Vane compressor

Abstract

The present invention relates to a vane compressor comprising: a stator; a rotor disposed within the stator and having a body and a plurality of vanes, the body being internally tangent to a sidewall of the stator, the plurality of vanes sliding in corresponding seats formed in the body of the rotor and being pushed in a centrifugal direction to seal against the sidewall of the stator; and a lubrication system comprising one or more continuous jet nozzles and at least one axial spray nozzle, the one or more continuous jet nozzles being arranged in the sidewall of the stator to guide a continuous jet toward the rotor.

Description

[0001] This application is a divisional application of the application filed on July 27, 2018 (entered the Chinese national phase on March 26, 2020), with national application number 201880062702.9 (international application number PCT / IB2018 / 055636) and entitled "Vannel Compressor with Improved Lubrication System". Cross-references to related applications

[0002] This application claims priority to Italian Patent Application No. 102017000086572, filed on July 27, 2017, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a vane compressor. Background Technology

[0004] Known vane compressors include: a stator having an inlet and a delivery port; a rotor eccentrically housed in the stator, internally tangent to the sidewalls of the stator and provided with a plurality of vanes that slide relative to the rotor in the radial direction and are sealed to the stator; and a lubrication system comprising a plurality of mutually aligned solid jet nozzles arranged in the sidewalls of the stator to guide a continuous jet toward the rotor.

[0005] The oil jet provided by the nozzle serves three purposes:

[0006] - Lubricate the relative sliding areas between the blades and the rotor body, between the blade head and the stator barrel, and between the blade tip and the top of the cover;

[0007] - This helps to form a seal between the blades and the stator, and between the blades and the cover; and

[0008] - Cool the compressor to achieve compression as close as possible to adiabatic compression.

[0009] It has been calculated that in known compressors of the type described, only 10% of the oil flow is sufficient to perform the first two functions. This means that approximately 90% of the oil flow is actually used to cool the compressor.

[0010] This means that a lot of power is needed to pump the oil.

[0011] To optimize heat exchange between air and oil and thus reduce the amount of oil required to cool the compressor, axial spray nozzles have been proposed to replace radial orifices. Experimental studies have shown that this solution allows for energy savings compared to conventional solutions using continuous jet nozzles. Summary of the Invention

[0012] The object of the present invention is to provide a vane compressor with an improved lubrication system that allows for a reduction in the amount of oil used and thus a reduction in energy loss associated with the amount of oil used.

[0013] This objective is achieved by a vane compressor according to a key aspect of the invention.

[0014] The combined use of one or more axial spray nozzles and one or more continuous jet nozzles allows each type of nozzle to be optimized according to its primary function, and to achieve optimal cooling and lubrication with less oil compared to conventional solutions.

[0015] Preferably, the axial spray nozzle is arranged upstream of the continuous jet nozzle, in a position corresponding to the start of the compression phase, and the axial spray nozzle is a vortex nozzle used to ensure a fine spray of oil.

[0016] If the size of the compressor allows, multiple axial spray nozzles arranged continuously in the circumferential direction can be used.

[0017] According to a preferred embodiment of the invention, the blades are inclined relative to the radial direction along the direction of rotor movement at an angle between 10° and 20°, preferably approximately equal to 15°. This allows for reduced friction and stress, thereby reducing the power absorbed by the compressor.

[0018] Preferably, one or more continuous jet nozzles are also tilted at an angle of 10° to 40° relative to the radial direction along the direction of rotor movement, preferably at an angle of about 25°. In this way, the continuous jet applies a force with a tangential component to the blades, thereby generating useful work for driving the rotor in rotation.

[0019] According to another preferred embodiment of the invention, the compressor includes at least two continuous jet nozzles aligned with each other in the axial direction and supplied by a common axial manifold. Attached Figure Description

[0020] To better understand the present invention, preferred embodiments are described below by way of non-limiting examples and with reference to the accompanying drawings, in which:

[0021] Figure 1 It is a perspective view of a compressor unit including a vane-type compressor according to the present invention;

[0022] Figure 2 yes Figure 1 A 3D view of the compressor;

[0023] Figure 3 and Figure 4 These are the side view and rear view of the compressor, respectively.

[0024] Figure 5 It is along Figure 3 A cross-sectional view of line VV;

[0025] Figure 6 It is along Figure 4 A cross-sectional view of line VI-VI;

[0026] Figure 7 and Figure 8 They are along Figure 3 Cross-sectional views of lines VII-VII and VIII-VIII; and

[0027] Figure 9 This is a 3D view of the compressor; parts have been removed for clarity. Detailed Implementation

[0028] Reference Figure 1 The compressor unit, generally represented by 1, includes a vane compressor 2 and an electric motor 3. The compressor unit shown is preferably used as an on-board compressor for motor vehicles such as trucks, but the invention is not limited to this application and can be applied to compressors of any power and size for vehicle or industrial applications.

[0029] The electric motor 3 shown for simple reference is not described further as it is not part of the present invention.

[0030] Figures 2 to 9 The compressor 2 shown has a housing 4 formed by the middle portion of the stator 5 that defines the compressor 2, a front cover 6, and a rear flange 7 for connection to the electric motor 3. The front cover 6 and the flange 7 are fixed to the stator 5 at opposite axial positions by means of a plurality of screws 11.

[0031] The stator 5 is provided with a sidewall 8 that internally defines a cylindrical cavity 9 having an axis A. Figure 5 ).

[0032] The compressor 2 also includes a rotor 10 having a generally cylindrical shape, which has an axis B that is parallel to but different from axis A. The rotor 10 is housed inside the cylindrical cavity 9 of the stator 5 and is rotatable about axis B.

[0033] The rotor 10 includes a generally cylindrical body 12, the outer surface 12a of which is tangent to the inner surface 9a of the cylindrical cavity 9 of the stator 5 along the generatrix G.

[0034] An annular chamber 18 with radially variable amplitude is defined between the rotor 10 and the stator 5.

[0035] The rotor 10 is also provided with a plurality of blades 13 that are evenly spaced in the circumferential direction, the plurality of blades 13 being arranged relative to the radial direction along the rotation direction of the rotor (by...). Figure 5 (The arrow in the image indicates that the angle is inclined at an angle between 10° and 20°, preferably equal to 15°.)

[0036] The blade 13 is slidably accommodated in a corresponding seat 14, which includes a slot formed in the body 12 of the rotor 10 and open on the side surface 12a of the body.

[0037] The blade 13 is pushed outward under the action of centrifugal force and pressure, thereby making a substantially sealed sliding contact with the inner surface 9a of the stator 5 (unless a lubricating oil gap is provided as described below). Therefore, the blade 13 is preferably provided with a rounded outer edge 15.

[0038] Shaft 16 with axis B ( Figure 3 and Figure 4 The shaft is rigidly connected to the rotor 10, the shaft protruding axially from the flange 7 through the center hole of the flange 7 and adapted to be connected to the output shaft of the electric motor 3 in a known and not shown manner.

[0039] The blade 13 divides the chamber 18 into multiple spaces 17 with variable volumes.

[0040] Compressor 2 includes components formed in the front cover 6 ( Figure 1 The axial intake pipe 20 in the rotor 8 communicates with the inlet 21 defined by the recess of the wall 8 of the stator 5, which extends in the direction of rotor movement with an angular width equal to at least two compartments 17 and is arranged downstream of the tangential region between the rotor 8 and the stator 5.

[0041] Similarly, compressor 2 is included in front cover 6 ( Figure 1 An axial delivery pipe 22 is obtained in the lower region of the chamber 18. The axial delivery pipe 22 communicates with a delivery port 23 defined by the recess of the wall 8 of the stator 5. The delivery port 23 extends in the lower region of the chamber 18 with an angular width approximately equivalent to the angular width of the space 17 and is arranged upstream of the tangential region between the rotor 8 and the stator 5 in the direction of rotor movement.

[0042] The compressor 2 includes a lubrication system 24 configured to carry lubricating oil into the chamber 18 and to the relative sliding surfaces of the compressor.

[0043] According to the present invention, the lubrication system 24 ( Figures 6 to 9 It includes a plurality of continuous jet nozzles 25 having a transverse axis relative to the axis of compressor 2, and at least one axial spray nozzle 26.

[0044] A continuous jet nozzle 25 is housed in the wall 8 of the stator 5, thereby injecting a jet into the chamber 18 in a direction inclined relative to the radial direction along the direction of rotor movement. In particular, the axis of the continuous jet nozzle 25 is inclined relative to the radial direction at an angle between 15° and 40°, preferably 25°.

[0045] In the embodiment shown by way of example, there are two nozzles 25 and they are aligned with each other in the axial direction. The continuous jet nozzles 25 are arranged at approximately 90° to the end of the inlet in the direction of movement in the circumferential direction relative to the chamber 18, and the continuous jet nozzles 25 have an axis inclined at 25° relative to the radial direction.

[0046] The nozzle 26 is housed in the flange 7 and retracts into the chamber 18 in a radial position.

[0047] The nozzle 26 is arranged upstream of the continuous jet nozzle 25 relative to the rotation direction of the rotor 14, and the nozzle 26 is preferably a vortex nozzle.

[0048] In these nozzles, the oil moving in rotational motion within the vortex chamber is subjected to high centrifugal force, which facilitates oil atomization. A tangential component provided to the fluid allows for a spray with a wide dispersion angle. In vortex spray nozzles, the fluid is rotated due to a special tangential insert or conduit, which ensures very fine atomization and a fairly uniform distribution of droplets across the spray area.

[0049] The spray nozzle 26 is positioned along the chamber 18 in an angular direction such that, during the initial compression phase, immediately after the space 17 has been isolated from the inlet 21, an atomized jet is injected into the space 17. In other words, this means that the spray nozzle 26 must be at least an angular distance from the end of the inlet 21 corresponding to the sum of the angular width of the chamber 17 and the angular width of the angle formed between the blade 13 and the surface 9a.

[0050] In order to supply nozzles 25 and 26, the lubrication system 24 basically includes a supply fitting 27 arranged on the cover 6 and configured to be connected to a source of pressurized oil.

[0051] Lubrication system 24 includes a plurality of oil pipes configured in a known manner as orifices sealed by corresponding plugs, these oil pipes in Figures 5 to 9 It is shown in gray patterns.

[0052] Specifically, accessory 27 is connected to the lubrication hole 28 in the axial contact area between rotor 10 and cover. Figure 6 By arranging it inside the cover 6 and only... Figure 6The visible channel 29 in the middle section is connected to the fitting 27 to the axial manifold 30, which axially crosses the stator 5 and terminates in the flange 7, and is provided with an inner channel 31, which connects the axial manifold 30 to a cavity 32 closed by a plug 33, into which the spray nozzle 26 is immersed.

[0053] Two conduits 34 branch off from the axial manifold 30. Figure 5 , Figure 6 and Figure 9 ), to supply oil to nozzle 25.

[0054] Figure 7 and Figure 8 Channels 35 and 36, respectively formed in flange 7 and cover 6, are shown for supplying lubricating oil from axial manifold 30 to corresponding sliding bearings 37 and 38 that support shaft 16.

[0055] The operation of compressor 1 is as follows.

[0056] Rotor 10 is driven by electric motor 3 (see reference) Figure 5 (Counterclockwise). Starting from the tangent generatrix G between the rotor 10 and the stator 5, the volume of compartment 17 increases and air is drawn in from inlet 21; once past the inlet, compartment 17 is isolated, and starting from an angular position opposite to one of the tangent generatrixes, the volume of compartment 17 gradually decreases, thereby achieving compression. Compressed air is discharged through outlet 23.

[0057] At the start of compression, the jet from nozzle 26 axially traverses each compartment 17. This jet provides a powerful cooling effect, which is performed particularly effectively because the fine atomization of the jet facilitates heat exchange between the air and the oil. The mass flow rate of the lubricant jet depends on the compressor size, the number of nozzles, and the jet pressure, and is typically about 5 to 10 times the air flow rate handled by the compressor. The flow rate and the size of the (conical) jet can also be selected based on the compartment dimensions to prevent or delay, as much as possible, the jet's contact with the metal walls of the compartments and subsequent coalescence of the oil, which reduces the exchange surface. Typically, these conditions are met at a jet passage velocity of approximately 20 m / s.

[0058] The continuous jet generated by the nozzle 25 has the main purpose of lubricating the relative sliding area between the blade 13 and the corresponding seat 14, especially the interlocking area near the blade where stress is concentrated.

[0059] The tilt position of the nozzle 25, combined with the tilt position of the blade 13, causes the continuous oil jet to assist the blade 13 with a tangential force component, which generates useful work for driving the rotor 10 in rotation.

[0060] The described "hybrid" lubrication (combination of axial spray nozzles and continuous jet nozzles) achieves a 50% oil flow saving. This allows for the use of less oil or doubles the maintenance intervals for the same volume of oil used.

[0061] By reducing the energy consumed in pumping oil and due to the tilted position of blade 13, a 7% saving in absorption power has been achieved.

[0062] Finally, it is clear that the described compressor is subject to modifications and variations within the scope of protection defined by the claims.

[0063] In particular, the number of nozzles can be varied depending on the size of the compressor. With a larger axial dimension, more than two continuous jet nozzles can be used, and with a more powerful industrial compressor, a series of spray nozzles arranged continuously in the circumferential direction can be used.

Claims

1. A vane compressor, comprising: The stator (5) has an axis (A) and is provided with at least one inlet (21) and at least one delivery port (23). The rotor (10) is housed in the stator (5) and has an axis (B) parallel to the axis (A) of the stator (5). The rotor (10) is provided with a body (12) and a plurality of blades (13). The body (12) is internally tangent to the sidewall (8) of the stator (5). The plurality of blades (13) slide in corresponding seats (14) formed in the body (12) of the rotor (10) and are pushed in the direction of centrifugal force to seal against the sidewall (8) of the stator (5). The blades (13) define a plurality of compartments (17) with different volumes in pairs. The lubrication system (24) includes at least one continuous jet nozzle (25) disposed in the sidewall (8) of the stator (5) to guide a continuous jet toward the rotor (10). The lubrication system (24) is characterized in that it includes at least one axial spray nozzle (26) combined with the at least one continuous jet nozzle (25), the axial spray nozzle (26) being configured to inject a spray jet into the compartment (17) in an axial direction relative to the stator (5) and the rotor (10), and the axial spray nozzle (26) being arranged upstream of the continuous jet nozzle (25) with reference to the rotation direction of the rotor (10).

2. The compressor according to claim 1, characterized in that, The axial spray nozzle (26) is arranged to be at least angularly distanced from the inlet (21) from the sum of the angular width of one of the compartments (17) and the angular width of the angle opposite to the blade (13).

3. The compressor according to claim 1, characterized in that, The spray nozzle (26) is a vortex nozzle.

4. The compressor according to claim 1, characterized in that, The compressor includes a plurality of axial spray nozzles arranged continuously in the circumferential direction.

5. The compressor according to claim 1, characterized in that, The blade (13) is inclined relative to the radial direction along the direction of motion of the rotor (10).

6. The compressor according to claim 1, characterized in that, The inclination of the blade (13) relative to the radial direction is between 10° and 20°.

7. The compressor according to claim 6, characterized in that, The blade (13) is tilted approximately 15° relative to the radial direction.

8. The compressor according to claim 1, characterized in that, At least one of the continuous jet nozzles (25) has an axis that is inclined relative to the radial direction along the direction of motion of the rotor (10).

9. The compressor according to claim 1, characterized in that, The inclination of the axis of the continuous jet nozzle (25) relative to the radial direction is between 15° and 40°.

10. The compressor according to claim 9, characterized in that, The blade (13) is tilted approximately 25° relative to the radial direction.

11. The compressor according to claim 1, characterized in that, The compressor includes at least two mutually aligned continuous jet nozzles (25) arranged in the axial direction and supplied through a common axial manifold (30).

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