| Linear compressor, particularly refrigerant compressor -> Monitor Keywords |
|
|
 
Linear compressor, particularly refrigerant compressorRelated Patent Categories: Pumps, Motor Driven, Electric Or Magnetic Motor, Reciprocating Rigid Pumping Member, Reciprocating Motor, Unitary Pump And Motor Working MemberLinear compressor, particularly refrigerant compressor description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070041853, Linear compressor, particularly refrigerant compressor. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] Applicant hereby claims foreign priority benefits under U.S.C. .sctn. 119 from German Patent Application No. 10 2005 038 784.5 filed on Aug. 17, 2005, the contents of which are incorporated by reference herein. This Application relates to German Patent Applications No. 10 2005 038 783.7 (Attorney Docket No. 6495-0168); No. 10 2005 038 785.3 (Attorney Docket No. 6495-0170); No. 10 2005 038 781.0 (Attorney Docket No. 6495-0172); No. 10 2005 038 780.2 (Attorney Docket No. 6495-0173), filed on the same date herewith. FIELD OF THE INVENTION [0002] The invention concerns a linear compressor, particularly a refrigerant compressor, with a first component group comprising a stator of a linear motor and a cylinder, a second component group comprising a reciprocating piston and an armature of the linear motor as well as a piston rod connecting the armature to the piston, an oil sump in a housing and an oil pump, the second component group being movable in relation to the first component group. BACKGROUND OF THE INVENTION [0003] With such a linear compressor, a corresponding electrical supply of the stator will make the armature reciprocate in the stator. The armature drives the piston in a likewise reciprocating movement. The stator is connected to the cylinder, so that the piston is moved in the cylinder, thus increasing and reducing a compression volume. [0004] During operation such a compressor must currently be supplied with oil. The oil has two tasks. Firstly, it lubricates parts, which move in relation to each other. Secondly, it helps sealing a gap between the piston and the cylinder, so that the compression behaviour of the compressor is improved. [0005] U.S. Pat. No. 6,089,352 shows a linear compressor as mentioned in the introduction. The oil pump is fixed on the stator. It has an oblong chamber, whose first end is connected to an oil sump and whose second end is connected to an oil reservoir surrounding the cylinder. During operation, the stator oscillates with the frequency, with which the piston moves in the cylinder. Through inertia forces, which act upon the oil in the chamber during this oscillating movement of the stator, the oil is transported to the oil reservoir. However, it is necessary that the chamber is filled from the beginning. An unfilled chamber cannot work. [0006] U.S. Pat. No. 5,993,175 shows a further linear compressor, in which the oil pump is located in the stator. It has a pump chamber, in which is located a displacement element that is connected to the stator and the armature via springs. When the armature moves in relative to the stator, the displacement element starts oscillating and sucks oil via a suction pipe from the oil sump into the pump chamber. From here, the oil can reach the piston-cylinder-gap of the compressor via several openings. The displacement element displaces excessive oil from the pump chamber via an outlet opening. [0007] US 2004/0052658 A1 shows a further linear compressor, in which the stator is connected to an oil pump, which has a pump body that is immersed in the oil sump. The pump body has an opening, which extends perpendicularly to the movement direction of the armature. During operation, the stator oscillates as a reaction to the movement of the armature. Through the opening in the pump body oil from the oil sump can enter, while the other end of the pump body is connected via a pipe to an oil passage formed in the stator, the oil passage ending in the gap between the piston and the cylinder. In this connection, the cylinder is formed by the inside of the stator and the piston is located in the stator. [0008] Such oil pumps have a relatively low delivery rate. [0009] JP 2000 154 778 A2 shows a linear compressor with an oil pump. The oil pump has a pump chamber immersing in the oil sump, the pump chamber being formed as a cylinder, in which a piston moves. The piston is connected to the armature. During a stroke of the armature in one direction, the piston displaces oil from the pump chamber into an oil reservoir, which again supplies the gap between the piston and the cylinder and a piston rod bearing with oil. During a return stroke of the armature, the oil pump piston sucks in oil through another opening. The path back from the oil reservoir is blocked via a non-return valve. Such a pump supplies an increased amount of lubricant. However, it is relatively expensive to manufacture and requires a certain space inside the compressor housing. BRIEF SUMMARY OF THE INVENTION [0010] The invention is based on the task of providing a simple design to ensure lubrication for a linear compressor. [0011] With a linear compressor as mentioned in the introduction, this task is solved in that the oil pump has a pump housing that is permanently connected to the piston rod, the pump housing immersing with at least a suction opening into the oil sump, the oil pump supplying oil to the inside of the piston rod. [0012] The design of such an oil pump is relatively simple and only requires little space. As the pump housing is permanently connected to the piston rod, they reciprocate synchronously. The piston rod has the same stroke as the piston, so that also the pump housing with its suction opening will be moved through the oil sump via a corresponding stroke. Thus, a sufficient amount of oil will reach into the pump housing, the oil being supplied from here to the inside of the piston rod. The piston rod is then used as auxiliary means for transporting the oil to the area of piston and cylinder. [0013] It is preferred that the oil pump is located at the end of the piston rod facing away from the piston. This embodiment has several advantages. In a manner of speaking, the free end of the piston rod facing away from the piston projects from the stator, so that the pump housing is free to move. Design measures for preventing a collision between the pump housing and other parts of the linear compressor are not necessary. Secondly, the oil is transported through the linear motor, and is thus able to dissipate the heat occurring here. This will heat up the oil and reduce its viscosity, so that it gets highly liquid. This again reduces frictional losses between the piston and the cylinder. [0014] Preferably, the piston rod has a channel, which is connected to a piston joint. In order to equalise alignment errors, it may be favourable not to locate the piston rigidly on the piston rod, but via a joint, for example, a ball joint. In order to keep the friction small here in spite of possibly occurring small movements, the oil from the oil pump is supplied directly into this joint. [0015] Preferably, the piston rod is supplied with at least one pressure equalisation opening. The channel inside the piston rod will usually not be completely filled with oil. On the contrary, due to gravity the oil will only fill a partial area of the cross-section. Over the oil a gas volume then remains, which is connected to the inner chamber of the compressor housing via the pressure equalisation opening. Thus, the pressure equalisation opening permits a pressure equalisation, which is particularly advantageous, when leakage gas is pushed backwards from the compression chamber through the lubrication channels inside the piston. An involved pressure build-up could counteract the supply efficiency of the oil pump. This is reliably prevented by the pressure equalisation opening. [0016] Preferably, the piston rod has a connecting element to the piston, whose inner diameter tapers. Thus, a steadily supplied amount will increase the pressure, so that the oil can leave towards the piston at a certain pressure. [0017] It is also preferred that at least one inner diameter reduction is located inside the piston rod. This inner diameter reduction is then some kind of return flow prevention, the return flow prevention managing without movable parts. Nevertheless, within certain limits, it has the same effect as a non-return valve. [0018] This is further improved in that a recess is located adjacent to the inner diameter reduction. A movement of the piston rod in the direction of the cylinder will make the oil dam up in this recess, as basically the oil film is inert and will not on its own follow the movement of the piston rod. When the piston rod is moved in the opposite direction, the inertia of the oil transported through the inner diameter reduction and into the recess will cause it to remain in the position, to which it has been transported, so that subsequent movements of the piston rod over a short period will transport the oil from the pump housing to the position, in which it will evolve its effect. [0019] Preferably, the piston rod has a suction end, whose outer diameter reduces in a direction away from the piston. At least section-wise, the suction end can also have a slightly conical shape. This reduces the mass of the piston rod at this end. At the same time, fixing the piston rod on the side facing away from the piston will only require smaller surface. This is particularly advantageous, when this end is fixed in a resonance spring arrangement. [0020] It is preferred that the suction end has a suction channel, which ends inside the piston rod and has a smaller inner diameter than the piston rod, the end of the suction channel being surrounded by a projection pointing in the direction of the piston. This causes that a relatively large oil volume is permanently available inside the piston rod. At the same time, however, the cross-section in the suction area is kept small, so that smaller pressures are required to transport the oil from the oil sump to the level of the piston rod. Continue reading about Linear compressor, particularly refrigerant compressor... Full patent description for Linear compressor, particularly refrigerant compressor Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Linear compressor, particularly refrigerant compressor patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. 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 Linear compressor, particularly refrigerant compressor or other areas of interest. ### Previous Patent Application: Linear compressor, particularly refrigerant compressor Next Patent Application: Fan housing with strain relief Industry Class: Pumps ### FreshPatents.com Support Thank you for viewing the Linear compressor, particularly refrigerant compressor patent info. IP-related news and info Results in 0.35142 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
