WO2011117083A1

WO2011117083A1 - Power efficient sliding door

Info

Publication number: WO2011117083A1
Application number: PCT/EP2011/053667
Authority: WO
Inventors: Esbjörn BECKMANN
Original assignee: Assa Abloy Ip Ab
Priority date: 2010-03-24
Filing date: 2011-03-11
Publication date: 2011-09-29

Abstract

The present invention relates to the field of door automation and more particularly to a method to reduce power dissipation and increase power efficiency in a door system. In particular it relates to a sliding door system (150, 550), a door drive (100) and a method for moving at least one door panel (151, 551), wherein the electrical motor (103, 503) driving the door panel (151, 551) is also arranged to operate as a generator braking the movement of the door panel. The invention further relates to storing the energy generated during the brake cycle in an electrical energy storage (105, 505) driving the door.

Description

POWER EFFICIENT SLIDING DOOR

TECHNICAL FIELD

The present invention relates to the field of door automation and more particularly to a method to reduce power dissipation and increase power efficiency in a sliding door system. The invention also relates to a corresponding arrangement for automatic door control.

BACKGROUND

Automatic sliding doors are commonly used e.g. in commercial, health care and residential applications. Nowadays, reducing energy consumption in all types of electronic arrangements is a high wanted need. Introducing power efficient electronic equipments is resulting in both economic and environmental value. Due to the high number of repetitions of opening and closing even the small amount of energy required in order to operating a sliding door system will result in a considerable amount of energy over the time.

An automated sliding door opening cycle typically has two phases; an accelerating phase, when the door starts moving and increases its speed and a retarding phase, when the door is slowed down as it is reaching its stop position.

Currently and traditionally, retardation of a sliding door is achieved by mechanical losses in the door, gearbox and/or motor as well as by means of an electronic brake. Typically the mechanical loss is 80% in the gearbox when it operates reversely to brake the door. This works as an efficient mechanical brake, and the power dissipation in the gearbox is substantial. The additional electronic brake consists of resistors that are electronically connected across the motor that drives the door and thus increases the torque in the motor. The brake energy is then dissipated as heat in the resistors. A problem with the current solutions is the bad power efficiency of the door drive system, due to the power consumed by the motor driving the doors in the acceleration phase. The momentum energy required to accelerate the door is high, which puts high requirements on the electrical components of the door drive.

Another problem is the power dissipation in the motor, gearbox and brake resistors. The power dissipation in the brake system may even cause the control unit to overheat.

Furthermore in some situations it is problematic that the automatic door is dependent on an electrical power supply in order to operate. This may cause problems at general power failures or at emergency escapes. If a backup battery is used, it will soon be discharged du to the power dissipation.

Therefore, finding a way to reduce the amount of energy consumed by automated sliding door systems would be most welcome.

SUMMARY OF THE INVENTION

It is an object of the invention to achieve an improved method to reduce the power dissipation and additionally improve the efficiency of a sliding door operator.

According to the invention a power efficient sliding door is achieved by converting the kinetic brake energy released while braking the door to electrical energy and storing it for future use. This effect may be improved further, by optimizing the system so that the overall drive-system is optimized in efficiency both when working to drive the door, and when the system brakes the door, i.e. to minimize the overall mechanical power loss.

With the above description in mind, then, one aspect of the present invention is to provide a door drive and a method for driving a door which seeks to mitigate, alleviate, or eliminate one or more of the above- identified deficiencies in the art and disadvantages singly or in any combination.

A first aspect of the present invention relates to a door drive for a sliding door system adapted to slide at least one door panel from a first position to a second position, wherein the door drive comprises:

- an electrical motor arranged to accelerate the at least one door panel from the first position towards the second position in an acceleration phase and

- an electrical energy storage arranged to drive the electrical motor,

wherein the electrical motor is also arranged to operate as a generator and to brake the movement of the door panel when approaching the second position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage for storage.

In one aspect of the invention the door drive comprises a cable inlet for connection to an electrical power supply for charging the energy storage with electrical power. In one aspect of the invention the door drive comprises a gearbox connected to the electrical motor. In one aspect of the invention the gearbox has symmetrical efficiency in both directions. In another aspect of the invention the gearbox is bevel gear. In one aspect of the invention the door drive comprises a control unit controlling the amount of power that is fed to the electrical motor, gearbox and sliding door system to and from the electrical energy storage.

In one aspect of the invention the door drive is further arranged to drive the at least one first door panel from the second position to the first position. In one aspect of the invention the electrical motor is also arranged to operate as a generator and to brake the movement of the door panel when approaching the first position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage for storage.

In one aspect of the invention the door drive is further arranged to drive a second door panel from a third position to a fourth position. In one aspect of the invention the door drive is further arranged to drive a third door panel from a fifth position to a sixth position.

One aspect of the invention relates to a method for driving a sliding door system adapted to move at least one door panel from a first position towards a second position, using an electrical motor driven by an electrical energy storage, wherein the method comprises the following steps:

- accelerating the at least one door panel from the first position towards the second position with the electrical motor,

- braking the movement of the door panel when approaching the second position using the brake force from the electrical motor operating as a generator and

- storing the energy generated by the generator in the electrical energy storage.

In one aspect of the invention the method comprises the step of charging the energy storage with electrical power from an electrical power supply. In one aspect of the invention the method comprises the step of changing the gearing of the electrical motor/generator using a gearbox. In one aspect of the invention said gearbox has symmetrical efficiency in both directions. In another aspect of the invention said gearbox is bevel gear.

In one aspect of the invention the method comprises the step of controlling the amount of power that is fed to the electrical motor, gearbox and sliding door system to and from the electrical energy storage using a control unit.

In one aspect of the invention the method comprises the step of driving the door from the second position to the first position.

In one aspect of the invention the method further comprises the step of braking the movement of the door panel when approaching the first position by operating the electrical motor/generator as a generator applying a brake force on the door panel and storing the energy generated by the generator in the electrical energy storage.

In one aspect of the invention the method comprises the step of accelerating a second panel from a third position towards a fourth position. In one aspect of the invention the method comprises the step of accelerating a third panel from a fifth position towards a sixth position.

In one aspect the invention relates to a sliding door system comprising at least one door panel and a door drive adapted to move at least one door panel from a first position to a second position, wherein the door drive comprises:

- an electrical energy storage arranged to drive the electrical motor,

wherein the electrical motor is also arranged to operate as a generator and to brake the movement of the door panel when approaching the second position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage for storage. One advantage of the invention is that the overall power consumption is reduced, as the energy is kept within the sliding door system during the complete operation cycle.

Another effect of the invention is that as the door is driven by an internal electrical energy storage. Thereby, in case of a power failure, the door may be operated in normal mode and be opened even if the power supply is cut off.

A further effect is that reducing power loss enables reduction in size and cost of both electronic and mechanical components. Thereby, the overall cost of the door system can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and features, of the present invention will appear from the following detailed description of embodiments of the invention, wherein the embodiments will be described in more detail with reference to the accompanying drawings, in which:

Figure 1 shows a sliding door with a door drive. Figure 2 shows a schematic view of a door drive arrangement.

Figure 3a -3c shows the operation of a sliding door.

Figure 4 shows an exemplary embodiment of a bevel gear suitable for use in a door operation arrangement. It should be added that the following description of the embodiments is for illustration purposes only and should not be interpreted as limiting the invention exclusively to these embodiments/aspects. DETAILED DESCRIPTION

Embodiments of the present invention relate, in general, to the field of automatic sliding doors and to operation of automatic sliding doors. One examples of such a system is Besam^® Sliding Door Operator UniSlide.

Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference signs refer to like elements throughout.

Figure 1 shows a sliding door system 150 with an electromechanical door drive 100. Figure 2 shows a door drive 100 schematically.

The sliding door system 150 comprises two door panels 151 and two surrounding walls 153. The door panels 151 are fitted to door adapter/carriage wheel fittings 152 and hangs on a sliding track. The guiding at the bottom is carried out by means of floor guides (not shown).

The door drive 100 comprises drive means 101 ,102, an electrical motor/generator 103, a control unit 104, an electrical energy storage 105 such as a battery 105, a cable inlet (not shown) for connecting an electrical power supply and a gearbox 107 all assembled in a support beam 108 with an integrated cover 109. An electrical motor 103 transmits movement to and from the door panels 151 by the drive means. The drive means is a drive wheel 101 and a tooth belt 102. The tooth belt 102 is connected to the door adapter/carriage wheel fittings 152 situated on the upper side of the door panels. Using wheel and belt in a door drive is commonly known and the operation will therefore not be described in more detail. One example of a operator using wheel and belt drive is Besam^® Sliding Door Operator UniSlide.

The electrical motor generator 103 is connected to the battery 105 such that current can flow from the electrical motor/generator 103 to the battery in both directions. The electrical motor generator 103 and the gearbox 107 are arranged to transmit movement to and from the tooth belt 102. The gearbox 107 is optimized in both directions and provides for different gearing between the electrical motor/generator 103 and the tooth belt 102. The electrical motor/generator 103 is arranged to be able to operate in both directions, i.e. as a motor accelerating the door panel 151 or as a generator converting the kinetic energy of the door panel to electrical energy. The control unit 104 is arranged to control the operation of the door drive 100, e.g. the control unit adjusts the amount of current flowing between the battery and the electrical motor/generator 103. The battery 105 is further connected to an electrical power supply 106 via a cable inlet (not shown). The electrical power supply provides a standby current for the electronics of the door drive and further provides a charging current to the battery 105. In case of a power failure of the electrical power supply 106, the standby current may instead be provided by the battery 105.

When an "opening impulse" is received the motor starts and the tooth belt 102 moves. Then the tooth belt 102 drives the door panel 151 towards an open position. When the door panel 151 approaches the open position the movement is braked. The closing starts when no "opening impulse" is received and the "hold open time" has run out. Figure 3a to 3c shows the operation of a sliding door and a door drive arrangement according to the invention, while opening the sliding door described in figures 1 and 2. The operation of the door includes three different phases, a rested phase, an acceleration phase and a retardation phase. Figure 3a shows the door is in a rested phase, in a closed position. Figure 3b shows the acceleration phase and figure 3c shows the retardation phase.

In the rested phase shown in figure 3a the door panel 151 is in a closed position, there is no current flowing from the battery 105 to the electrical motor 103 i.e. l_motor = 0. The drive wheel 101 and the tooth belt 102 are not moving. The motor does not apply any force on the door panel 151 , i.e. F=0. The electrical power supply 106 charges the battery 105 with a low current and provides a standby current to the electronics of the door operator such as sensors, accessories etc. In this phase a high portion of the total amount of energy in the system is stored as electrical energy in the battery 105.

In the acceleration phase, shown in figure 3b, the door panel is accelerated towards an open position. This typically happens when a person approaches the door and an "opening impulse" is sent by e.g. a motion sensor. When an "opening impulse" is received the control unit 104 sets the current l_motor flowing from the battery 105 and electrical power supply 106 to the electrical motor generator 103 to l_aCc cc corresponds to a current high enough to start the motor and accelerate the door panel 151 . The control unit 104 continuously controls the amount of power that is fed to the electrical motor generator 103 from the battery. The electrical motor/generator 103 applies an acceleration force on the door panel 151 (F_acc)- The electrical energy stored in the battery 105 is converted to kinetic energy in the door mass. At the end of this phase a high portion of the total amount of energy in the system is stored in the mass of the door panel 151 as kinetic energy. As a consequence, the electrical power supply 106 can operate at low effect throughout this phase, as the effect required for accelerating the door panel 151 is mainly taken from the battery 105.

In the retardation phase, shown in figure 3c, the door panel is retarded at an open position. The retardation phase typically starts when the door panel approaches a closed position. During the retardation phase, control unit 104 controls the retardation of the mechanical system. The brake force is created by setting the current I _motor flowing from the battery 105 to the electrical motor generator 103 to reverse polarity. When a reverse current is fed through the electrical motor generator 103, the electrical motor generator 103 starts operating reversely as a generator. The electrical motor/generator 103 applies an acceleration force on the door panel 151 (F_brake). The generator will convert the kinetic energy back to electrical energy. The battery 105 is charged with the current that is induced by the generator. When the kinetic energy of the door panel 151 has reached the open position the major part of the system energy is converted back to electrical energy. Due to power loss in the electrical and mechanical systems the battery 105 is to be charged with additional power from the electrical power supply 106. However, the amount of power is minimized in comparison to prior art solutions. During the retardation phase the gear may also be changed in order to get a stronger break force.

The retardation phase follows right after the acceleration phase. However, according to one aspect of the invention, there may be a pause in between these phases, wherein no current is fed to the electrical generator 103; the door panel 151 simply slides towards its destination, without the electrical motor/generator 103 affecting its operation.

After the retardation phase follows a rested phase. However, the door panel 151 is now rested in an open position. The person now typically enters the door opening. When no "opening impulse" is received and the "hold open time" has run out, the closing of the door starts and the acceleration phase follows. In the acceleration phase the door panel will be accelerated towards a closed position. The operation in the acceleration phase is the same as described above, with the difference that the door panel is accelerated in the opposite direction. In the same manner as when opening the door the retardation phase follows the acceleration phase. This time the door will be retarded at the closed position.

The battery 105 is used for driving the electrical motor/generator 103. The battery is continuously charged with the current that is induced by the generator and by an external electrical power supply 106, connected via a cable inlet (not shown), see figure 1 . It is due to power loss in the electrical and mechanical systems that the battery 105 needs to be charged with additional power from the electrical power supply 106. However, the capacity of the battery may be enough to open and close the door system several times without extra charging. Hence, e.g. in case of a power failure, the door can be opened even if the external electrical power supply 106 is disconnected. The battery 105 can also be charged in other ways, e.g. during night time. An alternative is to exchange the battery when it is discharged.

Furthermore, the overall system is arranged to provide a minimum power loss in both the electrical and mechanical systems for both the acceleration and the retardation phase. Typically the gearbox has symmetrical efficiency in both directions. A typical implementation of this e.g. by using a bevel gear, shown in figure 4, that has a much improved efficiency operating in the backwards mode. By using the system described in figures 1 -3, the mechanical energy can be converted to usable electrical energy and stored in a battery, capacitor or other energy storage that can be used in the next opening cycle. The overall drive system is arranged in a way that can balance the conversion between electrical energy & kinetic energy in an optimal way. Further, this system allows parallel coupling of several motors to one or more gearboxes as the symmetrical gearbox properties will balance any difference in load between the motors. In one aspect of the invention the door system will comprise a door with two or more door panels. If the door system is a sliding door system with wheel and belt drive as described above, two door panels may be attached to the same belt. The motor will then operate to accelerate and brake both the panels. Figure 4 discloses a bevel gear. This type of gear typically has a symmetrical efficiency in both direction and is therefore suitable for use in the door drive 100 according to the invention. Bevel gears as such are commonly known and are therefore not described more in detail . Other types of gears with these properties may also be used e.g. a worm gearbox. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should be regarded as illustrative rather than restrictive, and not as being limited to the particular embodiments discussed above. The different features of the various embodiments of the invention can be combined in other combinations than those explicitly described. It should therefore be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention defined by the following claims.

Claims

A door drive (100) for a sliding door system (150, 550) adapted to move at least one door panel from a first position to a second position, wherein the door drive (100) comprises:

- an electrical motor (103,503) arranged to accelerate the at least one door panel (151 ,551 ) from the first position towards the second position in an acceleration phase and

- an electrical energy storage (105,505) arranged to drive the electrical motor (103,503),

wherein the electrical motor (103,503) is also arranged to operate as a generator and to brake the movement of the door panel (151 ,551 ) when approaching the second position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage (105,505) for storage.

A door drive (100) according to claim 1 wherein the electrical energy storage 105 is further connected to an electrical power supply (106,606) charging the energy storage with electrical power.

A door drive (100) according to claim 1 , further comprising a gearbox (107) connected to the electrical motor (103,503).

A door drive (100) according to claim 3, wherein the gearbox (107) has symmetrical efficiency in both directions.

A door drive (100) according to claim 4, wherein the gearbox (107) is a bevel gear.

6. A door drive (100) according to claim 1 , further comprising a control unit (104,606) arranged to control the amount of power that is fed to the electrical motor (103,503), gearbox (107) and sliding door system (150, 550) to and from the electrical energy storage (105,505) .

7. A door drive (100) according to claim 1 , wherein the door drive (100) is further arranged to drive the at least one first door panel (151 ,551 ) from the second position to the first position.

8. A door drive (100) according to claim 7, wherein the electrical motor (103,503) is also arranged to operate as a generator and to brake the movement of the door panel (151 ,551 ) when approaching the first position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage (105,505) for storage.

9. A door drive (100) according to claim 7, wherein the door drive (100) is further arranged to drive a second door panel from a third position to a fourth position.

10. A door drive (100) according to claim 8, wherein the door drive (100) is further arranged to drive a third door panel from a fifth position to a sixth position.

1 1 . A method for a sliding door system (150, 550) driving at least one door panel (151 ,551 ) from a first position towards a second position, using an electrical motor (103,503) driven by an electrical energy storage (105,505) , wherein the method comprises the following steps:

- accelerating the at least one door panel (151 ,551 ) from the first position towards the second position with the electrical motor (103,503),

- braking the movement of the door panel (151 ,551 ) when approaching the second position by operating the electrical motor/generator 103 as a generator applying a brake force on the door panel (151 , 551 ) and - storing the energy generated by the generator in the electrical energy storage (105,505) .

12. A method for driving sliding door system (150, 550) according to claim 1 1 , further comprising the step of charging the energy storage with electrical power from an electrical power supply (106).

13. A method for driving sliding door system (150, 550) according to claim 1 1 , further comprising the step of changing the gearing of the electrical motor/generator 103 using a gearbox (107).

14. A method for driving sliding door system (150, 550) according to claim

13, wherein said gearbox (107) has symmetrical efficiency in both directions.

15. A method for driving sliding door system (150, 550) according to claim

14, wherein said gearbox (107) is bevel gear.

16. A method for driving sliding door system (150, 550) according to claim 1 1 , further comprising the step of controlling the amount of power that is fed to the electrical motor (103,503), gearbox (107) and sliding door system (150, 550) to and from the electrical energy storage (105,505) using a control unit (104,604).

17. A method for driving sliding door system (150, 550) according to claim 10, further comprising the step of driving the door panel (151 ,551 ) from the second position to the first position.

18. A method for driving sliding door system (150, 550) according to claim 17, further comprising the step of braking the movement of the door panel (151 ,551 ) when approaching the first position by operating the electrical motor/generator 103 as a generator applying a brake force on the door panel (151 , 551 ) and storing the energy generated by the generator in the electrical energy storage (105,505).

19. A method for driving sliding door system (150, 550) according to claim 1 1 , further comprising the step of accelerating a second door panel from a third position towards a fourth position.

20. A method for driving sliding door system (150, 550) according to claim 19, further comprising the step of accelerating a third door panel from a fifth position towards a sixth position.

21 . A sliding door system (150, 550) comprising at least one door panel (151 ,551 ) and a door drive (100) adapted to move the at least one door panel (151 ,551 ) from a first position to a second position, wherein the door drive (100) comprises:

22. A sliding door system (150, 550) according to claim 21 , wherein the sliding door system (150, 550) further comprises a cable inlet for connection to an electrical power supply (106) for charging the energy storage with electrical power.

23. A sliding door system (150, 550) according to claim 21 , wherein the door drive (100) further comprises a gearbox (107) connected to the electrical motor (103,503).

24. A sliding door system (150, 550) according to claim 23, wherein the gearbox (107) has symmetrical efficiency in both directions.

25. A sliding door system (150, 550) according to claim 24, wherein the gearbox (107) is bevel gear.

26. A sliding door system (150, 550) according to claim 21 , wherein the door drive (100) further comprises a control unit (104,604) controlling the amount of power that is fed to the electrical motor (103,503), gearbox (107) and sliding door system (150, 550) to and from the electrical energy storage (105,505) .

27. A sliding door system (150, 550) according to claim 21 , wherein the door drive (100) is further arranged to drive the at least one first door panel (151 ,551 ) from the second position to the first position.

28. A sliding door system (150, 550) according to claim 27, wherein the electrical motor (103,503) is also arranged to operate as a generator and to brake the movement of the door panel (151 ,551 ) when approaching the first position in a retardation phase and wherein the generator is further arranged to transfer the generated energy to the electrical energy storage (105,505) for storage.

29. A sliding door system (150, 550) according to claim 21 , comprising a second door panel and wherein the door drive (100) is further arranged to drive the second door panel from a third position to a fourth position.

30. A sliding door system (150, 550) according to claim 29, comprising a third door panel and wherein the door drive (100) is further arranged to drive the third door panel from a fifth position to a sixth position.