Housing for a Motor or Compressor

Abstract

A housing for a motor or compressor has an elongate crankcase with two end surfaces. At least one cylinder chamber is provided in which a piston is caused to perform a movement by rotation of the crankshaft. The internal diameter of the crankcase narrows monotonously from the first end surface to the second end surface. A crankcase shaped in this way can be manufactured particularly easily by virtue of the casting being performed around a shaping mandrel. A shaping mandrel of this type must likewise narrow monotonously in order that, after the casting has been performed around it, the shaping mandrel can be pulled out of the housing at a first end. By way of the shaping of the crankcase, it is possible for the housing to be of unipartite and at the same time very compact construction.

Claims

1. A housing for a motor or compressor, comprising: an elongate crank chamber, which has two end surfaces, for accommodating a crankshaft; and at least one cylinder chamber for accommodating a piston which is caused to perform a reciprocating movement by a rotation of the crankshaft, wherein the crank chamber has, in a first end surface, an opening through which the crankshaft is insertable into said crank chamber, and an inner diameter of the crank chamber narrows monotonously from the first end surface to the second end surface.

2. The housing as claimed in claim 1, wherein the crank chamber tapers in the shape of a cone or frustum from the first end surface to the second end surface.

3. The housing as claimed in claim 2, wherein a shell of the cone or frustum is inclined with respect to its axis of symmetry by an angle of between 0.5 and 10 degrees.

4. The housing as claimed in claim 1, wherein the said housing is cast in one piece.

5. The housing as claimed in claim 2, wherein the said housing is cast in one piece.

6. The housing as claimed in claim 1, wherein the said housing is composed at least partially of aluminum, magnesium, titanium or an aluminum, magnesium or titanium alloy.

7. The housing as claimed in claim 5, wherein the said housing is composed at least partially of aluminum, magnesium, titanium or an aluminum, magnesium or titanium alloy.

8. A motor or compressor, comprising: a crankshaft; a housing for the motor or compressor, the housing including an elongate crank chamber that accomodates the crankshaft wherein an inner diameter of the crank chamber narrows monotonously from the first end surface to a second end surface; one connecting rod per cylinder chamber, which connecting rod is rotatably mounted by a first connecting-rod eye on the crankshaft and by a second connecting-rod eye on a piston which runs in a cylinder chamber, wherein in comparing the two connecting rods mounted along an axis of the crankshaft, an outer diameter of the connecting rod in a region of the first connecting-rod eye and/or an inner diameter of the first connecting-rod eye also narrows with the inner diameter of the crank chamber that narrows monotonously from the first end surface to the second end surface.

9. The motor or compressor as claimed in claim 8, wherein the pistons have identical diameters and/or identical stroke travels.

10. The motor or compressor as claimed in claim 8, wherein a flange is arranged on the first end surface of the crank chamber.

11. The motor or compressor as claimed in claim 10, wherein the crankshaft is led through the flange for connection to an output or drive.

12. The motor or compressor as claimed in claim 10, wherein the flange is designed to: fasten the motor or compressor in an engine bay of a vehicle, and/or fasten a further assembly, which is driven by the crankshaft, to the motor or compressor.

13. A method for producing a housing, the method comprising the acts of: manufacturing an elongated crank chamber having two end surfaces, the crank chamber being configured to accommodate a crankshaft, wherein the first end surface of a crank chamber has an opening to which the crankshaft is insertable and wherein an inner diameter of the crank chamber narrows monotonously from the first end surface to the second end surface; wherein the manufacturing of the crank chamber is carried out by casting housing material around an elongate shaping madrel having two ends, an outer diameter of the elongate shaping mandrel narrowing monotously from a first end to the second end.

14. The method as claimed in claim 13, further comprising the act of: pulling the shaping mandrel at its first end out of the housing after the casting act is carried out.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 shows a crankcase manufactured in two parts according to the prior art.

[0029] FIG. 2 shows a crankcase manufactured in two parts according to the prior art, with an additional flange for the connection to the drive source.

[0030] FIG. 3 shows the manufacture of a housing according to an embodiment of the invention.

[0031] FIG. 4 shows a comparison of two connecting rods which, in one refinement of the invention, are used in a housing with two cylinders.

[0032] FIG. 5 shows an exterior view of a housing according to an embodiment of the invention with an additional flange for the connection to the drive or output.

DETAILED DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows a compressor housing manufactured in two parts according to the prior art. The compressor housing is composed of the housing parts 11 and 12. It is disadvantageous that, at its end 13 through which the crankshaft is inserted, a T-shaped seal is required in the connection to the drive source. This seal is susceptible to leakage.

[0034] FIG. 2 shows a further compressor housing according to the prior art. The housing is also manufactured in two parts 21 and 22. For the connection to the drive source, an additional flange 23 is provided. By means of said flange, the sealing of the two housing parts 21 and 22 with respect to one another is decoupled from the sealing with respect to the connection to the drive source. In this way, the risk of leakage is reduced. Cumbersome assembly is disadvantageously still necessary, and the bolts and nuts required for this purpose are often difficult for a user to access owing to the constricted space conditions.

[0035] FIG. 3 shows the manufacture of a housing 3 according to an embodiment of the invention. The housing has a crank chamber 31 and a first cylinder chamber 32a and a second cylinder chamber 32b. The crank chamber has two ends 31a and 31b. At its end 31a, the crank chamber has an opening 33 through which the crankshaft can be inserted into the crank chamber 31. In the state illustrated in FIG. 3, the shaping mandrel 34 with the ends 34a and 34b is situated in the opening and in a part of the crank chamber. The shaping mandrel narrows from its end 34a to its second end 34b. In the position illustrated in FIG. 3, the shaping mandrel has already been partially pulled out of the housing 3 after the cast material has cooled.

[0036] FIG. 4 shows the comparison of two connecting rods which are used in the exemplary embodiment of the compressor housing illustrated in FIG. 3. The first connecting rod 41a and the movement space 45a that it requires in the crank chamber are shown to the left of the line A. The second connecting rod 41b and the movement space 45b that it requires in the crank chamber are shown to the right of the line A. The second connecting rod 41b is used in the cylinder chamber 32b which is further removed from the opening 33 than the first cylinder chamber 32a. The first connecting rod 41a is used in the cylinder chamber 32a. Here, the available movement space is greater.

[0037] The first connecting rod 41a has a first connecting-rod eye 42a and a second connecting-rod eye 43a. By means of the first connecting-rod eye 42a, the first connecting rod is rotatably mounted on the crankshaft, specifically in an axis of rotation which is offset with respect to the axis of rotation of the crankshaft. Thus, the first connecting rod is caused to perform an upward and downward movement by a rotation of the crankshaft. The movement is converted into an upward and downward movement of the piston, by means of the second connecting-rod eye 43a, which is mounted so as to be rotatable relative to the piston. The region surrounded by the first connecting-rod eye 42a is denoted by the designation 44a. Its maximum radius of action during a movement around the crankshaft defines the movement space 45a that the first connecting rod requires in the crank chamber.

[0038] Analogously, the second connecting rod 41b has a first connecting-rod eye 42b by means of which said second connecting rod is mounted on the crankshaft. By means of its second connecting-rod eye 43b, the second connecting rod is mounted on the second piston. The connecting-rod eye 42b is surrounded by a region 44b, the maximum radius of action of which defines the total movement space 45b that the connecting rod requires within the crank chamber 31. The movement space 45b of the second connecting rod 41b is smaller than the movement space 45a of the connecting rod 41a. This allows for the fact that the inner diameter of the crank chamber 31 has narrowed at the location of the cylinder chamber 32b in relation to the location of the cylinder chamber 32a.

[0039] FIG. 5 shows an external view of the finished housing 5. A flange 52 has been mounted onto the opening 51 into which the crankshaft can be inserted. If the housing 5 is used in a compressor, the drive is connected to the flange 52. By contrast, if the housing 5 is used in a motor, the output is connected to the flange 52. The cylinder chambers 53a and 53b are situated only partially within the housing 5. The cylinder chambers end at a base plate 54 with fastening devices 55. The cylinder head is subsequently mounted on the base plate 54. The pistons run not directly on the aluminum of the cylinder chambers 53a and 53b but on pressed-in cylinder barrels which can be exchanged when they have become worn.

[0040] The housing can be manufactured by high-pressure casting methods or else using other aluminum casting methods, such as for example sand casting or mold casting. The housing also need not be manufactured from aluminum, but may for example also be manufactured from cast iron.

LIST OF REFERENCE DESIGNATIONS

[0041] 11, 12 Housing parts [0042] 21, 22 Housing parts [0043] 3 Housing [0044] 31 Crank chamber [0045] 31a, 31b Ends of the crank chamber 31 [0046] 32a, 32b Cylinder chambers [0047] 33 Opening at the end 31a of the crank chamber 31 [0048] 34 Shaping mandrel [0049] 34a, 34b Ends of the shaping mandrel 34 [0050] 41a, 41b Connecting rods [0051] 42a, 42b First connecting-rod eye of the connecting rods 41a and 41b [0052] 43a, 43b Second connecting-rod eye of the connecting rods 41a and 41b [0053] 44a, 44b Region encompassing the first connecting-rod eye 42a and 42b [0054] 45a, 45b Movement spaces of the connecting rods 41a and 41b in the crank chamber 31 [0055] 5 Housing [0056] 51 Opening of the housing 5 [0057] 52 Flange [0058] 53a, 53b Cylinder chambers [0059] 54 Base plate [0060] 55 Fastening devices

[0061] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.