Variable-pitch and reversing fan

Abstract

The utility model discloses a variable-pitch and reversing fan which solves the problem that in the existing variable-pitch fan technology, when fluid media push fan blades to change angles or directions, thrust is too small, and therefore action is slow. A front shell of the fan is provided with a front side shaft barrel extending towards the interior of a shell, a rear shell is provided with a rear side shaft barrel extending towards the interior, the rear side shaft barrel is mechanically connected with the front side shaft barrel, an air inlet assembly is installed in a shaft hole of the front side shaft barrel, a piston is installed on the outer side of the rear side shaft barrel in a sliding fit mode, and the piston is mechanically connected with a fan blade shaft assembly. A spring is installed between the piston and the front shell, a first cavity is formed in the rear side shaft barrel and communicated with the air inlet assembly, a second cavity is formed between the piston and the rear shell, and a medium channel is formed between the first cavity and the second cavity and communicated with the first cavity and the second cavity. According to the technology, the thrust in the fan blade angle adjusting process is improved, and the resistance in the fan blade angle adjusting process is efficiently overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of variable pitch fans. Background Art

[0002] In motor vehicles, there are many application scenarios that require heat dissipation. In the heat dissipation application scenario, the role of the fan is to increase the flow speed of the airflow by blowing air to the radiator, thereby increasing the heat dissipation effect.

[0003] In theory, the blowing effect of the fan on the radiator should be adjustable according to the needs. At present, a variable pitch and reversing fan is used for the radiator in motor vehicles. The so-called variable pitch fan means that the angle of the fan blades can be adjusted when the fan shaft rotates without reversing, that is, the wind force of the fan can be adjusted by changing the angle of the fan blades, and even the wind force can be reversed, that is, backblowing can also be achieved. Among them, the adjustment of wind force is based on the demand for heat dissipation efficiency, and backblowing is based on the demand for automatic cleaning of the radiator.

[0004] For reference, take a cotton picker as an example. When a variable pitch fan is used on a cotton picker, the angle of the fan blades is adjusted. The greater the heat dissipation effect of the fan angle, the faster the reversal action is completed when the fan blades are reversed, and the better the backblowing effect.

[0005] Taking patent document WO2011072381A1 as an example, the patent document discloses a variable pitch fan. The solution recorded in the technical document cannot adjust the wind force quickly enough. That is to say, due to the limited force area (circular projection) between the piston and the inner wall of the front shell, when the fluid medium is pressurized, the total thrust is small, which limits the action sensitivity of the variable pitch fan. Summary of the invention

[0006] In order to solve the deficiencies of the prior art, the utility model provides a variable pitch and reversing fan to solve the problem in the prior art of variable pitch fans that when the fluid medium pushes the fan blades to change angles or directions, the thrust is too small, resulting in slow movement.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] A variable pitch and reversing fan, in which the front shell, rear shell and intermediate body are enclosed and combined to form a combined shell structure, and the intermediate body has multiple sets of blade shaft assemblies evenly installed in the circumference, characterized in that the front shell has a front shaft cylinder extending toward the interior of the shell, and the rear shell has a rear shaft cylinder extending toward the interior, and the rear shaft cylinder is mechanically connected to the front shaft cylinder, and an air intake assembly is installed in the axial hole of the front shaft cylinder, and a piston is installed on the outer side of the rear shaft cylinder in a sliding fit, and the piston is mechanically connected to the blade shaft assembly, and a spring is installed between the piston and the front shell, and a first chamber is provided in the rear shaft cylinder, and the first chamber is connected to the air intake assembly, and a second chamber is provided between the piston and the rear shell, and a medium channel is provided between the first chamber and the second chamber and connected.

[0009] The piston includes a piston sleeve I, an annular circular plate, and a piston sleeve II which are arranged from the center to the outside and configured in concentric circles, wherein the piston sleeve I is slidably matched with the rear shaft cylinder, there is a gap between the annular circular plate and the inner wall of the rear shell, and the piston sleeve II is slidably matched with the annular inner wall of the rear shell.

[0010] Furthermore, the medium channel is an elongated hole arranged on the rear side shaft cylinder wall.

[0011] Furthermore, there are multiple medium channels, and the multiple medium channels are evenly distributed on the piston with the center of the piston as the center of the circle.

[0012] Furthermore, a shaft sleeve is installed on the piston sleeve I, and the shaft sleeve is slidably matched with the rear shaft sleeve.

[0013] Furthermore, a sealing ring installation groove is provided on the piston sleeve II and a sealing ring is installed in the sealing ring installation groove to prevent the fluid medium from overflowing from the second chamber.

[0014] A sealing ring is arranged at the matching surface between the air intake assembly and the rear shaft cylinder.

[0015] Furthermore, a concave annular groove is provided on the surface of the annular circular plate where the second chamber is located. The presence of the concave annular groove can effectively ensure the initial space of the second chamber, thereby improving the sensitivity of the piston action in the initial state and achieving rapid startup.

[0016] Furthermore, the piston is provided with a bolt hole, and the eccentric pin shaft of the fan blade shaft assembly is fixed by means of a support sleeve, a pressure plate and screws.

[0017] Furthermore, the driving medium of the fan is compressed air or hydraulic oil.

[0018] The beneficial effects of the utility model are:

[0019] In this technical solution, the effective working area of ​​the piston is annular, which increases the working area, so that under the premise of a certain fluid medium injection pressure in the variable pitch fan, the thrust of the piston body is multiplied, thereby effectively improving the thrust during the angle adjustment process and efficiently overcoming the resistance during the blade angle adjustment process. This has a positive significance for achieving rapid reversing or rapid angle adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the structural diagram of the variable pitch fan (initial state).

[0021] Figure 2 This is the structural diagram of the variable pitch fan (operating status).

[0022] Figure 3 This is style 1 of the back shell.

[0023] Figure 4 This is the second style of the back shell.

[0024] Figure 5 This is style three of the back shell.

[0025] Figure 6 This is style one of the pistons.

[0026] Figure 7 This is the second style of piston.

[0027] Figure 8 For piston style three.

[0028] In the figure:

[0029] 22. Spring collar,

[0030] 21. Annular inner wall,

[0031] 20. Bolt mounting holes,

[0032] 19. Rear shaft barrel,

[0033] 18. Self-lubricating oil-free bushing,

[0034] 17. Spring,

[0035] 16. O-type sealing ring,

[0036] 15. Fan shaft assembly,

[0037] 14. Hexagon socket countersunk screws,

[0038] 13. Support sleeve,

[0039] 12. Press plate,

[0040] 11. Circlip,

[0041] 10. Air intake assembly,

[0042] 9. Front shell, 91 front side shaft tube,

[0043] 8. O-type sealing ring,

[0044] 7. Eccentric pin,

[0045] 6. Intermediates,

[0046] 5. O-ring,

[0047] 4. O-type sealing ring,

[0048] 3. Hexagon socket head screws,

[0049] 2. Piston, 201 piston sleeve Ⅰ, 202 annular disc, 203 piston sleeve Ⅱ, 204 bolt hole, 205 spring installation groove, 2021 concave annular groove,

[0050] 1. Back cover. DETAILED DESCRIPTION

[0051] A variable pitch fan is a special fan that needs to be installed in motor vehicles, especially diesel engine motor vehicles. It is required to be able to adjust the angle and reversing of the fan blades. The variable pitch fan can be quickly adjusted to control the direction (variable one, reversing) and air volume (variable two, adjustable angle) of the wind generated by the fan.

[0052] The function of reverse blowing is to reverse blow the radiator to reduce or eliminate overheating caused by radiator blockage. The function of air volume control is to provide airflow according to the temperature curve of the radiator, thereby achieving heat dissipation control.

[0053] refer to Figures 1 to 6 In this embodiment, the front shell 9, the rear shell 1, and the intermediate body 6 of the fan are enclosed and combined to form a combined shell structure, and the three are fastened by the hexagonal cylindrical head screw 3 to form an integral body, and the interior thereof is a mounting cavity. Furthermore, there is a mounting shaft hole for the blade shaft assembly 15 between the front shell and the rear shell, and the above-mentioned blade shaft assembly 15 is rotatably mounted at the mounting shaft hole. The driving mode of the blade shaft assembly 15 in this embodiment is the eccentric pin 7, that is, the angle of the blade in the blade shaft assembly is adjusted by the position of the eccentric pin 7. The specific structure of the blade shaft assembly 15 belongs to the relatively mature existing technology in this field and will not be repeated.

[0054] Generally speaking, the front housing 9, the rear housing 1 and the intermediate body 6 are preferably made of aluminum castings, which are formed by pressure casting and then machined to meet the mechanical assembly requirements.

[0055] The rear shell 1 in this embodiment is a disc-like component as a whole, and has a rear shaft cylinder 19 on the rear shell. The rear shaft cylinder is a protrusion extending from the inner wall of the rear shell to the inside. The rear shaft cylinder and the inner wall of the rear shell form a cylindrical space, which is also the forming space of the first chamber. The rear shaft cylinder 19 is plugged and matched with the front shaft cylinder 91 on the front shell, and it can be selected whether to set an O-ring on the matching surface as needed.

[0056] The rear housing is provided with bolt mounting holes 20 for connecting a power shaft, that is, connecting the power shaft of the fan.

[0057] Figures 3 to 5 Three common design styles are given by type, that is, in the three styles, the medium channel 103 is set at an angle or horizontally. This is based on the difficulty of the processing technology. No matter which design is used, as long as it can penetrate the first and second cavities, it is within the protection scope of the present utility model.

[0058] The number of the above-mentioned medium channels 103 can be one or more. When there are more than one, it is best if the multiple medium channels are arranged in the circumferential direction of the circle to balance the force of the medium. These designs are within the protection scope of the present utility model.

[0059] Furthermore, the style of the rear shell is based on the appearance design of the fan and is not limited.

[0060] The intermediate body 6 is an annular component. A sealing ring mounting groove and a blade shaft mounting groove are formed on the intermediate body 6 by machining. The intermediate body is installed between the front shell and the rear shell and fixed as a whole by screws. The blade shaft assembly 15 is installed at the corresponding blade shaft mounting groove. The eccentric pin shaft 7 on the installed blade shaft assembly is located inside the shell and is mechanically matched with the piston.

[0061] Furthermore, an O-shaped sealing ring 5 is provided at the joint surface between the intermediate body 6 and the front shell and the rear shell. The O-shaped sealing ring 5 is used to seal the mating surface to keep the internal space clean.

[0062] The front shell 9 is similar in structure to the above-mentioned rear shell, and the front shell 9 has a front shaft cylinder 91 extending into the inner shell, and the front shell where the front shaft cylinder is located has a cavity, and the circular cavity is used to install the air intake assembly 10. The rear shell 1 has a rear shaft cylinder 19 extending inwardly. After the rear shell and the front shell are docked, the above-mentioned front shaft cylinder 91 and the rear shaft cylinder 19 are plugged and docked with each other, and a through cavity is formed between the two, which is also the installation part of the air intake assembly 10. After the air intake assembly is installed, the air intake assembly 10 is installed on the front shaft cylinder and fixed with an A-type hole elastic retaining ring 11. After fixing, the air intake assembly 10 forms air supply to the inside of the shell, and a first chamber 101 is formed inside the rear shaft cylinder 19. The first chamber is a relatively independent chamber formed by the rear shaft cylinder 19, the inner wall of the rear shell, and the air intake assembly, and an O-ring 8 is arranged at the annular mating surface between the rear shaft cylinder 19 and the air intake assembly to improve the sealing performance. The first chamber 101 is a flow channel for the fluid medium. Furthermore, the piston 2 includes a piston sleeve Ⅰ201, an annular disc 202, and a piston sleeve Ⅱ203 arranged from the center to the outside and arranged in concentric circles, wherein the piston sleeve Ⅰ and the rear shaft cylinder 19 are slidably matched, that is, they are sleeved on the outside of the front shaft cylinder to form a piston match, which is marked as piston matching surface Ⅰ. The annular disc 202 is fitted with the inner wall of the above-mentioned rear shell and maintains a certain gap (in the initial state), and a second chamber 102 is formed between the annular disc and the inner wall of the rear shell. The second chamber 102 in the initial state means that when the piston 2 is partially in contact with the inner wall of the above-mentioned rear shell, the second chamber still exists, and in this state, the second chamber is still connected with the first chamber through the medium channel.

[0063] The piston sleeve II 203 forms a sliding fit with the annular inner wall 21 of the rear shell 1, that is, it is sleeved inside the front shell to form a piston fit, marked as piston fit surface II, and the above two piston fit surfaces are arranged concentrically with each other. A medium channel 103 is opened on the rear side shaft cylinder wall between the first chamber and the second chamber. As a specific style, the medium channel 103 is formed by drilling a hole on the rear side shaft cylinder, refer to Figure 4 The medium channel 103 connects the first chamber and the second chamber through and through, and after the connection, the medium between the two chambers can flow freely.

[0064] The two piston matching surfaces II and piston matching surfaces I are co-centered and have a common machining reference, thus having better machining accuracy.

[0065] After the above improvements, the thrust force received by the piston 2 in the axial projection direction forms a circular cross section, that is, the fluid medium forms an annular thrust region in the axial projection direction of the piston. By appropriately reducing the diameter of the rear shaft cylinder 19, a greater thrust force can be obtained.

[0066] The fluid medium in this technology can be a hydraulic medium or a pneumatic medium.

[0067] The above-mentioned medium channel 103 can be set as one or more. When the number is multiple, the multiple medium channels 103 are evenly distributed on the piston with the center of the rear shaft cylinder 19 as the center. In theory, the setting of multiple medium channels has a positive significance for the diversion of the medium.

[0068] Furthermore, a self-lubricating oil-free bushing 18 and an O-ring 16 are provided on the above-mentioned piston mating surface I. For example, in this embodiment, the self-lubricating oil-free bushing 18 is fixedly installed on the piston sleeve I, that is, it is fixed on the piston sleeve I by means of expansion and interference fit. The provision of the self-lubricating oil-free bushing 18 can improve the wear resistance of the sliding fit between the piston sleeve I and the rear shaft cylinder 11 at the piston mating surface I. This has the significance of improving the wear resistance of the aluminum casting shell and the piston fit.

[0069] Furthermore, a sealing ring installation groove is provided on the piston sleeve II where the piston matching surface II is located, and an O-type sealing ring 4 is installed in the sealing ring installation groove to prevent the fluid medium from overflowing from the second chamber.

[0070] Furthermore, a concave annular groove 2021 is provided on the surface of the annular circular plate 202 where the second chamber is located. The presence of the concave annular groove can effectively ensure the initial space of the second chamber, thereby improving the sensitivity of the piston action in the initial state and achieving rapid startup.

[0071] The piston 2 and the front housing 9 are provided with spring installation grooves 205 arranged opposite to each other, and a spring 17 is installed between the two. The spring is a compression spring. Under the action of the spring 17, the initial state of the piston 2 is that the piston is located on one side of the rear housing 1. When the fluid medium is injected into the first chamber and the second chamber, the resistance of the spring is overcome and the piston moves toward the front housing 9.

[0072] The piston 2 has a bolt hole 204, and the eccentric pin 7 on the blade shaft assembly 15 is fixed by a support sleeve 13, a pressure plate 12 and a hexagonal countersunk screw 14. That is, the eccentric pin 7 is fixed by a support sleeve and a small sleeve, and the eccentric movement of the eccentric pin 7 is driven by the up and down piston movement, thereby realizing the angle adjustment of the blade shaft assembly.

[0073] A self-lubricating oil-free bushing 18 is installed in an embedded manner inside the above-mentioned piston mating surface I. The self-lubricating oil-free bushing is installed at the piston mating surface I to transition the sliding fit between the piston and the rear shaft cylinder 19, thereby improving the sliding performance of the sliding fit.

[0074] Furthermore, the self-lubricating oil-free bushing 18 may be in a straight shape with uniform wall thickness, or may be in an L shape, for example Figure 1 The L-shape shown in FIG. Figure 8 Series design in.

[0075] Furthermore, a shoulder is provided at the shaft hole where the self-lubricating oil-free bushing 18 is installed and an O-ring 16 is installed to seal the second chamber 102, and a spring retaining ring 22 is provided in the mounting hole of the piston to fix the above-mentioned self-lubricating oil-free bushing 18 and O-ring 16.

[0076] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements to the present invention by relevant technical personnel in the field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A variable pitch and reversing fan, wherein the front shell, the rear shell, and the intermediate body of the fan are enclosed and combined to form a combined shell structure, and the intermediate body is evenly installed with multiple sets of fan blade shaft assemblies in the circumferential direction, characterized in that: The front shell has a front shaft cylinder extending toward the interior of the shell, the rear shell has a rear shaft cylinder extending toward the interior, and the rear shaft cylinder and the front shaft cylinder are mechanically connected, and an air intake assembly is installed in the axial hole of the front shaft cylinder, a piston is installed on the outer side of the rear shaft cylinder in a sliding fit, the piston is mechanically connected to the fan shaft assembly, a spring is installed between the piston and the front shell, a first chamber is provided in the rear shaft cylinder, the first chamber is connected to the air intake assembly, a second chamber is provided between the piston and the rear shell, and a medium channel is provided between the first chamber and the second chamber and connected.

2. The variable pitch and reversing fan according to claim 1, characterized in that: The piston includes a piston sleeve I, an annular circular plate, and a piston sleeve II which are arranged from the center to the outside and configured in concentric circles, wherein the piston sleeve I is slidably matched with the rear shaft cylinder, there is a gap between the annular circular plate and the inner wall of the rear shell, and the piston sleeve II is slidably matched with the annular inner wall of the rear shell.

3. The variable pitch and reversing fan according to claim 1, characterized in that: The medium channel is an elongated hole arranged on the rear side shaft cylinder wall.

4. The variable pitch and reversing fan according to claim 1, characterized in that: There are multiple medium channels, and the multiple medium channels are evenly distributed on the piston with the center of the piston as the center of the circle.

5. The variable pitch and reversing fan according to claim 1, characterized in that: A shaft sleeve is installed on the piston sleeve I, and the shaft sleeve is slidably matched with the rear shaft sleeve.

6. The variable pitch and reversing fan according to claim 1, characterized in that: The piston sleeve II is provided with a sealing ring installation groove and a sealing ring is installed in the sealing ring installation groove.

7. The variable pitch and reversing fan according to claim 1, characterized in that: A sealing ring is arranged at the matching surface between the air intake assembly and the rear shaft cylinder.

8. The variable pitch and reversing fan according to claim 1, characterized in that: The surface of the annular circular plate where the second chamber is located is provided with an inwardly concave annular groove.

9. The variable pitch and reversing fan according to claim 1, characterized in that: The piston is provided with a bolt hole, and the eccentric pin shaft of the fan blade shaft assembly is fixed by means of a support sleeve, a pressure plate and screws.

10. The variable pitch and reversing fan according to claim 1, characterized in that: The driving medium of the fan is compressed air or hydraulic oil.

Images