JPH06185479A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent deterioration of volumetric efficiency and performance by preventing deterioration of sealing performance when a driving frequency of an inverter becomes lower than a prescribed value. CONSTITUTION:In a scroll compressor which houses a scroll compression element 2 on the upper side in a closed container 1 and a motor-driven element 3 on the lower side and has an oil pump 21 and an inverter 25 to drive the motor-driven element 3, oil supply restricting means 23 and 24 and a driving frequency detecting means 28 of the inverter 25 are provided. When the fact that a driving frequency of the inverter 25 is lower than a prescribed value is detected by the driving frequency detecting means 28, oil is supplied to an air intake position of the scroll compression element 2 from the oil pump 21, and when the fact that the driving frequency of the inverter 25 becomes equal to or higher than the prescribed value is detected, oil supply is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an inverter driven scroll compressor.

[0002]

2. Description of the Related Art A conventional inverter-driven scroll compressor is constructed, for example, as disclosed in Japanese Patent Publication No. 4-68475. This will be described with reference to FIG. 3. An upper frame 111 and a lower frame 112 are respectively assembled inwardly and upwardly of the closed container 100, and a compression consisting of a fixed scroll 121 and a swing scroll 122 is attached to the upper frame 111. In addition to supporting the element 102, a motor (electrical element) 103 whose rotation speed is variable by frequency conversion is supported between the upper frame 111 and the lower frame 112. The motor 103 and the compression element 102 are interlockingly connected by a drive shaft 104 bearing-supported by each frame 111, 112, and the compression element 102 is rotated by the rotation of the drive shaft 104 when the motor 103 is driven.
The orbiting scroll 122 is orbitally driven with respect to the fixed scroll 121, and the refrigerant gas is compressed between the two scrolls 121 and 122. Further, at the lower end of the drive shaft 104, the bottom oil sump 101 of the closed container 100 is
The oil supply pump device 105 facing the above is assembled, and the oil supply pump device 105 is used to pump up to the oil supply passage 141 vertically penetrating the inside of the drive shaft 104.
The lubricating oil is supplied from 41 to the bearings of the drive shaft 104 and the frames 111 and 112, the bearings of the drive shaft 104 and the swing scroll 122, and other lubrication points. In addition, 130 converts the AC power supplied from the power source 131 into DC power, and the AC power is used by the motor 103.
Is an inverter for driving the. In the above configuration, the oil supply pump device 105 used for the compressor is used to
For example, a constant-capacity control is performed so that the oil supply amount is linearly increased or decreased in direct proportion to the rotation speed of the drive shaft 104 according to the frequency of the motor 103 driven by the motor 130.

[0003]

By the way, in the conventional scroll compressor driven by the inverter, when the drive frequency of the inverter becomes lower than a predetermined value, a fixed scroll forming a compression space of the scroll is formed. -The sliding property between the wrap of the scroll and the oscillating scroll and the end plate, and the sealing property of the lap contact area of both scrolls decrease the leakage of compressed gas, which reduces the volumetric efficiency and the freezing. There was a problem of reduced ability. This is because when the drive frequency of the inverter becomes low, the flow rate of the intake gas per unit time decreases and the flow velocity also decreases, so the oil contained in the gas separates and drip in the compressor internal space, and the scrolling occurs. This is because the amount of oil in the intake gas at the lulap intake position decreases and the oil supply required for the seal of the compression chamber is insufficient. Also,
When the drive frequency of the inverter becomes low, the sliding speed between the lap of the fixed scroll and the oscillating scroll forming the compression space of the scroll and the end plate, and the sliding speed of the lap contact area of both scrolls. Since it becomes difficult to form the oil film required for the seal, more oil is required for forming the oil film, which is also a problem. An object of the present invention is to provide a scroll compressor which solves the above-mentioned conventional problems (problems).

[0004]

In order to solve the above-mentioned problems, the present invention accommodates a scroll compression element on the upper side and an electric element on the lower side in an airtight container, and comprises an oil pump and the electric element. And a drive frequency detecting means for the inverter, and an oil supply limiting means, and the drive frequency of the inverter is set to a predetermined value by the drive frequency detecting means. If it is detected that the temperature is lower than the
The oil supply limiting means is operated so that the oil supply is stopped when the drive frequency of the inverter is detected to exceed a predetermined value. In this case, it is desirable that the oil supply limiting means is constituted by either or both of an electromagnetic valve and a capillary tube provided in the oil supply path from the oil pump to the scroll compression element. Further, it is desirable to limit the supply of oil by controlling the opening and closing of a solenoid valve provided in the oil supply path from the oil pump to the scroll compression element according to the detected value of the drive frequency of the inverter.

[0005]

According to the present invention, when the drive frequency of the inverter becomes lower than a predetermined value as described above, this is detected and the oil required for the seal of the compression chamber is scrolled from the oil pump. Since it is supplied to the intake position, the sealability of the compression chamber is improved, and the volume efficiency and performance are prevented from decreasing. On the other hand, when the driving frequency exceeds a predetermined value, this is detected and the oil supply is stopped. When the oil is supplied from the oil pump, the solenoid valve provided in the supply path is opened and closed in relation to the drive frequency of the inverter so that the supply time is always appropriate. Of the oil supplied to the capillary tube, the pressure of the supplied oil is controlled by the capillary tube.
It is decompressed to an appropriate value with a knob.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on an embodiment shown in FIGS. FIG. 1 is a system diagram including an overall structure sectional view of an inverter-driven scroll compressor to which the present invention is applied and a piping diagram used for control thereof.
2 is an enlarged sectional view of the scroll compressor shown in FIG. In each drawing, 1 is a closed container, and the container 1 accommodates a scroll compression element 2 on the upper side and an electric element 3 for driving the compression element 2 on the lower side. Has become. Reference numeral 5 denotes a frame, and a bearing portion 7 for supporting a drive shaft 6 is provided at the center of the frame 5. The scroll compression element 2 is composed of a fixed scroll 8 and an oscillating scroll 9. Fixed scroll 8
Is brought into pressure contact with the inner wall of the closed container 1 so that the high pressure chamber 10
Disk-shaped end plate 12 that divides the end plate into a low pressure chamber 11, an annular wall 13 protruding from the peripheral edge of one surface of the end plate 12, and an involute installed on the end plate surrounded by the annular wall 13. Or a spiral wrap 14 having a curved line approximate to this. End plate 1 of fixed scroll 8
2 is a discharge hole 15 communicating with the high pressure chamber 10 in the closed container 1.
Is provided. The fixed scroll 8 has the annular wall 13 and the wrap 14 protruding downward. The oscillating scroll 9 includes a disk-shaped mirror plate 16, a spiral wrap 17 formed on one surface of the mirror plate 16 and having an involute shape or a curve similar to this, and a mirror plate 16. It is configured with a boss portion 18 protruding in the center of the other surface. The oscillating scroll 9 faces the wrap 14 of the fixed scroll 8 and meshes with the protruding direction of the wrap 17 facing upward to form a plurality of compression chamber spaces 19 therein. Further, an oil pump 21 connected to the drive shaft 6 is provided below the electric element 3, and the oil pump 21 is disposed in the oil stored in the bottom container of the closed container 1 and is connected to the oil pump 21. The oil pressurized by is the oil supply passage of the drive shaft 6 (shown by the broken line in FIG. 1).
Oil is supplied to each sliding portion of the scroll compression element 2 through the oil supply pipe 22 that penetrates the bottom container of the closed container 1.
It is designed to be taken out by a. Reference numeral 23 is a solenoid valve, and 24 is a capillary tube. Oil supply pipe 22
a is a capillary via a solenoid valve 23 and an oil supply pipe 22b.
This capillary tube 2 is connected to the tube 24.
The other end of the oil supply pipe 22c connected to No. 4 penetrates the closed container 1 to face it, and is arranged at the intake position of the scroll compression element 2 so that oil can be supplied. 25 is an inverter, power source 2
The AC power from 6 is converted into DC power, converted into AC power of a frequency corresponding to the voltage of this DC power, and the supply line 27
To the input terminal of the electric element 3 to drive the drive shaft 6. A control device 28 detects the drive frequency of the inverter 25 and outputs an operation signal for opening and closing the solenoid valve 23 depending on whether the drive frequency value is less than a predetermined value or more than a predetermined value. . The predetermined frequency for performing this control is lower than the rated frequency of the inverter 25 in consideration of the structure of the scroll compressor, the capacity of the oil pump, etc., and is appropriate for performing the operation described below. It shall be preset to a predetermined value. As an example, in the case of an inverter having a rated frequency of 50 to 60 Hz (maximum frequency of 80 to 85 Hz), the set frequency for controlling the opening and closing of the solenoid valve may be set to a value of about 40 Hz. With the above configuration, when the electric element 3 is driven by the AC power supplied from the inverter 25, the oil pump 21 pressurizes the oil linearly increased and decreased in proportion to the rotation speed of the drive shaft 6. While being supplied to each sliding portion of the scroll compression element 2 by the oil supply passage of the drive shaft 6, the oil supply pipe 22 is provided.
a, solenoid valve 23, oil supply pipe 22b, capillary tube
The scroll compression element 2 through the valve 24 and the oil supply pipe 22c.
Is supplied to the intake position of the compression chamber space 19, and the required lubrication is performed for each lubrication point in the compression chamber space 19. When the drive frequency of the inverter 25 reaches the frequency of the rated operating state, the solenoid valve 23 is normally closed by the detection signal from the control device 25 after reaching the required refrigerant circulation amount and contained in the refrigerant. The oil that is supplied supplies oil to each part. For some reason, the inverter 2
When the driving frequency of the motor 5 decreases below a predetermined value, as described above, the sliding portion between the fixed scroll and the oscillating scroll forming the compression chamber space of the scroll and the end plate, and both scrolls. The sliding speed of the lap contact area of the lap is reduced, making it difficult to form the oil film necessary for the seal, and the sealability of the lap sliding part and the lap contact areas of both scrolls is reduced. Increased leakage reduces volumetric efficiency and reduces its performance. However, according to the present invention, the inverter 25
The drive frequency of the oil pump 2 is constantly monitored by the control device 28, and when it is detected that the drive frequency becomes less than a predetermined value, the solenoid valve 23 is immediately opened.
Since the pressurized oil supplied from No. 1 is reduced to an appropriate value by the capillary tube 24 and supplied to the intake position of the scroll compression element 2, the seal of the compression chamber space 19 is reduced. The required amount of lubricating oil is ensured, and deterioration of volume efficiency and performance are prevented. When the drive frequency of the inverter has recovered to a predetermined value or higher, the control device 24 detects this again and closes the solenoid valve 23 to close the scroll valve.
The supply of oil to the intake position of the compression element 2 is stopped.

[0007]

As described above, according to the present invention, in the inverter drive type scroll compressor, the control means for detecting the drive frequency of the inverter and outputting a predetermined control signal according to the value of the drive frequency is provided. Since the oil supply amount limiting means for limiting the supply amount supplied from the oil pump to the scroll is provided, and the oil supply amount limiting means is controlled by a signal from the control means, It has the following excellent effects. When the drive frequency of the inverter becomes less than a predetermined value, the oil required for the seal in the compression chamber space is automatically transferred from the oil pump to the intake position of the scroll by the control signal from the control means. , The sealability of the compression chamber space is always secured, and the volume efficiency and performance can be improved. Further, when a necessary amount of oil is supplied to the seal in the compression chamber space and the drive frequency of the inverter increases above a predetermined value, the oil supply limiting means is automatically closed by a signal from the control means. As a result, the supply of excess oil to the intake position of the compression element is stopped, so that lubricating oil is always supplied properly. The solenoid valve used as the oil supply limiting means is controlled to open and close quickly and accurately in relation to the drive frequency of the inverter, and the capillary tube also has an oil pump when the solenoid valve is open. It reduces the pressure of the pressurized lubricating oil supplied from the compressor to an appropriate pressure, and can be compactly arranged via a pipe between the oil pump and the compression element of the scroll compressor. Therefore, the practical advantage of applying the oil supply limiting means constituted by one or both of the solenoid valve and the capillary tube to the present invention is great.

[Brief description of drawings]

FIG. 1 is a system diagram including an overall structure sectional view of an inverter-driven scroll compressor showing an embodiment of the present invention.

2 is an enlarged cross-sectional view of the scroll compression element of FIG.

FIG. 3 is a sectional view of the entire structure of a conventional inverter-driven scroll compressor.

[Explanation of symbols]

 1: Closed container 2: Scroll compression element 3: Electric element 8: Fixed scroll 9: Swing scroll 12, 16: End plate 14, 17: Wrap 21: Oil pump 23: Solenoid valve 24: Capillary Tube 25: Inverter 28: Controller (driving frequency detecting means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location F04C 29/02 321 A 6907-3H (72) Inventor Michio Yasuka 2 chome, Keihanhondori, Moriguchi-shi, Osaka 18 Sanyo Electric Co., Ltd. (72) Inventor Kazuya Sato 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A fixed scroll in which a scroll compression element is housed in an upper side of a closed container and an electric element is housed in a lower side thereof, and the scroll compression element has a spiral wrap on a mirror plate. And an orbiting scroll in which a spiral wrap is erected on the end plate that faces and meshes with this fixed scroll,
The oscillating scroll is fixed to the fixed scroll so that the plurality of compression spaces formed by the oscillating scroll and the fixed scroll are gradually contracted from the outside to the inside. A drive means for rotating the drive means, an oil pump attached to the lower end of the drive means for supplying oil to the sliding portion, a joint for revolving the swing scroll with respect to the fixed scroll so as not to rotate. A scroll compressor provided with an inverter for driving the electric element, comprising drive frequency detecting means for the inverter and oil supply limiting means for limiting oil supply, and the drive frequency detecting means. When it is detected that the drive frequency of the inverter is lower than the predetermined value, the oil is supplied from the oil pump to the intake position of the scroll compression element, and the drive frequency of the inverter is set to the predetermined value. When it became the upper is detected it is characterized in that so as to actuate the oil supply limiting means to stop the supply of the oil scroll -
Le compressor. 2. The oil supply limiting means is constituted by either an electromagnetic valve or a capillary tube or both of them, which are provided in the oil supply path from the oil pump to the scroll compression element. The scroll compressor according to claim 1, further comprising: 3. The restriction of the oil supply is performed by controlling the opening and closing of a solenoid valve provided in an oil supply path from the oil pump to the scroll compression element according to the detected value of the drive frequency of the inverter. The scroll compressor according to claim 1.