KR100919857B1 - Elevator motor brake torque measurement device - Google Patents

Abstract

The elevator machine 20 useful in the elevator system 10 includes a motor frame 26 that supports a motor 24 that selectively rotates the motor shaft 28. The brake 36 selectively applies braking force to prevent rotation of the motor shaft 28. One or more load sensors 46 prevent undesired movement of the brake 36 and provide an indication of the load generated from the application of braking force. The disclosed example uses the first resistance member 46 to inhibit movement of the brake relative to the motor frame 26 when the load is below the threshold load and to inhibit movement when the load exceeds the threshold load. And using the second resistance member 60 for this purpose.

Description

Elevator motor brake torque measuring device {ELEVATOR MOTOR BRAKE TORQUE MEASUREMENT DEVICE}

The present invention relates generally to elevator brakes, and more particularly to elevator machine brakes comprising a load sensor indicative of a load on the elevator machine brake.

Elevator systems are widely known and used. Typical devices include an elevator car that moves between the landings of a building to transport passengers or cargo between different building floors. Motorized elevator machines typically move a rope or belt assembly that supports the weight of the vehicle body and moves the vehicle body through a hoistway.

The elevator machine includes a machine shaft that is selectively rotatably driven by a motor. The machine shaft typically supports sheaves that rotate with the machine shaft. Ropes or belts are tracked through the sieve so that the vehicle body descends when the elevator machine rotates the sheave in one direction and the vehicle body rises when the sheave rotates in the opposite direction. The elevator machine also includes a brake that engages a disk or flange that rotates with the machine shaft to hold the machine shaft and sheaves stationary when the vehicle body is in the selected platform.

Conventional elevator systems include a controller that collects weight information of the vehicle body and controls the elevator machine based on the weight information. Typically, the controller receives weight information from load-measuring devices installed on the floor of the vehicle body. Disadvantageously, floor-mounted load-measuring devices often do not provide sufficiently accurate weight information. For example, floor-mounted load-measuring devices when the weight in the vehicle body is small may not accurately distinguish the small load from the background weight of the vehicle body (effects due to noise generated during measurement). Also, loads centered within the bodywork will not provide accurate weight information. Additional load-measuring devices may be used to increase accuracy, but each additional device increases the cost and maintenance effort of the elevator system. Changes to the elevator or modifications to the body, such as counterweights, are not taken into account by the floor sensors.

Other elevator systems use elevator brakes to represent weight on the body. Typically, these systems utilize a load cell utilized between the brake and the floor of the elevator machine room. The torque generated from the application of the brake creates a predetermined load on the load cell. Disadvantageously, these systems require a large amount of space in the elevator machine room and are inaccurate and expensive due to the brake or machine weight added to the amount of load cells. In this type of construction the elevator brake and load cells may be stopped to operate properly under high levels of torque, which may cause undesirable conditions in the elevator system. One proposed solution involves making the load cells larger and stronger, but this can cause a loss of sensitivity indicative of the weight of the vehicle body.

There is a need for a strong, compact and sensitive system to provide elevator body weight information. The present invention addresses this need and provides improved capabilities while avoiding the disadvantages and drawbacks of the prior art.

1 schematically illustrates selected portions of an exemplary elevator system;

2 is a schematic cross-sectional view of selected portions of an exemplary elevator machine.

3 is a schematic view of the exemplary elevator machine of FIG. 2 corresponding to the cross-sectional view taken along line 3-3;

4 is a schematic view of selected portions of another embodiment of an exemplary elevator machine;

5 is a schematic partial cross-sectional view of selected portions of another embodiment of an exemplary elevator machine;

6 is a schematic partial cross-sectional view of selected portions of another embodiment of an exemplary elevator machine;

7 is a schematic view of selected portions of another embodiment of an exemplary elevator machine.

8 is a schematic view of selected portions of another embodiment of an exemplary elevator machine;

9 is a schematic partial cross-sectional view of selected portions of another embodiment of an exemplary elevator machine.

Exemplary elevator machines useful in elevator systems include a motor frame that supports a motor that selectively rotates the motor shaft. The brake selectively applies braking force to prevent rotation of the motor shaft. One or more load sensors inhibit the movement of the brake relative to the motor frame. The load sensor provides an indication of the load derived from the application of the braking force, in which the associated elevator car represents the weight of the imbalance in relation to the counterweight.

In another example, the elevator machine assembly includes a first member, the first member resisting the movement of the braking member relative to the rigid member against the load between the braking member and the rigid member below the critical operating load of the first member. do. The second member inhibits movement when the load exceeds the threshold operating load.

In one example, the first member is a load cell.

Various features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiments below. The drawings that accompany the detailed description can be briefly described as follows.

1 shows selected portions of an example elevator system 10 that includes an elevator body 12 that moves in a hoistway 14 between the landings 16 of a building. In the example shown, the platform 18 above the elevator car 12 supports the elevator machine 20. The elevator machine 20 moves the body 12 and counterweights 22 upwardly and downwardly as generally known within the hoistway 14 to transport cargo, passengers or both.

2 shows a cross-sectional view of selected portions of an exemplary elevator machine 20 that includes a motor 24 supported by a motor frame 26. Motor 24 selectively drives shaft 28 in response to signals from controller 30. Rotation of the shaft 28 moves the traction sheaves 32 that move the ropes or belts to move the elevator car 12 and counterweight 22 in the hoistway 14 as is known.

Exemplary shaft 28 includes disk 34 in brake 36. The brake-applying portion 38 of the brake 36 selectively applies a braking force to the disk 34 to prevent rotation of the shaft 28. In one example, the controller 30 commands the brake-applying portion 38 to hold the elevator car 12 at the selected building platform 16 or to apply a braking force to slow the movement of the elevator car 12.

3 corresponds to a bottom view of the longitudinal axis 42 of the shaft 28 of selected portions of the exemplary elevator machine 20 of FIG. 2. The brake 36 includes mounting bosses 44a, each of which supports one end of the load sensor 6. In one example, the load sensors 46 include a tension-compression load cell that can represent both tensile loads and compression loads. In other examples, load sensors 46 may include other known types of sensors, such as potentiometers, proximity sensors, optical sensors, or piezoelectric materials, for example.

The motor frame 26 includes corresponding mounting bosses 44b, each of which supports opposite ends of the corresponding load sensor 46. In the example shown, the load sensors 46 are secured to the mounting bosses 44a and 44b using fasteners, although other methods of attachment may alternatively be used.

Application of the braking force on the disc 34 creates a load between the brake 36 and the motor frame 26. The load represents the weight difference between the elevator body 12 and the counterweight 22 (that is, the weight of cargo, passengers, etc. in the elevator body 12). The weight difference urges a relative rotational motion (ie torque) relative to the axis 42 between the brake 36 and the motor frame 26. The load sensors 46 prevent this movement and, for example, provide an indication of the load to the controller 30.

These features can provide the benefits of detecting a drag on the brake 36 used in already known assemblies and removing brake sensors (eg, microswitches and proximity sensors). Dragging on the brake 36 occurs when the brake-applying portion 38 fails to completely remove the braking force from the disk 34. In known assemblies, brake sensors detect whether the braking force is removed and provides feedback to the controller 30. The load sensors 46 replace this function by indicating the load between the brake 36 and the motor frame 26.

In the example shown, the corresponding points on the load sensors 46 (eg, points of attachment to the mounting boss 44a) are disposed at approximately 180 ° circumferentially from each other with respect to the axis 42. do. In one example, this provides the advantage of a balanced resistance to movement with respect to the shaft 28 and maintains or increases the sensitivity in the indication of the load.

Each of the motor frame 26 and the brake 36 has corresponding locking members 48a that inhibit movement between the brake 36 and the motor frame 26 when the load exceeds the threshold operating load of the load sensors 46. And 48b). An example critical actuation load causes one or more of the load sensors 46 to disengage from either of the mounting bosses 44a or 44b or otherwise fails to continuously block the relative rotational movement between the brake and the motor housing. It's a load to let you do. The locking members 48a and 48b may move relative to the motor frame 26 by an amount corresponding to the nominal distance before cooperating to prevent movement. This feature allows the load sensors 46 to support the load under normal conditions and reduces or eliminates the load-absorbing interference between the locking members 48a and 48b when the load is below the critical operating load. To maintain or increase the sensitivity of the (46).

In the example shown, the locking member 48b is a brake lock member located between two motor frame lock members 48a. If the load exceeds the threshold operating load of the load sensors 46, the brake 36 may reach the load limit of the load sensors. When rotating the amount corresponding to the nominal distance between the locking members 48a and 48b, the brake lock members 48b correspond to one of the motor frame lock members 48a to further prevent movement of the brake 36. Meshes with one member. This feature allows the use of smaller, less robust and more accurate load sensors 46 compared to known assemblies since the load sensors 46 are not designed to withstand loads above the threshold load. Can provide benefits.

The example shown includes the elastic cushion material 54 in whole or in part between the locking members 48a and 48b. The elastic cushion material 54 absorbs the load at least partially when the locking members 48a and 48b cooperate to prevent relative rotational movement between the brake 36 and the motor frame 26. This feature can provide the benefit of reducing noise when the locking members cooperate.

4 shows selected portions of another exemplary elevator machine 20 including a resistance member 60, a traction member, which cooperates with a single load sensor 46 to prevent movement during brake application. In the example shown, the resistance member 60 may be appreciated that other types of resistance members 60 of other devices may be used, but the portion of the motor frame 26 and one of the brake mounting bosses 44a may be used. A rod received through the opening 61.

The portion and opening 61 of the motor frame 26 containing the resistance member 60 are related to the outer diameter of the resistance member 60 to allow the brake 36 to move in a limited amount relative to the motor frame 26. It includes an inner diameter to enable easy rotational motion. When the brake 36 applies a braking force to the shaft 28, the load generated between the brake 36 and the motor frame 26 propels the brake 36 to rotate relative to the motor frame 26. The load and load sensor 46 is adapted to prevent the large-scale radial movement of the brake 36 with respect to the motor frame 26 (but permits rotational movement of the brake 36). Provides load balancing. Some movement causes the load to transfer or react from the load to the load sensor 46. Large-scale movements are prevented, in which absence of such large-scale movements prevents the load from being transferred to the load sensor 46. The rod thus provides dual functions of stabilizing the brake 36 against the acting load and transferring the load to the load sensor 46. The resistive member 60 may provide the advantages of a cheaper system compared to a system having a plurality of load sensors, for example shown in FIG. 3.

5 shows selected portions of another exemplary elevator machine 20 that includes a bearing resistance member 64 extending circumferentially around a portion of the shaft 28. The bearing resistance member 64 includes an inner diameter and an outer diameter and is received in the corresponding opening 65 of the brake 36 and the motor frame 26. The outer diameter of the bearing resistance member 64 is slightly smaller than the inner diameter of the opening 65 to allow the brake 26 to move slightly relative to the motor frame 36. Similar to the rod resistance member 60 in the example of FIG. 4, the bearing resistance member 64 is capable of large-scale radial movement (ie, non-rotation) of the brake 36 relative to the motor frame 26. Cooperate with a single load sensor 46 to balance the load generated between the brake 36 and the motor frame 26 to prevent.

6 shows selected portions of another example elevator machine 20 that includes a sleeve bushing resistance member 66. Similar to the bearing resistance member 64, the sleeve bushing resistance member 66 and the load sensor 46 are designed to prevent (but, slightly) prevent large-scale radial movement of the brake 36 relative to the motor frame 26. Movement of the motor) cooperates to balance the generated load between the brake 36 and the motor frame 26.

FIG. 7 shows selected portions of another example elevator machine 20 similar to the example shown in FIG. 3, including a metal spacer 68 instead of one of the load sensors 46. . Similar to the examples of bearings, rods and sleeves, the metal spacer 68 and the load sensor 46 may (but are slightly) prevent the large-scale radial movement of the brake 36 relative to the motor frame 26. Movement allows for balancing of the generated load between the brake 36 and the motor frame 26. The metal spacer 68 includes one end attached to the brake boss 44a and a distal end attached to the motor frame mounting boss 44b, using the respective fasteners 70a and 70b. The fasteners 70a and 70b in this example allow some movement of the brake 36 relative to the motor frame so that the load sensor 46 can react to the load and provide an indication thereof.

8 shows selected portions of another exemplary elevator machine 20 that includes compression load sensors 46, for example compression load cells. Each of the illustrated compression load sensors 46 includes a base portion 78 and an input portion 80. In the example shown, the base portion 78 is mounted facing the motor frame 26 with the input portion 80 facing the brake extension member 82. In the case where the brake 36 applies a braking force to the shaft 28, the compression load sensors 46 are produced from the tendency of the brake to rotate relative to the motor frame 26 and the brake extension member 82 and the motor frame ( 26) Display the load between. In one example, the compression load sensor of one of the compression load sensors 46 indicates a load when the brake impedes movement of the shaft in one direction, and the compression load of the other of the compression load sensors 46. The sensor indicates the load when the brakes impede the movement of the shaft in the other direction.

If the load exceeds the threshold load of the compression load sensors 46, the brake extension member 82 acts as a brake lock member 48 and cooperates with the motor from the lock member 48a to brake 36 as described above. Inhibits further movement).

In the example shown, the brake 36 also includes a second brake extension member 84 disposed opposite from the brake extension member 82. In the example shown, the second brake extension member 84 is associated with the resistance member 60. This resistance member may be replaced with the retaining member, and an elastic member 86 may be used instead. The cushion material 86 includes a stiffness less than the stiffness of the compression load sensors 46 so that only a small portion of the load is absorbed by the elastic cushion material 86. This example includes the benefit of increased sensitivity of the compressive load sensors 46 because only a small portion of the load can be removed through absorption by the elastic cushion material 86 and the resistance member 60.

9 shows a partial cross-sectional view of selected portions of another exemplary elevator machine 20 that includes a rigid housing 92 affixed firmly to the motor frame 26. The housing 92 supports the sensing element 94 comprising an elastic element 96 received relative to the brake extension member 82. The outer portion 98 of the sensing element 94 is one electrode of the capacitor and the brake extension member 82 is the other electrode. Elastic element 96 establishes the dielectric properties of the sensing element.

In one example, the elastic element 96 includes a known polymer material that changes the capacitance of the sensor element 94 when the dimension of the polymer material changes. In the example shown, the polymeric material changes dimensions (eg, diameter D) in response to the load between the brake 36 and the motor frame 26 when the brake 36 applies a braking force. The load is transmitted through the brake extension member 82 to compress the elastic element 96. In one example, the load compresses the polymeric material and the sensing elements 94 provide an indication of the change in electrical capacitance resulting from the compression of the polymeric material. The change in electrical capacitance corresponds to the compressed dimension D of the polymeric material in a known manner. The dimension (D) corresponds to the load on the polymeric material, for example, through known stress versus strain analysis, as is known. The controller 30 accepts the capacitance and determines the load between the brake 36 and the motor frame 26 based on a predetermined correlation between the electrical capacitance and the load.

While preferred embodiments of the invention have been disclosed, those skilled in the art will recognize that certain modifications may be made within the scope of the invention. For that reason, the following claims should be considered to determine the scope and content of the present invention.

Claims (20)

In an elevator machine assembly, At least a motor frame for supporting a motor for selectively rotating the shaft; A brake for selectively applying braking force to prevent rotation of the shaft relative to the motor frame; And And at least one load sensor that inhibits movement of the brake relative to the motor frame and provides an indication of the load generated from the application of the braking force. The method of claim 1, And the load sensor comprises a load cell having a frame attachment portion attached directly to the motor frame and a brake attachment portion attached directly to the brake. The method of claim 1, And at least one stop member for preventing rotation of said brake relative to said motor frame when said load exceeds a threshold of said load sensor. The method of claim 1, And the load sensor includes a base and a load input portion, wherein the load sensor is positioned between the brake and the motor frame such that the load input portion receives the load. The method of claim 1, And the load sensor is positioned between corresponding surfaces on the brake and on the motor frame such that the load sensor is subjected to a compressive load during application of the braking force. The method of claim 5, wherein And the load sensor is spaced apart by a nominal distance from at least one of the corresponding surfaces. The method of claim 6, Elevator machine assembly, in whole or in part, comprising a cushion material between the load sensor and the at least one surface. The method of claim 1, And an reaction member cooperating with the load sensor to prevent movement of the brake. The method of claim 8, And the reaction member inhibits radial movement of the brake about the longitudinal axis of the shaft. The method of claim 8, And the reaction member comprises a second load sensor providing an indication of the load. The method of claim 8, And the reaction member is spaced apart in the circumferential direction by at least 90 ° from the position of the load sensor with respect to the longitudinal axis of the shaft. The method of claim 8, And said reaction member comprises a cushion which absorbs said load in whole or in part. In elevator machine assembly, A first member for inhibiting movement of the braking member relative to the rigid member against a load between the braking member and the rigid member which is up to a critical operating load of the first member; And And a second member for inhibiting movement of said braking member relative to said rigid member if said load is greater than said critical operating load. The method of claim 13, The second member includes a locking member supported on each of the rigid member and the braking member, wherein the locking members prevent movement of the braking member relative to the rigid member when the load exceeds the critical operating load. Elevator machine assembly characterized in that for cooperating. The method of claim 14, And the locking members are spaced apart by the nominal distance such that the braking member can move by an amount corresponding to the nominal distance with respect to the rigid member prior to cooperating to prevent movement. The method of claim 15, Elevator machine assembly, characterized in that it comprises a cushion material between the locking members in whole or in part to absorb the load in whole or in part. The method of claim 13, And said first member comprises a load sensor providing an indication of the load between said braking member and said rigid member. A method for measuring a load of an elevator assembly, comprising: an elevator machine having a motor supported by a motor frame, a shaft selectively driven by the motor, and a brake for selectively preventing rotation of the shaft. Applying a braking force to the shaft that generates a load that urges the brake to move relative to the motor frame; Using a first resistance member to inhibit movement of the brake relative to the motor frame and provide an indication of the load when the load is below a threshold load; And Using a second resistance member to inhibit movement of the brake relative to the motor frame when the load exceeds the threshold load. The method of claim 18, And the first resistance member comprises a load sensor to provide an indication of the load. The method of claim 19, Determining the weight of the elevator car based on the indication of the load.