Clothes dryer commutator

Abstract

The application discloses a dryer commutator, under the condition that the output speed of an output shaft guarantees that the fan output wind power is sufficient, that is, under the condition that the output rotating speed of the traditional commutator is the same, the dryer commutator can greatly reduce the input speed of an input shaft, thereby greatly reducing the rotating speed of an input gear, and the forward one-way transmission mechanism and the reverse one-way transmission mechanism also have obvious speed reduction, that is, the angular speed of other gears except the output gear is greatly reduced, so that the lubricating grease is prevented from being thrown off, the staying capacity of the lubricating grease on the tooth surface of the other gears is greatly enhanced, the amount of the lubricating grease required to be filled is reduced, under the conditions of the speed reduction and the lubricating grease adhesion, the noise of the gears is reduced, the wear of the gears is reduced, and the service life of the gears is prolonged, and due to the lubricating grease supplied by the meshing gears, the wear of the output gear is also reduced, and the service life of the output gear is also obviously prolonged.

Description

Technical Field

[0001] This invention relates to the field of commutation mechanism technology, specifically to a commutator for a clothes dryer. Background Technology

[0002] In a clothes dryer, the fan needs to rotate continuously in one direction to ensure hot air circulation, while the drive motor frequently starts and stops, and alternates between forward and reverse rotation during actual operation. The commutator's function is to convert the motor's bidirectional input into the unidirectional rotation of the output shaft, ensuring that the fan's airflow direction remains constant.

[0003] Traditional commutators maintain consistent rotational speeds between the input and output shafts using needle roller bearings in conjunction with spur gears. This means two needle roller bearings are placed on either the input or output shaft to ensure bidirectional input is converted to unidirectional output rotation. However, as dryers evolve towards higher efficiency and quieter operation, the shortcomings of traditional commutators at high speeds (2700 r / min) are becoming increasingly apparent: gear lubricating grease is dislodged by centrifugal force, the transmission system overheats, and grease liquefaction fails. These problems threaten gear wear life, resulting in a shorter lifespan for traditional commutators, necessitating improvement. Summary of the Invention

[0004] One of the technical problems to be solved by this application is to overcome the defects of the above-mentioned related technologies and provide a dryer commutator with a long service life.

[0005] The technical solution adopted by this invention to solve the technical problem is: a commutator for a clothes dryer, comprising: The input shaft and input gear are coaxially connected, and the input shaft is connected to the drive motor. The output gear and output shaft are coaxially driven, and the output shaft is connected to the fan drive. A forward unidirectional transmission mechanism is located next to the input shaft and the output shaft. It meshes with the input gear and has a transmission ratio of i1:1. It also meshes with the output gear. It is used to drive the output shaft to rotate at n times the speed of the input shaft when the input shaft rotates in the forward direction, and to cut off the transmission when the input shaft rotates in the reverse direction. A reverse unidirectional transmission mechanism is located next to the input shaft and the output shaft. It meshes with the input gear and has a transmission ratio of i2:1. It also meshes with the output gear. It is used to drive the output shaft to rotate at n times the speed of the input shaft when the input shaft rotates in the reverse direction, and to cut off the transmission when the input shaft rotates in the forward direction. Among them, i1 <n,i2<n,2≤n≤5。

[0006] Preferably, the forward unidirectional transmission mechanism includes: a first linkage gear, a first needle roller one-way bearing, a first transmission shaft, and a first drive gear; the first linkage gear meshes with the input gear, the first linkage gear is coaxially connected to the first transmission shaft through the first needle roller one-way bearing, the first drive gear is coaxially connected to the first transmission shaft, and the first drive gear meshes with the output gear; The reverse one-way transmission mechanism includes: a reversing gear, a pivot, a second linkage gear, a second needle roller one-way bearing, a second transmission shaft, and a second drive gear. The reversing gear meshes with the input gear, is coaxially connected to the pivot, meshes with the second linkage gear, and is coaxially connected to the second transmission shaft via the second needle roller one-way bearing. The second drive gear is coaxially connected to the second transmission shaft and meshes with the output gear. The transfer of the needle roller one-way bearing to the forward and reverse one-way transmission mechanisms results in two improvements: first, a reduction in rotational speed; second, a reduction in the impact of vibration from the drive motor or fan, leading to a decrease in coaxiality misalignment. This also effectively reduces the noise of the needle roller one-way bearing, solving the problem of excessive noise from needle roller one-way bearings.

[0007] Compared with related technologies, this invention has the following advantages: When the output speed of the output shaft ensures sufficient airflow from the fan (i.e., the same output speed as a traditional commutator), the commutator of this dryer can significantly reduce the input speed of the input shaft, thereby significantly reducing the speed of the input gear. The forward and reverse unidirectional transmission mechanisms also experience significant speed reduction, meaning the angular velocity of gears other than the output gear is significantly reduced, preventing the lubricating grease from being thrown off. This greatly enhances the retention capacity of the lubricating grease on the tooth surfaces of other gears, reducing the amount of lubricating grease required. With reduced speed and lubricating grease adhesion, these gears experience reduced noise, reduced wear, and increased service life. Furthermore, the output gear, due to the lubricating grease supplied by the meshing gears, also experiences reduced wear and a significantly increased service life.

[0008] Preferably, the transmission ratio of the first linkage gear to the input gear is 1:1, and the transmission ratio of the first drive gear to the output gear is 1:3; the transmission ratio of the reversing gear, the second linkage gear to the input gear is 1:1:1, and the transmission ratio of the second drive gear to the output gear is 1:3.

[0009] Preferably, the input shaft rotates at a speed of 900 r / min, and the output shaft rotates at a speed of 2700 r / min.

[0010] Preferably, a hollow bearing seat is provided at the center of the intermediate support plate between the upper and lower housings. An oil-impregnated bearing is assembled inside the hollow bearing seat. The upper end of the input shaft is connected to the lower part of the oil-impregnated bearing, and the lower end of the output shaft is connected to the upper part of the oil-impregnated bearing. The oil-impregnated bearing improves the concentricity of the input and output shafts.

[0011] Preferably, the lower part of the lower housing is provided with a downwardly protruding mating ring, which matches a groove on the drive motor; the lower end of the input shaft is provided with an internal spline, which matches an external spline on the drive shaft of the drive motor; the internal spline and the mating ring are coaxially arranged. This is used for assembly with the drive motor, protecting the spline connection and preventing external contaminants from entering the spline connection and causing corrosion and adhesion, which would make subsequent disassembly difficult.

[0012] Preferably, the upper housing, lower housing, and intermediate support plate are all provided with multiple lugs, and the lugs are provided with threaded holes for fixed installation with the drive motor.

[0013] Preferably, the input gear, the first linkage gear, the reversing gear, and the second linkage gear are all helical gears with a helix angle ≤ 15°; the first drive gear, the second drive gear, and the output gear are all helical gears with a helix angle ≤ 15°. The meshing transmission of helical gears can reduce noise.

[0014] Furthermore, the bearings between the first and second drive shafts and the upper and lower housings are all ball bearings. The ball bearings are matched with the meshing transmission of the helical gears, avoiding the sliding friction caused by the axial movement of the helical gears, which would affect the bearing life.

[0015] Preferably, the filling lubricating grease is a semi-solid lithium-based lubricating grease. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of an embodiment.

[0017] Figure 2 This is a partial exploded view of an embodiment.

[0018] As shown in the figure: 1. Upper housing; 2. Lower housing; 3. Intermediate support plate; 4. Input shaft; 5. Input gear; 6.1. First linkage gear; 6.2. First needle roller one-way bearing; 6.3. First transmission shaft; 6.4. First drive gear; 7.1. Reversing gear; 7.2. Pivot; 7.3. Second linkage gear; 7.4. Second needle roller one-way bearing; 7.5. Second transmission shaft; 7.6. Second drive gear; 8. Output gear; 9. Output shaft. Detailed Implementation

[0019] First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The commutator of the clothes dryer of the present invention is realized based on a general concept, including: The input shaft 4 and the input gear 5 with coaxial transmission, and the input shaft 4 is in transmission connection with the driving motor; The output gear 8 and the output shaft 9 with coaxial transmission, and the output shaft 9 is in transmission connection with the blower; The forward one-way transmission mechanism is arranged beside the input shaft 4 and the output shaft 9, meshes with the input gear 5, the transmission speed ratio of the forward one-way transmission mechanism to the input gear 5 is i1:1, meshes with the output gear 8, and is used to drive the output shaft 9 to rotate in a fixed direction at n times the speed of the input shaft 4 when the input shaft 4 rotates forward, and cut off the transmission when the input shaft 4 rotates backward; The reverse one-way transmission mechanism is arranged beside the input shaft 4 and the output shaft 9, meshes with the input gear 5, the transmission speed ratio of the reverse one-way transmission mechanism to the input gear 5 is i2:1, meshes with the output gear 8, and is used to drive the output shaft 9 to rotate in a fixed direction at n times the speed of the input shaft 4 when the input shaft 4 rotates backward, and cut off the transmission when the input shaft 4 rotates forward; Among them, i1 < n, i2 < n, 2 ≤ n ≤ 5. That is, when the driving motor rotates forward at a low speed, it drives the input shaft 4 and the synchronous input gear 5 to rotate forward at a low speed,带动 the forward one-way transmission mechanism to rotate at the same speed or slightly increase the speed, and then drives the synchronous output gear 8 and the output shaft 9 to rotate in a fixed direction at a high speed, driving the blower to rotate at a high speed for air supply operation. At this time, the reverse one-way transmission mechanism acts as an inert mechanism and does not participate in the transmission; when the driving motor rotates backward at a low speed, it drives the input shaft 4 and the synchronous input gear 5 to rotate backward at a low speed,带动 the reverse one-way transmission mechanism to rotate at the same speed or slightly increase the speed and complete commutation, and then drives the synchronous output gear 8 and the output shaft 9 to rotate in a fixed direction at a high speed, driving the blower to rotate at a high speed for air supply operation. At this time, the forward one-way transmission mechanism acts as an inert mechanism and does not participate in the transmission.

[0022] Compared to existing conventional commutators where the input and output speeds are the same, this invention's dryer commutator can significantly reduce the input speed of the input shaft 4, thereby significantly reducing the speed of the input gear 5, while ensuring sufficient airflow from the fan at the output speed of the output shaft 9 (i.e., the same output speed as a conventional commutator). The forward and reverse unidirectional transmission mechanisms also experience significant speed reduction, meaning the angular velocities of gears other than the output gear 8 are greatly reduced, preventing lubricating grease from being thrown off. This significantly enhances the retention capacity of lubricating grease on the tooth surfaces of these other gears, reducing the amount of lubricating grease required. With reduced speed and lubricating grease adhesion, these other gears experience reduced noise, reduced wear, and increased service life. Furthermore, the output gear 8 also experiences reduced wear and a significantly increased service life due to the lubricating grease supplied by the meshing gears. Example

[0023] In this embodiment, the commutator of the dryer specifically includes an upper housing 1, a lower housing 2 and an intermediate support plate 3. An assembly space (also called a gearbox) is formed between the upper housing 1 and the lower housing 2. The forward unidirectional transmission mechanism and the reverse unidirectional transmission mechanism pass through the intermediate support plate 3, and the transmission speed ratio n between the output shaft 9 and the input shaft 4 is 3.

[0024] like Figure 1 and Figure 2 As shown, the forward unidirectional transmission mechanism includes: a first linkage gear 6.1, a first needle roller one-way bearing 6.2, a first transmission shaft 6.3, and a first drive gear 6.4; the first linkage gear 6.1 meshes with the input gear 5, the first linkage gear 6.1 is located below the intermediate support plate 3, the first linkage gear 6.1 is coaxially connected to the first transmission shaft 6.3 through the first needle roller one-way bearing 6.2, the inner ring of the first linkage gear 6.1 extends inward to wrap around the upper and lower ends of the first needle roller one-way bearing 6.2, the first drive gear 6.4 is coaxially connected to the first transmission shaft 6.3, the first drive gear 6.4 meshes with the output gear 8, and the first drive gear 6.4 is located above the intermediate support plate 3; The reverse one-way transmission mechanism includes: a reversing gear 7.1 (also called an idler gear), a pivot 7.2, a second linkage gear 7.3, a second needle roller one-way bearing 7.4, a second transmission shaft 7.5, and a second drive gear 7.6; the reversing gear 7.1 meshes with the input gear 5, the reversing gear 7.1 is coaxially connected to the pivot 7.2, the reversing gear 7.1 meshes with the second linkage gear 7.3, the second linkage gear 7.3 is coaxially connected to the second transmission shaft 7.5 through the second needle roller one-way bearing 7.4, the inner ring of the second linkage gear 7.3 extends inward to wrap around the upper and lower ends of the second needle roller one-way bearing 7.4, the second drive gear 7.6 is coaxially connected to the second transmission shaft 7.5, and the second drive gear 7.6 meshes with the output gear 8.

[0025] Transferring needle roller one-way bearings (also known as one-way needle roller bearings) to the forward and reverse one-way transmission mechanisms has two advantages: first, it reduces the rotational speed; second, it reduces the impact of vibration from the drive motor or fan, thus decreasing coaxiality misalignment. This effectively reduces the noise of needle roller one-way bearings, solving the problem of excessive noise. Traditional commutators used in dryers, due to space constraints, have slender needle rollers mounted on the input shaft 4 or output shaft 9. These are susceptible to coaxiality misalignment due to vibration from the drive motor or fan. At high speeds of 2700 r / min, the centrifugal force of the rolling elements increases, and the cage vibration intensifies. Simultaneously, the lubricating grease generates internal friction heat under high-speed shearing, with the bearing area temperature reaching 70℃. Long-term operation accelerates the oxidation and thinning of the lubricating grease, even leading to its loss. This causes the noise of the needle roller one-way bearing to exceed the noise levels of other components in the dryer during normal operation, resulting in excessive noise and a poor user experience. To prevent grease from slipping off, excessive filling is often used in engineering. However, this leads to a significant increase in grease loss due to churning. The viscous resistance torque of grease is directly proportional to the rotational speed and the amount of grease filled. Excessive lubricating grease is violently churned by the gears and converted into heat, causing the temperature to rise further. When the temperature exceeds the dropping point of the lubricating grease (usually 120℃~150℃), the lubricating grease liquefies and is lost, leaving the gears in a state of boundary lubrication or even no lubrication, resulting in an extremely high risk of wear.

[0026] In this configuration, the speed ratio between the first linkage gear 6.1 and the input gear 5 is 1:1, and the speed ratio between the first drive gear 6.4 and the output gear 8 is 1:3. The speed ratio between the reversing gear 7.1, the second linkage gear 7.3, and the input gear 5 is 1:1:1, and the speed ratio between the second drive gear 7.6 and the output gear 8 is 1:3. The input speed of the input shaft 4 is 900 r / min, and the output speed of the output shaft 9 is 2700 r / min, meeting the stable air output requirements of the fan. At this time, i1=i2=1. The module of the reversing gear 7.1 is greater than or equal to the sum of the module of the input gear 5 and the module of the second linkage gear 7.3. The input gear 5 and the second linkage gear 7.3 are staggered. In this embodiment, the second linkage gear 7.3 is positioned higher than the input gear 5. Experiments showed that the commutator of this dryer reduced the no-load noise from 58 dB(A) to 49 dB(A) compared to a traditional commutator. After two hours of continuous operation at an ambient temperature of 25°C, the highest temperature of the input shaft 3 bearing was 48°C, and the output shaft 9 bearing temperature was 62°C, significantly lower than the 70°C of a traditional commutator. This is because the adhesion of lubricating grease to the surface of a high-speed rotating gear relies primarily on surface tension and adhesion force. When the tooth tip velocity exceeds a critical value, the centrifugal force exceeds the adhesion force, causing the lubricating grease to be thrown off the tooth surface. Ordinary lubricating grease is difficult to adhere stably at the tooth tip velocity of a gear rotating at 2700 r / min, and dry friction quickly appears on the tooth surface.

[0027] Preferably, a hollow bearing seat is provided at the center of the intermediate support plate 3 between the upper housing 1 and the lower housing 2. An oil-impregnated bearing is assembled inside the hollow bearing seat. The upper end of the input shaft 4 is connected to the lower part of the oil-impregnated bearing, and the lower end of the output shaft 9 is connected to the upper part of the oil-impregnated bearing. The oil-impregnated bearing provides axial support for the upper end of the input shaft 4 and the lower end of the output shaft 9, which can improve the coaxiality of the assembly of the input shaft 4 and the output shaft 9, and the rotation of the input shaft 4 and the rotation of the output shaft 9 will not affect each other.

[0028] Preferably, the lower housing 2 has a downwardly protruding fitting ring at its lower part, which matches the groove on the drive motor; the lower end of the input shaft 4 has an internal spline, which matches the external spline of the drive shaft of the drive motor; the internal spline and the fitting ring are coaxially arranged.

[0029] Preferably, the upper housing 1, the lower housing 2, and the intermediate support plate 3 are all provided with multiple lugs, and the lugs are provided with threaded holes. The drive motor is installed and fixed by screws screwed onto the lugs.

[0030] As an improvement, the input gear 5, the first linkage gear 6.1, the reversing gear 7.1, and the second linkage gear 7.3 all employ helical teeth with a helix angle ≤15°; the first drive gear 6.4, the second drive gear 7.6, and the output gear 8 all employ helical teeth with a helix angle ≤15°. Furthermore, the bearings between the first drive shaft 6.3 and the second drive shaft 7.5 and the upper housing 1 and the lower housing 2 are all ball bearings. When spur teeth are used, the bearings between the first drive shaft 6.3 and the second drive shaft 7.5 and the upper housing 1 and the lower housing 2 are preferably oil-impregnated bearings.

[0031] Preferably, the filling lubricant is a semi-solid lithium-based lubricant, which has good water resistance, mechanical stability, corrosion resistance, and oxidation stability, and an operating temperature range of -30 to 120℃. An input gear linear velocity of 900 r / min is already within the "adhesive" zone of the lithium-based lubricant. Tests have shown that using NLGI Grade 2 lithium-based lubricant, with a filling amount of 30% to 40% of the gearbox volume, ensures a uniform oil film covering all gear surfaces, and there is no shedding during long-term operation. The amount of lubricant used is reduced by more than 50% compared to traditional commutators, which reduces costs and avoids the temperature rise caused by overfilling. After 500 hours of operation, disassembly and inspection revealed a uniform oil film on the gear surfaces, no signs of dry friction, and no significant discoloration or loss of the lubricant.

[0032] The commutator of the dryer in this embodiment was tested 100,000 times in both forward and reverse rotation, and the output direction was stable with no reverse drive phenomenon.

[0033] In summary, addressing the lubrication failure and noise issues of commutators in dryers under high-speed operation, this invention proposes a transmission optimization scheme of "input speed reduction + output speed increase." Combined with refined gear parameter design, optimized bearing selection, and coaxial reinforcement of the structure, this systematically solves the technical bottlenecks of traditional commutators. The following conclusions are drawn: 1. Rotational speed is a key factor affecting commutator performance. Reducing the input-side rotational speed from 2700 r / min to 900 r / min can significantly reduce bearing centrifugal force, improve gear lubrication, and directly reduce noise and temperature rise; 2. The critical speed at which lubricating grease adheres is an important constraint in commutator design. By reducing the operating speed to avoid the oil slinging zone, precise lubrication can be achieved, reducing the amount of lubricating grease used and heat generation. 3. The coaxial cable structure design helps improve transmission accuracy and bearing life, and is especially suitable for speed-increasing transmission systems.

[0034] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A commutator for a clothes dryer, comprising: The input shaft and input gear are coaxially connected, and the input shaft is connected to the drive motor. The output gear and output shaft are coaxially driven, and the output shaft is connected to the fan drive. Its features are, A forward unidirectional transmission mechanism is located next to the input shaft and the output shaft. It meshes with the input gear and has a transmission ratio of i1:

1. It also meshes with the output gear. It is used to drive the output shaft to rotate at n times the speed of the input shaft when the input shaft rotates in the forward direction, and to cut off the transmission when the input shaft rotates in the reverse direction. A reverse unidirectional transmission mechanism is located next to the input shaft and the output shaft. It meshes with the input gear and has a transmission ratio of i2:

1. It also meshes with the output gear. It is used to drive the output shaft to rotate at n times the speed of the input shaft when the input shaft rotates in the reverse direction, and to cut off the transmission when the input shaft rotates in the forward direction. Among them, i1 <n,i2<n,2≤n≤5。 2. The commutator for a clothes dryer according to claim 1, characterized in that, The forward unidirectional transmission mechanism includes: a first linkage gear, a first needle roller one-way bearing, a first transmission shaft, and a first drive gear; the first linkage gear meshes with the input gear, the first linkage gear is coaxially connected to the first transmission shaft through the first needle roller one-way bearing, the first drive gear is coaxially connected to the first transmission shaft, and the first drive gear meshes with the output gear; The reverse one-way transmission mechanism includes: a reversing gear, a pivot, a second linkage gear, a second needle roller one-way bearing, a second transmission shaft, and a second drive gear; the reversing gear meshes with the input gear, the reversing gear is coaxially connected to the pivot, the reversing gear meshes with the second linkage gear, the second linkage gear is coaxially connected to the second transmission shaft via the second needle roller one-way bearing, the second drive gear is coaxially connected to the second transmission shaft, and the second drive gear meshes with the output gear.

3. The dryer commutator according to claim 2, characterized in that, The transmission ratio between the first linkage gear and the input gear is 1:1, and the transmission ratio between the first drive gear and the output gear is 1:

3. The speed ratio of the reversing gear, the second linkage gear and the input gear is 1:1:1, and the speed ratio of the second drive gear and the output gear is 1:

3.

4. The dryer commutator according to any one of claims 1 to 3, characterized in that, The input shaft rotates at 900 r / min, and the output shaft rotates at 2700 r / min.

5. The dryer commutator according to any one of claims 1 to 3, characterized in that, A hollow bearing seat is provided at the center of the intermediate support plate between the upper and lower housings. An oil-impregnated bearing is assembled inside the hollow bearing seat. The upper end of the input shaft is connected to the lower part of the oil-impregnated bearing, and the lower end of the output shaft is connected to the upper part of the oil-impregnated bearing.

6. The commutator for a clothes dryer according to claim 5, characterized in that, The lower part of the lower housing is provided with a downwardly protruding fitting ring, which matches the groove on the drive motor; the lower end of the input shaft is provided with an internal spline, which matches the external spline of the drive shaft of the drive motor; the internal spline and the fitting ring are coaxially arranged.

7. The dryer commutator according to claim 3, characterized in that, The upper shell, lower shell and intermediate support plate are all provided with multiple lugs, and the lugs are provided with threaded holes.

8. The dryer commutator according to claim 2 or 3, characterized in that, The input gear, the first linkage gear, the reversing gear, and the second linkage gear all use helical teeth with a helix angle ≤15°. The first drive gear, the second drive gear, and the output gear all use helical teeth with a helix angle ≤15°.

9. The dryer commutator according to claim 8, characterized in that, The bearings between the first and second drive shafts and the upper and lower housings are all ball bearings.

10. The dryer commutator according to any one of claims 1 to 3, characterized in that, The filling lubricant is a semi-solid lithium-based lubricant.

Images