Fan wheel

Abstract

The invention relates to a fan wheel having fan blades which are mounted in a hub so as to be pivotable about the blade longitudinal axes thereof, the fan wheel having a drive flange which is connected to the hub via a limited free wheel; and a planetary gear is arranged between the driving flange and the fan blade. A sun gear of the planetary gear, which is connected to the drive flange in a rotationally fixed manner, and the drive flange are arranged on axially opposite end faces of the fan wheel.

Description

Technical Field

[0001] The invention relates to a fan wheel according to the preamble of claim 1, having fan blades which are arranged in a hub so as to be pivotable about their blade longitudinal axis. Background Art

[0002] A fan wheel with adjustable fan blades is known from WO2021 / 121648A1, which are connected to an adjustment ring via a planetary gear and can rotate around their blade axis in the hub. The fan wheel is driven via a drive flange that can be coupled to a drive motor. A guide groove is inserted into the adjustment ring, and a guide pin connected to the hub extends into the guide groove. The sun gear of the planetary gear is located on the drive flange and meshes with the planetary gear, which is placed on a planet carrier connected to the adjustment ring. In order to adjust the blade position, the drive speed is reduced, and then, due to inertia, the guide pin moves to the relative stop position in the guide groove, and the fan blade is adjusted to the desired changed angular position. The movement of the guide pin in the guide groove is braked via the planetary gear. Summary of the invention

[0003] The invention is based on the object of designing a fan wheel with pivotably mounted fan blades using simple constructional measures and in a compact design, so that high component loads are avoided during adjustment of the fan blades.

[0004] This object is achieved according to the invention with the features of claim 1. Appropriate developments are given in the dependent claims.

[0005] The fan wheel according to the invention is used, for example, in construction machinery or agricultural machinery and is characterized by the adjustability of the fan blades, which are pivotably mounted in the hub about their longitudinal blade axis. With the adjustment of the fan blades, the fan wheel switches from a blower mode to a cleaning mode in order to remove dust and dirt deposits from the fan wheel.

[0006] The fan wheel has a drive flange connected to the hub via a limited freewheel, wherein the angular position of the fan blades relative to the hub can be adjusted via the freewheel. The fan wheel is driven in rotation via the drive flange that can be coupled to a drive motor.

[0007] The fan wheel is provided with a planetary gear between the drive flange and the fan blades. The adjusting body driven by the planetary gear is arranged relative to the hub so that the adjusting body can perform a limited relative rotational movement relative to the hub superimposed on the rotary drive movement in the freewheel. If the adjusting body moves relative to the hub within the range of the freewheel, the desired change in the angular position of the fan blade is achieved. Each of the two end positions of the freewheel marks a stable position of the fan blade. These stable positions are in particular a conveying position as a standard position for conveying air and a cleaning position for cleaning the fan wheel by reversing the air conveying direction. The planetary gear causes the relative rotational movement between the adjusting body and the hub to be carried out in a braking manner within the range of the freewheel to adjust the angular position of the fan blade, thereby correspondingly reducing the component loads during the adjustment process and avoiding high impacts in particular when reaching the end position.

[0008] The fan wheel can only be driven in one direction of rotation. The desired change in the angular position of the fan blades can be achieved without reversing the direction of rotation of the fan wheel. Instead, it is sufficient to adjust the relative rotational movement between the regulating body and the hub, which is the carrier of the pivotally mounted fan blades, simply by changing the speed of the fan wheel drive movement due to the inertia of the fan blades and the hub. During the relative rotational movement, the regulating body adjusts the angular position of the fan blades. For example, during a speed reduction with minimal delay, the adjustment of the fan blades from the conveying position to the cleaning position is achieved, and during a speed increase with minimal acceleration, the adjustment of the fan blades from the cleaning position to the conveying position is achieved.

[0009] The fan wheel according to the present invention is configured such that the sun gear of the planetary gear is connected to the drive flange in a rotationally fixed manner, and the sun gear and the drive flange are arranged on axially opposite end faces of the fan wheel. Here, the teeth of the sun gear are arranged axially spaced apart from the drive flange, and the sun gear meshes with the planetary gears of the planetary gear via the teeth.

[0010] The advantage of this design is that the sun gear is designed independently of the drive flange, in particular the tooth area of ​​the sun gear is independent of the size of the drive flange. The sun gear is not located on the drive flange, but extends axially at the front end of the drive flange or a component connected to the drive flange, which allows the use of a small sun gear with a correspondingly small number of teeth. As a result, a transmission ratio in the planetary gear can be achieved, which achieves the desired braking movement and higher torques in the freewheel.

[0011] The sun gear of the planetary gear meshes with the planetary gears on the planetary carrier, wherein the planetary gears rotate inside the teeth of the ring gear. The sun gear, the planetary carrier and the ring gear are arranged coaxially with the drive flange and are advantageously all located on the same axial side of the fan wheel, axially opposite to the drive flange. Therefore, the components of the planetary gear and the drive flange can be designed independently of each other, thereby increasing the flexibility of the structural design and the fan wheel design.

[0012] According to an advantageous embodiment, the sun gear has a smaller outer diameter than the drive flange. This enables a large transmission ratio or reduction ratio to be achieved, so that a high drive speed can be converted into a small rotary adjustment movement of the adjustment body with a higher torque.

[0013] In another advantageous design, the adjusting body is formed by the planet carrier of the planetary gear. Therefore, a separately constructed adjusting body is not required, thereby achieving a reduction in the required installation space. In an alternative design, the adjusting body and the planet carrier can also be constructed as components that are independent of each other, but they are connected to each other in a rotationally fixed manner. The adjusting body can be constructed as an adjusting ring, for example.

[0014] According to another advantageous design, the adjusting body is provided with teeth and meshes with a blade pinion arranged on a shaft seat of the fan blade, wherein the shaft seat is pivotably mounted in the hub. The blade pinion is designed, for example, as a bevel gear. When the adjusting body rotates within the range of the freewheel, the blade pinion twists, thereby causing a rotational movement of the fan blade.

[0015] In a preferred design, the freewheel is formed by a guide pin which is directly or indirectly connected to the drive flange in a rotationally fixed manner and an arcuate guide groove arranged in the hub, wherein the guide pin extends into the guide groove and can be adjusted along the guide groove. The relatively front end of the guide groove marks the end position of the fan blade, which indicates the conveying position and the cleaning position of the fan blade. The guide groove is designed in the shape of an arc and advantageously extends over an angular section of more than 90°, in particular more than 120° and preferably at least 150°. The relatively long length of the guide groove enables precise adjustment of the angular position of the fan blade.

[0016] In an advantageous embodiment, two guide grooves arranged mirror-inverted to the longitudinal axis are inserted into the hub, wherein a respective guide pin projects into each guide groove. The advantages of providing two guide grooves are that the forces are evenly distributed, tilting moments are avoided and the drive torque is divided.

[0017] It may be appropriate to respectively arrange damping bodies at both ends of the guide groove. The damping bodies are configured as rubber buffers, for example, and buffer the impact of the guide pin on the front end of the guide groove when transferring from one end position to the other opposite end position.

[0018] In another advantageous embodiment, the drive flange is connected to the main shaft in a rotationally fixed manner, which is the carrier of the hub. The drive flange and the main shaft are two independent, coaxially arranged components, which are coupled to each other and can be designed independently of each other in terms of structure. The main shaft is located axially between the drive flange and the sun gear of the planetary gear, which is connected to the main shaft in a rotationally fixed manner.

[0019] According to another advantageous design, the ring gear of the planetary gear is connected to the hub in a rotationally fixed manner, in which the planetary gears roll. The sun gear, the ring gear and the planetary gears with the planet carrier are all located on the same axial end face of the fan wheel, at an axial distance from the drive flange. It may be expedient to cover the gears of the planetary gear with a gear cover, which is held, for example, on the axial outside of the ring gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages and expedient embodiments can be found in the other claims, the description of the figures and the drawings. The drawings show:

[0021] Figure 1 is a top view of a fan wheel with adjustable fan blades,

[0022] Figure 2 is based on Figure 1 A cross-sectional view of the fan wheel at section line II-II in FIG.

[0023] Figure 3 yes Figure 2 A magnified cross-sectional view of

[0024] Figure 4 is based on Figure 3 A sectional view of the hub along the section line IV-IV in FIG. 1 , which is transverse to the longitudinal direction of the fan wheel and the drive axis.

[0025] In the figures, identical parts are provided with the same reference numerals. DETAILED DESCRIPTION

[0026] The fan wheel 1 can be driven to rotate about its longitudinal and drive axis 2 ( Figure 2 , Figure 3 ), and has fan blades 3 distributed on the circumference and extending radially relative to the longitudinal and drive axis 2. In the hub 4, the fan blades 3 are pivotably mounted about their blade longitudinal axis 5 and can be pivoted, in particular, by approximately 180° between two end positions corresponding to the air supply mode and the cleaning mode. The position of the fan blades 3 corresponding to the air supply mode represents the standard position for generating an air flow by the rotating fan wheel 1. The position of the fan blades 3 corresponding to the cleaning mode is briefly occupied in order to remove dust and dirt from the fan blades by reversing the air supply direction.

[0027] The fan wheel 1 further comprises a drive flange 6, a main shaft 7 and a planetary gear 8, which has a sun gear 9, planetary wheels 10 on a planet carrier 11 and a ring gear 12. These components are arranged coaxially with the longitudinal and drive axis 2 or, in the case of the planetary wheel 10, move around the longitudinal and drive axis 2. The drive flange 6 is driven by a drive device, in particular by an electric motor or a hydraulic motor. The drive is only carried out in one direction of rotation; the direction of rotation does not change even when switching from the air supply mode to the cleaning mode.

[0028] The drive flange 6 comprises a hollow cylindrical flange section for coupling with a drive device and an annular shoulder with a greater radial extension connected to the hollow cylindrical flange section, which is connected to the spindle 7 in a rotationally fixed manner by means of connecting screws 13. The spindle is a carrier of the hub 4 located radially outside the spindle 7, wherein the hub 4 can perform relative rotational movements relative to the spindle 7 and the drive flange 6 within the scope of a freewheel. The freewheel is formed by a guide pin 14 and a circular arc-shaped guide groove 15, which is inserted into the hub 4 concentrically with the longitudinal and drive axis 2 ( Figure 3 , Figure 4 ) and extends over an angular section of approximately 180°. For the purpose of uniform force distribution, the hub 4 has two guide grooves 15 arranged in mirror-inverted relation to the longitudinal and drive axis 2, into which guide pins 14 extend respectively. Damping bodies 16 in the form of rubber buffers are arranged at each end of the guide grooves 15, which damp the impact of the guide pins 14 during the adjustment movement between the air supply mode and the cleaning mode.

[0029] The drive flange 6 and the planetary gears 8 are located on axially opposite sides of the main shaft 7. The sun gear 9 of the planetary gear 8 is connected to the main shaft 7 in a rotationally fixed manner and is also coupled to the drive flange 6 in a rotationally fixed manner via the main shaft 7. The teeth of the sun gear 9 are located axially at a distance from the main shaft 7 and therefore also at a distance from the drive flange 6. The outer diameter of the sun gear 9 is smaller than the outer diameter of the drive flange 6 both in the region of the hollow cylindrical flange section and in the region of the annular shoulder.

[0030] The sun gear 9 meshes with the planetary gears 10 on the planetary carrier 11, which is located on the shoulder of the main shaft 7 but is not connected to the main shaft 7 in a rotationally fixed manner. The planetary gears 10 mesh radially on the outside with the internal teeth of the ring gear 12, which is adjacent to the hub 4 and is connected to the hub 4 in a rotationally fixed manner. The planetary carrier 11 forms an annular adjustment body for the angle adjustment of the fan blades 3. For this purpose, the planetary carrier 11 is provided with side teeth 17, in particular bevel teeth, on the side facing the drive flange 6, which mesh with a conical blade pinion 18 located on the radial inside of the shaft seat 19 of each fan blade 3. The shaft seat 19 is rotatably arranged in the hub 4 and enables the fan blade 3 to rotate about the blade longitudinal axis 5.

[0031] In order to adjust the fan blades 3 from the air supply mode to the cleaning mode, the drive speed of the fan wheel 1 is reduced in such a way that minimal delay is achieved. Due to inertia, the fan blades 3 strive to maintain their original speed, which results in a relative movement between the drive flange 6 or the main shaft 7 and the hub 4. The guide pins 14 connected to the main shaft 7 then move in the guide grooves 15 inserted in the hub 4 towards the opposite end stop position. The relative movement between the drive flange 6 and the main shaft 7 results in a change in the angular position of the fan blades 3 about their respective blade longitudinal axis 5, without the direction of rotation of the fan wheel 1 being reversed.

[0032] Due to the coupling with the planetary gear 8, the adjustment of the fan blade 3 about the blade longitudinal axis 5 does not take place suddenly, but at a reduced speed that depends on the transmission ratio of the planetary gear 8. Due to the rigid coupling of the sun gear 9 to the main shaft 7 and the drive flange 6, the reduction in the drive also has a direct effect on the sun gear 9 and the other gears of the planetary gear 8. Therefore, the planet carrier 11 rotates with the teeth 17 relative to the blade pinion 18, and the shaft seat 19 rotates with the fan blade 3 about the blade longitudinal axis.

[0033] In order to adjust the fan blade 3 in the opposite direction, i.e. from the cleaning mode to the air supply mode, the drive speed of the fan wheel 1 is increased in such a way that minimal acceleration is achieved. Even in this adjustment movement, the fan blade 3 still tries to maintain its original speed due to inertia, which in turn leads to a relative movement between the drive flange 6 or the main shaft 7 and the hub 4, and the guide pin 14 moves in the guide groove 15 towards the relative starting position. The fan blade 3 is adjusted back to its starting position corresponding to the air supply mode, wherein the adjustment movement of the fan blade 3 is also carried out at a reduced speed due to the coupling with the planetary gear 8.

Claims

1. A fan wheel having fan blades, which are pivotally mounted in a hub (4) about their blade longitudinal axis (5), wherein the fan wheel (1) has a drive flange (6) connected to the hub (4) via a limited freewheel; a planetary gear (8) is provided between the drive flange (6) and the fan blades (3), wherein an adjustment body (11) driven by the planetary gear (8) is arranged relative to the hub (4) in such a way that the adjustment body (11) can perform a limited relative rotational movement relative to the hub (4) superimposed on the rotational drive movement in the freewheel, It is characterized in that The sun gear (9) of the planetary gear (8) is connected to the drive flange (6) in a rotationally fixed manner, the sun gear (9) and the drive flange (6) are arranged on axially opposite end faces of the fan wheel (1), wherein the teeth of the sun gear (9) are arranged axially spaced apart from the drive flange (6), and the sun gear (9) meshes with the planetary gears (10) of the planetary gear (8) via the teeth.

2. The fan wheel according to claim 1, It is characterized in that The sun gear (9) has a smaller outer diameter than the drive flange (6).

3. The fan wheel according to claim 1 or 2, It is characterized in that The regulating body (11) is formed by the planet carrier (11) of the planetary gear.

4. A fan wheel according to any one of claims 1 to 3, It is characterized in that The adjusting body (11) has teeth (17) meshing with a blade pinion (18), and the blade pinion is arranged on a shaft seat (19) of the fan blade (3).

5. The fan wheel according to any one of claims 1 to 4, It is characterized in that The freewheel is formed by a guide pin (14) connected to the drive flange (6) in a rotationally fixed manner and an arcuate guide groove (15) arranged in the hub (4), wherein the guide pin (14) projects into the guide groove (15).

6. The fan wheel according to claim 5, It is characterized in that The guide groove (15) in the hub extends over an angular section of greater than 90°, in particular greater than 120°, preferably at least 150°.

7. The fan wheel according to claim 5 or 6, It is characterized in that Damping bodies (16) are respectively arranged at both ends of the guide groove (15).

8. A fan wheel according to any one of claims 5 to 7, It is characterized in that Two guide grooves (15) arranged in mirror-inverted relation to the longitudinal and drive axis (2) are inserted into the wheel hub (4), wherein a respective guide pin (14) projects into each guide groove (15).

9. A fan wheel according to any one of claims 1 to 8, It is characterized in that The drive flange (6) is connected in a rotationally fixed manner to a spindle (7) which is a carrier of the hub (4).

10. The fan wheel according to claim 9, It is characterized in that The sun gear (9) is axially adjacent to the main shaft (7) and is connected to the main shaft (7).

11. A fan wheel according to any one of claims 1 to 10, It is characterized in that The ring gear (12) of the planetary gear (8) is connected to the hub (4) in a rotationally fixed manner, and the planetary gears (10) roll in the ring gear.

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