JP2006266084A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric compressor capable of suppressing that the fine vibration and the operating sound of the compressor buried in an engine sound are transmitted, as discomfortable noise, to a driver and occupants through the frame of a vehicle body when only the compressor is operated by stopping an engine to temporarily stop a hybrid automobile according to a traffic signal. <P>SOLUTION: In this electric compressor, a communication passage 70 for directly feeding lubricating oil from the rear recessed part 18 of a swing scroll 12 to a key groove 35 of the swing scroll 12 in which an Oldham's ring 57 of a rotation prevention mechanism slides therein. Thus, since the lubricating oil is filled in the key groove 35, vibration from a rotation prevention mechanism can be suppressed by a cushioning effect obtained by the viscosity of the lubricating oil to reduce discomfortable noise. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric compressor in which a housing is provided with a compression mechanism portion that sucks, compresses and discharges refrigerant, and a motor that drives the compression mechanism portion.

  As this kind of electric compressor, various applications regarding similar compressors have been made and published by many manufacturers, and various compressors are actually used as compressors for home room air conditioners and refrigerators. It's being used. Recently, it has begun to be used as a compressor for automobile air conditioners.

  In recent years, hybrid vehicles that run using different engines and motors have been put into practical use and are rapidly spreading. In the case of a hybrid vehicle, from the original purpose of reducing the influence of the engine on the environment, when the vehicle is temporarily stopped by a signal or the like, the engine may be stopped and only the compressor may be operated frequently. In such a case, there has been a problem that even a minute vibration or operating sound of the compressor that has been buried in the engine sound is transmitted as an unpleasant sound to the driver or the occupant through the frame of the vehicle body.

As one of the measures to reduce the noise of the compressor for the purpose of mounting on the vehicle, there is a technology for absorbing the vibration and noise and reducing the noise by interposing an elastic member between the bearing portion and the support member. It is disclosed (for example, Patent Document 1).

FIG. 4 is a sectional view of a conventional electric compressor. When the main rolling bearing 3 is fitted to the main support member 45, a resin ring 48 is fitted on the outer periphery of the outer race 3a of the main rolling bearing 3 and press-fitted. The elastic force of the resin ring 48 acts between the outer race 3a and the main support member 45 to absorb vibrations and noises, and to improve driving stability and quietness.
JP-A-11-44296

  However, an unpleasant sound is an abnormal noise that occurs discontinuously rather than a continuous operating noise, and in particular, it has been observed that mechanical noise caused by torque fluctuations during one revolution of the compressor is extremely annoying. It became clear by experiment. These discontinuous sounds are caused by minute gaps between the components, and the force applied to the components fluctuates, so that they interfere with each other and generate abnormal noise. In particular, it was found that the striking sound caused by vibration generated between the multiple key parts of the Oldham ring that prevents the rotation of the movable scroll and the key groove on which these key parts slide is the main cause of abnormal noise. .

  Therefore, even if the technique disclosed in Patent Document 1 is applied, the operating sound level can be reduced, but these abnormal sounds cannot be improved.

  In view of the above-described conventional problems, an object of the present invention is to provide a structure that can reduce interference of an Oldham ring.

In order to achieve the above-described object, the most important characteristic point of the electric compressor according to the present invention is that the Oldham ring mechanism is such that the lubricating oil from the oil supply passage of the drive shaft is directly supplied to the key groove portion on which the Oldham ring slides. A passage is formed, and a communication passage is provided between the recess on the back of the movable scroll and the key groove on which the key part of the Oldham ring provided on the movable scroll slides, and lubricates the key groove from the recess on the back. Oil is supplied.

  By doing so, the key groove portion is filled with the lubricating oil, and a buffering effect due to the viscosity of the lubricating oil is generated, so that the vibration of the key can be reduced.

  According to the electric compressor of the present invention, it becomes possible to reduce vibration and noise associated with the sliding of the Oldham ring with a simple structure, and even when the engine is stopped, generation of minute unpleasant noise from the compressor can be suppressed. .

  A first aspect of the present invention is a compression mechanism having a fixed scroll and a movable scroll for sucking, compressing and discharging refrigerant, a drive shaft for turning the movable scroll with respect to the fixed scroll, and a rotating motion of the turning movable scroll. An anti-rotation mechanism for preventing rotation, a main bearing and a main bearing member that support the drive shaft, and the anti-rotation mechanism includes a key groove portion formed on the movable scroll and a key groove portion formed on the main bearing member. And an Oldham ring formed with a key portion that engages and slides with each of the key groove portions, and is formed on the movable scroll and a back recess of the movable scroll that engages with one end of the drive shaft. The electric compressor is characterized in that a communication passage is provided which communicates with the key groove portion and supplies lubricating oil from the rear concave portion to the key groove portion.

  As a result, the key groove is filled with lubricating oil, and a buffering effect due to the viscosity of the lubricating oil is generated, so that the vibration of the key can be reduced, and vibration and noise associated with the sliding of the Oldham ring can be reduced with a simple structure. It can be reduced, and even when the engine is stopped, the generation of minute unpleasant noise from the compressor can be suppressed.

  In the second invention, the key groove provided in the movable scroll is formed up to the outer peripheral end of the movable scroll, and the communication path can be processed directly from the outer peripheral end of the movable scroll, and a simple processing method is adopted. Can do.

  In the third invention, the communication path is formed by drilling linearly in the radial direction of the movable scroll from the key groove side, and can be formed by a simple method, so that the processing cost can be suppressed.

  In the fourth aspect of the invention, a throttle valve for adjusting the amount of oil supply is provided in the communication passage, so that it is possible to always supply a substantially constant amount of lubricating oil even if the operating conditions fluctuate, and the performance of the compressor is reduced. The noise reduction can be achieved without causing it to occur.

  In the fifth aspect of the present invention, the communication passage is internally threaded, the throttle valve is formed into a hollow cylindrical screw shape, and is fixed by screwing into the communication passage, so that it can be easily attached and the workability is improved.

  Embodiments of an electric compressor according to the present invention will be described below with reference to FIGS. The technical elements described below can be employed in various combinations as long as they do not contradict the purpose of the present invention.

  In the present embodiment, an example is shown in which the present invention is applied to a so-called horizontal motor built-in type compressor that is installed in a state in which the rotation center axis of an electric motor that drives a compression mechanism is substantially along the horizontal direction. A scroll type compression mechanism is employed as the compression mechanism.

(Embodiment 1)
FIG. 1 is a cross-sectional view of the electric compressor according to Embodiment 1 of the present invention. FIG. 2 is an exploded view of the Oldham ring mechanism of the electric compressor.

  In FIG. 1, a main bearing member 51 having a pump 13, a secondary bearing 41, a motor 5, and a main bearing 42 is disposed in the main casing 3 of the electric compressor 1 from the one end wall 3a side in the axial direction. is there. The pump 13 is accommodated from the outer surface of the end wall portion 3a and is held between the lid body 52 and the pump body 53 which is inserted into the lid body 52. 54 is connected to the liquid storage section 6 through 54. The auxiliary bearing 41 is supported by the end wall 3a and pivotally supports the side of the drive shaft 14 connected to the pump 13. The motor 5 includes a stator 5a fixed to the main body casing 3 by an annular member 17 and a rotor 5b fixed around the drive shaft 14 so that the drive shaft 14 can be driven to rotate. The main bearing member 51 is fitted to the opening end of the casing 3, and the fixed scroll 11 and the subcasing 102 are fixed with a bolt or the like (not shown), and the compression mechanism portion 4 side of the drive shaft 14 is pivotally supported by the main bearing 42. ing. Further, the movable scroll 12 is sandwiched between the main bearing member 51 and the fixed scroll 11 to form the compression mechanism unit 4 to constitute a scroll compressor.

  An Oldham ring 57 is provided between the main bearing member 51 and the movable scroll 12 to prevent the movable scroll 12 from rotating and circularly move, and the drive shaft 14 is connected to the movable scroll 12 via the eccentric bearing 43. Thus, the movable scroll 12 can be turned on a circular orbit.

  The compression mechanism section 4 is provided with a discharge hole 31 and a reed valve 31a, and is opened to a discharge chamber 62 formed between the sub casing 102 and the discharge mechanism 31. The discharge chamber 62 is formed in the fixed scroll 11 and the main bearing member 51, or the discharge port 9 between the compression mechanism portion 4 and the end wall 3a through a communication passage 63 formed between them and the main casing 3. It communicates with the motor 5 side space.

  The motor drive circuit unit 101 is configured by housing a circuit board 103 and an electrolytic capacitor (not shown) in the sub casing 102 on the opposite side of the suction chamber 61 and the discharge chamber 62 with an end wall 102a therebetween. An IPM (intelligent power module) 105 including a switching element with high heat generation is mounted on the circuit board 103, and the IPM 105 is in contact with the end wall 102a of the suction chamber 62 in order to be cooled by a low-temperature suction refrigerant. The motor drive circuit unit 101 is electrically connected to the motor 5, a sensor (not shown), and the like via the compressor terminal 106, and drives the motor 5 while monitoring necessary information such as temperature. The motor drive circuit unit 101 is provided with a harness connector (not shown) for electrical connection with the outside.

  As described above, the motor 5 is driven by the motor drive circuit unit 101, causes the compression mechanism unit 4 to move in a circular orbit via the drive shaft 14, and drives the pump 13.

  In the compression mechanism section 4, a fixed space 11 is formed by meshing the fixed scroll 11 and the movable scroll 12 whose blades rise from the movable end plate 11 a and the movable scroll 12, and the movable scroll 12 is driven by the motor 5 via the drive shaft 14. Thus, when the fixed scroll 11 is moved in a circular orbit, the volume of the compression space 10 is changed as the compression space 10 moves, whereby the refrigerant returning from the external cycle is sucked, compressed, and discharged to the external cycle. The refrigerant enters and exits the electric compressor 1 through the suction port 8 provided in the compression mechanism unit 4 and the discharge port 9 provided in the main body casing 3.

  At the same time, by driving the positive displacement pump 13 with the drive shaft 14, the lubricating oil stored in the liquid storage section 6 of the main body casing 3 is driven to turn the movable scroll 12 through the oil supply passage 15 of the drive shaft 14. Along with this, the liquid is supplied to the liquid reservoir 21 in the back recess 18 of the movable scroll 12. A part of the lubricating oil supplied to the liquid reservoir 21 is supplied to the back side space 26 on the outer peripheral portion of the movable scroll 12 through the movable scroll 12 to a predetermined restriction base such as a throttle 23 and back pressure is applied to the movable scroll 12. Give support. Another part of the lubricating oil supplied to the liquid reservoir 21 passes through the eccentric bearing 43, the liquid reservoir 22, and the main bearing 42 while being lubricated, and then flows out into the space on the motor 5 side to be stored in the liquid storage section 6. Is recovered.

  Next, the details of the rotation prevention mechanism according to the first embodiment of the present invention will be described with reference to FIG.

  The rotation prevention mechanism of the movable scroll 12 includes an Oldham ring 57, a main bearing member 51, and the orbiting scroll 12. The protrusion 32 formed on the main bearing member 51 side of the Oldham ring 57 and also formed on the orbiting scroll 12 side. The projected portions 33 are configured to slidably engage with a key groove 34 formed on the main bearing member 51 and a key groove 35 formed on the movable end plate 12a.

  The key portions 32 and 33 of the rotation prevention mechanism and the key grooves 34 and 35 are engaged with each other with a slidable minute clearance. Normally, the key groove 34 is caused by the rotation force of the movable scroll 12. , 35 with one surface of each of the key portions 32, 33 pressed in the radial direction.

  However, since the rotation force generated in the movable scroll 12 greatly fluctuates during one rotation due to the compressed gas force generated by the compression movement of the compressor, the centrifugal force of the movable scroll 12, and the like, the pressing force to the key grooves 34 and 35 is increased. As a result, the behavior of the movable scroll 12 becomes unstable, and the key portions 32 and 33 may vibrate in the key grooves 34 and 35 to generate noise.

  However, when the Oldham ring 57 slides in the back side space 26 of the movable scroll 12, the key portions 32 and 33 and the key grooves 34 and 35 are caused by a part of the lubricating oil supplied in the back side space 26. In the situation where a sufficient oil film is formed between them, the above noise may not occur. This is considered that the vibration is suppressed by the buffering effect of the oil film.

  Therefore, the inventor paid attention to this point and invented a structure in which the lubricating oil is stably supplied to the sliding portion of the Oldham ring 57 under any operating condition. Embodiment 1 of the present invention shown in FIG. Will be described based on a cross-sectional view of the movable scroll of the electric compressor.

  In FIG. 3, a communication path 70 that communicates the liquid reservoir 21 of the back recess 18 of the movable scroll 12 and the key groove 35 is provided, and a throttle valve 71 is provided in the middle of the communication path 70. The throttle valve 71 is fixed by machining the communication passage 70 with a female screw 70a, forming the throttle valve 71 into a hollow cylindrical screw shape and forming a male screw 71a around it.

  With this configuration, a part of the lubricating oil supplied through the oil supply passage 15 of the drive shaft 14 can be supplied directly from the liquid reservoir 21 to the key groove 35 of the movable scroll 12, and the sliding portion of the Oldham ring 57 is lubricated. Filled with oil, vibration can be suppressed by the buffer effect.

  Further, by providing the throttle valve 71 in the middle of the oil supply passage 70, it becomes possible to always supply a certain amount of lubricating oil even if the operating conditions fluctuate, and the above-mentioned purpose can be achieved without degrading the performance of the compressor. Can be achieved.

  Further, by forming the key groove 35 from the position of the communication path 70 to the outer peripheral end 12b of the orbiting scroll 12, the communication path 70 is drilled linearly in the radial direction of the movable end plate 12 from the outer peripheral end side of the key groove 35. Therefore, it can be formed easily, and the processing cost can be suppressed.

  Furthermore, by forming the communication passage 70 with the female screw 70a and forming the throttle valve 71 with a hollow cylindrical screw shape on the male screw 71a, it is possible to easily attach and improve workability.

  The electric compressor according to the present invention can reduce noise and noise during operation by suppressing component vibration of the compression mechanism, and is particularly useful for environmental vehicles such as hybrid vehicles. The present invention can be applied to a compressor that has a structure and particularly requires noise reduction.

Sectional drawing of the electric compressor in Embodiment 1 of this invention Exploded view of Oldham ring mechanism of the electric compressor Sectional view of the movable scroll of the electric compressor Cross section of a conventional electric compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric compressor 4 Compression mechanism part 5 Motor 11 Fixed scroll 12 Movable scroll 12b Outer peripheral end 14 Drive shaft 18 Back surface recessed part 32,33 Key part 34,35 Key groove part 42 Main bearing 51 Main bearing member 57 Oldham ring 70 Communication path 70a Female Screw 71 Throttle valve 71a Male thread

Claims (5)

A compression mechanism having a fixed scroll and a movable scroll for sucking, compressing and discharging refrigerant, a drive shaft for turning the movable scroll with respect to the fixed scroll, and a rotation prevention mechanism for preventing the rotation of the turning movable scroll And a main bearing that holds the drive shaft and a main bearing member, and the anti-rotation mechanism includes a key groove formed in the movable scroll, a key groove formed in the main bearing member, and a key groove formed in each key groove. An Oldham ring formed with a key portion that engages and slides, and a back recess of the movable scroll that engages with one end of the drive shaft communicates with a key groove formed on the movable scroll. An electric compressor characterized in that a communication passage for supplying lubricating oil from the back concave portion to the key groove portion is provided. The electric compressor according to claim 1, wherein a key groove provided in the movable scroll is formed up to an outer peripheral end of the movable scroll. The electric compressor according to claim 2, wherein the communication path is formed by drilling linearly in the radial direction of the movable scroll from the key groove side. The electric compressor as described in any one of Claims 1-3 which provided the throttle valve which adjusts the amount of oil supply in a communicating path. 5. The electric compressor according to claim 4, wherein the communication passage is internally threaded, and the throttle valve is formed in a hollow cylindrical screw shape and fixed by being screwed into the communication passage.