DE102009028152B4 - Load torque lock - Google Patents

Abstract

Lastmomentsperre for locking load-side torques in both directions with a non-rotatable component (1) and a rotatable component (2) by means of an actuator (11, 12, 13) rotatably connected to each other and detachable, characterized in that at least one blocking element ( 8) is movably mounted on a clutch disc (4), that the clutch disc (4) relative to the rotationally fixed component (1) limited rotation and by means of the actuator (11, 12, 13) against a complementary coupling surface (5) of the rotatable component (2 ) is axially displaceable, and that on the non-rotatable component (1) cooperating with the at least one locking element (8) cam assembly (9, 10) is provided, the blocking element (8) from an inoperative position into a rotation of the rotatable component ( 2) relative to the rotationally fixed component (1) positively locking position then moves when the clutch disc (4) with the complementary coupling surface (5) of the rotatable component (2) is engaged.

Description

The invention relates to a load torque lock for locking load-side torques in both directions of rotation with a non-rotatable component and a rotatable component, which by means of an actuator rotatably connected to each other and are detachable.

Load torque locks are used when an adjusting movement is effected by means of a drive member and at standstill of the drive member for externally acting loads such actuating movement should be automatically blocked to hold a locking position when not operating the drive member, so that an inadvertent adjustment of a load part is prevented ,

For example, if an actuator is operated electrically, pneumatically or hydraulically, the load part must be automatically blocked in the current position in the event of a power failure or a pressure drop, for which different brakes are available. There are actuated by spring pressure or by means of permanent magnets single and multi-surface brakes that engage automatically in case of power failure or pressure drop. Such single or multi-surface brakes, such as disc brakes, may also have electromechanically, electromagnetically, pneumatically or hydraulically actuated brake pistons which, however, must then comprise an independent system for actuation which remains operative in the event of a power failure or pressure drop of the actuator.

From the DE 10 2007 045 371 A1 is a load torque lock known, which allows automatic locking load-side torques in both directions. In case of failure of the power supply to an actuator, the load torque lock acts automatically and can safely lock high load moments in the locked position.

The load torque lock is rotatably arranged with an input and an output element in a housing and has a first and a second component, which are each rotatable about an axis of rotation. These are rotatable relative to one another from a neutral position by a maximum angle in a first direction of rotation and a further maximum angle in a second direction of rotation, wherein the second component is stationary and is in operative connection with the input element. The first component is in operative connection with the output element, wherein the second component is in operative connection with a brake, which transmits a torque acting on the output member to the housing. There are at least two gradients on the first or second component, which are designed such that the first component is moved along its axis of rotation during a relative rotation between the first and the second component, which opens the brake. In a continuation of the relative rotation about the respective maximum angle, a positive connection between the first and the second component is produced, so that a torque transmission from the input element to the output element is possible.

Electromagnetically actuated, frictionally engaged single-surface brakes are offered by the company magneta GmbH & Co. KG. Their load bearing is limited by the electromagnetically caused frictional engagement. A higher load torque absorption can be achieved by a positive engagement of the brake elements, for example by toothed couplings with electromagnetic actuation, which are offered for example by the company Maschinenfabrik Mönninghoff GmbH & Co. KG. A disadvantage of these brakes or clutches is the use of an actuating mechanism, for which an independent energy source is required if these known brakes or clutches are to be automatically activated in the event of a power failure or pressure loss. This is especially true when such load torque locks are used in conjunction with actuators in the field of automotive technology, materials handling, handling technology and building services. Thus, most generic brakes on a spring which constantly load the brake elements with a closing force, while the brake associated actuator actively presses apart the brake elements. In case of failure of the power supply for the actuator, therefore, the spring automatically closes the brake. A disadvantage of these last-mentioned brakes is that when they have positively acting clutch or brake components, these components by construction and centrifugal force above a limit speed reject each other axially and thus open the brake again. In addition, the engagement force and thus the braking force is directly dependent on the Aktuatorkraft, because the responsible for the automatic closing of the brake spring can be interpreted only as strong in terms of their closing force, as the opening force of the associated actuator.

To avoid this disadvantage, self-switching freewheels are often used, blocking the restoring torques. The company LuK GmbH & Co. OHG offers a sprag freewheel that locks in both directions when the drive stops. In this freewheel, there is the disadvantage that the freewheel opens when the driven part rotates faster due to operational conditions than the actuator, so that the freewheel opens briefly and then closes again, which leads to a jerking of the output leads, with alternately the drive and the output run faster.

This also applies, for example, to one in the DE 10 2005 023 250 A1 described actuator which performs a desired adjustment of a wheel guide member of a motor vehicle and having a switchable in both directions Klemmrollengesperre which causes external forces that are introduced via the chassis in the actuator backwards, be safely collected without the actuator undesirable due to these external forces Performs adjusting movements.

Although such Klemmrollengesperre work very safe, but they jerky, so that when operating the actuator under load, the very unfavorable case of blocking pressure can occur when torques that are introduced backwards into the actuator, are faster than the actuation of the actuator by the Drive part, so that the Klemmrollengesperre blocked and then released immediately.

Similarly, one in the DE 197 53 106 A1 described load torque lock, which instead of clamping rollers clamping body, which may have both a non-positive and a positive engagement between the drive member and the output member.

The invention has for its object to provide a load torque lock for automatically locking load-side torques in both directions, which acts automatically in case of failure of the power supply to an actuator, and can safely lock high load moments in the locked position. It would also be advantageous if the blocking effect occurs progressively.

To solve this problem, it is proposed that a load torque lock for locking load-side torques in both directions with a non-rotatable component and a rotatable component, which are connected by an actuator rotatably connected to each other and detachable, such form that at least one locking element is movably attached to a clutch disc in that the clutch disc is limitedly rotatable with respect to the non-rotatable component and axially displaceable by means of the actuator against a complementary coupling surface of the rotatable component, and that a cam arrangement cooperating with the at least one blocking element is provided on the non-rotatable component, which isolates the blocking element from an inoperative position into one a rotation of the rotatable component relative to the rotationally fixed component positively locking position then moves when the clutch disc with the complementary coupling surface of the rotatable component in E is in.

The clutch disc thus initially rotated limited relative to the rotationally fixed component, since it is taken away from the rotatable component until the locking member is moved by the cam assembly from its inoperative position in the rotatable component holding position, wherein in the end position a positive engagement takes place and the size of the lockable, load-side torque depends only on the dimensioning of the cam assembly and the locking element.

An advantageous embodiment is that the at least one blocking element is arranged so elastically displaceable on the clutch disc that it can be guided by the cam arrangement radially displaceable for positive engagement with at least one locking projection on the rotatable component and for positive engagement with a radially opposite locking surface on the cam assembly is. This can preferably be effected by a cam arrangement on the non-rotatable component comprising at least one radially inwardly leading ramp and at least one radial latching surface at the end of the ramp.

For a symmetrical structure, which is also suitable for high speeds, and for an increase in the load-side torque are preferably two diametrically opposed pairs of locking elements on the clutch disc, two diametrically opposite pairs of locking projections on the rotatable component and two diametrically opposed locking surfaces provided on the cam assembly, of which each one pair acts in one direction of rotation and the other pair in the other direction of rotation.

The locking elements can be connected by means of flexible webs with the clutch disc, which have to transmit only small forces. The flexible webs are arranged radially on the outside of the clutch disc.

The actuator may comprise, for example, an armature connected to the clutch disc and a co-operating, non-rotatably mounted electromagnetic coil, however, a pneumatic or hydraulic actuator may be provided for axial displacement of the clutch disc.

Preferably, the actuator comprises a spring engaging the clutch disc with the complementary clutch face of the rotatable member, while the solenoid coil or a pneumatic or hydraulic actuator disengages the clutch sprocket by energization. To this It is achieved that the load torque lock according to the invention in case of power failure or pressure drop comes into effect and thus no power supply is required.

If the actuator comprises a cylindrical helical compression spring which acts on the clutch disc in engagement with the complementary coupling surface of the rotatable component, then one end thereof may be fixed non-rotatably with respect to the non-rotatable component, while the other end is non-rotatably attached to the clutch disc , As a result, the cylindrical helical compression spring acts not only as a compression spring for pressing the clutch plates to the complementary clutch surface, but also generates a torsional resistance against rotation of the clutch disc, whereby the casserole of the locking projections is delayed on the ramps of the cam order and locking the load torque lock according to the invention in case of power failure or pressure drop is progressive.
As a variant of the embodiment described above can be provided according to the invention that instead of the cam assembly, a cam gear is used, which has at least two relatively rotatable components, at least one of these components has a curved guide surface on which the at least other component at a relative rotation of these components can be guided along. In a specific embodiment, each of these two components of the cam gear has curved guide surfaces which slide against each other, so that in comparison to the described cam arrangement in a much more variable manner temporally non-linear axial actuation profiles can be realized.

• 1 einen schematischen Querschnitt durch die erfindungsgemäße Lastmomentsperre in ihrer entsperrten Stellung,
• 2 einen verkleinerten, schematischen Längsschnitt durch die Lastmomentsperre gemäß 1, und
• 3 die Lastmomentsperre der 1 in ihrer Sperrstellung.

The invention will be explained below with reference to an embodiment shown in the drawing. In the drawing shows

• 1 a schematic cross section through the load torque lock according to the invention in its unlocked position,
• 2 a reduced, schematic longitudinal section through the load torque lock according to 1 , and
• 3 the load torque lock the 1 in their locked position.

From the load torque lock invention, only the essential components are shown, in particular, no drive is shown. A non-rotatable component 1 coaxial with a rotatable component 2 can be arranged in a transmission, serves to the rotatable component 2 to hold in the instantaneous position when the power supply of an actuator having this load torque lock fails.

On the rotatable component 2 are four at an angle of 90 °, radially projecting locking projections 3 arranged. One to the rotatable component 2 Coaxially arranged clutch disc 4 has one with a complementary coupling surface 5 on the rotatable component 2 co-operating coupling surface 5 ' on, with these clutch surfaces 5 . 5 ' are preferably provided with friction linings to a frictional engagement between the rotatable component 2 and the clutch disc 4 to effect. However, the complementary coupling surfaces 5 . 5 ' Also have radial teeth, so that a positive connection between the clutch disc 4 and the rotatable component 2 is possible.

At the clutch disc 4 are four at a angle of 90 ° arranged radial leg 6 attached, the circumferentially extending resilient webs 7 go over, at the ends towards the rotatable component 2 extending blocking elements 8th are attached. On the non-rotatable component 1 a cam arrangement is provided which consists of radially inwardly extending ramps 9 and radial locking surfaces 10 consists. The clutch disc 4 can be by means of an actuator from an electromagnetic coil 11 , an anchor axially displaceable therein 12 and a cylindrical helical compression spring 13 move axially.

Will the solenoid coil 11 energized, it becomes the anchor 12 with the clutch disc attached thereto 4 towards the electromagnetic coil 11 drawn. In this case, the cylindrical helical compression spring 13 squeezed and the clutch disc 4 is from the complementary coupling surface 5 on the rotatable component 2 lifted. Here take the at the clutch disc 4 attached locking elements 8th the in the 1 shown position in which they by the spring action of the webs 7 be held radially outside and with the locking projections 3 on the rotatable component 2 do not come into contact.

Is the power supply to the electromagnetic coil 11 interrupted, so presses the cylindrical helical compression spring 13 the anchor 12 and the attached clutch disc 4 with its coupling surface 5 ' against the complementary coupling surface 5 on the rotatable component 2 , This will cause the rotation of the rotatable component 2 on the clutch disc 4 transfer. The clutch disc 4 can twist limited, with the locking elements 8th through the ramps 9 be guided radially inward until they at the radial locking surface 10 on the non-rotatable component 1 nudge. In this position, the locking elements protrude 8th in the space between two adjacent locking projections 3 radially in, and they prevent the rotatable component 2 at a further rotation, as soon as the locking projections 3 at the locking elements 8th abut, which can not move in the circumferential direction, as they at the radial locking surfaces 10 abutment (see 3 ).

For a progressive braking effect between the clutch disc 4 and the complementary coupling surface 5 on the rotatable component 2 to reach is an end 14 the cylindrical helical compression spring 13 with the non-rotatable component 1 connected while the other end 15 with the clutch disc 4 over the anchor 12 connected is. This causes the clutch disc to rotate 4 when attached to the complementary coupling surface 5 is pressed against the torsional resistance of the cylindrical helical compression spring 13 , so that thereby the rotatable component 2 is slowed down before the locking projections 3 on the rotatable component 2 to the radially inwardly migrated locking elements 8th abut and the further rotation of the rotatable component 2 then block positively.

For each direction of rotation act two diametrically opposed locking projections 3 , Locking elements 8th and radial locking surfaces 10 together, but can also more locking projections 3 and blocking elements 8th be provided for then a corresponding number of cam assemblies 9 . 10 is to be provided.

For locking in only one direction of rotation are a locking projection 3 , a blocking element 8th a ramp 9 and a radial locking surface 10 required. For locking in both directions with only one locking projection on the rotatable component 2 are two blocking elements 8th , two ramps 9 and two radial locking surfaces 10 required, but the load torque lock also works with any number of these coupling elements.

The torsionally rigid with the clutch disc 4 and the non-rotatable component 1 connected helical compression spring 13 as well as the elastic deformation of the webs 7 turn the clutch disc 4 upon actuation of the actuator 11 . 12 and an active turning back of the rotatable component 2 in the starting position, whereby the load torque lock is unlocked.

The advantage of the load torque lock according to the invention lies in the actuation of the locking elements 8th passing through the rotatable component to be blocked 2 and the cam assembly 9 . 10 be moved radially inwardly, whereby a self-energizing effect is achieved in the operation, without jamming the load torque lock. Furthermore, the stroke of the actuator 11 . 12 . 13 be very low for an actuation of the load torque lock, since only the air gap of the clutch disc 4 must be overcome, which keeps the required space small.

The load torque lock according to the invention consists of few and simple components, which allow a cost-effective production. The load torque lock is particularly suitable for closing at high relative speed, as to the engagement of the load torque lock, the friction between the clutch disc and the complementary clutch surface 5 on the rotatable component 2 supports.

Since the load torque lock according to the invention a small relative rotation of the rotatable component 2 relative to the non-rotatable component 1 requires, in particular, despite this property is very advantageous used when the rotatable component 2 a transmission with high translation is connected downstream.

LIST OF REFERENCE NUMBERS

1

Non-rotating component

2

Rotatable component

3

catch projection

4

clutch disc

5

Coupling surface on the rotatable member. 2

5 '

Clutch surface on the clutch disk 4

6

radial leg

7

Springy bars

8th

blocking element

9

ramp

10

Radial locking surface

11

Electromagnetic coil

12

anchor

13

Cylindrical helical compression spring

14

Axial end of the helical compression spring 12

15

Other axial end of the helical compression spring 12th

Claims (9)

Lastmomentsperre for locking load-side torques in both directions with a non-rotatable component (1) and a rotatable component (2) by means of an actuator (11, 12, 13) rotatably connected to each other and detachable, characterized in that at least one blocking element ( 8) is movably mounted on a clutch disc (4) that the clutch disc (4) relative to the rotationally fixed Component (1) limited rotatable and by means of the actuator (11, 12, 13) against a complementary coupling surface (5) of the rotatable component (2) is axially displaceable, and that on the non-rotatable component (1) with the at least one blocking element (8 ) cooperating cam assembly (9, 10) is present, which then moves the blocking element (8) from an inoperative position into a rotation of the rotatable component (2) relative to the non-rotatable component (1) positively locking position when the clutch disc (4) with the complementary coupling surface (5) of the rotatable component (2) is engaged. Load torque lock after Claim 1 , characterized in that the at least one blocking element (8) is arranged so elastically displaceable on the clutch disc (4) that it (8) by the cam assembly (9, 10) radially displaceable for positive engagement with at least one latching projection (3) on rotatable component (2) and for positive engagement with a radially opposite latching surface (10) on the cam assembly (9, 10) can be guided. Load torque lock after Claim 2 , characterized in that two pairs of diametrically opposed locking elements (8) on the coupling disc (4), two diametrically opposite pairs of locking projections (3) on the rotatable component (2) and two diametrically opposed locking surfaces (10) on the cam assembly (9, 10) are provided. Load torque lock after Claim 2 or 3 , characterized in that the locking elements (8) by means of flexible webs (7) are connected to the coupling disc (4). Lastmomentsperre after one of Claims 2 to 4 , characterized in that the cam arrangement (9, 10) on the rotationally fixed component (1) consists of at least one radially inwardly leading ramp (9) and at least one radial latching surface (10). Lastmomentsperre after one of Claims 1 to 5 , characterized in that the actuator (11, 12, 13) has an armature (12) connected to the clutch disc (4) and a co-operating, non-rotatable electromagnetic coil (11). Load torque lock after Claim 6 characterized in that the actuator (11, 12, 13) comprises a spring (13) engaging the clutch disc (4) with the complementary clutch surface (5) of the rotatable component (2), while the electromagnetic coil (11) comprises the clutch disc (4) disengages by applying an electrical voltage. Lastmomentsperre after one of Claims 1 to 7 characterized in that the actuator (11, 12, 13) comprises a cylindrical helical compression spring (13) acting on the clutch disc (4) in engagement with the complementary clutch face (5) of the rotary member (2), one of which End (14) rotationally fixed with respect to the rotationally fixed component (1) is fixed and the other end (15) rotationally fixed to the clutch sprocket (4) is attached. Lastmomentsperre after one of Claims 1 to 8th , characterized in that instead of the cam assembly (9, 10) a cam disc is used, which has at least two relatively rotatable components, both components of the cam gear having curved guide surfaces which slide against each other, so that in a relative rotation of these components temporally non-linear axial actuation profiles can be realized.

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