Clothes dryer and control method thereof

Abstract

The invention relates to a clothes dryer which comprises a driving device, a driving shaft of the driving device is in transmission connection with a roller and an impeller, so that the roller and the impeller are driven to rotate at the same time, and the driving device can be controlled by a control device to enable the driving shaft to be switched between rotation in a first direction and rotation in a second direction. And the gear transmission assembly is connected between the driving shaft and the impeller, so that the rotation of the driving shaft in the changing direction is converted into the rotation in the same direction all the time, and the rotation is transmitted to the impeller. The invention also relates to a control method of the clothes dryer, which comprises the following steps: in the process of running a drying program, controlling the driving device to simultaneously drive the roller and the impeller, and enabling the roller and the impeller to rotate for a first preset time along a first direction, and then enabling the roller and the impeller to rotate for a second preset time along a second direction opposite to the first direction.

Description

[Technical field]

[0001] The invention relates to a clothes dryer and a control method for the clothes dryer, and also relates to an impeller for driving air flow and a transmission device connecting the impeller and a driving device. [Background technology]

[0002] The clothes dryer includes a rotatable drum and an air passage connected to the drum. When the clothes dryer performs a drying process, the air in the air passage is heated and then enters the drum, where it comes into contact with the wet clothes, causing the moisture in the clothes to evaporate and the air to become humid. The hot and humid air re-enters the air passage and is cooled therein, whereupon the moisture in the air is condensed and liquid water is separated. Usually, the air that has become dry again is heated again and re-enters the drum to enter the next cycle, and the cycle is repeated so that the moisture in the clothes is gradually separated.

[0003] Some clothes dryers include a motor to drive the drum and the impeller in the air passage at the same time. During the drying process, the motor is turned on and the drum and the impeller rotate synchronously. Because the drum and the impeller share a motor, costs are saved and the already limited installation space is saved. In order to make the clothes contact the hot air more evenly, so as to dry the clothes more quickly and evenly, and to prevent the drum from continuously rotating in one direction and causing the clothes to knot or form a ball, the rotation direction of the drum needs to be frequently switched. However, since the shape of the impeller is generally suitable for rotating in one direction, such as the forward direction, it has a greater blowing capacity when rotating, while the blowing capacity is greatly reduced when rotating in the other direction, such as the reverse direction. Therefore, when the motor rotates in the reverse direction, there may be many disadvantages, such as: the air volume is weak, which reduces the drying efficiency; if a heat pump heat exchange device is used in the air passage, due to the weak air volume, the heat of the heat pump cannot be released in time, increasing the risk of damage to the heat pump; the air flow direction is changed, and the contact sequence with the heating and cooling heat exchange devices is changed, further reducing the drying efficiency; and the change in the air flow direction may also make the filter function ineffective, and the fluff on the filter re-enter the drum. Considering these disadvantages when rotating in reverse, some existing dryers make the motor rotate forward most of the time, and only rotate in reverse for a small proportion of the time (for example, one tenth of the time). Obviously, this compromise solution cannot achieve ideal drying efficiency, and there are still some adverse effects caused by the reverse rotation of the impeller.

[0004] In order to improve drying efficiency and avoid the many adverse effects caused by the reverse rotation of the impeller, some dryers are equipped with drive motors for the drum and the impeller that drives the drying air. In this way, the impeller can only rotate in the forward direction, and the duration of the forward and reverse rotation of the drum can be configured more freely. However, compared with the above dryers, such a configuration increases the cost of the machine, and two motors must be installed in an already very limited space, which increases the difficulty of design. [Summary of the invention]

[0005] The object of the present invention is to improve at least one of the defects existing in the prior art, such as those mentioned above.

[0006] One aspect of the present invention discloses a clothes dryer, comprising a driving device, wherein a driving shaft of the driving device is respectively connected to a drum and an impeller for driving, thereby driving the drum to rotate and the impeller to rotate at the same time, wherein the driving device can be controlled by a control device to switch the driving shaft between rotating in a first direction and rotating in a second direction, thereby enabling the drum to rotate synchronously in the first direction or in the second direction, and a gear transmission assembly is connected between the driving shaft and the impeller, outputs the rotational motion of the driving shaft in the first direction to the impeller while maintaining the rotational direction unchanged, and converts the rotational motion of the driving shaft in the second direction into rotational motion in the first direction and outputs it to the impeller.

[0007] The gear transmission assembly converts the rotation of the drive shaft in a direction that changes direction into a rotation that always stays in one direction, thereby making the rotation direction of the drum more freely switchable and making the impeller always rotate in a favorable direction. Moreover, the gear transmission assembly is less expensive and occupies less space than a separate motor for the impeller.

[0008] Optional embodiments also include: the gear transmission assembly includes an input gear group connected to the drive shaft and an output gear group connected to the impeller, the input gear group includes a swing arm and a swing gear connected to the swing arm, the swing gear is driven by the drive shaft, the output gear group includes a first output gear and a transition gear that are meshed with each other, the output shaft is directly or indirectly connected to the first output gear, and when the drive shaft rotates in a first direction, the swing arm swings in the first swing direction, and the swing gear meshes with the transition gear, and when the output shaft rotates in a second direction, the swing arm swings in the second swing direction, and the swing gear meshes with the first output gear.

[0009] Optional embodiments include: the swing gear includes a first swing gear and a second swing gear, the first swing gear and the second swing gear have the same rotation direction, when the drive shaft rotates along the first direction, the first swing gear is meshed with the transition gear, and the second swing gear is idle, when the drive shaft rotates along the second direction, the second swing gear is meshed with the first output gear, and the first swing gear is idle.

[0010] Optional embodiments include: the input gear set includes a clutch gear driven by a drive shaft, a swing gear meshes with the clutch gear, a swing arm is coaxially mounted with the clutch gear and can swing around the axis relative to the clutch gear, the swing gear is rotatably mounted on the swing arm, and when the swing gear rotates, the friction force applied to the swing arm is sufficient to drive the swing arm to swing.

[0011] An optional embodiment includes: an elastic device acts between the swing gear and the swing arm, so that the swing gear applies direct or indirect pressure to the swing arm. The pressure causes the swing gear to generate greater friction force on the swing arm when rotating, thereby driving the swing arm to swing.

[0012] An optional embodiment includes: the second output gear as a driven wheel of the first output gear is meshed with the first output gear, the output shaft is connected to the second output gear, and the output shaft is drivingly connected to the impeller.

[0013] Optional embodiments include: the impeller is located in an air channel connected to the drum space, and a heating device and a dehumidification device are also provided in the air channel. The rotation of the impeller along a first direction drives the air to circulate in the drum and the air channel, and the air flows in a direction of passing through the heating device-drum-dehumidification device-heating device in sequence, and repeats the cycle.

[0014] An optional embodiment includes: both ends of the air channel are connected to the drum space to form a circulation channel. The heating device and the dehumidifying device are implemented as a condenser and an evaporator of a heat pump. The evaporator and the condenser of the heat pump are located in the air channel and are used to dehumidify and heat the air flowing through. The heat pump also includes a compressor, and the airflow driven by the rotation of the impeller in the first direction flows in the direction of condenser-drum-evaporator-condenser in sequence.

[0015] An optional embodiment includes: a filter is provided on the path where the air is driven from the drum into the air passage to capture fluff in the air.

[0016] An optional embodiment includes: a first end of the drive shaft is drivingly connected to the roller, and a second end of the drive shaft is connected to the gear transmission assembly.

[0017] An optional embodiment includes: the driving device is coaxially located on the side of the drum with the gear transmission assembly, and the driving shaft is parallel to the central axis of the drum and lower than the central axis of the drum.

[0018] If technical conditions permit, the above embodiments may be combined in any manner.

[0019] A second aspect of the present invention provides a control method for a dryer according to the various embodiments above, wherein, during the running of a drying program, a driving device is controlled to simultaneously drive the drum and the impeller and rotate them in a first direction for a first predetermined time, and then rotate them in a second direction opposite to the first direction for a second predetermined time.

[0020] An optional embodiment includes: during the running of the drying program, the driving device rotates alternately in the first direction and in the second direction for multiple times.

[0021] An optional embodiment also includes: the proportion of the first predetermined time to all rotation times is greater than or equal to 40% and less than or equal to 60%.

[0022] A third aspect of the present invention provides a clothes dryer, comprising a control device, wherein the control device is configured to operate the clothes dryer according to the control method of the above embodiment.

[0023] Some specific embodiments of the present invention will be described below with reference to the accompanying drawings. Other advantages of the present invention will also be described below with reference to various specific embodiments.

Brief Description of the Drawings

[0024] Figure 1 It is a brief schematic diagram of the main components and connection methods of a clothes dryer;

[0025] Figure 2 It is a schematic diagram of the local structure of the clothes dryer;

[0026] Figure 3 This is an exploded view of the gear transmission assembly;

[0027] Figure 4 A three-dimensional view of the gear transmission assembly in a first direction after a portion of the housing is removed;

[0028] Figure 5 for Figure 4 A cross-sectional view of the gear transmission assembly along a vertical plane passing through the drive shaft;

[0029] Figure 6 for Figure 4 A three-dimensional view of the gear transmission assembly in a second direction, wherein the moving component is in a first moving state;

[0030] Figure 7 for Figure 4 A stereoscopic view of the gear transmission assembly in the second direction, wherein the moving parts are in the second moving state. [Specific embodiment]

[0031] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention, and each embodiment may share the same view or multiple views for description, but all features appearing in the same figure cannot be interpreted as features that must be possessed by an embodiment. On the contrary, as long as they are not mutually exclusive technically, they can be combined in any suitable manner. Moreover, for the sake of simplicity, different embodiments of different aspects may be presented in the same specific design, but such presentation does not mean that the embodiments of these aspects should appear together. The disassembly and / or combination of all possible embodiments and / or technical features should also take into account the description of the specification and the content that can be directly and unambiguously determined by those skilled in the art based on the description of the specification.

[0032] like Figure 1 The illustrated embodiment discloses the main components and connection methods of a clothes dryer 1, which includes a drum 2 for accommodating clothes 8. A heat exchange device 10 is connected to the space in the drum 2 through an air passage 3. An impeller 4 is located in the air passage 3, and when the impeller 4 is driven to rotate, it can drive air to flow in the drum 2 and the air passage 3. In this embodiment, both ends of the air passage 3 are connected to the space of the drum 2 to form a circulation passage.

[0033] The heat exchange device 10 is arranged in the air passage 3. The heat exchange device 10 includes a heating device 101 and a dehumidifying device 102. The rotation of the impeller 4 drives the air to circulate in the drum 2 and the air passage 3, and the air flows in the direction of passing through the heating device-drum-dehumidifying device-heating device in sequence, and repeats the cycle. Thus, the heating device 101 of the heat exchange device 10 can heat the air. The heated air flows to the drum 2, heats the wet clothes in the drum 2, and evaporates the moisture in the clothes. The high-temperature air carrying moisture recirculates into the air passage 3, exchanges heat with the dehumidifying device 102 in the heat exchange device 10, and the moisture therein is condensed and separated. The air with greatly reduced temperature and humidity re-enters the heating part of the heat exchange device 10, is heated again, and enters the next cycle. This is repeated continuously to gradually dry the moisture in the clothes.

[0034] The heat exchange device 10 can be implemented as a heat pump device, including a condenser 11 as a heating device of the heat exchange device, an evaporator 12 as a dehumidification device of the heat exchange device, and a compressor 14 and a throttling device 15 connected to the condenser 11 and the evaporator 12 through a refrigerant pipe 13. The heat pump type heat exchange device 10 also includes a water receiving container 16 to receive condensed water condensed from the air. The airflow driven by the rotation of the impeller 4 flows in the direction of condenser-drum-evaporator-condenser in sequence.

[0035] Figure 1 In the embodiment shown, a filter 5 for capturing fluff in the air is provided on the path where the air is driven from the drum 2 into the air passage 3. During the drying process of clothes, the fluff in the clothes will flow with the air. The fluff entering the air passage 3 and the heat exchange device 10 will affect the performance of the heat exchange device 10 and reduce the drying efficiency. The filter 5 can capture most of the fluff and reduce the fluff entering the heat exchange device 10.

[0036] The clothes dryer 1 further includes a control device 100 for controlling various electrical components in the clothes dryer 1 .

[0037] The driving system of the drum 2 and the impeller 4 will be described in detail below.

[0038] Advantageous aspects of the embodiments of the present invention include: using the same drive device 6 to simultaneously drive the drum 2 and the impeller 4 to rotate. The drive device 6 is a single power source, for example, it is specifically implemented as a motor. The drive device 6 has a drive shaft 61 that outputs rotational power outward. The drive shaft 61 is respectively connected to the drum 2 and the impeller 4, so that the drum 2 is driven to rotate while driving the impeller 4 to rotate. The drive shaft 61 can be a single shaft, and the drum 2 and the impeller 4 are both connected to the single drive shaft 61. For example, the first end of the drive shaft 61 is connected to the drum 2, and the second end of the drive shaft 61 is connected to the impeller 4. The transmission connection is understood in a broad sense in the context, including both direct connection and indirect connection. The drive shaft 61 can also be in the form of a non-single shaft. For example, the motor outputs two shafts, which drive the drum 2 and the impeller 4 respectively.

[0039] Advantageous aspects of the embodiment of the present invention also include: the gear transmission assembly 20 is connected between the drive shaft 61 and the impeller 4, and the rotational motion of the drive shaft 61 along the first direction is output to the impeller 4 while maintaining the rotational direction unchanged, and the rotational motion of the drive shaft 61 along the second direction is converted into the rotational motion along the first direction and output to the impeller 4. That is, no matter how the rotational direction of the drive shaft 61 changes, the impeller 4 always rotates in a fixed direction through the action of the gear transmission assembly 20. Therefore, the impeller 4 can always rotate in a direction that is conducive to it driving a larger flow of air. Here, "connection" includes direct connection and indirect connection through other transmission devices.

[0040] The driving device 6 can be controlled by the control device 100 to switch the driving shaft 61 between rotating in the first direction and rotating in the second direction. The driving shaft 61 is connected to the drum 2 through a general transmission structure, such as a pulley structure, so that the drum 2 and the driving shaft 61 can rotate synchronously in the first direction or in the second direction, which includes synchronously switching the rotation direction. It is beneficial and necessary to switch the rotation direction of the drum 2 from time to time during the drying process, which can reduce the entanglement of clothes, reduce the generation of wrinkles, make the clothes more fluffy, and increase the drying efficiency.

[0041] Figure 2 The positional relationship between the drive system, the drum 2 and the air passage 3 is more specifically shown. The drive device 6 and the gear transmission assembly 20 are coaxially located on the side of the drum 2. The drive shaft 61 is parallel to the central axis 7 of the drum 2 and is lower than the central axis 7 of the drum 2. It can be seen that the drive device 6 and the gear transmission assembly 20 can use the space below the side of the drum 2. This layout is beneficial to the dryer 1 with very limited space.

[0042] like Figure 2 As shown, at least a portion of the air passage 3 is located outside the end of the drum 2, and the impeller 4 is located in the portion of the air passage 3. The impeller 4 and the gear transmission assembly can be as shown in FIG. Figure 2 The direct connection shown may also be an indirect connection via other transmission mechanisms, such as pulleys or gears.

[0043] Thus, during the drying process, the control device 100 can control the driving device 6 to rotate in different ways to simultaneously drive the drum 2 and the impeller 4 to rotate, and the drum 2 and the impeller 4 can rotate in their favorable directions. After the drying process is started, the heat exchange device 10 and the driving device are turned on. The drum 2 rotates, driving the clothes 8 therein to tumble, and the impeller 4 drives the air flow, so that the air heated by the heat exchange device 10 enters the drum 2 to dry the clothes. Advantageously, the driving device 6 is controlled to rotate in a first direction for a first predetermined time during the drying process, and then rotate in a second direction opposite to the first direction for a second predetermined time; and rotate alternately in the first direction and in the second direction for multiple times. Preferably, in each cycle of alternating directions, the time (i.e., the length of time) of rotating in the first direction is close to the time of rotating in the second direction. For example, it can be defined as follows: the proportion of the first predetermined time to all rotation times is greater than or equal to 40% and less than or equal to 60%.

[0044] The control result of the driving device 6 is reflected on the drum 2 and the impeller 4, that is, during the drying process, the drum 2 rotates alternately in two directions, and at the same time, the impeller 4 always rotates in one of the favorable directions, thereby driving the airflow to circulate between the drum 2 and the air channel 3 along one direction.

[0045] The following will be combined Figures 3 to 7 The gear transmission assembly 20 is described in detail.

[0046] The gear transmission assembly 20 comprises a housing formed by assembling a lower housing 21 and an upper housing 22. A support seat 211 is disposed in the lower housing 21. The driving shaft 61 is supported on the lower housing 21 and the support seat 211.

[0047] The gear transmission assembly 20 includes an input gear set 23 drivingly connected to the drive shaft 61 and an output gear set 24 drivingly connected to the impeller 4. The input gear set 23 and the output gear set 24 are located in a space enclosed by the lower housing 21 and the upper housing 22.

[0048] The input gear set 23 includes a clutch gear 231 driven by the driving shaft 61. The swing arm 232 is coaxially mounted with the clutch gear 231 and can swing around the axis relative to the clutch gear 231. Figure 3 In the specific embodiment shown, the swing arm 232 is sleeved on the drive shaft 61, and the swing arm 232 and the drive shaft 61 are preferably designed to minimize friction so that the swing arm 232 can swing smoothly and freely around the drive shaft 61. The swing arm 232 has a first arm 2321 and a second arm 2322 that extend radially at an angle. A first swing gear 233 is rotatably mounted on the outer end of the first arm 2321. A second swing gear 234 is rotatably mounted on the outer end of the second arm 2322. Both the first swing gear 233 and the second swing gear 234 are meshed with the clutch gear 231 and are driven to rotate by the clutch gear 231. The first swing gear 233 and the second swing gear 234 rotate in the same direction.

[0049] When the swing gears 233 and 234 rotate, the friction force on the swing arm 232 is sufficient to drive the swing arm 232 to swing. Figure 6 When the driving shaft 61 rotates in the first direction, the clutch gear 231 rotates in the same direction as the driving shaft 61, and the first swing gear 233 and the second swing gear 234 meshing therewith rotate in the second direction. Due to the existence of friction between the swing gears 233, 234 and the swing arm and the friction is large enough, the rotation of the swing gears 233, 234 in the second direction drives the swing arm 232 to swing in the first swing direction through the friction. Figure 6 As shown by the dashed arrow in the middle. The first swing direction is opposite to the first direction of rotation of the drive shaft 61. The swing mentioned here is actually a rotation in a smaller range. On the contrary, refer to Figure 7When the driving shaft 61 rotates in the second direction, the swing arm 232 is driven to swing in the second swing direction. Figure 7 As shown by the dashed arrow in the middle, the second swinging direction is opposite to the second direction in which the driving shaft 61 rotates.

[0050] In order to make the swing gears 233, 234 and the swing arm 232 have appropriate friction, there are many ways to achieve it. For example, the elastic device 235 acts between the swing gears 233, 234 and the swing arm 232, so that the swing gears 233, 234 exert direct or indirect pressure on the swing arm 232. Figure 3-7 The specific implementation method in the illustrated embodiment is that the elastic device 235 presses the swing gears 233 and 234 toward the swing arm 232.

[0051] The swing gears 233 and 234 mentioned above may refer to the first swing gear 233 and / or the second swing gear 234. In some other embodiments, there may be one or more swing gears.

[0052] The output gear set 24 includes a first output gear 241 and a transition gear 242 meshing with each other, and the output shaft 243 is directly or indirectly connected to the first output gear 241. In the illustrated embodiment, the second output gear 244 meshes with the first output gear 241 as a driven gear of the first output gear 241, the output shaft 243 is connected to the second output gear 244, and the output shaft 243 is connected to the impeller 4.

[0053] The positions and connection relationship of the input gear set 23 and the output gear 24 are configured such that the swing gears 233 and 234 are close to the first output gear 241 and the transition gear 242 and can selectively mesh with each other.

[0054] For example, Figure 6 As shown, when the driving shaft 61 rotates in the first direction, the first swing gear 233 and the second swing gear 234 both rotate in the second direction, and the swing arm 232 swings in the first swing direction, so that the first swing gear 233 is meshed with the transition gear 242. The second swing gear 234 is idle. The rotation of the first swing gear 233 in the second direction is transmitted to the first output gear 241 through the transition gear 242. The first output gear 241 then rotates in the second direction. The rotation of the first output gear 241 further drives the second output gear 244 to rotate in the first direction. Thus, the output shaft 243 rotates in the first direction.

[0055] like Figure 7As shown, when the driving shaft 61 rotates in the second direction, the first swing gear 233 and the second swing gear 234 both rotate in the first direction, and the swing arm 232 swings in the second swing direction, so that the second swing gear 234 meshes with the first output gear 241. The first swing gear 233 is idle. The rotation of the second swing gear 233 in the first direction directly drives the first output gear 241 to rotate in the opposite direction of its rotation. The first output gear 241 then rotates in the second direction. The rotation of the first output gear 241 further drives the second output gear 244 to rotate in the first direction. Thus, the output shaft 243 rotates in the first direction.

[0056] It can be seen that no matter what the rotation direction of the drive shaft 61 is, the rotation direction of the first output gear 241 remains unchanged, so the rotation direction of the second output gear 244 also remains unchanged. If the first output gear 241 is used as the gear for external output, it is also valid and feasible and also falls within the scope of the present invention.

[0057] The terms "first", "second" and so on in the above text are only used to indicate distinction and do not constitute actual limitations. Figure 7 The rotation direction of the middle driving shaft 61 is called the first direction. Figure 6 The rotation direction of the middle drive shaft 61 is called the second direction. The names of the rotation directions of other parts are changed accordingly. However, the actual technical concept does not change.

[0058] The various specific embodiments described above and shown in the drawings are only used to illustrate the present invention. Within the scope of the basic technical concept of the present invention, any form of changes made by ordinary technicians in the relevant technical field to the present invention are within the protection scope of the present invention.

Claims

1. A clothes dryer, comprising a driving device (6), wherein a driving shaft (61) of the driving device is respectively connected to a drum (2) and an impeller (4), thereby driving the drum to rotate and the impeller to rotate at the same time, wherein the driving device can be controlled by a control device (100) to switch the driving shaft between rotating in a first direction and rotating in a second direction, thereby causing the drum to rotate synchronously in the first direction or in the second direction, characterized in that: The gear transmission assembly (20) is connected between the drive shaft and the impeller, outputs the rotational motion of the drive shaft along the first direction to the impeller while maintaining the rotational direction unchanged, and converts the rotational motion of the drive shaft along the second direction into the rotational motion along the first direction and outputs it to the impeller.

2. The clothes dryer according to claim 1, characterized in that: The gear transmission assembly (20) comprises an input gear set (23) drivingly connected to a drive shaft (61) and an output gear set (24) drivingly connected to an impeller, the input gear set comprising a swing arm (232) and swing gears (233, 234) connected to the swing arm, the swing gear being driven by the drive shaft, the output gear set (24) comprising a first output gear (241) and a transition gear (242) meshing with each other, the output shaft being directly or indirectly drivingly connected to the first output gear, and when the drive shaft rotates in a first direction, the swing arm swings in a first swinging direction, the swing gear meshes with the transition gear, and when the output shaft rotates in a second direction, the swing arm swings in a second swinging direction, the swing gear meshes with the first output gear.

3. The clothes dryer according to claim 2, characterized in that: The swing gears (233, 234) include a first swing gear (233) and a second swing gear (234). The first swing gear and the second swing gear have the same rotation direction. When the drive shaft (61) rotates in the first direction, the first swing gear (233) meshes with the transition gear (242) and the second swing gear (234) idles. When the drive shaft (61) rotates in the second direction, the second swing gear (234) meshes with the first output gear (241) and the first swing gear (233) idles.

4. The clothes dryer according to claim 2, characterized in that: The input gear set (23) comprises a clutch gear (231) driven by a driving shaft (61), swing gears (233, 234) meshing with the clutch gear (231), a swing arm (232) coaxially mounted with the clutch gear (231) and capable of swinging around the axis relative to the clutch gear, the swing gears (233, 234) rotatably mounted on the swing arm (232), and when the swing gears rotate, the friction force exerted on the swing arm is sufficient to drive the swing arm to swing.

5. The clothes dryer according to claim 4, characterized in that: The elastic device (235) acts between the swing gears (233, 234) and the swing arm (232), so that the swing gears exert direct or indirect pressure on the swing arm.

6. The clothes dryer according to claim 2, characterized in that: The second output gear (244) serves as a driven wheel of the first output gear (241) and meshes with the first output gear (241); the output shaft (243) is connected to the second output gear (244), and the output shaft (243) is drivingly connected to the impeller (4).

7. The clothes dryer according to claim 1, characterized in that: The impeller (4) is located in an air passage (3) that is in spatial communication with the drum (2), and a heating device (101) and a dehumidifying device (102) are also provided in the air passage. The rotation of the impeller (4) in a first direction drives air to flow in the drum (2) and the air passage (3), and the air flows in a direction of passing through the heating device - the drum - the dehumidifying device - the heating device in sequence, and the cycle is repeated.

8. The clothes dryer according to claim 7, characterized in that: Both ends of the air channel (3) are in communication with the space of the drum (2) to form a circulation channel. The evaporator (11) and condenser (12) of the heat pump are located in the air channel and are used to dehumidify and heat the air flowing through the air channel. The heat pump also includes a compressor (14). The airflow driven by the rotation of the impeller (4) in a first direction flows in sequence in the direction of condenser-drum-evaporator-condenser.

9. The clothes dryer according to claim 7, characterized in that: On the path where the air is driven from the drum (2) into the air passage (3), a filter (5) for capturing fluff in the air is provided.

10. The clothes dryer according to claim 7, characterized in that: The first end of the driving shaft (61) is drivingly connected to the drum (2), and the second end of the driving shaft (61) is connected to the gear transmission assembly (20).

11. The clothes dryer according to claim 1, characterized in that: The driving device (6) is coaxially located with the gear transmission assembly (20) on the side of the drum (2), and the driving shaft is parallel to the central axis (7) of the drum and is lower than the central axis of the drum.

12. The control method for a clothes dryer according to any one of claims 1 to 11, characterized in that: During the drying process, the driving device (6) is controlled to simultaneously drive the drum (2) and the impeller (4) to rotate in a first direction for a first predetermined time, and then rotate in a second direction opposite to the first direction for a second predetermined time.

13. The control method according to claim 12, characterized in that: During the drying process, the driving device (6) rotates alternately in the first direction and in the second direction for multiple times.

14. The control method according to claim 12, characterized in that: The proportion of the first predetermined time to the total rotation time is greater than or equal to 40% and less than or equal to 60%.

15. A clothes dryer comprising a control device, characterized in that: The control device is configured to operate the dryer (1) according to the control method according to any one of claims 12-14.

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