DE3025359A1 - Reciprocating compressor for refrigerants - has guide shoe on crank pin proportioned to reduce friction and energy requirements - Google Patents

Abstract

A piston (2) reciprocates in a cylinder (1). The piston sits on the outside of a guide sleeve (3) which produces the reciprocation. A shoe (4) slides axially inside the sleeve and at right angles to the piston motion. It has a bore (8) into which the crank pin (9) of a crankshaft (10) fits. The pin enters through a slot (11) in the sleeve. The shoe has bearing surfaces (5,6) on the sleeve which are arcs of circles. The chord (7) of the upper surface is less than the dia. of the surface. The lower surface (6) has a smaller bearing surface. This reduces the work required to drive the compressor.

Description

"Motor Compressor"

The invention relates to a motor compressor according to the preamble of the first claim.

It is the same with motor compressors, especially in refrigeration units For cooling devices, it is generally known that the compressor piston is used vertically to be arranged on a sliding bush in which a sliding block is axially displaceable is. The sliding block has a bore into which the pin of a motor-driven Crankshaft engages. For the passage of the pin, the sliding bush has in its Mantle surface a corresponding opening extending in the axial direction on. The sliding bush has a cylindrical inner jacket surface in which the sliding block adapted in diameter slides.

The invention is based on the object of a according to the preamble of the first claim trained motor compressor measures by which the energy required to move the sliding block is reduced.

The solution to this problem takes place according to the invention by the characterizing Features of the first claim.

The design of the sliding block according to the invention is the Friction surface between the sliding bush and the sliding block on the parts of the outer surface of the sliding block, taking into account the permissible surface pressure required are. These surfaces are those facing the piston or faces facing away from the sliding block, while that in the axial direction of the bore lying surfaces of the sliding block through the originating from the piston, transversely to the bore axis the forces acting on the sliding block remain practically unloaded. This unencumbered According to the invention, surfaces are no longer in frictional contact with the sliding bush, so that the friction and the oil pumping required to lubricate the sliding block in this area is not applicable. In addition, there are fewer errors in the shape of the sliding block the weight and the access of oil to the sliding surfaces is made clear. Furthermore- the sliding block can be produced in a vortex sintering mold in which the mold dividing surfaces can be arranged outside the sliding surfaces, so that the expense of rework can be kept to a minimum.

Advantageous refinements of the invention are set out in the further claims specified.

The invention is explained below with reference to the drawings of exemplary embodiments explained in more detail.

1 shows a slider crank drive for a motor compressor with sliding block shown in cross section, Fig. 2 a sliding block with opposite the hole differently placed flats and Fig. 3 is a front view a sliding block with longitudinal grooves.

In a motor compressor, not shown in detail, there is a cylinder 1 provided, in which a piston 2 for the suction and compression of a gaseous Medium, in particular a refrigerant, is slidably mounted.

The piston 2 sits on the outer surface of a sliding bush 3, in which an axially displaceable sliding block 4 is slidably mounted. The sliding bush 3 has a ground inner jacket surface and encompasses the radius accordingly adapted, only part of the sliding block circumference encompassing sliding surfaces 5 or 6 of the sliding block 4. The sliding surface 5 faces the piston 2 while the sliding surface 6 is arranged on the side of the sliding block facing away from the piston 2 is. the The sliding surface 5 transmits the during the compression stroke occurring forces and must take into account the permissible surface pressure accordingly be sized large.

The opposite sliding surface 6, however, only takes over Much smaller forces occurring during the suction stroke and can therefore according to FIG 2 comprise a smaller circular arc section. Parallel to the dash-dotted line Lines 7 indicated chords of the circular arc sections occupied by the sliding surfaces 5, 6 runs in the sliding block 4 a bore 8, in which a pin 9 of a driven Crankshaft 10 engages. The pin 9 is by one in the axial direction of the sliding block 4 extending opening 11 of the sliding bush 3 passed through.

The sliding block 4 according to Figure 1 has two parallel to each other Flats 12 which are perpendicular to the axis of the bore 8. Through this are free spaces between the sliding block 4 and the sliding bush 3 formed, whereby a frictional engagement and an oil pump between these two parts of the circumference no longer occurs.

This reduces the drive energy required.

In order to compare the sliding surface 6, which is less heavily loaded during operation To reduce the sliding surface 5, the flats 12 can either be wedge-shaped be inclined or, according to FIG. 2, only inclined at the transition to the sliding surface 6 Have sections 13.

According to FIG. 3, the sliding block 4 can extend over its length Grooves 14 may be provided through which support sliding surfaces 15 formed will. These support sliding surfaces 15 prevent deformation under high loads the sliding bush 3. In addition, the outer surface of the sliding block 4 can outside the sliding surfaces 5, 6 also be curved with a smaller radius to a gap To reach sliding bush 3 out. Of course, in the wall of the Sliding bush 3 corresponding recesses may be provided in order to achieve a friction decoupling to reach between the sliding block and the sliding bush 3.

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Claims (8)

Claims S motor compressor with a slider crank drive, the has a sliding block that is slidably mounted in a cylindrical sliding bush, which is placed with a bore on a pin of a crankshaft, thereby characterized in that the sliding block (4) has at least two opposite sliding surfaces (5, 6), the radius of which is adapted to the inner radius of the sliding bush (3) and that the chord (7) of the circular arc section of a sliding surface (5, 6) is smaller than is twice the radius of the sliding surfaces (5, 6). 2. Motor compressor according to claim 1, characterized in that the Sliding block (4) has at least one flat (12) over its entire length Length is enough. 3. Motor compressor according to claim 2, characterized in that the The flat (12) is penetrated by the bore (8). 4. Motor compressor according to claim 2 or 3, characterized in that that the flat (12, 13) by at least two different from the axis of the Bore (8) inclined, abutting surfaces is formed. 5. Motor compressor according to claim 1 or one of the following, characterized characterized in that the chord (7) is at least approximately parallel to the axis of the bore (8) run. 6. Motor compressor according to claim 5, characterized in that on the outer circumferential surface of the sliding bush (4) a piston (2) is provided and that the chord (7) of the sliding surface (5) facing the piston (2) is longer than that of the facing away from the sliding surface (6). 7. Motor compressor according to and claim 1 or one of the following, thereby characterized in that the sliding block (4) has grooves extending over its entire length (14) is provided. 8. Motor compressor according to claim 1, 5 or 6, characterized in that that the outer surface of the sliding block (4) outside the sliding surfaces (5, 6) a has a smaller radius than the sliding surfaces (5, 6).