Variable pitch fan with thrust increase

Abstract

The utility model discloses a variable-pitch fan with increased thrust, which solves the problem of slow action caused by too small thrust when a fluid medium pushes fan blades to change angles or directions in the existing variable-pitch fan technology. A piston in the fan comprises a center circular plate, a piston sleeve I, an annular circular plate and a piston sleeve II which are concentrically arranged from the center to the outer side, in the initial state, the center circular plate and the inner end of a cylinder part are arranged in parallel, a first cavity is formed between the center circular plate and the inner end of the cylinder part, and a second cavity is formed between the annular circular plate and the inner wall of a front shell; and a medium channel through which a fluid medium passes is arranged between the first chamber and the second chamber. According to the variable-pitch fan, the first cavity is communicated with the second cavity, so that the effective surface of the piston body under the action of a fluid medium is multiplied, the thrust of the piston body is multiplied on the premise that the injection pressure of the fluid medium is certain in the variable-pitch fan, and the thrust in the angle adjusting process is effectively improved.

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 needs. At present, a variable pitch fan is used for the radiator in motor vehicles. The so-called variable pitch fan means that the angle of the fan blades is adjustable, that is, the wind force of the fan is adjusted by changing the angle of the fan blades, and even the direction of the wind force can be reversed, that is, back blowing can also be achieved. Among them, the adjustment of wind force is based on the demand for heat dissipation efficiency, and back blowing 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, since the force bearing area (local) of the piston is limited, its total thrust is small when the fluid medium is pressurized, thereby limiting 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 fan with thrust increasing function, and solves the technical problem that in the prior variable pitch fan technology, when the fluid medium pushes the fan blades to change angle or direction, 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 fan with increased thrust, wherein the front shell, rear shell and intermediate body of the fan are enclosed and combined to form a combined shell structure, a blade shaft assembly is installed at the mounting shaft hole of the intermediate body, the front shell has a cylindrical portion extending toward the interior of the shell, a piston is installed on the cylindrical portion, and a spring is installed between the piston and the rear shell, the piston is mechanically connected to the blade shaft assembly and drives the blade shaft assembly to change pitch, characterized in that: the piston includes a center circular plate, a piston sleeve I, an annular circular plate and a piston sleeve II arranged concentrically from the center to the outside, wherein, in an initial state, the center circular plate is arranged parallel to the inner end of the cylindrical portion and has a first chamber therebetween, the first chamber is connected to the air intake assembly, the piston sleeve I is slidably fitted with the cylindrical portion, a second chamber is provided between the annular circular plate and the inner wall of the front shell, the piston sleeve II is slidably fitted with the annular inner wall of the front shell, and a medium channel for fluid medium to pass through is provided between the first chamber and the second chamber.

[0009] Furthermore, the medium channel is an elongated hole arranged in the piston sleeve I.

[0010] Furthermore, the medium channel is arranged in an elongated groove on the inner surface of the piston sleeve I.

[0011] Furthermore, the medium channel is an elongated hole arranged in the cylindrical portion.

[0012] Furthermore, the medium channel is arranged in an elongated groove on the outer surface of the cylindrical portion.

[0013] Furthermore, an annular groove is provided at the center circular plate corresponding to the medium channel, and the annular groove forms a transition between the elongated groove or the elongated hole and the first chamber.

[0014] 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.

[0015] Furthermore, a shaft sleeve is installed on the cylindrical portion, and the shaft sleeve is slidably matched with the piston.

[0016] Furthermore, a sealing ring installation groove is provided on the piston sleeve II and an O-ring is installed in the sealing ring installation groove to prevent the fluid medium from overflowing from the second chamber.

[0017] 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.

[0018] 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.

[0019] Furthermore, the fluid medium is compressed air or hydraulic oil.

[0020] The beneficial effects of the utility model are:

[0021] This technology multiplies the effective surface area of ​​the piston body affected by the fluid medium by connecting the first chamber and the second chamber, so that the thrust of the piston body is multiplied under the premise of a certain fluid medium injection pressure in the variable pitch fan, thereby effectively improving the thrust during the angle adjustment process and efficiently overcoming the resistance of the fan blades. This has a positive significance for achieving rapid reversing or rapid angle adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the structural diagram of the variable pitch fan (initial state).

[0023] Figure 2 This is the structural diagram of the variable pitch fan (operating state).

[0024] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0025] Figure 4 This is style one of the pistons.

[0026] Figure 5 This is the second style of piston.

[0027] Figure 6 For piston style three.

[0028] Figure 7 for Figure 4 The corresponding top view.

[0029] Figure 8 for Figure 6 The corresponding top view.

[0030] Fig. 9 It is a cross-sectional view of the second embodiment.

[0031] Fig.10 It is a cross-sectional view of the front shell in the second embodiment.

[0032] In the figure:

[0033] 17 eccentric pin,

[0034] 16. Fan shaft assembly,

[0035] 15. Small bushing,

[0036] 14. Bushing,

[0037] 13. Air intake assembly,

[0038] 12. Circlip,

[0039] 11. Piston, 111 center circular plate, 112 piston sleeve I, 113 annular circular plate, 114 piston sleeve II, 115 sealing ring installation groove, 116 concave annular groove, 117 bolt hole,

[0040] 10. O-type sealing ring,

[0041] 9. front shell, 91 cylindrical portion, 101 first chamber, 102 second chamber, 103 medium channel,

[0042] 8. Intermediates,

[0043] 7. Support sleeve,

[0044] 6. Press plate,

[0045] 5. Hexagon socket countersunk screws,

[0046] 4. Hexagon socket head screws,

[0047] 3. O-type sealing ring,

[0048] 2. Spring,

[0049] 1. Back cover. DETAILED DESCRIPTION

[0050] A variable pitch fan is a special fan that needs to be configured in motor vehicles, especially diesel engine motor vehicles. 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.

[0051] 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.

[0052] Embodiment 1

[0053] refer to Figures 1 to 8 In this embodiment, the front shell 9, the rear shell 1, and the intermediate body 8 in the fan are enclosed and combined to form a combined shell structure, and the three are fastened using hexagonal cylindrical head screws 4 to form an integral body, the interior of which is an installation cavity. Furthermore, there is a mounting shaft hole for the fan blade shaft assembly 16 between the front shell and the rear shell, and the above-mentioned fan blade shaft assembly 16 can be rotatably installed at the mounting shaft hole.

[0054] In this embodiment, the front housing 9, the rear housing 1 and the intermediate body 8 are preferably made of aluminum castings.

[0055] Furthermore, an O-ring 3 is provided at the joint surface between the intermediate body 8 and the front shell and the rear shell. The O-ring 3 is used to seal the mating surface to keep the internal space clean.

[0056] Specifically, the front shell 9 has a cylindrical portion 91 extending into the inner shell, and the axial hole of the cylindrical portion is the installation space of the air intake assembly 13, which is a stepped hole, that is, the air intake assembly 13 is installed in the cylindrical portion and fixed with an A-type hole elastic retaining ring 12. After being fixed, the air intake assembly forms an air supply to the inside of the shell. Further, the inner end stepped hole of the cylindrical portion faces and is arranged opposite to the piston 11. The piston 11 includes a central circular plate 111, a piston sleeve I 112, an annular circular plate 113, and a piston sleeve II 114 arranged from the center to the outside and arranged in concentric circles, wherein the central circular plate is arranged parallel to the inner end of the cylindrical portion of the front shell, and a first chamber 101 is formed between the two, and the first chamber 101 is a flow channel for the fluid medium. The sliding fit of the piston sleeve I and the cylindrical portion 91, that is, it is sleeved on the outside of the cylindrical portion to form a piston fit, marked as the piston fit surface I. The annular circular plate 113 is fitted with the inner wall of the front shell, and a second chamber 102 is formed between the annular circular plate and the inner wall of the front shell. The piston sleeve II forms a sliding fit with the annular inner wall of the front shell, 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 concentric with each other. A medium channel 103 is set between the first chamber and the second chamber. As a specific style, the medium channel 103 is formed by drilling a slender hole in the piston sleeve I, referring to Figure 4 The medium channel connects the first chamber and the second chamber, and after the connection, the medium between the two chambers can flow freely. Further, the center circular plate corresponding to the medium channel 103 is provided with an annular groove 104, referring to Figure 5 The existence of the annular groove enables the end of the elongated hole to communicate with the first chamber. The design of the annular groove simplifies the molding process of the medium channel.

[0057] As another specific style, refer to Figure 6 The medium channel 103 is an elongated groove formed by milling grooves on the inner surface of the piston sleeve I. The elongated groove connects the first chamber and the second chamber. After the connection, the medium between the two chambers can flow freely. Furthermore, an annular groove 104 is provided at the center circular plate corresponding to the above-mentioned medium channel. The existence of the annular groove expands the portion where the end of the elongated groove communicates with the first chamber. In mechanical processing, slotting is easier to process than elongated holes. Both elongated grooves and elongated holes are within the protection scope of the present utility model.

[0058] Through the above improvements, the thrust on the piston in the axial projection direction is increased, that is, the fluid medium fully covers the piston in the axial projection direction.

[0059] When the medium channel is in the form of an elongated groove, the corresponding annular groove 104 may also be omitted.

[0060] The above-mentioned medium channel can be set to one or more. When the number is multiple, the multiple medium channels 103 are evenly distributed on the piston with the center of the piston as the center. In theory, the setting of multiple medium channels has a positive significance for the diversion of the medium.

[0061] Furthermore, since both the housing and the piston are made of aluminum, which has poor wear resistance, a sleeve 14 needs to be provided on the piston mating surface I. The sleeve 14 is made of a wear-resistant alloy material. For example, in this embodiment, the sleeve 14 is fixedly mounted on the cylindrical portion 91, that is, fixed to the cylindrical portion 91 by means of an expansion interference fit. The provision of the sleeve 14 can improve the wear resistance of the sliding fit between the piston sleeve I and the cylindrical portion 91 at the piston mating surface I. This has the significance of improving the wear resistance of the housing and piston fit of the aluminum casting.

[0062] Furthermore, a sealing ring installation groove 115 is provided on the piston sleeve II where the piston matching surface II is located, and an O-type sealing ring 10 is installed in the sealing ring installation groove to prevent the fluid medium from overflowing from the second chamber.

[0063] Furthermore, a concave annular groove 116 is provided on the surface of the annular circular plate where the second chamber 102 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.

[0064] The piston 11 and the rear housing 1 are provided with spring installation grooves arranged opposite to each other, and a spring 2 is installed between the two. The spring is a compression spring. Under the action of the spring, the initial state of the piston 11 is: the piston is located on one side of the front housing. 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 rear housing 1.

[0065] The piston 11 has a bolt hole 117, and the eccentric pin on the blade shaft assembly 16 is fixed by means of a support sleeve 7, a pressure plate 6 and a hexagonal countersunk screw 5. That is, the eccentric pin 17 is fixed by means of the support sleeve 7 and the small sleeve 15, and the movement of the piston drives the above-mentioned eccentric pin to move, thereby realizing the angle adjustment of the blade shaft assembly.

[0066] Embodiment 2

[0067] refer to Fig. 9 and Fig.10In this embodiment, the difference from the first embodiment is that in this embodiment, the medium channel 103 is arranged on the outer surface of the cylindrical portion 91, that is, a slender groove is formed on the surface of the cylindrical portion 91, and the slender groove is arranged along the circumference of the cylindrical portion and penetrates the first chamber and the second chamber. Correspondingly, the wear-resistant sleeve 14 is embedded and fixed in the sliding matching shaft hole of the piston, that is, Fig. 9 The shaft sleeve is in the shaft hole of the piston sleeve Ⅰ112, and the sleeve and the cylindrical part are slidably matched to improve the wear resistance between the two.

[0068] Embodiment 3

[0069] The difference from the second embodiment is that in this embodiment, the medium channel 103 can also be formed by drilling in the cylindrical portion 91. The drilling requires horizontal and longitudinal drilling to connect the first chamber and the second chamber. This processing difficulty is greater than the slender groove design in the second embodiment.

[0070] The solutions of the above three embodiments are all within the protection scope of the present utility model.

[0071] 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 fan with increased thrust, wherein the front shell, the rear shell, and the intermediate body of the fan are enclosed and combined to form a combined shell structure, a fan shaft assembly is installed at the mounting shaft hole of the intermediate body, the front shell has a cylindrical portion extending into the shell, a piston is installed in the cylindrical portion, and a spring is installed between the piston and the rear shell, the piston is mechanically connected to the fan shaft assembly and drives the fan shaft assembly to change pitch, characterized in that: The piston includes a center circular plate, a piston sleeve I, an annular circular plate and a piston sleeve II which are arranged concentrically from the center to the outside, wherein in an initial state, the center circular plate is arranged parallel to the inner end of the cylindrical portion and has a first chamber therebetween, the first chamber is connected to the air intake assembly, the piston sleeve I is slidably fitted with the cylindrical portion, a second chamber is provided between the annular circular plate and the inner wall of the front shell, the piston sleeve II is slidably fitted with the annular inner wall of the front shell, and a medium channel for allowing fluid medium to pass through is provided between the first chamber and the second chamber.

2. The variable pitch fan with increased thrust according to claim 1, characterized in that: The medium channel is an elongated hole arranged in the piston sleeve I.

3. The variable pitch fan with increased thrust according to claim 1, characterized in that: The medium channel is arranged in an elongated groove on the inner surface of the piston sleeve I.

4. The variable pitch fan with increased thrust according to claim 1, characterized in that: The medium passage is an elongated hole provided in the cylindrical portion.

5. The variable pitch fan with increased thrust according to claim 1, characterized in that: The medium channel is arranged in an elongated groove on the outer surface of the cylindrical portion.

6. The variable pitch fan with increased thrust according to claim 2 or 3, characterized in that: An annular groove is arranged at the center circular plate corresponding to the medium channel, and the annular groove forms a transition between the elongated groove or the elongated hole and the first chamber.

7. The variable pitch fan with increased thrust according to claim 1, characterized in that: A shaft sleeve is installed on the cylindrical part, and the shaft sleeve is slidably matched with the piston.

8. The variable pitch fan with increased thrust according to claim 1, characterized in that: The piston sleeve II is provided with a sealing ring installation groove and an O-type sealing ring is installed in the sealing ring installation groove to prevent the fluid medium from overflowing from the second chamber.

9. The variable pitch fan with increased thrust 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.

10. The variable pitch fan with increased thrust according to claim 1, characterized in that: The fluid medium is compressed air or hydraulic oil.

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