HK1092199A - Modular swash plate compressor - Google Patents

Description

Modular swash plate compressor

Technical Field

The invention relates to a device and a method for generating compressed air. More specifically, the invention relates to a modular axial piston compressor for motor vehicles having a single body and interchangeable parts connected to the single body.

Background

Swash plate compressors are generally known in the art. These compressors typically use a cylinder block having a plurality of piston passages mounted on a drive shaft. A plurality of pistons are slidably disposed in the piston channels and are coupled to a swash plate, which is also mounted on the drive shaft. In accordance with the rotation of the drive shaft, the swash plate pivots, causing the pistons to reciprocate in the piston passages, thereby alternately forming suction and compression strokes.

These compressors use a variety of mechanisms for pivoting the swash plate using the rotational force of the drive shaft, such as an actuating assembly having an inclined surface located below the swash plate, which is disclosed in U.S. Pat. No. 6,439,857 to Koelzer, which is now assigned to the assignee of the present application; rotating and non-rotating plate assemblies, disclosed in U.S. patent No. 5,626,463 to Kimura; and a rotary cylinder block, which is disclosed in U.S. Pat. No. 5,394,698 to Takagi.

When the swash plate pivots, the pistons reciprocate in the piston passages of the cylinder block, alternately sucking a fluid to be compressed into the passages and then compressing and discharging the fluid. In this way, the rotational force of the shaft is converted into axial movement of the piston, enabling the piston to alternately perform suction and compression functions, whereby fluid is first drawn into the piston passage, then compressed and discharged from the piston passage.

However, due to the special arrangement of the components in such a system, mutual exclusivity between the individual components of the compressors for different types of vehicles is no longer necessary. Thus, when the compressors are constructed so that they comprise individual components (such as the swash plate housing) as permanent components and which are designed to be mated only with other individual components of a particular design or are constructed to be mountable only on a particular type of vehicle, compressors of the type described above unnecessarily complicate the manufacture and maintenance of these compressors and increase the manufacturing and maintenance costs, further reducing the versatility of the main housing piece of the compressor.

Accordingly, a method and apparatus for compressing fluid is desired that allows a single main housing to be used with different kinds of special individual components designed for different vehicle configurations and models. A further desire is for a method and apparatus that allows individual compressor components to be replaced with newer versions of those components without replacing the entire compressor.

Disclosure of Invention

It is therefore an object of the present invention to provide a swash plate compressor which allows a single main housing to be used with shafts, flanges and covers of different vehicle types.

It is another object of the present invention to provide a swash plate compressor which allows the same main housing to be used with a newer structural shaft, flange or cover as required by the subsequent model of the particular vehicle.

It is a further object of the present invention to provide a swash plate compressor which allows the shaft, flange or cover to be easily replaced when needed, such as when one of these components is damaged or found to be defective, without the need to replace the remainder of the compressor.

To overcome the deficiencies of the prior art and to achieve at least some of the objects and advantages listed, the present invention comprises a modular swash plate compressor comprising: a compressor housing; a swash plate disposed in the housing, the swash plate having a passage therein; a drive shaft disposed in the housing and the channel, the drive shaft configured to operate in a particular type of vehicle; and a mounting flange secured to the housing, the flange configured to mount the compressor to a particular type of vehicle, wherein the housing and the swash plate are adapted to accommodate any one of the drive shafts and at least one other drive shaft configured to be operable in at least one other type of vehicle, wherein the housing is adapted to be mounted to any one of the mounting flange and the at least one other mounting flange configured to mount the compressor to the at least one other type of vehicle.

In another embodiment, the invention comprises a modular swash plate compressor comprising: a compressor housing; a swash plate disposed in the housing, the swash plate having a passage therein; a drive shaft selected from a plurality of drive shafts disposed in the housing and the passageway, each of the plurality of drive shafts configured to operate in a different type of vehicle; and a mounting flange selected from a plurality of mounting flanges secured to the housing, wherein each of the plurality of mounting flanges is configured to mount the compressor to a different type of vehicle.

In another embodiment, the present invention includes a modular swash plate compressor comprising a plurality of mounting flanges, each mounting flange configured to mount the compressor to a different type of vehicle; a compressor housing adapted to be mounted to either of the mounting flanges; a swash plate disposed in the housing, the swash plate having a passage therein; and a plurality of drive shafts, each of the plurality of drive shafts configured to be operable in a different type of vehicle, wherein the housing and the swash plate are adapted to accommodate either of the drive shafts.

In yet another embodiment, the present invention comprises a modular swash plate compressor comprising: providing a compressor housing; disposing a swash plate having a channel therein in a compressor housing; selecting a drive axle from a plurality of drive axles, each of the plurality of drive axles configured to be operable in a different type of vehicle; disposing the selected drive shaft in the passage of the housing and the swash plate; selecting a mounting flange from a plurality of mounting flanges, each of the plurality of mounting flanges adapted to mount the compressor to a different type of vehicle; and securing the housing to the selected mounting flange.

Drawings

FIG. 1 is an isometric view of a swash plate compressor according to the present invention;

FIG. 2 is a side partial cross-sectional schematic view of a prior art compressor;

FIG. 3 is a side partial cross-sectional view of the prior art;

FIG. 4 is a plan view of a different combination of the swash plate compressor of FIG. 1;

FIG. 5 is a side partial cross-sectional view of the compressor of FIG. 1;

fig. 6 is an end partial sectional view of the compressor of fig. 1.

Detailed Description

In fig. 1, the basic elements of one embodiment of a modular swash plate compressor according to the invention are shown. As used in this specification, the terms "top," "bottom," "above," "below," "upward," "downward," "above," "below," "forward," "behind," "back," "forward," and "rearward" are described with reference to the objects as oriented in the figures, but not necessarily in the orientations necessary to achieve the objects of the invention.

Compressor 10 includes a main housing 12, a rear mounting cover 14, and a front mounting flange 16. In use, the compressor 10 is mounted on a vehicle, such as an over-the-road truck (over-the-road truck), and generates compressed air for a vehicle pressure system, which typically includes a tank (not shown), which delivers the compressed air to various accessories, such as a brake system. The generation of compressed air, which may or may not be delivered from a turbocharger (not shown), is initiated by drawing in air in response to the air pressure in the air system decreasing to or below a reference pressure.

The basic elements of one embodiment of main housing 12 of compressor 10 are shown in fig. 2-3. The main housing 12 includes a fixed swash plate housing 20 defining a crank chamber 22 therein, a swash plate 24 disposed in the crank chamber 22, and a fixed cylinder block 26 connected to the housing 20. A plurality of pistons 30 are coupled to the swash plate 24, and the cylinder block 26 has a plurality of passages 32 that receive the pistons 30. The piston 30 is reciprocally movable in the passage 32 to provide intake and compression strokes. The space 34 in the channel 32 above the piston 30 is in fluid communication with the air system through a plurality of intake ports 36 and exhaust ports 38. The air pressure in the space 34 thus corresponds to the air pressure in the air system, ensuring a pressure-balanced state of the compressor 10, as will be explained further below.

In order to maintain fluid communication between the suction port 36 and the discharge port 38, the compressor has a top plate (not shown) provided with a plurality of check valves 39, 37 for preventing reverse flow of air to be discharged. In some preferred embodiments, the check valve may be reed-type or poppet-type, allowing air to flow along the passageway from a high pressure region to a low pressure region. Thus, when the pressure in the air system downstream of the compressor 10 drops, an air flow is directed from the passage 32 into the air system through a valve 37 provided in an exhaust port 38. Accordingly, the air pressure above the pistons 30 drops, causing movement of the swash plate 24 and the pistons 30. Thus, the intake stroke generates a negative pressure sufficient to cause air to enter the cylinder block 26 through the valve 39 provided in the intake port 36.

As shown more clearly in fig. 5, the cylinder block 26 has a first drive shaft passage 100 and the swash plate 24 has a second drive shaft passage 102. Thus, in addition to main housing 12, compressor 10 includes drive shaft 40 disposed in passage 104, passage 104 being defined by passages 100 and 102.

Referring again to fig. 2-3, the swash plate 24 includes a rotatable inner member 44 connected to a pin 48 for rotation about the shaft 40, and an outer member 42 connected to the inner member 44 by a bearing assembly 46. In some embodiments, to prevent rotation of the outer member 42 of the swash plate 24, the swash plate houses radially extending stops 59, the stops 59 engaging axial grooves of the housing 20. The stop is dimensioned such that: even when the swash plate 24 is maximally moved from the position perpendicular to the shaft 40, the stopper head does not slip out of the groove to be disengaged. In other embodiments, a gimbal arm (not shown) may be used to prevent rotation of the outer member 42.

The entire swash plate 24 pivots relative to the shaft 40. The mechanism for converting the pivotal movement of the swash plate 24 into reciprocal axial movement of the pistons 30 includes a plurality of ball linkages, each of which includes a rod 52 and a ball element 54. In some embodiments, the rods 52, which are spaced angularly equidistant from each other along the outer periphery of the swash plate 24 and extend radially therefrom, are threaded bolts having threads 56 at one end and nuts 58 at the opposite end. The ball element 54 has a spherical outer surface slidingly engaging the piston rod 60 for synchronous axial movement and angular displacement of the piston rod 60 and the ball element 54 relative to each other, wherein the piston rod 60 extends parallel to the rotational axis 40.

To move the pistons 30 and the swash plate 24 relative to each other as the swash plate 24 pivots, each piston rod 60 has a flange 62, the inner surface of the flange 62 engaging the outer end of the ball element 54. Thus, as the swash plate 24 is angularly displaced from a position perpendicular to the drive shaft 40, the interfitting surfaces between the ball elements 54 and the flange 62 slide relative to each other. This relative movement causes the piston rod 60 and the ball element 54 to move axially together and the ball element 54 to rotate within the flange 62 in response to angular movement of the swash plate 24. Although the mating surfaces of the ball element 54 and the flange 62 are depicted as being annular, in some embodiments, other shapes that move in unison and angularly displaced relative to each other may be used.

When the piston-generating force acting on the swash plate 24 and corresponding to the air pressure in the space 34 above the pistons 30 is equal to and opposite to the thrust force generated by the actuator 70 against the swash plate 24, the pistons 30 are idle in a pressure balanced state. This equilibrium condition occurs when the swash plate 24 is in a substantially vertical position relative to the drive shaft 40. Once the balance of the air pressure is disturbed, the thrust of the actuator 70 exceeds the lower piston-generating force to angularly displace the swash plate 24 from its vertical position. Thus, the piston 30 begins to reciprocate within the passage 32, as will be explained further below. Thus, the more the air pressure in the air system drops, the greater the angular displacement of the swash plate 24 and the longer the stroke of the pistons 30.

Under the thrust exerted by the actuator 70, the swash plate 24 pivots about the pin 48. In some preferred embodiments, actuator 70 includes a resilient member 72, such as a Belleville washer, and a protruding collar 74. The washer 72 is connected to a male collar 74, the male collar 74 having a convex surface that is inclined relative to the shaft 40, with an extension of the male collar 74 always contacting the swash plate 24. The swash plate 24 is always under pressure above the pistons 30, so in order to maintain the swash plate 24 in a position perpendicular to the shaft 40 during a balanced condition, the cam ring 74 must continuously preload the swash plate 24. However, this contact at equilibrium does not produce sufficient thrust to overcome the pressure above the pistons and pivot the swash plate 24. In operation, the gasket 72 expands in response to a pressure drop in the air system or below a reference value. Thus, the camming collar 74 moves axially to pivot the swash plate 24, the movement of the swash plate 24 producing the suction and compression strokes of the pistons 30.

Due to this arrangement, the shaft 40 continues to rotate even when the piston 30 is idle and thus the compressor 10 is not compressing air. Thus, the accessory, such as a fuel pump, connected to the shaft 40 continues to operate. In addition, because the drive shaft 40 is rotatably disposed within the swash plate 24, rather than being integrally formed therewith or fixedly attached thereto, the shaft 40 can be easily removed from the main housing 12 of the compressor 10 by simply separating the housing 20 from the cylinder block 26, disconnecting the means, such as the pins 48, that secure the inner members 44 of the swash plate 24 to the shaft 40, and sliding the shaft 40 out of the swash plate 48.

Although actuator 70 is shown rotationally mounted on shaft 40, in some embodiments, actuator 70 can be mounted on housing 20. Additionally, in some embodiments, other types of resilient elements, such as different types of compression springs 78, such as bellows (Bellow), are used in place of the Belleville washers described above. In other embodiments, the actuator includes a servo piston (not shown) that is actuated in response to a control signal that represents a reference value for air system pressure and is generated by an external source once the pressure drops to or below a threshold value. Servo pistons connected to mechanical linkages such as forks (fork) move the cam ring 74 to generate thrust to pivotally move the swash plate 24.

To temporarily disconnect the truck's engine from additional loads under certain conditions, such as when the vehicle is ascending a steep grade, the solenoid 86 closes the exhaust port 38 in response to a start-command signal from the driver. Therefore, the pressure in the space 34 above the piston 30 rapidly rises, enabling the compressor 10 to reach a balanced state in a short period of time. Solenoid 86 is opened to return compressor 10 to the normal operating mode.

Additionally, the vehicle is provided with a central processor 90 for receiving a signal generated by a pressure sensor 92 after the air pressure in the air system reaches a predetermined upper threshold value. Once the signal is processed, solenoid 86 is actuated to block exhaust port 38.

In addition, the central processor 90, which is typically a computer, can process signals indicative of the total load on the vehicle engine. Thus, if the signal indicative of load exceeds a certain threshold, the central processor 90 generates a control signal that actuates the solenoid 86, wherein the solenoid 86 closes the exhaust port 38. In this case, the compressor quickly reaches the equilibrium state explained above and stops compressing the air.

Because the reciprocating motion of the piston is stopped after the equilibrium condition is reached, the need for lubrication between the piston 30 and the cylinder block 26 is reduced. In some embodiments, to further reduce lubrication requirements, the channel 32 and piston 30 are coated with an anti-wear material. Thus, the piston 30 may, for example, be coated with a material selected from the group consisting of: PTFE material filled with bronze and molybdenum disulfide and PTFE material filled with graphite and PPS, and an anodized aluminum coating (hardness close to 60RC) may be applied to the surface of the channel 32. Thus, by selecting the appropriate coating material and controllable movement of the piston 30, lubrication between the piston 30 and the wall of the cylinder block 26 is not required.

As shown in FIG. 4, to properly mount the compressor 10 to a particular type and/or model of vehicle, the compressor includes a front mounting flange 16 connected to a swash plate housing 20. Similarly, in some instances, the rear mounting head 14 is attached to the cylinder block 26 when these are required by a particular type and/or model of vehicle in which the compressor 10 is used. The front mounting flange 16 and rear mounting cover 14 (if applicable) correspond to the drive shaft 40, such that these three components are selected to accommodate a particular configuration and/or model of vehicle in which the compressor 10 is used.

The housing 12 is adapted to be mounted to any one of a plurality of mounting flanges 16, the mounting flanges 16 being configured to mount the compressor to a particular type of vehicle. Similarly, the housing 12 and swash plate 24 are adapted to receive any of a plurality of shafts 40 configured to cooperate with a particular type of vehicle. In some preferred embodiments, the housing 12 is also adapted to be secured to any of a plurality of rear mounting covers 14 configured for a particular type of vehicle.

As shown in fig. 5-6, the front mounting flange 16, swash plate housing 20, cylinder block 26 and rear mounting cover 14 have first, second, third and fourth sets of fastener bores 110, 112, 114, 116, respectively, which are axially aligned. Thus, the four components are simultaneously interconnected by fasteners 120, such as bolts, disposed in the fastener-hole sets 110, 112, 114, 116.

The particular arrangement described above, which relates to the manner in which shaft 40 is disposed within main housing 12 and the manner in which front mounting flange 16, swash plate housing 20, cylinder block 26 and rear mounting cap 14 (if applicable) are coupled together, facilitates easy interchangeability of shaft 40, front mounting flange 16 and rear mounting cap 14 with main housing 12 of compressor 10. Thus, the main housing 12 may be operated in any of a number of different vehicles by simply removing the fasteners 20 from the fastener holes 110, 112, 114, 116, separating the housing 20 from the cylinder block 26, removing the pins 48 (if applicable), disposing the appropriate drive shaft 40 in the drive shaft passage 104, inserting the pins 48 (if applicable), and fastening the front mounting flange 16, the swash plate housing 20, the cylinder block 26, and the rear mounting cap 14 together by replacing the plurality of fasteners 120 in the fastener holes 110, 112, 114, 116.

In this way, the main housing 12 can also be used at another time for a different set of corresponding components-i.e., the shaft, the front mounting flange, and the rear mounting cover (if applicable). Similarly, any of the previously described corresponding components may be quickly and easily removed and replaced with a new component when damaged or obsolete.

It can be understood that: the foregoing description is illustrative and not restrictive, and various changes may be made by those skilled in the art without departing from the spirit of the invention. Accordingly, reference should be made primarily to the following claims, rather than the foregoing specification, to determine the scope of the invention.

Claims (12)

1. A modular swash plate compressor, comprising:

a compressor housing;

a swash plate disposed in the housing, the swash plate having a channel therein;

a drive shaft selected from a plurality of drive shafts disposed in the housing and the passageway, each of the plurality of drive shafts configured to be operable in a different type of vehicle; and

a mounting flange selected from a plurality of mounting flanges secured to the housing, each of the plurality of mounting flanges configured to mount the compressor to a different type of vehicle.

2. The compressor of claim 1, wherein said housing has a first end and a second end, said mounting flange being secured to said first end of said housing, the compressor further comprising a mounting cap selected from a plurality of mounting caps secured to said second end of said housing, each of said plurality of mounting caps being configured for use with a different type of vehicle.

3. The compressor of claim 1, wherein the compressor housing comprises:

a swash plate housing secured to the mounting flange; and

a cylinder block secured to the swash plate housing.

4. The compressor of claim 3, wherein the mounting flange has a first set of fastener bores, the swash plate housing has a second set of fastener bores axially aligned with the first set of fastener bores, the cylinder block has a third set of fastener bores axially aligned with the first and second sets of fastener bores, the compressor further comprising a plurality of fasteners, each of the plurality of fasteners disposed in one of each of the first, second, and third sets of fastener bores.

5. The compressor of claim 1, wherein the housing has at least one piston passage therein, the compressor further comprising:

at least one piston disposed in the at least one piston channel and coupled to the swash plate;

an actuator disposed in said housing, said actuator having a cam with a bore axially aligned with a channel in said swash plate, said cam being rotatable with any one of a plurality of drive shafts, said actuator applying a force to said swash plate in a first position, wherein said force is adapted to maintain said swash plate in a position perpendicular to the channel in the swash plate to keep said at least one piston idle; in the second position, the actuator applies a force to the swash plate adapted to pivot the swash plate, thereby causing the at least one piston to reciprocate in the piston channel.

6. A modular swash plate compressor, comprising:

a plurality of mounting flanges, each of the plurality of mounting flanges configured to secure the compressor to a different type of vehicle;

a compressor housing adapted to be mounted to either of said mounting flanges;

a swash plate disposed in the housing, the swash plate having a channel therein; and

a plurality of drive axles, each of said plurality of drive axles being configured to be operable in a different type of vehicle, wherein said housing and said swash plate are adapted to accommodate any of said drive axles.

7. A method of assembling a modular swash plate compressor, the method comprising:

providing a compressor housing;

disposing a swash plate having a channel therein in a compressor housing;

selecting a drive axle from a plurality of drive axles, each of the plurality of drive axles configured to be operable in a different type of vehicle;

disposing the selected drive shaft in the passage of the housing and swash plate;

selecting a mounting flange from a plurality of mounting flanges, each of the plurality of mounting flanges adapted to mount the compressor to a different type of vehicle; and

the housing is secured to the selected mounting flange.

8. The method of claim 7, further comprising securing the mounting flange to the vehicle.

9. The method of claim 7, wherein the housing has a first end and a second end, wherein the securing step includes securing the first end of the housing to the mounting flange, the method further comprising:

selecting a mounting cap from a plurality of mounting caps, each of the plurality of mounting caps being configured for use with a different type of vehicle; and

securing the selected mounting cap to the housing.

10. The method of claim 9, further comprising securing the mounting cover to the vehicle.

11. The method of claim 7 wherein the housing comprises a swash plate housing and a cylinder block, and wherein the step of securing the compressor housing to the mounting flange comprises securing the swash plate housing to the cylinder block.

12. The method of claim 11, wherein the mounting flange has a first set of fastener bores, the swash plate housing has a second set of fastener bores axially aligned with the first set of fastener bores, the cylinder block has a third set of fastener bores axially aligned with the first and second sets of fastener bores, and wherein the step of fastening includes disposing a plurality of fasteners into the first, second, and third sets of fastener bores.