JPH06185486A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To provide a scroll type fluid machine by which damage of a sealing member can be detected simply in the initial stage and clean fluid can be delivered. CONSTITUTION:A detecting passage 29 is formed in a casing 1 so as to be communicated with a sealing chamber 27, and the detecting passage 29 is connected to a pressure sensor 35 outside of the casing 1 through a connecting pipe 30, and pressure in the sealing chamber 27 is detected by the pressure sensor 35. When a sealing member 24 is damaged and the side of a suction passage 22 is communicated with the inside of the sealing chamber 27, since the inside of the sealing chamber 27 is put in a negative pressure condition by suction pressure on the suction passage 22 side, a pressure change at this time can be detected by the pressure sensor 35 through the detecting passage 29, so that the existence of damage of the sealing member 24 can be identified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor or a vacuum pump, and particularly to a semi-oil type scroll in which only the inside of a casing is lubricated with oil liquid or the like. Type fluid machinery.

[0002]

2. Description of the Related Art Generally, a semi-lubricating scroll type fluid machine includes a casing for containing oil and liquid therein, a drive shaft rotatably provided in the casing, and a tip side extending into the casing serving as a crank. An orbiting scroll rotatably provided on a crank of the drive shaft and having a spirally wound wrap portion standing on an end plate; and a wrap of the orbiting scroll fixed to the casing facing the orbiting scroll. Fixed scroll in which spiral-shaped wrap portions that form a plurality of compression chambers are formed upright between the compression chambers, and the suction port and the innermost peripheral side that communicate with the outermost compression chamber of the compression chambers. Of the discharge port communicating with the compression chamber of the compressor, and a seal member disposed radially outside the wrap portion of the orbiting scroll and the fixed scroll so as to shut off the compression chamber from the inside of the casing. It is largely constituted from.

When this type of scroll type fluid machine is used as an air compressor, the orbiting scroll is orbited by rotating the drive shaft from the outside with an electric motor or the like, and the air sucked from the suction port is supplied. The compressed air is discharged from the discharge port toward an external air tank or the like while being compressed in the compression chamber formed between the wrap portions of the orbiting scroll and the fixed scroll. At this time, the seal member elastically deforms while allowing the orbiting scroll to revolve inside the fixed scroll, while blocking the inside of the casing from the compression chamber to prevent oil liquid from leaking to the compression chamber side. .

[0004]

By the way, in the above-described air compressor according to the prior art, while the orbiting scroll is orbiting to perform the compression action, the orbiting scroll makes a circular motion relative to the fixed scroll. Since the seal member repeatedly deforms in the radial direction and the circumferential direction between the orbiting scroll and the fixed scroll, the material of the seal member such as rubber is likely to be damaged due to deterioration or wear.

Since the seal member cannot be directly observed from the outside, if the compressor is continuously operated without knowing the damage of the seal member, the seal member is damaged and the oil liquid contained in the casing is the outermost circumference of the orbiting scroll. There is a problem that the oil mist is sucked from the compression chamber on the side, the oil mist is mixed with the compressed air, and is discharged from the discharge port.

On the other hand, it is difficult to directly detect the oil mist by a sensor or the like, and even if the oil mist is discharged from the discharge port due to the damage of the seal member, there is no means for automatically notifying the damage of the seal member. When the damage of the seal member is detected from the occurrence of the above, there is a problem that a large amount of oil liquid is sucked into each compression chamber, and it is necessary to disassemble and clean the air compressor after that.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can easily detect damage to the seal member at an initial stage, and oil mist is contained in the fluid discharged from the discharge port. It is an object of the present invention to provide a scroll type fluid machine capable of preventing the mixture.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a bearing portion is provided on the base end side, and a thrust receiving portion extends on the tip end side in a direction substantially orthogonal to the axis of the bearing portion. A cylindrical casing provided in such a manner, the bearing part of the casing is rotatably provided, and the tip end side extends into the casing to form a crank, and the base end side protrudes outside the casing, and the end plate of the end plate. A revolving scroll in which the back side is slidably in contact with the thrust receiving portion of the casing and is pivotally provided on the crank of the drive shaft so as to cover the casing, and a spiral wrap portion is erected on the front side of the end plate. When,
A fixed scroll fixed to the tip end side of the casing so as to sandwich the orbiting scroll with the thrust receiving portion of the casing, and a spiral scroll-shaped wrap portion that overlaps the wrap portion of the orbiting scroll on the end plate. A plurality of compression chambers which are respectively formed between the wrap portion of the fixed scroll and the wrap portion of the orbiting scroll and discharge the fluid from the discharge port while compressing the fluid sucked from the suction port, and the outer circumference of the wrap portion of the fixed scroll. Provided on the side,
An annular suction passage communicating between the suction port and the outermost peripheral compression chamber, and the casing or the fixed scroll and the casing for preventing the oil liquid contained in the casing from entering the suction passage side. A seal member that is provided between the orbiting scroll and a thrust receiving portion of the casing that forms a seal chamber that is blocked from the suction passage, and is provided in the fixed scroll or the casing.
A configuration is adopted that includes a detection passage that communicates with the seal chamber and a pressure detection unit that is connected to the detection passage and that detects the pressure in the detection passage.

In this case, the pressure detecting means includes a closed container containing a liquid, and a pressure receiving chamber provided in the closed container and communicating with the detection passage on the liquid surface of the liquid contained in the closed container. And a partition part that defines an atmospheric pressure chamber that communicates with the outside air, and a liquid circulation part that is provided below the partition part and that circulates the liquid in the closed container between the pressure receiving chamber side and the atmospheric pressure chamber side. And a liquid level sensor provided on the atmospheric pressure chamber side of the closed container for detecting whether or not the liquid level of the liquid has changed to a predetermined level in the atmospheric pressure chamber.

The pressure detecting means is defined by a closed container which communicates with the inside of the casing and accommodates a part of the oil liquid in the casing, and a liquid level of the oil liquid in the closed container. A pressure receiving chamber communicating with the detection passage on the upper side of the closed container, and a liquid level level of the liquid provided in the closed container in the pressure receiving chamber and changed to a predetermined level according to the pressure on the detection passage side. It may be composed of a liquid level sensor for detecting whether or not the liquid level sensor is used.

[0011]

With the above structure, when the seal member is damaged and the suction passage side communicates with the seal chamber, the pressure inside the seal chamber becomes negative due to the suction pressure on the suction passage side. The pressure can be detected by the pressure detecting means through the, and the presence or absence of damage to the seal member can be determined.

Here, if the pressure detecting means is provided with a pressure receiving chamber and an atmospheric pressure chamber defined in a closed container and the detection passage is communicated with the pressure receiving chamber, the seal member is damaged and the seal is formed. When the pressure in the chamber becomes negative, the pressure in the pressure receiving chamber also becomes negative, so that the liquid in the closed container flows into the pressure receiving chamber side by the atmospheric pressure in the atmospheric pressure chamber, and the liquid level on the atmospheric pressure chamber side becomes a predetermined liquid level. The liquid level is lowered to the level, and the change in the liquid level can be detected as damage to the seal member by the liquid level sensor.

If the detection passage is communicated with a pressure receiving chamber defined in the upper part of the closed container, and the oil liquid in the casing is circulated in the pressure receiving chamber according to the pressure on the detection passage side, When the liquid level of the oil liquid rises in the pressure receiving chamber, this can be detected as damage to the seal member.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 9 by taking a scroll type air compressor as an example.

First, FIGS. 1 to 3 show a first embodiment of the present invention.

In the figure, reference numeral 1 denotes a casing, 2 denotes a casing body which constitutes the casing 1 together with a front casing 3 which will be described later, and the casing body 2 has a disc-shaped bottom portion 2A located at the base end side, A cylindrical portion 2B extending from the outer peripheral side of the bottom portion 2A toward the fixed scroll 15 side described later.
And a cylindrical bearing portion 2C formed on the inner peripheral side of the bottom portion 2A to form a stepped tubular shape with a bottom.

Reference numeral 3 denotes a stepped tubular front casing integrally formed by projecting radially inward from the front end side of the tubular portion 2B of the casing body 2. The front casing 3 abuts against a fixed scroll 15 described later. An annular abutting section 3A
A thrust receiving portion that is located on the inner peripheral side of the abutting portion 3A, extends in a direction substantially orthogonal to the axis of the bearing portion 2C, and slides in contact with the rear side of an orbiting scroll 7 described later to receive a load in the thrust direction. 3B and a plurality of notches 3C, 3C, ... (Only two are shown) that are located on the inner peripheral side of the thrust receiving portion 3B and are formed at predetermined intervals in the circumferential direction.

Reference numeral 4 denotes a drive shaft rotatably supported by a bearing portion 2C of the casing body 2 via bearings 5 and 6, and the tip end side of the drive shaft 4 extends into the casing 1 to form a crank 4A. The axis of the crank 4A is eccentric to the axis of the drive shaft 4 by a predetermined dimension d. Further, the base end side of the drive shaft 4 is provided outside the casing 1 with an electric motor 39 described later.
Is connected to the motor via a belt or the like, and is rotationally driven by the electric motor 39.

Reference numeral 7 denotes an orbiting scroll which is located in the casing 1 and is provided so as to be capable of orbiting on the crank 4A of the drive shaft 4. The orbiting scroll 7 has a disk-shaped end plate 8 and the end plate 8 of the end plate 8. It is composed of a spiral wrap portion 9 standing upright from the front surface 8A and a boss portion 10 provided in the center of the rear surface 8B side of the end plate 8, and a crank 4A is provided in the boss portion 10 via a slewing bearing 11. Installed. Also,
On the outer peripheral side of the end plate 8, there is integrally formed a cylindrical inner supporting portion 12 for supporting a seal member 26 described later from the inner peripheral side.

A plurality of key grooves 13, 13, ... (Only two are shown) are formed at predetermined intervals in the circumferential direction on the outer peripheral side of the back surface 8B of the end plate 8, and each of the key grooves 13 and the front casing are formed. An Oldham coupling 14 as a rotation preventing mechanism is disposed between each of the notches 3C and 3C. When the drive shaft 4 is rotationally driven, the orbiting scroll 7 is given a circular motion having a orbiting radius of the dimension d by the crank 4A, and the Oldham coupling 14 prevents the rotation of the drive shaft 4 to prevent the drive shaft 4 from rotating. It keeps turning (orbiting) around the axis.

Reference numeral 15 denotes a fixed scroll provided so as to abut on the tip end side of the casing 1 so as to sandwich the orbiting scroll 7 with the thrust receiving portion 3B of the front casing 3, and the fixed scroll 15 is An end plate 16 disposed in the central portion so that its center coincides with the axis of the drive shaft 4,
Similar to the wrap portion 9 of the orbiting scroll 7 from the end plate 16, a wrap portion 17 erected in a spiral shape and an end plate 16
Is formed so as to surround the outer peripheral side of the front casing 3, and is formed of a tubular portion 18 with a collar that abuts the abutting portion 3A of the front casing 3.
A suction passage 22 described later is provided on the inner peripheral side of the tubular portion 18. Then, the wrap portion 17 of the fixed scroll 15
, The orbiting scroll 7 overlaps with each other in a state in which the wrap portion 9 is displaced by a predetermined angle (for example, about 180 °).

.. indicate a plurality of compression chambers formed between the wrap portion 9 of the orbiting scroll 7 and the wrap portion 17 of the fixed scroll 15, and each compression chamber 19 is a wrap of the fixed scroll 15. While the orbiting scroll 7 makes an orbiting motion with respect to the portion 17, its volume is gradually reduced. The compression chambers 19 take in air from the suction port 20 via an intake silencer 28, which will be described later, as the orbiting scroll 7 orbits.
This air is sequentially compressed.

Reference numeral 20 denotes a suction port formed in the cylindrical portion 18 of the fixed scroll 15, and 21 denotes a discharge port formed in the central portion of the end plate 16 of the fixed scroll 15. The suction port 20 is the outermost peripheral side (low pressure). The discharge port 21 communicates with the compression chamber 19 of the most central side (high pressure side).

Reference numeral 22 is provided in the fixed scroll 15 so as to surround the outer peripheral side of the wrap portion 17, and the tubular portion 18 is provided.
5 shows an annular suction passage formed on the inner peripheral side of the suction passage 22. The suction passage 22 connects the suction port 20 and the outermost compression chamber 19 to each other.

Reference numeral 23 denotes a cylindrical outer supporting portion provided on the front end side of the front casing 3 so as to project from the abutting portion 3A, and 24 is between the outer peripheral surface of the outer supporting portion 23 and the outer peripheral surface of the inner supporting portion 12. Shows a sealing member formed in a bottomed tubular shape having a U-shaped cross section from a flexible resin material, and the inner peripheral side of the sealing member 24 is fixed to the outer peripheral surface of the inner support portion 12 by a fixing ring 25. Is fixed by the outer support 23
An annular seal chamber 27, which is fixed to the outer peripheral surface of the casing by a fixing ring 26, is formed between the seal member 24 and the thrust receiving portion 3B so as to be blocked from the suction passage 22. Then, the seal member 24 seals the suction passage 22 and the chamber A in the casing 1 in a gas-liquid tight manner, and the suction passage 22 is provided in the casing 1 via the front casing 3 and the orbiting scroll 7. Prevents communication with room A.

Reference numeral 28 denotes an intake silencer provided in the suction port 20. The intake silencer 28 produces intake noise when air is taken into each compression chamber 19 from the suction port 20 via the suction passage 22 or the like. Is to reduce.

Reference numeral 29 denotes a detection passage provided in the casing 1. The detection passage 29 is formed in the abutting portion 3A of the front casing 3 from the outside in the radial direction, and between the thrust receiving portion 3B and the outer supporting portion 23. It is bent into a substantially L shape and communicates with the inside of the seal chamber 27. The detection passage 29 is connected to a pressure sensor 35, which will be described later, via a connection pipe 30 extending outside the casing 1.

Reference numeral 31 denotes an oil scraper located inside the casing body 2 and fitted and fixed to the drive shaft 4. The oil scraper 31 is
It is arranged so that the outer peripheral side thereof comes into contact with the oil liquid 32 contained in the casing 1. When the drive shaft 4 rotates, the oil scraper 31 scrapes up the oil liquid 32 to supply the oil liquid 32 to the bearing 5, the swivel bearing 11, the thrust receiving portion 3B of the front casing 3, and the like. cooling,
It is to lubricate. Reference numeral 33 is a counter weight fixed to the oil scraper 31 to balance the rotation of the drive shaft 4, and reference numeral 34 is a breathing plug provided on the upper part of the casing body 2 for communicating the inside of the casing 1 with the outside air.

Reference numeral 35 denotes a pressure sensor provided outside the casing 1 as a pressure detecting means.
For example, a semiconductor strain gauge type pressure sensor, an adhesive metal strain gauge type pressure sensor, a differential inductance type pressure sensor, or the like is adopted, and its output side is connected to a control device 36 described later as shown in FIG. The pressure sensor 35 is connected to the seal chamber 27 via the detection passage 29 and the connecting pipe 30.
The internal pressure P is detected, and a detection signal corresponding to this pressure P is output to the control device 36.

Reference numeral 36 denotes a control device composed of a microcomputer or the like. On the input side of the control device 36, in addition to the main switch 37 such as the pressure sensor 35 and the electric motor 39, for example, the discharge port 21 and the air tank are connected. Another discharge pressure sensor (not shown) that detects the pressure between
The output side is connected to an alarm 38 as an alarm device, an electric motor 39, and the like. The control device 36 stores the program shown in FIG. 3 in its storage circuit and performs control processing of the electric motor 39 and the like. The storage circuit of the control device 36 has a storage area 36
A set pressure P0 or the like for determining whether or not the inside of the seal chamber 27 is in a negative pressure state is stored in A, and the set pressure P0 is stored.
0 is, for example, about -10 mmAq.

Further, 39 denotes an electric motor which is a drive source of the drive shaft 4, and the electric motor 39 is controlled by the control device 36 and rotationally drives the base end side of the drive shaft 4 via a belt or the like. Is.

The scroll type air compressor according to the present embodiment has the above-mentioned structure, and when the drive shaft 4 is rotationally driven by the electric motor 39, this rotation is caused by the crank 4
A is transmitted from A to the orbiting scroll 7 via an orbiting bearing 11, and the orbiting scroll 7 orbits about the axis of the drive shaft 4 with a orbiting radius of a predetermined dimension d, and this orbiting motion causes air to be sucked into the intake silencer 28 and suction. It flows from the port 20 into the compression chamber 19 on the outermost peripheral side through the suction passage 22.

Then, each compression chamber 19 is continuously reduced,
The taken-in air is sequentially sent to the compression chamber 19 on the inner peripheral side for compression, and the compressed air is discharged from the discharge port 21 to an external air tank (not shown) or the like to perform a compression action.

Here, while the air is being compressed, the suction passage 22 is moved by the orbiting motion of the orbiting scroll 7.
Since the air inside is sequentially taken into each compression chamber 19, the pressure inside the suction passage 22 is lower than the atmospheric pressure (outside air). Further, in the seal chamber 27 formed between the thrust receiving portion 3B of the casing 1 and the seal member 24, since the back surface 8B of the orbiting scroll 7 continues to slide on the thrust receiving portion 3B, the chamber A in the casing 1 And the inside of the casing 1 that communicates with the outside air via the breathing plug 34 at almost the same pressure (atmospheric pressure state).

However, when the seal member 24 is damaged and the suction passage 22 and the seal chamber 27 communicate with each other, the suction passage 2
Due to the suction pressure on the second side, the pressure P in the seal chamber 27 becomes a negative pressure state, and this pressure change is caused by the detection passage 29 and the connecting pipe 3.
It is transmitted to the pressure sensor 35 via 0, and the control processing by the control device 36 is performed.

Therefore, the control processing by the control device 36 will be described with reference to FIG.

First, when the processing operation starts, it is determined in step 1 whether or not the main switch 37 is in the ON state,
In the case of “YES”, the process proceeds to step 2 and, for example, whether or not the compression operation is being performed, that is, whether or not the electric motor 39 is rotating, from the discharge pressure sensor or the like between the discharge port 21 and the air tank. Is determined, and if “YES”, the process proceeds to step 3.

Then, in step 3, the pressure P in the seal chamber 27 is read from the pressure sensor 35, and in step 4, it is determined whether or not this pressure P is lower than the set pressure P0 stored in the memory area 35A. Then, in step 4, "Y
When it is determined to be “ES”, it is possible to determine that the pressure P in the seal chamber 27 is in a negative pressure state because the seal member 24 is damaged and the suction passage 22 and the seal chamber 27 communicate with each other. In step 5, the alarm 38 is activated to warn the operator, and in step 6, the electric motor 39 and the like are stopped to interrupt the compression operation.

On the other hand, if it is determined to be "NO" in step 1, the main switch 37 is in the OFF state and the operation of the compressor is stopped, so that the process returns in step 7. Further, even when it is determined to be “NO” in step 2, the electric motor 39 is in a stopped state, and therefore the process returns in step 7.

Further, when it is judged "NO" in step 4, the compressor is in the compression operation and the seal member 24
Since it can be determined that there is no damage to the
The subsequent processing is repeated.

Thus, in the present embodiment, the casing 1 is provided with the detection passage 29 communicating with the inside of the seal chamber 27, and the detection passage 29 is sealed by the pressure sensor 35 provided outside the casing 1 through the connecting pipe 30. The pressure P in the chamber 27 is detected, and when the pressure P in the seal chamber 27 becomes lower than the set pressure P0 and becomes a negative pressure state, the controller 36 activates the alarm 38 and stops the electric motor 39. Therefore, even if the seal member 24 is damaged and a small hole is generated, this can be promptly detected based on the pressure P in the seal chamber 27, and an alarm can be issued to stop the compression operation.

Further, the oil liquid 32 contained in the chamber A of the casing 1 has a relatively high viscosity, and even after the sealing member 24 is damaged and the inside of the sealing chamber 27 is in a negative pressure state, the casing 32 remains for a while. Since the oil liquid 32 in 1 does not leak to the suction passage 22 side, the operation of the compressor can be quickly stopped before the oil liquid is sucked into the compression chambers 19, and the inside of each compression chamber 19 can be stopped. It is possible to reliably prevent the oil liquid 32 from being sucked into the discharge port 21 and discharge the oil mist together with the compressed air from the discharge port 21, thereby improving reliability and facilitating maintenance and inspection.

Furthermore, since the pressure sensor 35 is provided outside the casing 1, the pressure P in the seal chamber 27 can be accurately adjusted by reducing the influence of vibration from the compressor, temperature change, noise, etc. on the pressure sensor 35. Therefore, various effects can be obtained, such as the detection by the control device 36 and the control by the control device 36 being surely performed.

Next, FIGS. 4 and 5 show a second embodiment of the present invention. The feature of this embodiment is that the pressure detecting means is contained in a hermetically sealed container and the liquid level of the liquid is a predetermined level. It is composed of a float type liquid level sensor for detecting whether or not the surface level is reached. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 40 denotes a check valve provided in the middle of the connecting pipe 30, and in the check valve 40, air flows through the connecting pipe 30 from the side of a closed container 42 described later to the side of the detection passage 29. Is allowed to prevent the reverse flow, and the negative pressure state once generated on the detection passage 29 side is maintained so that the pressure can be surely detected.

Reference numeral 41 represents a pressure detecting device 41 as a pressure detecting means, and the pressure detecting device 41 is a closed container 4 described later.
2, a partition plate 43, a float type liquid level sensor 50 and the like. The pressure detecting device 41 is positioned within the liquid level of the oil liquid 32 in the casing 1,
The oil liquid 32 inside is installed horizontally.

Reference numeral 42 denotes a closed container which constitutes the main body of the pressure detecting device 41. The closed container 42 includes a lid portion 42A, a bottom portion 42B and front, rear, left and right side portions 42 as shown in FIG.
C, 42C, ...
The oil liquid 32 in the casing 1 is accommodated as a liquid via the container 9. The closed container 42 is arranged at a predetermined height with respect to the casing 1 so that the liquid level on the pressure receiving chamber 44 side, which will be described later, is the same as the liquid level in the casing 1 during normal operation.

Reference numeral 43 denotes a partition plate which is fixed to the upper end side and front and rear both end sides to the lid portion 42A of the closed container 42 and the front and rear side surface portions 42C, and the lower end side of the partition plate 43 is It extends into the oil liquid 32 in the closed container 42, and the inside of the closed container 42 is divided into a large volume pressure receiving chamber 44 and a small volume atmospheric pressure chamber 45 above the liquid surface. The area ratio of the liquid surface of the atmospheric pressure chamber 45 is defined to be about 4.5: 1 to 5: 1. A connection pipe 30 communicating with the detection passage 29 of the casing 1 is connected to the lid 42A of the closed container 42 above the pressure receiving chamber 44, and a cylindrical ventilation pipe communicating with the outside air above the atmospheric pressure chamber 45. 46 is provided so as to project. Further, at the lower end side of the partition plate 43, a circulation part 47 is formed between the bottom part 42B of the closed container 42, and the circulation part 47 receives the oil liquid 32 in the closed container 42 from the pressure receiving chamber 44 side and the atmospheric pressure chamber. It is designed to be distributed to the 45 side.

Reference numeral 48 denotes a peep window provided on the side surface of the pressure receiving chamber 44. The peep window 48 is formed by attaching a transparent plate such as glass to the side surface portion 42C on the front side of the hermetically sealed container 42. The window 48 allows the liquid level in the pressure receiving chamber 44 to be directly visually recognized from the outside.

Reference numeral 49 denotes a communication pipe projecting from the side surface portion 42C of the closed container 42 and communicating with the inside of the casing 1. The communication pipe 49 allows the oil liquid 32 in the casing 1 to flow into the closed container 42 and the inside of the casing 1. The level of the oil liquid 32 is kept at the same level in the closed container 42. Here, as shown in FIG. 4, the communication pipe 49 is provided with a narrowed portion 49A having a narrow inner side.
Due to 9A, even if the liquid level in the pressure receiving chamber 44 rises, a delay time is provided until the oil liquid 32 in the casing 1 flows into the pressure receiving chamber 44, and when the pressure receiving chamber 44 becomes negative, the atmospheric pressure is reached. The liquid level in the chamber 45 is surely lowered.

Reference numeral 50 denotes a float type liquid level sensor provided in the atmospheric pressure chamber 45. The float type liquid level sensor 50 has a lid portion 42A of the closed container 42 at the upper end side.
A detection rod 51 whose bottom end extends toward the bottom portion 42B side, and a float 53 described later,
A reed switch 52 that operates by magnetic force is provided on the lower end side of the detection rod 51. The lead switches 52A, 52A are connected to the lower ends of the lead wires 52A, 52A. The lead wires 52A extend upward in the detection rod 51 and are pulled out from the lid 42A of the hermetically sealed container 42. It is connected to the device.

Reference numeral 53 designates a float provided in the atmospheric pressure chamber 45. The float 53 is made of a material having a specific gravity smaller than that of the oil liquid 32 and has a cylindrical shape.
It is inserted through A on the outer peripheral side of the detection rod 51.
Then, the float 53 floats above the liquid surface of the oil liquid 32 in the atmospheric pressure chamber 45, and moves in the vertical direction according to the vertical movement of the liquid surface of the oil liquid 32.

Reference numeral 54 designates an annular magnet provided in the float 53. The annular magnet 54 is embedded in the float 53 around the insertion hole 53A of the float 53, and the float 5
3 moves up and down along with the detection rod 51. Then, the liquid level of the oil liquid 32 is lowered in the atmospheric pressure chamber 45, and the annular magnet 54 moves along with the float to the reed switch 52.
When the reed switch 52 is moved to a position close to, the reed switch 52 is actuated by the magnetic force from the annular magnet 54, so that the control device activates an alarm such as an alarm and stops the operation of the compressor.

This embodiment has the structure described above, and when the seal member 24 is damaged and the pressure in the seal chamber 27 becomes a negative pressure, the seal chamber 27, the detection passage 29 and the connecting pipe 30 are connected. Pressure receiving chamber 44 in the closed container 42 communicating with each other
Since the inside is also in a negative pressure state, the pressure in the pressure receiving chamber 44 becomes relatively lower than that in the atmospheric pressure chamber 45 communicating with the outside air via the ventilation pipe 46, and the oil liquid 32 in the closed container 42 has this difference. Pressure flows from the atmospheric pressure chamber 45 side to the pressure receiving chamber 44 side,
In the pressure receiving chamber 44, the liquid level of the oil liquid 32 rises, and the atmospheric pressure chamber 4
The liquid level in 5 descends. The float 53, which is inserted through the detection rod 51 in the atmospheric pressure chamber 45, descends together with the liquid level in the atmospheric pressure chamber 45, and this liquid level is close to the reed switch 52. When the temperature of the lead wire 52A falls, the reed switch 52 is actuated by the magnetic force of the annular magnet 54 in the float 53, and
An alarm can be issued by the control device connected to and the operation of the compressor can be stopped.

In this embodiment, since the area of the liquid surface on the pressure receiving chamber 44 side is formed to be about 5 times larger than that on the atmospheric pressure chamber 45 side, even a slight negative pressure generated in the pressure receiving chamber 44 can be used. The liquid level on the atmospheric pressure chamber 45 side can be greatly changed, and the damage of the seal member 24 can be detected with high accuracy by the pressure detection device 41.

Further, the inside of the closed container 42 is made to communicate with the inside of the casing 1 through the communication pipe 49, and the side surface portion 42C on the front side is connected.
Since the peep window 48 is provided in the case, in the normal case where the seal member 24 is not damaged, the liquid level in the closed container 42 becomes the same level as the liquid level of the oil liquid 32 in the casing 1, and the peek window 48 is opened. By monitoring the liquid level in the closed container 42 via the pressure detecting device 41, the pressure detecting device 41 can also be used as an oil level gauge of the casing 1. Then, even when the oil liquid 32 in the casing 1 leaks to the outside or is consumed and the liquid level falls below a predetermined liquid level, the float type liquid level sensor 50 operates and the compressor is operated. The operation of can be stopped automatically.

Next, FIG. 6 shows a third embodiment of the present invention, which is characterized in that the liquid in the closed container constituting the pressure detecting means is replaced by the oil in the casing of the scroll air compressor. The purpose is to use an oil liquid different from the liquid. In this embodiment, the same components as those of the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 61 indicates a pressure detecting device as a pressure detecting means, and the pressure detecting device 61 comprises a closed container 62, a partition plate 64, a float type liquid level sensor 50 and the like which will be described later.

Reference numeral 62 designates a closed container which constitutes the main body of the pressure detection device 61. The closed container 62 includes a lid portion 62A, a bottom portion 62B and front, rear, left and right side portions 62 as shown in FIG.
C, 62C, ...
Is housed.

Reference numeral 64 denotes a partition plate which is fixed to the lid portion 62A of the closed container 62 and the front and rear side surface portions 62C at the upper end side and both front and rear end sides, and the lower end side of the partition plate 64 is It extends into the oil liquid 63 in the closed container 62, and the inside of the closed container 62 is divided into a large volume pressure receiving chamber 65 and a small volume atmospheric pressure chamber 66 above the liquid surface. Here, the pressure receiving chamber 65 is formed with a pressure receiving area (liquid surface area) which is about 4.5 to 5 times that of the atmospheric pressure chamber 66, and the upper side of the atmospheric pressure chamber 66 has a cylindrical shape communicating with the outside air. The ventilation pipe 67 is provided so as to project. A flow section 68 is formed at the lower end side of the partition plate 64 between the bottom section 62B of the closed vessel 62, and the flow section 68 receives the oil liquid 63 in the closed vessel 62 from the pressure receiving chamber 65 side and the atmospheric pressure chamber. It is distributed to the 66 side. The pressure receiving chamber 65 communicates with the detection passage 29 side via the connection pipe 30, the check valve 40, and the like.

Thus, although this embodiment having the above-described structure has substantially the same operational effect as that of the second embodiment, in particular, in this embodiment, the closed container 62 constituting the pressure detecting device 61 is used as the casing. Since the pressure detecting device 61 is provided independently of the above, the installation place can be freely selected when the pressure detecting device 61 is installed, and the liquid is not limited to the oil liquid 63, and a liquid such as alcohol can be used. is there.

Next, FIG. 7 shows a fourth embodiment of the present invention, which is characterized in that a thermistor type liquid level sensor is used as the liquid level sensor. In this embodiment, the same components as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 71 indicates a pressure detecting device as a pressure detecting means, and the pressure detecting device 71 is a closed container 62.
It is composed of a thermistor type liquid level sensor 72 described later.

Reference numeral 72 denotes a thermistor type liquid level sensor, which is the atmospheric pressure chamber 6
A sensor main body 72A mounted by being immersed in an oil liquid 63 in a predetermined depth to a predetermined depth, and the sensor main body 72A to the lid portion 62A.
And lead wires 72B and 72B connected to a control device (not shown). Then, by supplying a current of a predetermined value from the control device through the respective lead wires 72B, the sensor main body 72
A generates heat, and the thermal radiation constant of the sensor main body 72A greatly differs depending on whether the surroundings of the sensor main body 72A are oil liquid 63 or air. When the main body 72A is exposed from the liquid surface of the oil liquid 63, the current-voltage characteristic changes greatly.

This embodiment has the structure described above. If the seal member 24 is damaged, the pressure receiving chamber 65 inside the closed container 62 becomes the atmospheric pressure chamber 66 as in the third embodiment. On the other hand, a negative pressure is generated, and the oil liquid 63 in the closed container 62 flows from the atmospheric pressure chamber 66 side to the pressure receiving chamber 65 side via the circulation portion 68.

When the liquid level on the atmospheric pressure chamber 66 side drops to a predetermined level and the sensor body 72A of the thermistor type liquid level sensor 72 is exposed from the liquid level, the controller detects a change in the current-voltage characteristic. A warning can be issued to stop the operation of the compressor. In particular, according to this embodiment, since the thermistor type liquid level sensor is used as the liquid level sensor, the structure can be greatly simplified and the size can be easily reduced.

Next, FIG. 8 shows a fifth embodiment of the present invention, which is characterized in that an ultrasonic liquid level sensor is used as the liquid level sensor. Also in this embodiment, the same components as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 81 denotes a pressure detecting device as pressure detecting means, and the pressure detecting device 81 includes a closed container 62,
It is composed of an ultrasonic type liquid level sensor 82 described later.

Reference numeral 82 denotes an ultrasonic type liquid level sensor,
As shown in FIG. 8, the ultrasonic type liquid level sensor 82 includes a sensor main body 82A fixed inside the lid 62A in the atmospheric pressure chamber 66, and a closed container 62 from the sensor main body 82A via the lid 62A. And lead wires 82B and 82B connected to a control device (not shown). Here, the sensor main body 82A emits ultrasonic waves toward the liquid surface of the oil liquid 63 in the atmospheric pressure chamber 66, and measures the time until the reflected wave reflected by the liquid surface of the oil liquid 63 is received. A distance D between the sensor main body 82A and the liquid surface in the atmospheric pressure chamber 66 is detected, and when the distance D reaches a predetermined value, an alarm is issued by the control device and the operation of the compressor is stopped. .

Although this embodiment having the above-described structure has substantially the same operational effect as the third embodiment, the oil liquid 63 and the ultrasonic liquid level sensor 82 are not in contact with each other in this embodiment. The liquid level can be measured in the state, and the oil liquid 6
Even if there is a change in viscosity of 3, high-precision detection can be performed.

Next, FIG. 9 shows a sixth embodiment of the present invention. The feature of this embodiment is that only the pressure receiving chamber is provided in the closed container of the pressure detecting device, and the oil liquid in the casing is placed in the closed container. By guiding, the liquid level in the pressure receiving chamber rises when a negative pressure is generated on the detection passage side.

In the figure, reference numeral 91 denotes a pressure detecting device as a pressure detecting means, and the pressure detecting device 91 comprises a closed container 92, a float type liquid level sensor 95 and the like which will be described later.

Reference numeral 92 represents a closed container, and the closed container 92 has a lid portion 92A, a bottom portion 92B, and front, rear, left, right side portions 92C, 92C, ... Communication pipe 93 consisting of a hollow pipe on the lower side of 92C
Through the casing 1 of the scroll air compressor. However, unlike the communication pipe 49 described in the second embodiment, the communication pipe 93 is not provided with a throttle portion. Further, the closed container 92 is filled with the oil liquid 32 to the same level as the casing 1, and a pressure receiving chamber 94 is defined on the liquid surface of the oil liquid 32.

Reference numeral 95 denotes a float type liquid level sensor, which is composed of a detection rod 96, a float 53 and the like which will be described later.

Reference numeral 96 denotes a detection rod, and the detection rod 9
6 is similar to the detection rod 51 described in the second embodiment, the upper end side is fixed to the lid portion 92A of the closed container 92, the lower end side is extended to the bottom portion 92B side and immersed in the oil liquid 32. There is. Further, the detection rod 96 has a reed switch 9 which is operated by magnetic force above the liquid surface of the oil liquid 32.
7 is provided, and the lead wire 97 of the reed switch 97 is provided.
A and 97A are led out from the lid portion 92A to the outside of the closed container 92. The float 53 and the annular magnet 54 described in the first embodiment are provided on the outer peripheral side of the detection rod 51.
Are slidably provided, float on the liquid surface of the oil liquid 32, and move above and below the liquid surface on the detection rod 96.

The present embodiment has the above-described structure. When the seal member 24 is damaged, the inside of the casing 1 is normally communicated with the outside air via the breathing plug 34, so that the atmospheric pressure is maintained. Although the pressure receiving chamber 94 is connected,
0, since the back surface 8B of the orbiting scroll 7 continues to slide on the thrust receiving portion 3B, the seal chamber 27 communicating with the detection passage 29 communicates with the chamber A in the casing 1 through the throttle. Then, a negative pressure is applied to the inside of the casing 1.

Then, when the oil liquid 32 in the casing 1 flows into the closed container 92 and the liquid level rises, the float 53
Rises with the liquid level in the pressure receiving chamber 94, and when the liquid level rises to a predetermined liquid level near the reed switch 97, the magnetic force of the annular magnet 54 in the float 53 activates the reed switch 97. Each lead wire 9
An alarm can be issued by the control device connected to 7A and the operation of the compressor can be stopped.

Therefore, according to the present embodiment configured as described above, substantially the same operational effects as those of the above-described embodiments can be obtained, but particularly according to the present embodiment, only the pressure receiving chamber 94 is provided in the closed container 92. Therefore, the closed container 92 can be formed in a small size.

In each of the above embodiments, the detection passage 29 communicating with the inside of the seal chamber 27 is described as being formed in the front casing 3 of the casing 1. However, the present invention is not limited to this, and for example, the front casing 3 may be provided. A ventilation pipe or the like is provided so as to radially penetrate from the tubular portion 18 of the fixed scroll 15 that abuts the abutting portion 3A toward the outer support portion 23, and the tip end side of the aeration pipe communicates with the seal chamber 27. You may comprise a detection path by. Further, in this case, it is preferable that the ventilation pipe is provided on the tubular portion 18 of the fixed scroll 15 or the like through a cushioning material such as felt.

On the other hand, in each of the above-mentioned embodiments, the scroll type air compressor has been described as an example of the scroll type fluid machine, but the present invention is not limited to this, and may be used for a scroll type vacuum pump, for example. .

Further, in the second, third and sixth embodiments, the float type liquid level sensor 50 (95) is
The reed switch 52 (97) and the float 53 and the like have been described as an example, but the present invention is not limited to this, and for example, a float type liquid level detector or the like provided in a fuel tank or the like is used. Alternatively, a differential inductance sensor or the like may be used. Alternatively, an optical liquid level sensor or the like may be used.

[0082]

As described above in detail, in the present invention, the seal provided between the casing or the fixed scroll and the orbiting scroll is provided in order to prevent the oil liquid contained in the casing from entering the suction passage side. A seal chamber is formed between the thrust receiving portion of the casing and the suction passage of the casing, and a detection passage communicating with the suction chamber is provided in the fixed scroll or the casing in a radial direction. Since the pressure in the detection passage is detected by the pressure detecting means, when the seal member is damaged and the suction passage communicates with the seal chamber and the pressure in the seal chamber becomes negative due to the suction pressure on the suction passage side. The negative pressure at this time can be detected by the pressure detection means, and the damage to the seal member can be determined early.

Here, the oil liquid contained in the casing has a relatively high viscosity, and even after the air in the seal chamber is sucked into the suction passage side to be in a negative pressure state, the oil liquid in the casing remains for a while. Is not sucked into each compression chamber,
Damage to the seal member can be detected before oil liquid is sucked into the compression chambers, and oil mist can be reliably prevented from being sucked into each compression chamber and discharged from the discharge port, improving reliability. Therefore, maintenance and inspection can be facilitated. If the pressure detecting means is provided outside the casing or the fixed scroll, it is possible to reliably prevent the pressure detecting means from being affected by vibration, temperature change, noise, etc.
The pressure fluctuation in the seal chamber can be accurately detected.

Further, the pressure detecting means is provided with a closed container containing the liquid, a pressure receiving chamber provided in the closed container and communicating with the detection passage on the liquid surface of the liquid contained in the closed container, and the outside air. A partition part that defines an atmospheric pressure chamber that communicates with, and a liquid circulation part that is provided below the partition part and that circulates the liquid in the closed container between the pressure receiving chamber side and the atmospheric pressure chamber side, Provided on the atmospheric pressure chamber side of the hermetically sealed container, and comprising a liquid level sensor for detecting whether or not the liquid level of the liquid in the atmospheric pressure chamber has changed to a predetermined liquid level, The pressure receiving chamber becomes the same pressure as the seal chamber, and when the pressure in the pressure receiving chamber decreases due to damage to the seal member, the liquid on the atmospheric pressure chamber side flows into the pressure receiving chamber side through the flow section, and This decrease in the liquid level is detected by the liquid level sensor as the liquid level decreases. It can be detected I can determine the damage to the seal member at an early stage.

Further, the detection passage is communicated with a pressure receiving chamber defined on the liquid surface in the closed container, and the oil liquid in the pressure receiving chamber flows from the casing to the pressure receiving chamber according to the pressure on the detection passage side. With such a connection, the atmospheric chamber can be omitted from the closed container, and the pressure detecting means can be downsized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a scroll type air compressor according to a first embodiment of the present invention.

FIG. 2 is a control block diagram showing a control device and the like.

FIG. 3 is a flowchart showing a control process of the electric motor.

FIG. 4 is a vertical cross-sectional view showing a scroll air compressor according to a second embodiment of the present invention.

5 is an enlarged vertical sectional view showing the pressure detection device in FIG.

FIG. 6 is an enlarged vertical sectional view showing a pressure detecting device according to a third embodiment of the present invention.

FIG. 7 is an enlarged vertical sectional view showing a pressure detecting device according to a fourth embodiment of the present invention.

FIG. 8 is an enlarged vertical sectional view showing a pressure detecting device according to a fifth embodiment of the present invention.

FIG. 9 is an enlarged vertical sectional view showing a pressure detecting device according to a sixth embodiment of the present invention.

[Explanation of symbols]

1 Casing 2C Bearing part 3B Thrust receiving part 4 Drive shaft 4A Crank 7 Orbiting scroll 8,16 End plate 9,17 Lap part 15 Fixed scroll 19 Compression chamber 20 Suction port 21 Discharge port 22 Suction passage 24 Seal member 27 Seal chamber 29 Detection passage 32, 63 Oil liquid (liquid) 35 Pressure sensor (pressure detection means) 41, 61, 71, 81, 91 Pressure detection device (pressure detection means) 42, 62, 92 Sealed container 43, 64 Partition plate (partition portion) 44 , 65,94 Pressure receiving chamber 45,66 Atmospheric pressure chamber 47,68 Circulating section 49,93 Communication pipe 50,95 Float type liquid level sensor (liquid level sensor) 72 Thermistor type liquid level sensor (liquid level sensor) 82 Ultrasonic Liquid Level Sensor (Liquid Level Sensor)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location F04C 27/00 331 6907-3H 29/00 J 6907-3H 29/02 321 A 6907-3H

Claims (3)

[Claims] 1. A cylindrical casing provided with a bearing portion on a base end side and a thrust receiving portion provided on a tip end side so as to extend in a direction substantially orthogonal to an axis line of the bearing portion, and a bearing portion of the casing. Rotatably provided, the distal end extending into the casing to form a crank, the proximal end protruding to the outside of the casing, and the rear side of the end plate slidably contacting the thrust receiving portion of the casing. An orbiting scroll provided to the crank of the drive shaft so as to be covered so as to be rotatable, and a spiral wrap portion standing on the front side of the end plate,
A fixed scroll fixed to the tip end side of the casing so as to sandwich the orbiting scroll with the thrust receiving portion of the casing, and a spiral scroll-shaped wrap portion that overlaps the wrap portion of the orbiting scroll on the end plate. A plurality of compression chambers which are respectively formed between the wrap portion of the fixed scroll and the wrap portion of the orbiting scroll and discharge the fluid from the discharge port while compressing the fluid sucked from the suction port, and the outer circumference of the wrap portion of the fixed scroll. Provided on the side,
An annular suction passage communicating between the suction port and the outermost peripheral compression chamber, and the casing or the fixed scroll and the casing for preventing the oil liquid contained in the casing from entering the suction passage side. A seal member that is provided between the orbiting scroll and a thrust receiving portion of the casing and that forms a seal chamber that is shut off from the suction passage, and is provided in the fixed scroll or the casing in a radial direction; A scroll-type fluid machine comprising a detection passage communicating with a seal chamber and a pressure detection unit connected to the detection passage for detecting a pressure in the detection passage. 2. The pressure detecting means includes: a closed container containing a liquid; a pressure receiving chamber provided in the closed container and communicating with the detection passage on a liquid surface of the liquid contained in the closed container. A partition part that defines an atmospheric pressure chamber that communicates with the outside air, and a liquid circulation part that is provided below the partition part and that circulates the liquid in the closed container between the pressure receiving chamber side and the atmospheric pressure chamber side. 2. A scroll type fluid machine according to claim 1, further comprising: a liquid level sensor provided in the closed container for detecting whether or not the liquid level of the liquid in the closed container has changed to a predetermined level. . 3. The pressure detecting means is defined by a closed container communicating with the inside of the casing and containing a part of the oil liquid in the casing, and a liquid level of the oil liquid in the closed container. A pressure receiving chamber communicating with the detection passage on the upper side of the closed container;
A liquid level sensor provided in the closed container in the pressure receiving chamber and configured to detect whether or not the liquid level of the liquid has changed to a predetermined level according to the pressure on the detection passage side. 1. The scroll type fluid machine according to 1.