GB2173279A

GB2173279A - Crosshead slideway columns for reciprocating piston machines

Info

Publication number: GB2173279A
Application number: GB08605211A
Authority: GB
Inventors: Paul Resch
Original assignee: Sulzer AG; Gebrueder Sulzer AG
Current assignee: Sulzer AG
Priority date: 1985-04-01
Filing date: 1986-03-03
Publication date: 1986-10-08
Also published as: CN1004510B; JPH0379569B2; IT8619705A0; JPS61233213A; NO162636B; IT1188421B; DK106686D0; NO162636C; NO861246L; DK106686A; DK159575C; FR2579696A1; FR2579696B1; DE3512347C1; GB2173279B; IT8619705A1; DK159575B; CN86101282A

Abstract

The facing walls (4) of the columns of a crosshead piston machine which receive the normally directed crosshead journal forces are supported on a box section comprising side walls (6) and outer walls (3). In the vertical direction the side walls (6) incline outwards towards the free ends of the facing walls (4). The box section therefore widens in the zone of maximum normal- acting forces - i.e., near the top dead centre position of the piston - but no increase in engine length is necessary for this purpose. The widening of the box section reduces load-induced deformations of the facing walls (4), particularly at their ends. <IMAGE>

Description

SPECIFICATION Crosshead slideway columns for reciprocating piston machines This invention relates to columns supporting the crosshead slideways of reciprocating piston machines, the slideways transmitting forces normal to the slideways from the crossheads to the columns. In a known construction such a column has vertical facing walls having the slideways on their facing surfaces, side walls, and outer walls which are inclined to the vertical, the facing walls, side walls and outer walls extending the height of the column between a base plate and a top plate.

Conventionally, to receive the forces which act transversely and which must be transmitted to the columns in a direction perpendicular to the crosshead slideways of reciprocating piston machines, more particularly diesel engines, either horizontal transverse ribs are distributed over the height of the slideways or a vertical reinforcing wall extends, as viewed in horizontal section, at an acute angle between each of the vertical edges of the facing walls and the adjacent side wall (CH-PS 625 603). It is found in practice that the constructions just described are costly.

Also, reciprocating engines are required to be of very compact construction, a requirement calling for very short between-cylinder distances which, of course, are produced by the sum of the necessary main bearing length, the length of the bottom connecting rod bearing and the dimensions of the two crank webs. Consequently, if engine length is not to be "wasted", the side walls must be very close together at the bottom near the crankshaft.

It is therefore an object of the invention to simplify the overall support for the slideways without producing excessive deformations of the end walls or increasing engine length. According to the invention, therefore, the side walls act in pairs, each pair supporting a facing wall and the side walls of each pair upwardly diverging from one another in the upper region of the respective column.

Of course, the forces acting normally to the slideways and, therefore, to the facing walls are greatest near the upper dead centre of piston movement and the construction of the side walls according to the invention leads in this zone to a relatively wide box formed by the facing wall, the outer wall and the two side walls. Near the top dead centre position of the piston the side walls bear the facing walls near their outer edges so that deformations can be kept within narrow limits.

The invention may be carried into practice in various ways but one engine embodying the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a purely diagrammatic view in section on the line l-l of Fig. 2 of one column of a diesel engine; Figure 2 is a plan view in section on the line ll-ll of Fig. 1 of two adjacent columns of the engine with a crosshead between them; and Figure 3 is a section on the line Ill-Ill of Fig.

2.

The drawings show columns which broadly are similar to columns of known construction and are formed, for example, by welding steel plates together. Each column has bottom plates 2 which co-operate with inclined outer walls 3 and vertical facing walls 4 to form two frames which in elevation are trapezoidal.

The frames are interconnected by a common cover plate 5. Side walls 6 fill out the trapezoidal frames between the outer walls 3 and the facing walls 4. Tie rods 7 (Fig. 2) run vertically between the side walls 6 and retain the engine cylinder head (not shown) with prestressing.

A crankshaft 16 is mounted in the baseplate 1 by means of a bearing shell 14 which comprises a top half and a bottom half and over which a bearing cover 15 is placed.

As can be gathered from Fig. 3, the engine length m necessary for a cylinder mainly comprises on each side half the length h of a main bearing 14, the length S of the bottom bearing 18 for the connecting rod 20 and the thicknesses d of the two crank webs 17. As previously mentioned, the engine length necessary per cylinder is required to be as small as possible.

In the central part between the facing walls 4 a central wall 8 replaces the side walls 6 and is closed on its underside by a crossbearer 9. As can be gathered from Fig. 2, the facing fronts of the facing walls 4 of two uprights form slideways for the slide shoe 10 of a crosshead journal 11 which in the usual way is connected to a piston rod 12 and is mounted in its bearing housing 13.

The side walls 6 are spaced apart at the bottom by a small distance just sufficient for the tie rod 7 to pass through. The side walls 6 are inclined upwardly away from one another so as to engage the facing walls 4 near the outer edges thereof in the zone-r- oughly represented by the position of the crosshead in Figs. 1 and 3-associated with the top dead centre of piston movement. The walls 3, 4 and 6 therefore form a relatively wide and rigid "box" in the latter zone without causing any increase in engine length m.

Spacer walls 19 reinforce the "box" in the space between the side walls 6 in order to increase the rigidity of the relatively larger-area side wall in the region of heavy loading.

1. A reciprocating piston machine having crossheads sliding on crosshead slideways

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Crosshead slideway columns for reciprocating piston machines This invention relates to columns supporting the crosshead slideways of reciprocating piston machines, the slideways transmitting forces normal to the slideways from the crossheads to the columns. In a known construction such a column has vertical facing walls having the slideways on their facing surfaces, side walls, and outer walls which are inclined to the vertical, the facing walls, side walls and outer walls extending the height of the column between a base plate and a top plate. Conventionally, to receive the forces which act transversely and which must be transmitted to the columns in a direction perpendicular to the crosshead slideways of reciprocating piston machines, more particularly diesel engines, either horizontal transverse ribs are distributed over the height of the slideways or a vertical reinforcing wall extends, as viewed in horizontal section, at an acute angle between each of the vertical edges of the facing walls and the adjacent side wall (CH-PS 625 603). It is found in practice that the constructions just described are costly. Also, reciprocating engines are required to be of very compact construction, a requirement calling for very short between-cylinder distances which, of course, are produced by the sum of the necessary main bearing length, the length of the bottom connecting rod bearing and the dimensions of the two crank webs. Consequently, if engine length is not to be "wasted", the side walls must be very close together at the bottom near the crankshaft. It is therefore an object of the invention to simplify the overall support for the slideways without producing excessive deformations of the end walls or increasing engine length. According to the invention, therefore, the side walls act in pairs, each pair supporting a facing wall and the side walls of each pair upwardly diverging from one another in the upper region of the respective column. Of course, the forces acting normally to the slideways and, therefore, to the facing walls are greatest near the upper dead centre of piston movement and the construction of the side walls according to the invention leads in this zone to a relatively wide box formed by the facing wall, the outer wall and the two side walls. Near the top dead centre position of the piston the side walls bear the facing walls near their outer edges so that deformations can be kept within narrow limits. The invention may be carried into practice in various ways but one engine embodying the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a purely diagrammatic view in section on the line l-l of Fig. 2 of one column of a diesel engine; Figure 2 is a plan view in section on the line ll-ll of Fig. 1 of two adjacent columns of the engine with a crosshead between them; and Figure 3 is a section on the line Ill-Ill of Fig. 2. The drawings show columns which broadly are similar to columns of known construction and are formed, for example, by welding steel plates together. Each column has bottom plates 2 which co-operate with inclined outer walls 3 and vertical facing walls 4 to form two frames which in elevation are trapezoidal. The frames are interconnected by a common cover plate 5. Side walls 6 fill out the trapezoidal frames between the outer walls 3 and the facing walls 4. Tie rods 7 (Fig. 2) run vertically between the side walls 6 and retain the engine cylinder head (not shown) with prestressing. A crankshaft 16 is mounted in the baseplate 1 by means of a bearing shell 14 which comprises a top half and a bottom half and over which a bearing cover 15 is placed. As can be gathered from Fig. 3, the engine length m necessary for a cylinder mainly comprises on each side half the length h of a main bearing 14, the length S of the bottom bearing 18 for the connecting rod 20 and the thicknesses d of the two crank webs 17. As previously mentioned, the engine length necessary per cylinder is required to be as small as possible. In the central part between the facing walls 4 a central wall 8 replaces the side walls 6 and is closed on its underside by a crossbearer 9. As can be gathered from Fig. 2, the facing fronts of the facing walls 4 of two uprights form slideways for the slide shoe 10 of a crosshead journal 11 which in the usual way is connected to a piston rod 12 and is mounted in its bearing housing 13. The side walls 6 are spaced apart at the bottom by a small distance just sufficient for the tie rod 7 to pass through. The side walls 6 are inclined upwardly away from one another so as to engage the facing walls 4 near the outer edges thereof in the zone-r- oughly represented by the position of the crosshead in Figs. 1 and 3-associated with the top dead centre of piston movement. The walls 3, 4 and 6 therefore form a relatively wide and rigid "box" in the latter zone without causing any increase in engine length m. Spacer walls 19 reinforce the "box" in the space between the side walls 6 in order to increase the rigidity of the relatively larger-area side wall in the region of heavy loading. CLAIMS

1. A reciprocating piston machine having crossheads sliding on crosshead slideways carried on columns, the slideways transmitting forces normal to the slideways from the crossheads to the columns, each column having vertical facing walls having the slideways on their facing surfaces, side walls, and outer walls which are inclined to the vertical, the facing walls, side walls and outer walls extending the height of the column between a base plate and a top plate, characterised in that the side walls act in pairs each pair supporting a facing wall and the side walls of each pair upwardly diverging from one another in the upper region of the respective column.

2. A machine as claimed in Claim 1 in which the side walls of each pair are straight and diverge from bottom to top of each pair.

3. A machine as claimed in Claim 1 or Claim 2 which is a diesel engine.

4. A diesel engine having crosshead slideway columns which are constructed substantially as described herein with reference to the accompanying drawings.