FreshPatents.com Logo
stats FreshPatents Stats
n/a views for this patent on FreshPatents.com
Updated: October 13 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

Follow us on Twitter
twitter icon@FreshPatents

Fluid machine

last patentdownload pdfdownload imgimage previewnext patent


20120301330 patent thumbnailZoom

Fluid machine


A fluid machine includes a lubrication mechanism (70, 72) configured to utilize a rotary shaft (14) to supply lubricating oil stored in an inside bottom (2a) of a hermetic container (2) to an upper region in the hermetic container, a frame (36) secured to the hermetic container and disposed in contact with an upper surface (16a) of a cylinder block (16) to support a driven unit (6), the frame having an upper surface (38a) onto which the lubricating oil supplied to the upper region in the hermetic container flows down, a connecting rod (20) arranged under the frame and coupling the rotary shaft to a piston (18), a piston pin (66) coupling the connecting rod to the piston, a first oil feed hole (78) formed through the frame and the cylinder block, and a second oil feed hole (80) formed through the frame.
Related Terms: Fluid Machine

Inventor: Teruo Higuchi
USPTO Applicaton #: #20120301330 - Class: 417313 (USPTO) - 11/29/12 - Class 417 
Pumps > Combined

view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20120301330, Fluid machine.

last patentpdficondownload pdfimage previewnext patent

TECHNICAL FIELD

The present invention relates to fluid machines, and more particularly, to a fluid machine suitable for use as a hermetic type reciprocating compressor for compressing a carbon dioxide refrigerant.

BACKGROUND ART

As a fluid machine of this type, a hermetic type compressor has been known which is provided with a hermetic container storing lubricating oil in an inside bottom thereof, an electric motor arranged inside the hermetic container, a compression mechanism arranged inside the hermetic container and including a piston driven by the electric motor through a rotary shaft and a cylinder block having a cylinder bore formed therein, the piston being reciprocated within the cylinder bore to draw in and discharge a working fluid, and a lubrication mechanism configured to utilize centrifugal force produced by rotation of the rotary shaft, to supply the lubricating oil stored in the inside bottom of the hermetic container to an upper region in the hermetic container.

Patent Document 1 discloses a hermetic type compressor in which an oil feed hole is formed in the cylinder block to connect the cylinder bore to the outside of the cylinder bore, and an annular groove is formed in the outer peripheral surface of the piston. When the piston is at its bottom dead center, the oil feed hole communicates with the annular groove, and when the piston is at it top dead center, the oil feed hole communicates with the cylinder bore.

PRIOR ART LITERATURE Patent Document

Patent Document 1: Japanese Laid-open Patent Publication No. 2009-197684

SUMMARY

OF THE INVENTION Problems to be Solved by the Invention

The above conventional technique permits the lubricating oil to be effectively supplied to the piston or cylinder bore and also enables lubrication of the gap between the piston and the cylinder block. No special consideration is, however, given to localized lubrication of a connecting rod coupling the rotary shaft to the piston and of a piston pin coupling the connecting rod to the piston. Thus, there still is a demand for improvement in the lubrication performance and reliability of fluid machines.

The present invention was created in view of the above circumstances, and an object thereof is to provide a fluid machine improved in lubrication performance and reliability.

Means for Solving the Problems

To achieve the object, the present invention provides a fluid machine comprising: a hermetic container storing lubricating oil in an inside bottom thereof; a driving unit arranged inside the hermetic container; a driven unit arranged inside the hermetic container and including a piston driven by the driving unit through a rotary shaft and a cylinder block having a cylinder bore formed therein, the piston being reciprocated within the cylinder bore to draw in and discharge a working fluid; a lubrication mechanism configured to utilize the rotary shaft to supply the lubricating oil stored in the inside bottom to an upper region in the hermetic container; a frame secured to the hermetic container and disposed in contact with an upper surface of the cylinder block to support the driven unit, the frame having an upper surface onto which the lubricating oil supplied to the upper region in the hermetic container flows down; a connecting rod arranged under the frame and coupling the rotary shaft to the piston; a piston pin coupling the connecting rod to the piston; a first oil feed hole formed through the frame and the cylinder block; and a second oil feed hole formed through the frame (claim 1).

When the piston is at a bottom dead center thereof, the first oil feed hole is located immediately above the piston pin and the second oil feed hole is located immediately above the connecting rod (claim 2).

When the piston is at a top dead center thereof, the first and second oil feed holes are located immediately above the connecting rod (claim 3).

The frame has oil reservoir sections formed by spot-facing respective openings of the first and second oil feed holes (claim 4).

The connecting rod has an oil groove formed in an upper surface thereof and extending from a location near the rotary shaft to a vicinity of the piston pin (claim 5).

Pressure of the working fluid drawn into and discharged from the driven unit prevails in an interior of the hermetic container, and the working fluid is a carbon dioxide refrigerant (claim 6). Advantageous Effects of the Invention

The fluid machine according to claim 1 is provided with the first and second oil feed holes, and the first and second oil feed holes allow the lubricating oil to reliably drop onto the piston, the piston pin and the connecting rod, which are arranged under the frame. This is because the frame is secured to the hermetic container and the lubricating oil that flows from the upper region in the hermetic container down to the upper surface of the frame is not acted upon by the centrifugal force produced by the rotation of the rotary shaft. Accordingly, the lubricating oil can effectively lubricate the driven unit without being influenced by the centrifugal force, whereby the lubrication performance and reliability of the fluid machine can be improved.

According to the invention of claim 2, when the piston is at the bottom dead center, the first oil feed hole is located immediately above the piston pin, and the second oil feed hole is located immediately above the connecting rod. Accordingly, when the piston is at the bottom dead center and thus the pressure of the working fluid in the cylinder bore is low, the lubricating oil can be made to drop from the first and second oil feed holes directly onto the piston pin and the connecting rod, respectively, without being influenced by the pressure of the working fluid slightly leaking from the cylinder bore. The driven unit can therefore be lubricated more effectively, making it possible to further improve the lubrication performance of the fluid machine.

According to the invention of claim 3, when the piston is at the top dead center, the first and second oil feed holes are located right above the connecting rod.

Thus, also when the piston is at the top dead center and thus the working fluid pressure in the cylinder bore is high, the lubricating oil can be made to drop from the first and second oil feed holes directly at least onto the connecting rod. The driven unit can therefore be lubricated more effectively, making it possible to further improve the lubrication performance of the fluid machine.

According to the invention of claim 4, the frame has the oil reservoir sections for temporarily storing the lubricating oil that flows from the upper region in the hermetic container down to the upper surface of the frame. It is therefore possible to cause the lubricating oil to intermittently drip little by little, and since the driven unit can be lubricated more effectively, the lubrication performance of the fluid machine can be further improved.

According to the invention of claim 5, the connecting rod has the oil groove formed in the upper surface thereof, and the oil groove permits the lubricating oil dropped from the first and second oil feed holes onto the connecting rod to be guided to those portions at which the connecting rod is coupled to the rotary shaft and the piston pin. Thus, since the driven unit can be lubricated more effectively, the lubrication performance of the fluid machine can be further improved.

According to the invention of claim 6, the working fluid is a carbon dioxide refrigerant. Where a carbon dioxide refrigerant is used as the working fluid, the pressure of the working fluid discharged from the cylinder bore is high, so that the pressure of the working fluid leaking from the cylinder bore and prevailing in the interior of the hermetic container may possibly become high. Consequently, the lubricating oil dropping, in particular, from the first oil feed hole directly onto the piston pin is greatly influenced by the pressure of the working fluid. With the aforementioned configuration, however, the driven unit can be effectively lubricated without the influence of the pressure of the working fluid, whereby the lubrication performance of the fluid machine can advantageously be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a compressor according to a first embodiment.

FIG. 2 is an enlarged view of a principal part of a compression mechanism shown in FIG. 1.

FIG. 3 illustrates lubrication channels in the compressor of FIG. 1.

FIG. 4 is an enlarged view of the principal part of the compression mechanism, illustrating lubrication channels formed when a piston shown in FIG. 1 is at its bottom dead center.

FIG. 5 is an enlarged view of the principal part of the compression mechanism, illustrating lubrication channels formed when the piston in FIG. 1 is at its top dead center.

MODE OF CARRYING OUT THE INVENTION

FIGS. 1 through 5 illustrate a compressor 1 as a fluid machine according to a first embodiment.

The compressor 1 is a hermetic type reciprocating compressor, which is more particularly classified as displacement type compressor referred to as reciprocating compressor or piston compressor, and is used as a device constituting a refrigeration cycle, not shown, incorporated in an automatic vending machine, for example.

The refrigeration cycle has a path through which a refrigerant as a working fluid for the compressor 1 is circulated. For the refrigerant, carbon dioxide, which is a non-flammable natural refrigerant, is used, for example.

As illustrated in FIG. 1, the compressor 1 is provided with a hermetic container 2. The hermetic container 2 contains an electric motor (driving unit) 4 and a compression mechanism (driven unit) 6 to which driving force of the electric motor 4 is transmitted.

The hermetic container 2 has a shell structure constituted by a top shell 2A covering the electric motor 4 and a bottom shell 2B joined to the top shell 2A by welding and surrounding the compression mechanism 6. The electric motor 4 is housed with its longitudinal axis directed in a depth direction of the top shell 2A. The top shell 2A has a depth greater than that of the bottom shell 2B. The compression mechanism 6, on the other hand, is housed with its longitudinal axis directed in a radial direction of the bottom shell 2B. The bottom shell 2B has a smaller depth than the top shell 2A.

The electric motor 4 includes a stator 8 configured to generate a magnetic field when supplied with electric power, and a rotor 10 configured to rotate by the magnetic field generated by the stator 8. The rotor 10 is arranged inside the stator 8 coaxially therewith and is secured by shrink fitting to a main shaft section 24 of a crankshaft (rotary shaft) 14, described later. The stator 8 is supplied with electric power from outside of the compressor 1 through electric equipment 12 fixed to the hermetic container 2, and leads, not shown.

The compression mechanism 6 includes the crankshaft 14, a cylinder block 16, a piston 18, and a connecting rod 20. The crankshaft 14 has an eccentric shaft section 22 and the main shaft section 24 and is positioned perpendicularly to the connecting rod 20.

As illustrated in FIG. 2, a cylinder bore 26 is formed through the cylinder block 16. A cylinder gasket 28, a suction valve 50, described later, a valve plate 30, a head gasket 32 and a cylinder head 34 are urgingly fixed, in the mentioned order from the cylinder block side, to the cylinder block 16 by bolts, so as to close an outer open end of the cylinder bore 26.

The stator 8 shown in FIG. 1 is fixed by bolts to the cylinder block 16 with a frame 36 therebetween, and the frame 36 is secured to the hermetic container 2. The frame 36 is disposed in contact with an upper surface 16a of the cylinder block 16.

Specifically, the electric motor 4 and the compression mechanism 6 are supported by a seating section 38 forming a lower part of the frame 36, and the frame 36 is secured at the seating section 38 to the hermetic container 2. At a cylindrical section 40 forming an upper part of the frame 36, on the other hand, a bearing 42 for the main shaft section 24 is arranged on an inner peripheral surface 40a of the cylindrical section 40, and a bearing 44 for receiving thrust load of the rotor 10, such as a thrust race (bearing) or thrust washer, is arranged on an upper end face 40b of the cylindrical section 40.

As illustrated in FIG. 2, the valve plate 30 has a suction hole 46 and a discharge hole 48 for letting the refrigerant in and out, respectively. The suction and discharge holes 46 and 48 are respectively opened and closed by the suction and discharge valves 50 and 52, each constituted by a reed valve.

The cylinder head 34 has a suction chamber 54 and a discharge chamber 56, both for the refrigerant. When the discharge valve 52 is open during compression stroke of the piston 18, the discharge chamber 56 communicates with the cylinder bore 26 through the discharge hole 48. On the other hand, when the suction valve 50 is open during suction stroke of the piston 18, the suction chamber 54 communicates with the cylinder bore 26 through the suction hole 46.

A suction pipe 58 and a discharge pipe 60 are fixed to the hermetic container 2 and have one ends connected to the suction and discharge chambers 54 and 56, respectively, of the cylinder head 34. The suction and discharge pipes 58 and 60 have respective other ends connected to the refrigeration cycle via a suction muffler and a discharge muffler, respectively, neither of which is shown. The mufflers serve to reduce pulsation and noise of the refrigerant flowing between the compressor 1 and the refrigeration cycle.

The connecting rod 20 has one end formed as a large end portion 62 to which the eccentric shaft section 22 of the crankshaft 14 is rotatably coupled, and has the other end formed as a small end portion 64 to which the piston 18 is coupled so as to be capable of reciprocating motion. The small end portion 64 is coupled to the piston 18 by a piston pin 66, and a fixing pin 68 prevents the piston pin 66 from coming off the piston 18.

With the individual parts configured in this manner, as the crankshaft 14 rotates, the connecting rod 20 makes a rocking motion on the piston pin 66 as a fulcrum, in conjunction with eccentric rotation of the eccentric shaft section 22, and the piston 18 makes a reciprocating motion within the cylinder bore 26 in conjunction with the rocking motion of the connecting rod 20.

Discharge pressure of the refrigerant mainly prevails in the interior of the hermetic container 2. A small amount of lubricating oil for lubricating individual sliding parts of the electric motor 4 and compression mechanism 6, such as the bearings 42 and 44, is stored in an inside bottom 2a of the hermetic container 2.

An oil passage (lubrication mechanism) 70 is formed in the crankshaft 14 so as to extend from a nearly axial center of a lower end face 22a of the eccentric shaft section 22 up to an intermediate portion of the main shaft section 24. The oil passage 70 opens, at an upper section thereof, in an outer peripheral surface 24a of the main shaft section 24, and is connected, at a lower section thereof, with an oil pipe (lubrication mechanism) 72. The oil pipe 72 has an inclined portion 74 at a distal end portion thereof, and the inclined portion 74 is so inclined as to extend from nearly the axial center of the eccentric shaft section 22 toward the axis of the main shaft section 24. A distal end of the inclined portion 74 of the oil pipe 72 extends to an oil reservoir 76 formed in the inside bottom 2a of the hermetic container 2 and having a concave shape as viewed in section.

The oil reservoir 76 has a size and a depth such that a small amount, for example, about 200 cc, of lubricating oil can be stored with its oil level located above the distal end of the oil pipe 74. As the oil pipe 72 eccentrically rotates together with the eccentric shaft section 22 due to rotation of the crankshaft 14, centrifugal force acts upon the lubricating oil in the inclined portion 74 of the oil pipe 72 in an obliquely upward and outward direction, so that the lubricating oil is drawn from the oil reservoir 76 upward into the oil passage 74 by the centrifugal force.

Operation and function of the compressor 1 will be now described.



Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Fluid machine patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Fluid machine or other areas of interest.
###


Previous Patent Application:
Airflow assembly having improved acoustical performance
Next Patent Application:
Tidal responsive barrier
Industry Class:
Pumps
Thank you for viewing the Fluid machine patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.50991 seconds


Other interesting Freshpatents.com categories:
QUALCOMM , Monsanto , Yahoo , Corning ,

###

Data source: patent applications published in the public domain by the United States Patent and Trademark Office (USPTO). Information published here is for research/educational purposes only. FreshPatents is not affiliated with the USPTO, assignee companies, inventors, law firms or other assignees. Patent applications, documents and images may contain trademarks of the respective companies/authors. FreshPatents is not responsible for the accuracy, validity or otherwise contents of these public document patent application filings. When possible a complete PDF is provided, however, in some cases the presented document/images is an abstract or sampling of the full patent application for display purposes. FreshPatents.com Terms/Support
-g2-0.2189
     SHARE
  
           

FreshNews promo


stats Patent Info
Application #
US 20120301330 A1
Publish Date
11/29/2012
Document #
13576152
File Date
01/27/2011
USPTO Class
417313
Other USPTO Classes
International Class
04B53/18
Drawings
6


Fluid Machine


Follow us on Twitter
twitter icon@FreshPatents