DK147685B - LUBRICATION FOR A CHRISTMAS BEARING IN A TWO STAMP COMBUSTION ENGINE - Google Patents

Description

in i 147685

BACKGROUND OF THE INVENTION The present invention relates to a lubrication device for a cross-head bearing in a two-stroke piston combustion engine of the kind set forth in the preamble of claim 1.

The cross-head bearings in diesel engines are bearings that are heavily loaded by gas and mass forces, and 10 that must operate under adverse lubrication conditions.

Due to the limited oscillation movement of the groove rod relative to the pin associated with the piston rod, no dynamic lubrication film can be formed. In the case of two-stroke engines, this ratio 15, in contrast to four-stroke engines, becomes worse in that the bearing is subjected to the same working pressure forces at each rotation.

20 It is already known from US-PS 3656582 in the cross heads of such engines to incorporate lubricating oil pistons to which the lubricating oil is fed from the normal common lubricating oil line. However, such pumping devices are complicated, cost the engine and provide a further source of interference.

Furthermore, in the introduction to US-PS 3656582 a known cross-head bearing lubrication is mentioned in a two-stroke piston-combustion engine of the kind described in the beginning. However, with this lubricant there is a risk that the lubricating oil is pushed back from the bearing gap in the bearing bearing area during the high bearing load, that is to say in the period in which the oil pressure in the bearing gap is higher than the transport pressure of the lubricating oil pumps. supplying the lubricating oil, which leads to a rapid reduction of the bearing gap and thus to a rapid approximation of a dangerous approximation of the bearing surface and cross-head loss.

SUMMARY OF THE INVENTION The present invention aims to provide a lubricating device of the kind in which this risk is largely avoided.

This is achieved according to the invention in that the piston combustion engine is designed as defined in the characterizing part of claim 1.

15

In this embodiment, an excessive reduction of the oil pad formed between the bearing surfaces and the pin during the periods when the bearing pressures are small is prevented under the influence of the lubricating pressure by the shut-off means which prevents lubricating oil during the periods when the bearing load is large, too quickly is pushed away from the bearing surface. It has been found that for this purpose no excessively high butter pressure is required, so that leakage losses can be ignored.

25 Furthermore, this device is so simple that there is no fear of disturbance, as is the case with lubricating oil pistons built into the cross heads.

The actual lubricating oil pump is located outside the internal combustion engine and readily accessible so that a spare pump can be mounted.

In designing the engine as claimed in claim 2, a particularly simple embodiment is obtained.

A check valve is also provided with the lubricating oil plunger pump described in US-PS 3656582 which is described in the cross-head bearing. However, this is the normal pressure valve on the pump to allow the suction rate.

In designing the motor as set forth in claim 3, the construction is likely to be very complicated, but a particularly reliable design of the locking means is obtained, in which the danger of clamping, e.g. can consist of an automatic valve, avoided.

In designing the engine as claimed in claims 4, 15, the lubricating notes generally serve to secure operation in the event of a disturbance in the shut-off means, e.g. a clamping of a non-return valve. This results in increased operational reliability.

20

The invention will now be explained in more detail with reference to the drawing, which schematically shows different embodiments of the motor, with fig. 1 is a partial sectional view of a two-stroke piston combustion engine with a shut-off valve for the lubricating oil supply; FIG. 2 is a sectional view taken along line II-II of FIG. 1, 4 Ϊ47685 1 fig. 3 shows an unfolding of the lower bearing surfaces of the crosshead bearings of FIG. 1 and 2, FIGS. 4-6 are schematic sections in bearings and bearing pins in different positions to explain the operation of the invention; FIG. Fig. 7 is a diagram showing the lubrication oil pressure in the bearing head bearings during a 10 duty cycle of the engine; 8 shows the magnitude of the bearing gap in the region of the lower running surface during the working cycle of FIG. 7, 15 FIG. 9 is a view of FIG. 1 corresponds to a partial section of a two-stroke piston combustion engine with a interlocking member acting as a turning member and a rotary jointed head sectional joint and a joint 20 formed lubricating oil supply section between the motor housing and the crosshead; FIG. 10 is a sectional view taken along a line X-X of FIG. 9; FIG. 11 is a view of FIG. 3 shows a corresponding unfolding of the lower bearing surfaces of the cross-head bearings in FIG. 9 and 10, FIG. 12 is a sectional view taken along line XII-XII of FIG. 9, 30 FIG. 13 and 14 are sectional views of a rotary eglider along a line XIII-XIII of FIG. 12, on a larger scale for various positions of the rotary slide, and FIG. 15 and 16 show FIG. 13 and 14 corresponding to the swivel slide, however, along a line XV-XV in fig. 12th

5 The embodiment of FIG. 1 and 2, a section of a two-stroke piston-combustion engine has a crosshead 1 having a crosshead pin 2. This pin is enclosed by crosshole supports 3 attached to a nursing rod 4. At the ends of the crosshead pin 2 are crosshead shoes 5, 10 which is known in a manner movable along a crosshead guide 6 in a motor housing 7. For supplying the crosshead bearings 3 with lubricating oil, there is a lubricating pump 8 which transports lubricating oil from a container not shown to a lubrication line 10. For connection of the crosshead 15 1 to the fixed part of the lubrication line 10, there are tubes 14 and 15 which are connected knee-like to each other by means of joints 11, 12 and 13

As shown in FIG. 1, the link 13 forms a connection for the pipe 15 and thus for the lubrication line 10 to a bore 16 which leads to a central bore 17 in the crosshead pin 2, in which a piston rod 18 is secured in the known manner in a known manner. Thread ring 19. Through a central bore 25 17, axial lubrication bores 20 are provided on both sides to which radial lubrication bores 21 join in the region of the outer edges of the bearings 3. 2nd

30 The radial bores 21 lead to connecting grooves 28, FIG. 3 of the bearing surfaces 23 in the lower parts 3 'of the cross-head bearings 3 · The connecting notes 22, which during the pivotal movement of the groove bar 4 are permanently connected to the bores 21, the bores 24 lead into the lower bearing portion 3' · In the groove bar 4 bores 25 which end into a longitudinal bore 26 in the connecting rod 4 are joined to the bores 24. From the longitudinal bore 26, the lubricating oil can e.g. is applied to the crank bearings in the care rods.

As shown in FIG. 2, at the upper end of the longitudinal bores 26 there is a non-return valve 27, which in the present case contains a ball 29 which is loaded by a spring 28. From the non-return valve 27 bores 30 lead to lubricating nuts 31 in the bearing surfaces 23, fig. Third

In FIG. 3, additional grease notes 32 are shown which connect directly to the connecting grooves 22 and thus, outside the check valve 27 being supplied with lubricating oil. The grease notes 32 are at the edge of a bearing region B which has approximately an anti-oval shape and extends substantially about a circumferential angle β of approx. 90 °. This bearing area is on the bearing surface 23 after a certain operating time for the engine to know that in that area machining grooves have been removed, either by mechanical wear by contact with the bearing surface of the pin or by erosion with the lubricating oil at high bearing pressure.

The operation of the invention will be explained below with reference to FIG. 4 to 8.

30

FIG. 7 shows the course of the average bearing pressures 2 on the bearing surfaces 23 in kp / cm during a working cycle of the motor. Pq represents the lubrication pump 8's lubrication pressure which is substantially constant and in the present case e.g. can denote 20 ato. From the curve P, J_f it can be seen that the bearing pressure in an area from the top dead center OTP drops below the butter pressure Pq.

5 Pig. 8 shows the progression of the size of the bearing gap h at the lowest location of the bearing. Under the largest bearing load under the expansion layer during a movement of the piston from the upper dead center OTP to the lower dead point UTP, an oil pad 10 in the bearing is slowly pushed away from the bearing surface until the bearing gap reaches the minimum value a ( Figure 6). At this moment, the bearing pressure P1 drops below the lubricating pressure Pq, so that the pressure of the lubricating oil opens the check valve 27 and the lubricating oil flows into the bearing gap between the bearing surface 23 and the pin 2. Thus, the bearing gap is increased by pressure of the lubricating oil to a value b. . 5 · This value can be limited by the pin 2 beating against the oil film in the upper region opposite the gap of size b. Then, an increase in bearing load towards the end of the compression layer and at the beginning of the ignition in the cylinder, whereby the check valve 27 is closed, fig. 6. At the top dead-end OTP of the engine, the bearing gap already has a 25 somewhat smaller size c.

The outermost grooves 32 are positioned at an angle β (FIG.

1 and 4) serves to support the supply of the lubricating oil bearing. At the same time, they ensure a satisfactory operation of the bearing also in the event that the non-return valve 27 fails, if it e.g. should have been jammed in the closing position.

As shown in FIG. 1 and 4, the lubricating notes 31 in circumferential direction are removed at an angle © C from each other, which may be the same size as the angle of oscillation of the groove rod * 1 during operation. This results in an optimal supply of the bearing area B with lubricating oil, since the lubricating oil during a rotation of the motor by the mutual movement of the bearing surface 23 and the pin 2 is distributed over the entire surface between the lubricating nuts 31.

10 As in the case of FIG. 1 and 2 a certain volume of lubrication bore exists between the bearing surface 23 and the check valve 27, a further advantageous effect arises. During the time when the greatest bearing load exists, lubricating oil is not only pushed away from the bearing surface in lateral direction, but also with the high pressure existing during this period penetrates into the bores 30. After lowering the high pressure, the oil flowing is collected in the volume of the bores 30, again 20 onto the bearing surface 23, thereby slowing the reduction of the bearing gap h.

In the embodiment shown in FIG. 9 to 16, other embodiments of the invention are parts corresponding to parts of FIG.

25 1 to 6, provided with the same reference numerals. Embodiment of FIG. 9 to 16 differ from the o-friend described in that the automatically acting non-return valve 27 is replaced by a swivel slider 40 disposed in one of the joints connecting the lubricants 30 jointly to one another. In order to obtain optimum conditions for operating the slider 40, according to FIG. 9 lubrication pipes at 42 and which are deflected at an angle upwards and in the lower dead center UTP of the motor occupy a position shown by dashed lines 41 'and 42 *. By this arrangement, larger angles of rotation are obtained for the pivoting slider 40, which has a housing 43 which is attached to the cross-head pin 44. As can be seen in particular from FIG. 12, 5 a pivot 45 is pivotally mounted in the slide housing 43 which is firmly connected to the tube 42. The pin 45 contains a guide channel 46 which cooperates with guide bores 47 and 48 in the housing 343.

13 to 16, the control channel 46 is permanently in operation 10 in connection with the control bore 48, FIG. 15 and 16.

The connection between the control channel 46 and the control bore 47 is interrupted periodically (paragraph d in Fig. 13).

The device is such that there is only a connection between the lubrication tube 42 and the guide bore 47, 15 when in the bearing of FIG. 7 there is a pressure lower than the lubricating pressure from the lubricating oil. Thus, the portion of the rotary slider with the control bore 47 corresponds in its function to the check valve 27.

20 Corresponding to this function of the guide slide is the guide bore 47 by means of a lubrication bore 50, fig. 12 connected to the bore 17 to the piston rod 18. From this bore, grease bores 51 lead to grease notes 52, which in this case are formed in the pin 44 and 25, correspond to the grease notes 31 in the embodiment of FIG. 1 to 3 ·

On the other hand, the bore 48, which is permanently connected to the lubrication tube 42, is connected by means of lubrication bores 53, 30 54 in the pin 44 to the connecting grooves 22 in the bed, which are formed in the same manner as in FIG. 3 in the bearing surface 23 and leads to additional lubrication 32. In FIG. 10 and 12 are additionally plotted lubrication bores 55 leading to the bearing surfaces of the cross-head shoes 5 · In addition, as in the embodiment of FIG. 1 to 3, a bore 26 in the pole 5 bar 4 by means of lubricating bores 56 with lubricating oil supplied through the connecting grooves 22; 10th

As with the embodiment of FIG. 1 to 3, the lubricating notes 32 are permanently supplied with lubricating oil, while the supply of the lubricating notes 52 is interrupted in the same way as by the check valve 27.

Claims (3)

147685 1. Lubricating device for a cross-head bearing in two-stroke piston combustion engines with a pump which continuously transports lubricating oil at a substantially constant pressure higher than the 5 lowest operating lubricating oil pressure and with a lubricating oil supply by means of which , in which the lubricating oil pressure in the bearing gap is lower than the lubricating oil pump transport pressure applied to lubricating oil for lubricating nuts located in the bearing bearing region, characterized in that within the lubricating oil supply, located near the bearing bearing area (B) a shut-off member (27, 40) which prevents a backflow of lubricating oil from the bearing slot (h) 15. the bearing bearing area (B) over the lubricating notes (31, 52.) to the lubricating oil supply during the time at which the lubricating oil pressure (P (h) is higher than the lubricating oil pump pressure (PQ) Lubricating device according to claim 1, characterized in that the shut-off means in the lubricating oil supply is an automatic acting non-return valve (27) which opens in the direction towards the cross-head bearing. 25 Lubricating device according to claim 1, characterized in that the lubricating oil supply on its leading part from the motor housing (7) to the crosshead (1) consists in two known lubricating tubes 30 known per se.