around a portion 22 of the hub 3 which projects from the housing 2; it is rotatable relative to the hub 3 and supported by rolling contact bearings 23 so as to be non-adjustable in the direction of the longitudinal axis 9. Securing means 24 prevent the electromagnet 6 from rotating when the friction coupling I starts operating.
The hub 3 and the housing 2 are associated with respective speed sensors 25, 26 which measure the speed per unit of time of the respective component. The first speed sensor 25, the second speed sensor 26 and the electromagnet 6 are connected to the control means 7, with the data measured by the speed sensors 25, 26 serving as input signals by means of which the electromagnet 6 can be controlled.
As a result of the electromagnet 6 being controlled, the torque transmitted during an acceleration of the driveline can be built up slowly to the required nominal torque. If, at the start of the coupling operation, there exists a high speed differential between the hub 3 and the housing 2, the specific surface pressure values existing between the housing plate 11 and the hub plates 12, 13 and the friction plates 21 can be minimised, as a result of which the generated heat, which has to be absorbed by the friction coupling 1, can also be minimised. The risk of overheating is reduced and the service life of the friction coupling I is increased. - If a predetermined speed differential between the housing 2 and the hub 3 is exceeded for a predetermined period of time, the speed sensors 25, 26 cause the electromagnet 6 to be activated via the control means 7 and thus relieve the load on the friction assembly 4. A warning signal indicates to the operative that overloading has occurred, so that the machine can be stopped and that any blockages which may have caused the overloading can be removed.
Furthermore, the control means 7 comprise a control member 27 which, when the friction coupling I starts operating, causes the actuating force generated by the electromagnet 6 and acting against the force of the pressure springs 15, 16 to drop from a maximum to zero during a predetermined period of time. If the electromagnet 6 no longer applies a force to the pressure plate 14 in a load relieving sense, then the friction coupling I is set to the required nominal torque.
In case the pressure plate 14 is to be loaded additionally, there may be provided a second electromagnet or an additional coil which may be arranged co-axially relative to the first electromagnet 6. It may be arranged to act on the anchor plate 19 in the opposite sense to the electromagnet 6. As a result, there can be achieved a brief increase in torque. A blocked implement can thus be freed and it is possible to compensate for a reduction in torque which occurs when the friction coupling I is heated due to a decreasing friction value between the housing plate I I and the hub plates 12, 13 and the friction plates 21.
Figure 2 shows an embodiment wherein, in addition to the friction coupling I with the control means 7, there is provided a claw coupling 28 connected in series relative to the friction coupling 1. A purely 6 electromagnetically actuated friction coupling I is disadvantageous in that when uncoupling the driveline, the electromagnet 6 requires continuously to be supplied with electric current. The claw coupling 28 achieves an energy-inputfree interruption in the power flow- if the driveline has to be disconnected over a long period of time. The claw coupling 28 is arranged and centred on the longitudinal axis 9 and comprises a claw 29 which engages a corresponding recess 32 in the hub 3 when the agricultural implement is in operation. If disconnection is to take place, the claw 29 of the claw coupling 28 is pulled out of the hub 3 by means of a switching yoke which can be made to engage a corresponding recess 33 of the claw coupling 28, so that the power flow is interrupted.
In the present specification "comprise" means "includes or consists of' and "comprising" means "including or consisting of'.
7

Claims (4)

1. A method of controlling a friction coupling which comprises a housing, a hub and a friction assembly loaded by a pressure plate, wherein the pressure plate is loaded by pressure springs and the pressure applied to the friction assembly is adjustable by an actuating device; wherein the adjustment is effected by control means and wherein during acceleration within a predetermined period of time, the pressure applied to the friction assembly is increased from a starting minimum value to the full value of pressure application; and wherein the speeds of the housing and hub are measured and compared and, if a predetermined speed differential is exceeded over a predeten-nined period of time, the pressure applied to the friction assembly is caused to be relieved and a warning signal is generated.
2. A method according to Claim 1, wherein the pressure applied to the friction assembly further is increased for a predetermined period of time.
3. A method according to Claims I and 2, wherein the minimum value of the pressure force is zero.
4. A method of controlling a friction coupling, substantially as hereinbefore described.
GB0119888A 1999-09-09 2000-06-28 Control of friction coupling for agricultural implements Expired - Fee Related GB2364556B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19943209A DE19943209C2 (en) 1999-09-09 1999-09-09 Coupling arrangement for agricultural implements
GB0015644A GB2354048B (en) 1999-09-09 2000-06-28 Coupling assembly for agricultural implements

Publications (3)

Publication Number Publication Date
GB0119888D0 GB0119888D0 (en) 2001-10-10
GB2364556A true GB2364556A (en) 2002-01-30
GB2364556B GB2364556B (en) 2002-12-18

Family

ID=26054899

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0119888A Expired - Fee Related GB2364556B (en) 1999-09-09 2000-06-28 Control of friction coupling for agricultural implements

Country Status (1)

Country Link
GB (1) GB2364556B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2414283A (en) * 2004-05-06 2005-11-23 Dyson Ltd A slip responsive clutch in a vacuum cleaner

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2164408A (en) * 1984-09-15 1986-03-19 Massey Ferguson Services Nv Clutch protection system
DE3540719A1 (en) * 1984-12-01 1986-06-05 Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen Device for safeguarding friction clutches against overloading
US5030942A (en) * 1989-02-27 1991-07-09 Jean Walterscheid Gmbh Process and device for measuring and indicating load conditions in drivelines of agricultural implements

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2164408A (en) * 1984-09-15 1986-03-19 Massey Ferguson Services Nv Clutch protection system
DE3540719A1 (en) * 1984-12-01 1986-06-05 Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen Device for safeguarding friction clutches against overloading
US5030942A (en) * 1989-02-27 1991-07-09 Jean Walterscheid Gmbh Process and device for measuring and indicating load conditions in drivelines of agricultural implements

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2414283A (en) * 2004-05-06 2005-11-23 Dyson Ltd A slip responsive clutch in a vacuum cleaner
US7731618B2 (en) 2004-05-06 2010-06-08 Dyson Technology Limited Clutch mechanism
US8011062B2 (en) 2004-05-06 2011-09-06 Dyson Technology Limited Vacuum cleaner motor assembly

Also Published As

Publication number Publication date
GB0119888D0 (en) 2001-10-10
GB2364556B (en) 2002-12-18

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20060628