CN209805594U - driving mechanism and electric curtain - Google Patents

Abstract

the utility model relates to an actuating mechanism technical field, concretely relates to actuating mechanism and electric window curtain. The drive mechanism includes a motor and a clutch, the motor including a hollow shaft having an open end; the clutch includes loose axle and functional part, the loose axle certainly the open end stretches into in the hollow shaft, and with functional part cooperation, the loose axle is used for the drive to wait to drive the part, functional part is used for making the loose axle with the hollow shaft relatively fixed or relative rotation. The utility model provides an actuating mechanism is even if under the outage state, also can make its inside loose axle relative hollow shaft rotate with the help of functional part to prevent under the outage state, unable regulation and this actuating mechanism complex treat drive unit's position or gesture.

Description

Driving mechanism and electric curtain

Technical Field

The utility model relates to an actuating mechanism technical field, concretely relates to actuating mechanism and electric window curtain.

background

Along with the development of science and technology, various automatic equipment are put into practical use and applied, so that the life of people is more and more convenient. For example, a power-driven curtain, a power-driven clothes hanger and the like, but once the power failure occurs in the current power-driven curtain, a motor cannot rotate, and the work of opening and closing the curtain cannot be finished, which brings inconvenience to the life of people.

SUMMERY OF THE UTILITY MODEL

The utility model discloses (one) the technical problem that solve is: the existing driving mechanism cannot rotate under the condition of power failure, and further inconvenience is possibly brought to production and life of people under certain conditions.

(II) technical scheme

in order to achieve the above technical problem, the present invention provides a driving mechanism, which includes a motor including a hollow shaft having an open end;

The clutch, the clutch includes loose axle and functional part, the loose axle certainly the open end stretches into in the hollow shaft, and with functional part cooperatees, the loose axle is used for the drive to wait to drive the part, functional part is used for making the loose axle with the hollow shaft relatively fixed or relative rotation.

Optionally, the functional part comprises an electromagnet and a magnetic part, the electromagnet is fixed relative to the hollow shaft, the magnetic part is connected with the movable shaft,

The movable shaft is arranged to be relatively fixed with the hollow shaft in a state that the electromagnet and the magnetic part are mutually attracted;

and under the state that the electromagnet is separated from the magnetic part, the movable shaft is arranged to rotate relative to the hollow shaft.

optionally, the functional part comprises an electromagnet and an iron block, the electromagnet and the hollow shaft are relatively fixed, the axial direction of the movable shaft is the same as the gravity direction, the iron block is positioned below the electromagnet and connected with the movable shaft,

The movable shaft is arranged to be relatively fixed with the hollow shaft in a state that the electromagnet is attracted with the iron block;

And under the state that the electromagnet is separated from the iron block, the movable shaft is arranged to rotate relative to the hollow shaft.

Optionally, a first limiting structure is arranged on the movable shaft, a second limiting structure and a rotating fit structure are arranged on the hollow shaft, and the first limiting structure is in limiting fit with the second limiting structure or is in movable fit with the rotating fit structure in the rotating direction of the hollow shaft.

Optionally, the first limiting structure is a key groove extending along the axial direction of the movable shaft, the key groove is recessed relative to the outer surface of the movable shaft, and at least one of two axially opposite ends of the key groove is provided with an opening;

the rotating fit structure is the inner surface of the hollow shaft, the second limit structure is a limit key, the limit key protrudes relative to the rotating fit structure, and the limit key is in limit fit with the key groove in the rotating direction of the hollow shaft.

Optionally, one end of the key groove, which is away from the opening, is provided with a clamping part, and the clamping part is in axial limiting fit with the limiting key along the hollow shaft.

Optionally, the key slot with the spacing key all is provided with a plurality ofly, and is a plurality of spacing key follows the direction of rotation interval of hollow shaft sets up, and is a plurality of key slot and a plurality of spacing key one-to-one cooperation.

Optionally, in the axial direction of the hollow shaft, the maximum length of the limit key is smaller than the maximum translation distance of the movable shaft relative to the hollow shaft.

Optionally, the utility model provides a driving mechanism still includes the reduction gear, the reduction gear with motor drive connects.

Based on the above arbitrary actuating mechanism that provides, the utility model discloses still provide an electric window curtain, it includes the curtain axle and arbitrary actuating mechanism of above-mentioned, actuating mechanism with the transmission of curtain axle is connected.

(III) advantageous effects

the utility model provides a driving mechanism, which comprises a motor and a clutch, wherein a movable shaft in the clutch is connected with a hollow shaft in the motor, and the movable shaft is also used for driving a curtain shaft to wait for a driving part; meanwhile, a function part is arranged in the clutch of the driving mechanism, and the movable shaft is matched with the function part so as to form a relatively fixed or relatively rotating connection relation between the movable shaft and the hollow shaft under different conditions by means of the function part; in detail, under the power-on state, the function part generates corresponding action, the hollow shaft and the movable shaft are relatively fixed, the hollow shaft rotates and drives the movable shaft connected with the hollow shaft to rotate, so that the curtain shaft is driven to wait for the driving part to rotate, and the work of opening or closing the curtain is completed; under the condition of power failure, the movable shaft and the hollow shaft can be separated from each other by means of the functional part, and then the part to be driven and the hollow shaft can rotate relatively, so that the rotation of the part to be driven is not limited by the motor reluctance effect any more.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

Fig. 1 is a schematic structural diagram of a driving mechanism provided in an embodiment of the present invention;

Fig. 2 is a schematic diagram of an internal structure of a driving mechanism according to an embodiment of the present invention;

Fig. 3 is a sectional view of a part of the structure of the drive mechanism according to the embodiment of the present invention;

fig. 4 is an assembly view of the movable shaft and the stop ring in the driving mechanism according to the embodiment of the present invention.

reference numerals

1-a motor;

11-a hollow shaft;

111-a stop collar;

112-a shaft body;

113-a limit key;

2-a clutch;

21-a movable shaft;

211-a keyway;

212-an opening;

213-a catch;

22-a functional part;

221-an electromagnet;

222-iron block;

3-a reducer;

4-a housing;

5-a drive shaft;

6-coupler.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

as shown in fig. 1, the utility model provides a driving mechanism, it includes motor 1 and clutch 2, wherein, motor 1 can drive the curtain axle under the effect of electric power and wait for the drive part (not shown in the figure) to rotate, and clutch 2 can realize connecting and separating motor 1 and the purpose of waiting for the drive part. The motor 1 comprises a hollow shaft 11, the hollow shaft 11 is a driving shaft of the motor 1, and the hollow shaft 11 is connected with the clutch 2 so as to drive a component to be driven by the motor 1 under the condition of electrifying, thereby improving the automation degree; in order to prevent under the circumstances of outage, cause hollow shaft 11 and wait to drive the part lock because of the magnetic resistance effect of motor 1, the utility model provides a hollow shaft 11 among actuating mechanism's motor 1 is provided with the open end to make in clutch 2's loose axle 21 stretches into the cavity of hollow shaft 11 through aforementioned open end, cooperate through function portion 22 that makes loose axle 21 and clutch 2 in, can be under the corresponding action of function portion 22, according to the difference of the condition of switching on and off, form relatively fixed or relative pivoted relation between messenger's loose axle 21 and the hollow shaft 11, thereby prevent under the outage circumstances, because of the magnetic resistance effect of motor 1, cause and wait to drive the part even if can not remove or change self position under the effect of other external forces.

in detail, under the condition of power on, the movable shaft 21 and the hollow shaft 11 can form a fixed connection relationship through the functional part 22, so that the motor 1 drives the component to be driven to reach the set position under a corresponding instruction, and locks the position of the component to be driven, thereby preventing the component to be driven from self-acting or acting by other external force; in the case of power failure, the movable shaft 21 and the hollow shaft 11 are separated from each other by the functional portion 22, so that a relative rotation condition is provided between the member to be driven and the hollow shaft 11, and the member to be driven can be moved relative to the hollow shaft 11 by a force such as manual driving of a user even if the motor 1 has a reluctance effect.

specifically, specific parameters such as the model and the power of the motor 1 can be selected according to actual conditions, and are not limited herein, and the size of the movable shaft 21 can be correspondingly selected according to the size and the specification of a curtain shaft waiting driving component; the movable shaft 21 and the part to be driven can be connected through a transmission part such as a gear mechanism, a chain transmission mechanism or a belt transmission mechanism; preferably, as shown in fig. 2, the driving mechanism provided by the present invention can also be provided with a separate driving shaft 5, and the driving shaft 5 and the movable shaft 21 can be in transmission connection through one or more couplings 6, in this case, the part to be driven can be directly in transmission connection with the driving shaft 5, so as to improve the convenience of use of the driving mechanism. Accordingly, the hollow shaft 11 may be sized to accommodate the movable shaft 21 such that the movable shaft 21 may extend into the hollow shaft 11 through the open end of the hollow shaft 11 and into a relatively fixed or rotatable relationship with the hollow shaft 11. The specific structure and the operation principle of the functional part 22 are various, for example, it can be a manual latch structure, so as to achieve the purpose of connecting or separating the hollow shaft 11 and the movable shaft 21 by means of a mechanical mechanism, and in the operation process of the driving mechanism, a user can achieve the purpose of connecting or separating the hollow shaft 11 and the movable shaft 21 by changing the position or the internal structure of the functional part 22, obviously, there are various common components having such functions, and they are not described one by one here; alternatively, the functional portion 22 may be an automatic locking structure, so as to lock and unlock the movable shaft 21 and the hollow shaft 11 by external force such as electric power or elastic force; for another example, the functional portion 22 may also use an electromagnetic principle, and connect or separate the movable shaft 21 and the hollow shaft 11 by an electromagnetic force, and the details will not be described herein in detail in view of the brevity of the text.

the utility model provides a driving mechanism, which comprises a motor 1 and a clutch 2, wherein a movable shaft 21 in the clutch 2 is connected with a hollow shaft 11 in the motor 1, and the movable shaft 21 is also connected with a curtain shaft waiting driving part; meanwhile, a function part 22 is arranged in the clutch 2 of the driving mechanism, and the movable shaft 21 is matched with the function part 22 so as to enable the movable shaft 21 and the hollow shaft 11 to form a relatively fixed or relatively rotating connection relationship under different conditions by means of the function part 22; in detail, in the power-on state, the functional part 22 generates corresponding action, the hollow shaft 11 and the movable shaft 21 are relatively fixed, the hollow shaft 11 rotates and drives the movable shaft 21 connected with the hollow shaft to rotate, so that the curtain shaft is driven to wait for the driving part to rotate, and the curtain opening and closing work is completed; in case of power failure, the movable shaft 21 can be separated from the hollow shaft 11 by the functional part 22, so that the component to be driven and the hollow shaft 11 can rotate relatively, and the rotation of the component to be driven is not limited by the reluctance effect of the motor.

alternatively, the function portion 22 may include an electromagnet and a magnetic portion, and the electromagnet may be provided with a separate power supply member such as a battery or the like, and the magnetic portion may be either an electromagnet or a permanent magnet. In the assembling process of the driving mechanism, current in a set direction can be introduced to the electromagnet according to the orientation of the two magnetic poles on the magnetic part, so that an acting force which is mutually attracted is generated between the electromagnet and the magnetic part, and the movable shaft and the hollow shaft form a relatively fixed relation, so that when the motor works, the movable shaft is driven to move together to drive the part to be driven to rotate; correspondingly, under the condition that the motor is powered off, the power supply part can be controlled to input reverse current into the coil of the electromagnetic part, so that the electromagnet and the magnetic part generate mutual repulsion force, the magnetic part drives the movable shaft to be far away from the electromagnet, and further the movable shaft is separated from the hollow shaft.

Specifically, the coil number of the electromagnet, the size of current led into the coil and other parameters can be determined according to actual conditions, and the maximum distance between the magnetic part and the electromagnet can also be determined according to actual conditions such as the maximum attraction between the electromagnet and the magnetic part and the like, so that the movable shaft and the hollow shaft can rotate relatively, and the electromagnet can be attracted with the magnetic part under the electrified condition; the magnetic portion may be an iron-cobalt-nickel magnet, the shape and size of which are not limited herein. When the function part 22 adopts the above structure, the installation position and the installation orientation of the clutch are not limited, so that the application scene of the driving mechanism is diversified and free, and the working process of the function part 22 with the structure is hardly interfered by external conditions, so that the driving mechanism is safe, reliable, flexible and changeable.

Alternatively, as shown in fig. 4, the function portion 22 may further include an electromagnet 221 and an iron block 222, wherein the electromagnet 221 and the hollow shaft 11 may be fixedly connected by a connecting member, during the process of assembling the driving mechanism, the axial direction of the movable shaft 21 may be the same as the gravity direction, the iron block 222 may be installed below the electromagnet 221, and the iron block 222 may be connected to the movable shaft 21, and by setting the corresponding structures of the movable shaft 21 and the hollow shaft 11, the movable shaft 21 and the hollow shaft 11 may be relatively fixedly connected in a state where the electromagnet 221 and the iron block 222 are attracted to each other, and correspondingly, the movable shaft 21 and the hollow shaft 11 may be relatively rotatably connected in a state where the electromagnet 221 and the iron block 222 are separated from each other.

In detail, the motor 1 and the electromagnet 221 can share an external power supply, so that under the condition that the motor 1 is electrified, current is also conducted in a coil of the electromagnet 221 to generate magnetic force, the iron block 222 is attracted to be close to the electromagnet 221, the iron block 222 drives the movable shaft 21 to move, the movable shaft 21 and the hollow shaft 11 form a relatively fixed connection relationship, and in this state, the motor 1 works to drive a component to be driven to rotate by virtue of the transmission effect of the clutch 2; on the contrary, in the case of deenergization of the motor 1, the electromagnet 221 is deenergized, and the iron block 222 falls under the combined action of itself and the gravity of the movable shaft 21, so that the movable shaft 21 and the hollow shaft 11 are separated from each other, and the movable shaft 21 can relatively rotate or move with respect to the hollow shaft 11, and accordingly, the part to be driven, which relatively rotates with respect to the hollow shaft 11, can also rotate and move under the action of other external forces.

it should be noted that the specific structure and function of the functional portion 22 may be changed according to its own structural composition, and it has a function of changing the connection relationship between the hollow shaft 11 and the movable shaft 21 under different conditions, and of course, other mechanisms or components may be added in the driving mechanism to change the connection relationship between the hollow shaft 11 and the movable shaft 21 when the relative positions of the hollow shaft 11 and the movable shaft 21 are different.

for example, the movable shaft 21 may be provided with a first limit structure, the hollow shaft 11 may be provided with a second limit structure and a rotation fit structure, and the first limit structure and the second limit structure are in limit fit or the first limit structure and the rotation fit structure are in movable fit along the rotation direction of the hollow shaft 11. During operation of the drive mechanism, the movable shaft 21 and the hollow shaft 11 may be brought into a relatively fixed or relatively rotatable relationship by changing the relative positions of the movable shaft 21 and the hollow shaft 11. In addition, there are other ways for the two to form a relatively fixed or relatively rotating relationship, such as the above-mentioned magnetic attraction way or the manual locking way.

specifically, the specific structures of the first limiting structure, the second limiting structure and the rotation matching structure may be various, for example, one of the first limiting structure and the second limiting structure may be a protrusion, the other may be a recess, and the arrangement positions of the first limiting structure and the second limiting structure are set, so that the movable shaft 21 and the hollow shaft 11 can form a limiting matching relationship in the rotation direction of the hollow shaft 11; accordingly, according to the specific form of the first limit structure, the specific structure of the rotation fit structure can be designed accordingly, so that the first limit structure is matched with the rotation fit structure by changing the relative positions of the hollow shaft 11 and the movable shaft 21, and the movable shaft 21 and the hollow shaft 11 can rotate relatively.

For example, the first limiting structure may be a bar-shaped protrusion-shaped structure, the second limiting structure may be a bar-shaped groove, the rotation fitting structure may be an annular groove, the rotation fitting structure is communicated with the second limiting structure, and the rotation fitting structure and the second limiting structure are distributed along the axial direction of the hollow shaft 11. In this case, when the movable shaft 21 extends into the hollow shaft 11, the first limit structure is inserted into the second limit structure, so that the movable shaft 21 and the hollow shaft 11 can form a limit fit relation in the rotation direction of the hollow shaft 11; and after the loose axle 21 has translated upwards for a certain distance along the axial of hollow shaft 11, first limit structure deviates from the second limit structure, and with the cooperation of normal running fit structure, normal running fit between first limit structure and the activity limit structure, also can rotate relatively between the two for loose axle 21 can rotate relative to hollow shaft 11, and treat that the drive part also separates from hollow shaft 11 each other, does not receive the restriction of motor 1, can change self position or gesture under the effect of other external forces.

Preferably, as shown in fig. 4, the first limiting structure may be a key groove 211, the extending direction of the key groove 211 is the axial direction of the movable shaft 21, and the key groove 211 is recessed relative to the outer surface of the movable shaft 21; the rotation fit structure may be an inner surface of the hollow shaft 11, and it is apparent that when the first limit structure is matched with the rotation fit structure, the hollow shaft 11 and the movable shaft 21 can rotate relatively; the second limiting structure is a limiting key 113, and is a relative rotation matching structure, that is, the inner surface of the hollow shaft 11 is convexly arranged, the limiting key 113 can extend into the key groove 211, and is in limiting matching with the key groove 211, so that the hollow shaft 11 and the movable shaft 21 form a limiting matching relation in the rotation direction of the hollow shaft 11; and in order to ensure that the limit key 113 can be disengaged from the key groove 211, at least one of the two opposite ends of the key groove 211 along the axial direction may have an opening 212, so that the limit key 113 may be disengaged from the key groove 211 by changing the relative position of the movable shaft 21 and the hollow shaft 11 in the axial direction of the hollow shaft 11, so as to break the limit connection relationship between the hollow shaft 11 and the movable shaft 21. Specifically, in the design and production process, the shapes and the sizes of the key groove 211 and the limit key 113 can be matched, so that the two can form a limit matching relationship.

Further, in order to prevent the movable shaft 21 from extending into the hollow shaft 11 under the action of the function portion 22, and the like, an offside phenomenon occurs due to inertia and the like, which may cause damage to the motor 1 or other components in the driving mechanism, it is preferable that, as shown in fig. 4, the key groove 211 is provided with a clamping portion 213 in a direction departing from the opening 212, and the clamping portion 213 and the limit key are in limited fit in the axial direction of the hollow shaft 11, so that the position of the movable shaft 21 is limited during relative movement of the movable shaft 21 and the hollow shaft 11 in the axial direction of the hollow shaft 11, and the hollow shaft 11 is prevented from exceeding a set position under the action of inertia and the like, which may damage the motor 1 and other components.

in addition, in order to adapt to hollow shafts 11 of different models and sizes, the second limiting structure and the shaft body of the hollow shaft 11 can be formed in a split forming mode, in order to improve the assembly convenience, a limiting ring 111 can be further arranged, and the limiting ring 111 can be made of materials with higher hardness, wear resistance and deformation resistance, such as metal, so that the limiting ring 111 is prevented from being damaged after the driving mechanism works for a period of time; the second limit structures such as the limit key 113 can be connected to the inner wall of the through hole of the limit ring 111, so that the limit key 113 and the limit ring 111 form an integral structure, and can be adapted to the shaft bodies 112 of hollow shafts 11 of different models and sizes according to different sizes, and the two can be connected through a connecting piece, and the open ends of the limit ring 111 and the shaft body 112 are respectively located at two opposite ends of the hollow shaft 11 along the axial direction of the hollow shaft 11, so that in the assembling and working processes of the driving mechanism, the position of the movable shaft 21 is limited at the position where the clamping part 213 is matched with the limit key 113 in the process of extending out of the hollow shaft 11 from the open end.

In order to further improve the limit matching effect between the movable shaft 21 and the hollow shaft 11, preferably, a plurality of limit keys 113 and key slots 211 may be provided, the plurality of limit keys 113 may be arranged at intervals along the rotation direction of the hollow shaft 11, and in the working process of the driving mechanism, the plurality of limit keys 113 and the plurality of key slots 211 may be matched in a one-to-one correspondence manner, so as to improve the reliability of the limit connection relationship between the hollow shaft 11 and the movable shaft 21. For example, the key groove 211 may be provided with two, three or more, and in order to improve the force uniformity of each limit key 113, preferably, a plurality of key grooves 211 may be uniformly distributed along the rotation direction of the movable shaft 21. In addition, in order to prevent the excessive number of key grooves 211 from causing excessive reduction in the stopper reliability between the groove walls of the key grooves 211 and the stopper key 113, it is preferable that two or three key grooves 211 be provided.

Further, in the axial direction of the hollow shaft 11, the maximum length of the limit key 113 may be smaller than the maximum moving distance of the movable shaft 21 relative to the hollow shaft 11, or the maximum length of the limit key 113 may be smaller than the maximum length of the key slot 211, so as to prevent the limit key 113 and the movable shaft 21 from rubbing against each other or even blocking during the rotation of the movable shaft 21 relative to the hollow shaft 11, and ensure that the movable shaft 21 can rotate relative to the hollow shaft 11 almost without blocking after the limit key 113 and the key slot 211 are separated from each other.

Further, as shown in fig. 1 and 2, the driving mechanism provided by the utility model can also include the speed reducer 3, in the assembling process of this driving mechanism, can make the speed reducer 3 be connected with the transmission of motor 1 to promote the output torque when reducing the rotational speed, and can also reduce the inertia of load, promote whole driving mechanism's life and working property. Specifically, the type and specific parameters of the speed reducer 3 may be determined according to the parameters of the selected motor 1, and the like, and are not limited herein. Additionally, the utility model provides an actuating mechanism still includes shell 4, and motor 1, clutch 2 and reduction gear 3 are all installed in shell 4 to provide certain guard action with the help of shell 4 to aforementioned three, prevent that external component from producing adverse effect to actuating mechanism's work, promote whole actuating mechanism's life and working property.

Based on the actuating mechanism that any embodiment of the aforesaid provided, the utility model discloses still provide an electric window curtain, it includes curtain axle and any actuating mechanism of the aforesaid, and actuating mechanism is connected with curtain axle transmission.

In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

in the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the communication may be direct, indirect via an intermediate medium, or internal to both elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

the above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims (10)

1. a drive mechanism, comprising:

a motor (1), the motor (1) comprising a hollow shaft (11) having an open end;

Clutch (2), clutch (2) include loose axle (21) and functional unit (22), loose axle (21) certainly the open end stretches into in hollow shaft (11), and with functional unit (22) cooperate, loose axle (21) are used for the drive to wait to drive the part, functional unit (22) are used for making loose axle (21) with hollow shaft (11) relatively fixed or relative rotation.

2. The drive mechanism according to claim 1, characterized in that the functional part (22) comprises an electromagnet, which is fixed relative to the hollow shaft (11), and a magnetic part, which is connected to the movable shaft (21),

The movable shaft (21) is arranged to be relatively fixed with the hollow shaft (11) in a state that the electromagnet and the magnetic part are mutually attracted;

the movable shaft (21) is arranged to rotate relative to the hollow shaft (11) in a state where the electromagnet and the magnetic portion are separated from each other.

3. The drive mechanism according to claim 1, wherein the function portion (22) comprises an electromagnet (221) and an iron block (222), the electromagnet (221) is fixed relative to the hollow shaft (11), the axial direction of the movable shaft (21) is the same as the direction of gravity, the iron block (222) is located below the electromagnet (221) and is connected with the movable shaft (21),

Under the state that the electromagnet (221) is attracted with the iron block (222), the movable shaft (21) is arranged to be relatively fixed with the hollow shaft (11);

The movable shaft (21) is arranged to rotate relative to the hollow shaft (11) in a state where the electromagnet (221) is separated from the iron block (222).

4. The drive mechanism according to any one of claims 1 to 3, wherein a first limit structure is provided on the movable shaft (21), and a second limit structure and a rotation fit structure are provided on the hollow shaft (11), and the first limit structure and the second limit structure are in limit fit or the first limit structure and the rotation fit structure are in movable fit in the rotation direction of the hollow shaft (11).

5. The drive mechanism according to claim 4, wherein the first limit structure is a key groove (211) extending in an axial direction of the movable shaft (21), the key groove (211) being recessed with respect to an outer surface of the movable shaft (21), and the key groove (211) having an opening (212) in at least one of the axially opposite ends;

The rotating fit structure is the inner surface of the hollow shaft (11), the second limit structure is a limit key (113), the limit key (113) is opposite to the protruding rotating fit structure, and the limit key (113) is in limit fit with the key groove (211) in the rotating direction of the hollow shaft (11).

6. the drive mechanism according to claim 5, characterized in that the end of the key groove (211) facing away from the opening (212) is provided with a catch (213), and the catch (213) is in limit fit with the limit key (113) in the axial direction of the hollow shaft (11).

7. The driving mechanism according to claim 5, wherein the key slot (211) and the limit key (113) are provided in plurality, the limit keys (113) are provided in plurality at intervals along the rotation direction of the hollow shaft (11), and the key slots (211) and the limit keys (113) are correspondingly matched one by one.

8. The drive mechanism according to claim 5, characterized in that the maximum length of the limit key (113) in the axial direction of the hollow shaft (11) is smaller than the maximum translational distance of the movable shaft (21) relative to the hollow shaft (11).

9. The drive mechanism according to any one of claims 1 to 3, further comprising a speed reducer (3), wherein the speed reducer (3) is in transmission connection with the motor (1).

10. A motorized window treatment comprising a window treatment shaft and a drive mechanism according to any one of claims 1 to 9, the drive mechanism being in driving connection with the window treatment shaft.