Rolling shutter driving device and rolling shutter apparatus utilizing same

A rolling shutter driving device includes a motor, a locking assembly and a gearbox. The motor includes a stator and a rotor. The rotor includes a rotary shaft connected to the gearbox. The rotary shaft drives through the gearbox a rolling shutter to extend or retract. The locking assembly includes a brake pad slidingly fitted on the rotary shaft and a rotary member fixedly mounted to the rotary shaft. The brake pad is circumferentially fixed relative to the stator. The brake pad is slidable relative to the rotary shaft so as to be selectively engaged with the rotary member to lock the rotary shaft and hence hold the load in position, or disengaged from the rotary member to unlock the rotary shaft.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application claims priority under 35 U.S.C. § 119(a) from Patent Application No. 201610303732.7 and No. 201610304025.X filed in The People's Republic of China on May 9, 2016.

FIELD OF THE INVENTION

The present invention relates to driving devices, and in particular to a rolling shutter driving device for driving a window curtain, a shutter, a projection screen in a room or in a car.

BACKGROUND OF THE INVENTION

Rolling shutters are common furniture in our lives. With continuous development of the technology of the rolling shutters, the rolling shutters are becoming more and more widely used for windows of some premium cars. Currently, in a common car window rolling shutter, retraction or extension of the rolling shutter is usually driven by a driving motor, an ideal stop position of the rolling shutter is controlled by a controller, and the rolling shutter is held at a desired position by self-locking of the motor. However, due to the over large weight of the rolling shutter itself, the current motors may not have sufficient self-locking capability to completely hold the rolling shutter at the desired position.

SUMMARY OF THE INVENTION

Thus, there is a desire for a rolling shutter driving device which can achieve stable locking.

There is also a desire for a rolling apparatus that utilizes the above rolling shutter driving device.

A rolling shutter driving device includes a motor, a locking assembly and a gearbox. The motor includes a stator and a rotor rotatable relative to the stator. The rotor includes a rotary shaft connected to the gearbox. The rotary shaft of the motor is configured to drive through the gearbox a rolling shutter connected to one end of the gearbox. The locking assembly includes a brake pad circumferentially fixed relative to the stator and a rotary member circumferentially fixed relative to the rotary shaft. The rotary member is fixed relative to the rotary shaft. The brake pad is slidable axially relative to the rotary shaft between a locking position where the brake pad is engaged with the rotary member to lock the rotary shaft and hence hold the rolling shutter in position, and an unlocking position where the brake pad is disengaged from the rotary member to unlock the rotary shaft.

Preferably, the locking assembly further comprises a magnetic conductive ring and a resilient element, the magnetic conductive ring is slidingly fitted on the rotary shaft and keeps connecting with the brake pad, the resilient element resists against the brake pad thereby forcing the brake pad towards the locking position, the stator of the motor comprises a winding, which, once energized, generates an electromagnetic force to force the magnetic conductive ring and the brake pad to move axially along the rotary shaft towards the unlocking position overcoming a resilient force of the resilient element.

Preferably, the motor further comprises an end cap disposed at an end of the stator, the locking assembly is disposed at an end of the motor far away from the end cap, the rotor is supported by the end cap and the locking assembly, and the rotor rotates around the stator under the action of the electromagnetic force of the winding.

Preferably, the winding is a concentrated winding.

Preferably, one side of the brake pad is provided with an accommodating portion for accommodating the magnetic conductive ring, the other side of the brake pad is provided with a plurality of extensions, and the extensions are engaged with the rotary member in response to the brake pad moves to the locking position.

Preferably, the rotary member defines a plurality of through holes, each extension is selectively engaged in one of the through holes in response to the brake pad moves to the locking position.

Preferably, the extensions and the through holes are arranged circumferentially, and are respectively disposed on brake pad and rotary member at even interval.

Preferably, the motor further comprises a housing fixed disposed at an end of the stator opposite to the end cap and close to the locking assembly, the housing of the motor is formed with a plurality limiting slots extending axially, an outer circumferential side of the brake pad is provided with a plurality of sliding blocks, each sliding block is fitted in a corresponding one of the limiting slots, and axially slidable in the corresponding limiting slot.

Preferably, the locking assembly further comprises a sleeve with a bearing seat disposed therein, a bearing is mounted in the bearing seat to support one of two opposite ends of the rotary shaft, one end of the sleeve is connected to the housing of the motor, and the other end of the sleeve is connected to the gearbox.

Preferably, the end of the sleeve is provided with a plurality of engagement blocks each engaged in one of the limiting slots.

Preferably, the end cap comprises another bearing seat with another bearing received therein to support the other one end of the rotary shaft.

Preferably, the resilient element sandwiched between the stator of the motor and the magnetic conductive ring.

Preferably, the stator comprises a yoke, a plurality of stator teeth radially extending for the yoke, a first winding bracket fixed to one of opposite axial ends of the plurality of the stator teeth close to the locking assembly, and a second winding bracket fixed to the other one axial end of the plurality of the stator teeth far away from the locking assembly, one of opposite axial ends of the yoke abuts the housing of the motor.

Preferably, the first winding bracket defines a receiving portion, one end of the resilient element received in the receiving portion and resists against the first winding bracket, the other end of the resilient element resists against the magnetic conductive ring.

Preferably, the first winding bracket axially extends a distance beyond the yoke, such that the winding mounted on the first winding brackets is partially located outside the yoke of the stator.

Preferably, the gearbox comprises a plurality of transmission gears and a transmission member mounted in the gearbox, the transmission gears are directly or indirectly connected to the rotary shaft, the transmission member is connected to the rolling shutter, and the rotary shaft drives the plurality of transmission gears to rotate which in turn drive the transmission member to drive the rolling shutter to rotate.

Preferably, the rolling shutter driving device further comprises a outer shell receiving the motor and the gearbox.

A rolling shutter apparatus includes a rolling shutter. The rolling shutter apparatus further comprises the rolling shutter driving device as described above, and the rolling shutter driving device is configured to drive the rolling shutter to retract or extend.

The present invention will be further described below with reference to the above drawings and the following embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various embodiments of the present invention will be described as follows with reference to the accompanying drawings. Elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the specification and figures. The figures are for the purposes of illustration only and should not be regarded as limiting. The figures are not drawn to scale and do not illustrate every aspect of the described embodiments. Unless otherwise specified, all technical and scientific terms have the ordinary meaning as commonly understood by people skilled in the art.

It is noted that, when a component is described to be “fixed” to another component, it can be directly fixed to the another component or there may be an intermediate component. When a component is described to be “connected” on another component, it can be directly connected to the another component or there may be an intermediate component. When a component is described to be “disposed” on another component, it can be directly disposed on the another component or there may be an intermediate component.

Referring toFIG. 1toFIG. 3, a rolling shutter apparatus200in accordance with an embodiment of the present invention, such as a home-use window curtain, a car window curtain, a screen, a rolling shutter door, a door curtain, includes a driving device100for driving a rolling shutter that retracts and extends via a rolling action. The rolling shutter driving device100includes an outer shell10, and a motor30, a locking assembly50and a speed reduction mechanism such as a gearbox60mounted in the outer shell10. The locking assembly50and the gearbox60perform an axial movement or a rotational movement under the driving of the motor. In this embodiment, the locking assembly50is attached around one end of the motor30, and the gearbox60is disposed at one end of the locking assembly50opposite from the motor30. The motor30drives the gearbox60which in turn drives the load connected to one end of the gearbox60, such as a rolling shaft of the rolling shutter, to rotate. The locking assembly50is slidable along an axial direction of the motor30so as to lock the motor30and the gearbox60and hence hold a position of the load when the motor30stops rotation. The gearbox60is used to convert a high speed rotation of the motor30into rotation of a preset speed outputted to the load.

The outer shell10sleeves the motor30and the gearbox60. In this embodiment, the outer shell10includes an cylindrical wall12and a cap13. The cylindrical wall12has a shape matching with an outer shape of the motor and gearbox60and is generally in the form of a hollow cylindrical structure, such that the cylindrical wall12is able to cover and to protect the motor30and the gearbox60. The cap13covers one end of the cylindrical structure of the cylindrical wall12, which is detachable relative to the cylindrical wall12thereby facilitating repair and replacement of the rolling shutter device100.

Referring toFIG. 4andFIG. 5, in this embodiment, the motor30is a single phase synchronous motor. It should be understood that the motor may also be a three phase motor in an alternative embodiment. The motor30includes an end cap32, a housing33, a stator35, two winding brackets36and a rotor38. The end cap32and the housing33are used to mount the stator35, winding brackets36and rotor38. In the illustrated embodiment, the end cap32and the housing33are disposed at opposite ends of a yoke352of the stator35. The end cap32and the housing33are connected to the yoke352through but not limited to snap-fit, adhering or soldering. It should be understood that, in another embodiment, the yoke352of the stator35may also be completely enclosed in an interior of the end cap32and housing33. The end cap32includes a bearing seat321for receiving therein a bearing322for supporting the rotor38. One end of the housing33opposite from the end cap32defines a plurality of limiting slots332(FIG. 3). In this embodiment, the limiting slots332are arranged at even interval along a circumferential wall of the housing33, with each limiting slot332in communication with an open end of the housing33. The limiting slots332are used to engage with the locking assembly50.

Referring toFIG. 6andFIG. 7, the stator35includes a stator core351and a concentrated winding37directly or indirectly wound around the stator core351. The stator core351includes the yoke351and a plurality of stator teeth353connected to the yoke352. In this embodiment, the number of the stator teeth353is two. The two stator teeth353are disposed on an inner surface of the yoke352and are opposed to each other to define an accommodating space for accommodating the rotor38. The yoke352is annular, and the stator teeth353extend inwardly from the yoke352.

The two winding brackets36are attached round the stator teeth353to insulate the stator teeth353from the winding37. The two winding brackets36are mounted to opposite ends of the stator teeth353, respectively. In this embodiment, the two winding brackets36are different in axial size such that, when the two winding brackets36are mounted to the two ends of the stator teeth353, an extension length of one of the winding brackets36, which is located adjacent to the locking assembly50, away from the stator35is greater than an extension length of the other one of the winding brackets36, which is adjacent to the end cap32, away from the stator35. It should be understood that the winding bracket36adjacent to the locking assembly50extends a distance beyond one end of the yoke352of the stator35and, therefore, the winding37wound around the winding bracket36extends outside the yoke352of the stator35. An electromagnetic force generated by the portion of the winding37extending outside the yoke352can better attract the locking assembly50.

The rotor38includes a rotary shaft381and a rotor main body383mounted on the rotary shaft381. In this embodiment, the rotor main body383includes two groups of permanent magnets that are axially arranged. Each group of permanent magnets includes two semicircular magnets that cooperatively define a hollow cylindrical structure. Each group of permanent magnets forms a plurality of permanent magnetic poles. The two groups of permanent magnets are attached around the rotary shaft381, with the two permanent magnets of each group opposed to each other. In particular, two adjacent ends of the two groups of cylindrical permanent magnets closely fit with each other. In an alternative embodiment, the rotor main body383may further include a rotor core disposed between the rotary shaft381and the permanent magnet. The permanent magnet may also be an integral annular magnet. One end of the rotary shaft381opposite from the end cap32passes through the locking assembly50to connect with the gearbox60.

FIG. 7is a sectional view of the motor30of the rolling shutter driving device100of the present invention. Each stator tooth353includes a pole shoe3531. The two pole shoes cooperatively define a generally circular hollow chamber for rotatably accommodating the rotor38. Slot openings355are formed at connecting areas between the two pole shoes3531. A pole arc face3533of each pole shoe3531and an outer surface of the rotor38define therebetween an air gap356. A positioning groove3535is defined in each pole arc face3533. Preferably, a major portion of each pole arc face3533other than the positioning groove3535is located on a cylindrical surface concentric with the rotor, such that each pole arc face3533and the rotor permanent magnet form a substantially even air gap therebetween. Since the motor30is a single phase synchronous motor in this embodiment, the provision of the positioning groove3535can make an initial position of the rotor deviate from a dead point position (i.e. a position where the rotor pole is aligned with the stator pole/tooth), thus avoiding motor startup failure. In this embodiment, the positioning groove3535is circular arc-shaped and, when viewed along the direction of the axis of the rotary shaft381, a perpendicular bisector of the circular arc of a projection of the positioning groove3535coincides with a perpendicular bisector of a projection of the stator tooth353. This configuration provides the motor30with a bidirectional startup capability and its startup direction is controlled by a driving circuit80(FIG. 10). It should be understood that it is also possible to deviate a center of the positioning groove3535from a center of the pole arc face3533of the stator tooth353, in which case the motor30has greater startup capability in one direction than in the other.

It should be understood that an outer circumferential surface of the rotor main body383is formed with two symmetrical mating faces3831. In this embodiment, the mating faces3831are planes, and each mating face3831extends on the outer circumferential surface of the rotor main body383along the direction of the axis of the rotary shaft381.

Referring toFIG. 8andFIG. 9, the locking assembly50includes a magnetic conductive ring51, a brake pad53, a rotary member55, a resilient element56, and a sleeve57. The magnetic conductive ring51is slidingly fitted around one end of the rotary shaft381opposite from the end cap32. The brake pad53is generally in the form of a hollow annular structure. The brake pad53is attached around the rotary shaft381. In this embodiment, one side of the brake pad53forms an accommodating portion531for accommodating the magnetic conductive ring51, such that the magnetic conductive ring51is able to drive the brake pad53to move when the magnetic conductive ring51moves under the electromagnetic force of the motor30. In this embodiment, the magnetic conductive ring51may be fixedly mounted on the brake pad53through interference-fit or over-molding, as long as the two elements can move together along the axial direction of the rotary shaft381. The other side of the brake pad53forms a plurality of extensions532for locking the rotary member55. An outer circumferential side of the brake pad53forms a plurality of sliding blocks535. Each sliding block535is slidably accommodated in a corresponding one of the limiting slots332of the housing33such that a position of the brake pad53in the rotational direction of the rotary shaft381is limited by the housing33of the motor30, i.e. the brake pad53is fixed relative to the housing33in the circumferential direction.

Preferably, the rotary member55is fixedly mounted on one end of the rotary shaft381passing through the brake pad53. The rotary member55defines a plurality of through holes551. Each extension532of the brake pad53is selectively engaged in one of the through holes551to lock the rotary member55. The resilient element56is attached around the rotary shaft381. In this embodiment, the resilient element56may be an element that can automatically restore to its original shape from a forced deformed state, such as, a spring or a resilient plastic member. The resilient element56has one end abutting against the winding bracket36and the other end abutting against the magnetic conductive ring51. The resilient element56is used to urge the magnetic conductive ring51and the brake pad53to slide along the rotary shaft381to lock or unlock the rotary member55. It should be understood that one end of the winding bracket36adjacent the resilient element36forms a receiving portion362for partially receiving the resilient element56.

It should be understood that the extensions532and the sliding blocks535are each arranged circumferentially, and are evenly disposed on one side of the brake pad53and the outer circumferential side of the brake pad53. The through holes551are arranged circumferentially and evenly disposed in the rotary member55.

The sleeve57is in the form of a cylindrical structure. A bearing seat571is disposed in an interior of the sleeve57, for cooperating with the end cap32to support the rotor38. One end of the sleeve57is provided with a plurality of engagement blocks573. Each engagement block573is engaged in one of the limiting slots332of the housing33, with the sliding blocks of the brake pad53located between the housing33and the engagement blocks573. One end of the sleeve57opposite from the motor30is connected to the gearbox60. In this embodiment, the other end of the sleeve57is formed with a plurality of engagement slots575for clamping the gearbox60. In an alternative embodiment, the sleeve57and the gearbox60may be connected by adhering or soldering other than clamping.

The gearbox60includes a plurality of transmission gears (not shown) and a transmission member62that are mounted in the gearbox. The transmission gears are directly or indirectly connected to the rotary shaft381. One end of the transmission member62is connected to the transmission gears, and the other end is connected to a rolling shutter300. The rotary shaft381drives the transmission gears to rotate, which in turn drive the transmission member62to drive the rolling shutter300to retract or extend.

Referring toFIG. 10, the motor30in accordance with the embodiment of the present invention further includes a driving circuit80. The driving circuit80is disposed in a control panel (not shown) of the motor30. The driving circuit80at least includes a controllable bidirectional AC switch81, an AC-DC conversion circuit82, a switch control circuit83, and a position sensor85. Preferably, the motor30is a single phase synchronous motor.

In the driving circuit80, the winding37of the motor30and an AC power supply90are connected in series between a first node A and a second node B of the driving circuit80. The AC power supply90is preferably a mains AC power supply, with a fixed frequency of, for example, 50 Hz or 60 Hz, and a voltage of, for example, 110V, 220V, or 230V.

The controllable bidirectional AC switch81is connected in parallel with the series-connected winding37and AC power supply90between the two nodes A and B. The controllable bidirectional AC switch81is preferably a three-terminal bidirectional thyristor (TRIAC), with two anodes thereof connected with the two nodes A and B, respectively. It should be understood that the controllable bidirectional AC switch81may also be implemented for example by two silicon-controlled rectifiers reversely connected in parallel, and a corresponding control circuit is provided to control the two silicon-controlled rectifiers in a predetermined manner. The AC-DC conversion circuit82and the controllable bidirectional AC switch81are connected in parallel between the two nodes A and B. The AC-DC conversion circuit82converts an alternating current between the two nodes A and B into a low-voltage direct current. The position sensor85can be powered by the low-voltage direct current output from the AC-DC conversion circuit82, and is configured to detect the magnet pole position of the permanent magnet rotor38of the motor30and output a corresponding signal. The switch control circuit83is connected with the AC-DC conversion circuit82, the position sensor85and the controllable bidirectional AC switch81, and is configured to control the controllable bidirectional AC switch81to switch between on and off states in a predetermined manner according to magnet pole position information of the rotor38detected by the position sensor85and polarity information of the AC power supply90acquired from the AC-DC conversion circuit82, such that the winding37drives the rotor38to rotate only along a fixed starting direction in a motor startup stage. In the present invention, when the controllable bidirectional AC switch81is switched on, the two nodes A and B are shorted, and the AC-DC conversion circuit82does not consume power any more since no current flows therethrough, thereby greatly improving the utilization efficiency of the electric energy.

The switch control circuit83includes three terminals connected to a relatively high voltage output terminal C of the AC-DC conversion circuit82, an output terminal H1of the position sensor85, and a control terminal G of the three-terminal bidirectional thyristor.

The working process of the rolling shutter driving device100is described below with reference to the drawings. The rolling shutter driving device100is assembled, with its transmission member62connected to the rolling shutter300. For ease of description, the state of the rolling shutter driving device100that is power off is defined as an initial state. In the initial state, no electrical current flows through the motor30, the concentrated winding37of the stator35generates no electromagnetic force, and the magnetic conductive ring51moves in a direction away from the motor30along the rotary shaft381under the spring force of the resilient element56, until the magnetic conductive ring51pushes the brake pad53connected thereto to be engaged with the rotary member55. At this time, the extensions532of the brake pad53are engaged in the respective through holes551, the sliding blocks535of the brake pad53are engaged in the limiting slots332of the housing33, and the brake pad53cannot rotate relative to the rotary shaft381. Therefore, the rotary shaft381that is fixedly connected with the rotary member55cannot rotate, either, by means of the engagement between the brake pad53and the rotary member55, and the whole rotor38of the motor30is thus locked with the housing33.

When the motor30is powered on, the concentrated winding37of the stator35generates an electromagnetic force. Under the action of the magnetic force, the magnetic conductive ring51drives the brake pad53to slide along the rotary shaft38toward the winding37against the spring force of the resilient element56. At this time, the sliding blocks535slide along their respective limiting slots332away from the rotary member55, such that the extensions532of the brake pad53are disengaged from their respective through holes551to unlock the rotor38of the motor30from the housing33. As a result, the rotary shaft381rotates under the electromagnetic force of the stator35, thereby driving the gearbox60connected to the end of the rotary shaft381to operate which in turn drives the rolling shutter300to rotate.

When it is desired to stop the rolling shutter300at a preset position, the power supply to the motor30is cut off. The rolling shutter driving device100restores to its initial state, and the rolling shutter300is locked with the housing33through the rotary shaft381.

Preferably, in this embodiment, the motor30of the rolling shutter driving device100of the present invention has an input voltage of 230V, a frequency of 50 Hz, a rotation speed of 3000 rpm, an efficiency of 27.63%, a diameter of a cross-section of 41.5 mm, and a length of 124 mm.

In the rolling shutter driving device100of the present invention, the brake pad53slidingly fitted on the rotary shaft381is pushed to be engaged in the rotary member55that is fixedly connected to the rotary shaft381by the spring force of the resilient element56disposed between the stator35and the brake pad53, and the brake pad53and the housing33of the motor30are fixed relative to each other in the circumferential direction, thereby locking the rotary shaft381with the housing33and hence holding the rolling shutter300in position. In addition, the brake pad53is driven to move toward the stator35by the electromagnetic force of the motor30to unlock the rotary shaft381from the housing33. The rolling shutter driving device100has a simple construction and achieves stable locking of the rolling shutter100. Moreover, the motor30is a single phase synchronous motor which is capable of providing more stable rotation speed and has improved efficiency, reduced size and weight in comparison with asynchronous motors.

In the above embodiments, the single phase synchronous motor has two permanent magnetic poles and two stator poles/teeth. It should be understood that the motor may also have four, six, eight permanent magnetic poles and four, six, eight stator poles/teeth.

It should also be understood that the rotary member55and the motor rotary shaft381may be connected by interference-fit or by engagement between a flat portion and an engagement block such that the two elements are fixed relative to each other in the circumferential direction and the axial direction.

The technical solutions of the embodiments of the present invention have been clearly and completely described above with reference to the accompanying drawings. Apparently, the embodiments as described above are merely part of, rather than all, embodiments of the present invention. Based on the embodiments of the present disclosure, any other embodiment obtained by a person skilled in the art without paying any creative effort shall fall within the protection scope of the present invention.