Radial piston hydraulic engine

Abstract

The invention concerns a radial piston hydraulic engine (10), which includes a rotated box section (11), with which box section (11) a cam ring (12) is connected. The radial piston hydraulic engine (10) includes a fixed non-rotary shaft (14), with which a cylinder body (15) in a fixed position is connected. The radial piston hydraulic engine includes a distributor (13), which is connected with the box section (11) and rotates together with it, whereby through channels located in the distributor a pressurized medium is conducted to pistons (16a1, 16a2 . . . ) of cylinders (P1, P2 . . . ) controlled by the distributing valve, that is, by distributor (13), and that at least some cylinders (P1, P2 . . . ) include in connection with themselves a shut-off valve (70a1, 70a2 . . . ) which is used to make some pistons (16a1, 16a2 . . . ) inoperative. Shaft (14) includes in the same cylinder-block (I) at least two control pressure channels (Y1, Y2) for the shut-off valves (70a1, 70a2) of its cylinder body (15), whereby by supplying pressure selectively into a channel (Y1 or Y2; Y1 and Y2) it is possible to make certain cylinders (P1, P2 . . . ) inoperative by directing control pressure to the shut-off valves (70a1, 70a2, 70a3 . . . ).

Description

[0001] This invention concerns a radial piston hydraulic engine.

[0002] Such radial piston hydraulic engine solutions are known in the state of the art, wherein a box section is rotated and to the box section is joined a distributor mounted to the same. The distributor is a so-called distributing valve, which includes borings made in the direction of the distributor bushing and opening from the distributor's end face. There are inlet channels to the distributor and outlet channels from it. The inlet channels open in the distributor's end face, as do the outlet channels. The respective channels of the distributing valve are alternately in connection with piston spaces, which piston spaces include pistons and pusher wheels connected with the pistons and adapted to move against a cam ring located in connection with the box section. Under these circumstances, some pistons are in the work stage and some are not. Those pistons which are in the work stage are supplied with a pressurised medium through the distributor's channels and, correspondingly, those pistons which have bypassed the work stage remove oil through the distributor by way of the outlet channels of the distributor. The pusher wheels located in the pistons push against the cam ring located in the box section. The cam ring includes a wavelike shape, whereby the cam ring and the box section connected to it are rotated with the aid of the pusher wheels. To ensure optimum operation of the distributor, the distributor's end face must be in a tight slide fit against that end face of the cylinder body wherein the channels leading to the piston spaces are located.

[0003] The application presents an improvement especially on the solution presented in the applicant's earlier FI 942304 application. The structure according to the invention is especially concerned with such a radial piston hydraulic engine, wherein the cylinder body and the shaft 14 are immovably connected to one another, e.g. by a groove coupling, and in which structure the cylinder body and its associated shaft are non-rotary. In accordance with the invention, those cylinder spaces P1, P2 . . . of the cylinder body, which are connected with cylinder block 1, in connection with themselves include oil channels, which are further connected with the distributor in the end face of the cylinder body. In some of these cylinder body channels shut-off valves are located, which are controlled by pressure. According to the invention, the shut-off valves are pre-controlled as follows. A channel boring is made through the shaft, and from the boring in question a control is branched off into certain cylinder spaces and into the shut-off valves located in connection with these. The structure according to the invention includes at least one other boring, from which controls are branched off to other piston spaces of the cylinder block and into their shut-off valves. Some of the channels connected with cylinder spaces in the cylinder body are such which do no include shut-off valves, and pressurised oil is also conducted to these in operation. Thus, by using the control channels selectively, different connections and thus different combinations of volume flows are achieved.

[0004] The radial piston hydraulic engine in accordance with the invention is characterised in that which is stated in the claims.

[0005] The invention will be described in the following by referring to some preferable embodiments of the invention, which are shown in the figures of the appended drawings, however, to which the invention is not intended to be exclusively limited.

[0006] FIG. 1 is a cross-sectional view of the radial piston hydraulic engine according to the invention.

[0007] FIG. 2 illustrates the use of channels Y1 and Y2 located in shaft 14 in order to bring about control of the shut-off valves located in the cylinder body.

[0008] FIGS. 3A and 3B show a ½revolution volume regulation implemented in a radial piston hydraulic engine according to the invention which includes 12 cylinders. FIG. 3A is a cross-section of the radial piston hydraulic engine, and FIG. 3B is a section I-I of FIG. 3A. Regulation variations are shown in corresponding sections I-I in FIGS. 4, 5A and 5B.

[0009] FIG. 4 shows so-called ¼revolution volume regulation.

[0010] FIG. 5A shows so-called ¾revolution volume regulation.

[0011] FIG. 5B shows the {fraction (1/1)}revolution volume regulation position.

[0012] FIG. 6A shows a distributing valve 100 connected to channels Y1 and Y2 used to direct the control pressure supply to channels Y1 and/or Y2. A shut-off valve 70 located in the cylinder body is connected with one channel Y1 to illustrate the operation of the shut-off valve.

[0013] FIG. 6B shows shut-off valve 70 on a larger scale.

[0014] FIG. 1 is a cross-sectional view of radial piston hydraulic engine 10. The radial piston hydraulic engine 10 includes a rotated box section 11. A cam ring 12 is connected to box section 11. In the embodiment shown in the figure, box section 11 is rotated, to which box section a distributor 13 is connected, which is in a fixed position in relation to box section 11. Distributor 13 is a distributing valve including several borings e1A; e2B, which are in connection with the inlet channel e1 and with the outlet channel e2 of a central shaft 14. Distributor 13 rotates with the box section 11, and the pressurised channels e1A and return oil channels e2B are brought alternately into contact with the channel ends of those flow channels of cylinder pistons 16a1, 16a2 . . . located in cylinder body 15, which lead to the cylinder spaces of cylinders P1, P2 . . . . Under these circumstances, some of the pistons 16a1, 16a2 . . . of cylinders P1, P2 . . . are in the work stage, whereby pressurised medium is conducted through distributor 13 to cylinders P1, P2 . . . and some pistons 16a1, 16a2 . . . are in the idle stage, whereby oil is conducted from the cylinder spaces of the cylinders P1, P2 . . . of the said pistons 16a1, 16a2 . . . through distributor 13 to outlet channel e2. The non-rotary cylinder body 15 located in the non-rotary central shaft 14 includes a cylinder block R1, whereby cylinder body 15 contains several cylinder spaces P1, P2 . . . and pistons 16a1, 16a2 . . . in these. Piston 16a1, 16a2 . . . is adapted to move in the cylinder space of cylinder P1, P2 . . . under the influence of the oil pressure supplied thereto. As shown in the figure, each piston 16 includes a pusher wheel 17a1, 17a2 . . . with a circular cross-section and placed freely on its top surface. When pushing piston 16a1, 16a2 . . . forcefully against the wavelike surface 12a of cam ring 12, cam ring 12 and the connected box section 11 and the distributing valve, that is distributor 13, connected with box section 11 are made to rotate.

[0015] Box section 11 is pivoted to rotate supported by bearings G1 and G2 in relation to the central shaft 14.

[0016] As shown in FIG. 1, the cylinder body in connection with the piston spaces includes pressure-controlled shut-off valves 70a1, 70a2 . . . , whereby by using the shut-off valves 70a1, 70a2 . . . it is possible to shut off the supply of pressurised oil to the cylinder spaces of cylinders P1, P2 . . . and thus to remove from operation the piston connected with the cylinder space in question. The volume flow of the engine can be regulated by directing the supply of control pressure to the shut-off valves 70a1, 7a2 . . . located in the cylinder body.

[0017] The radial piston hydraulic engine shown in FIG. 1 includes a channel Y1, through which control pressure is conducted to shut-off valves 70a1, 70a3, 70a5, 70a7, 70a9 and 70a11, which shut-off valves are further connected with cylinders P1, P3, P5, P7, P9 and P11. Correspondingly, oil channel Y2 is connected with shut-off valves 70a2, 70a6 and 70a10 to turn off or to turn on the operation of pistons P2, P6, P10 connected with the said cylinders.

[0018] Cylinders P4, P8 and P12 do not in connection with themselves include shut-off valves 70, whereby they are always in operation. Thus, the radial piston hydraulic engine in accordance with FIG. 1 preferably in the cylinder block includes a total of 12 cylinders; cylinders P1, P2 . . . P12. The number of cylinders P1, P2 . . . may also be a multiple of 12.

[0019] FIG. 2 illustrates the control operation of shut-off valve 70a1, 70a2 . . . so that through control channel Y1 a control pressure is conducted to the shut-off valve in order to close it. Channel Y1 opens into ring space 51, into which ring space also open e.g. the control channels of shut-off valves connected with six different pistons. Thus, by letting pressure affect in channel Y1 shut-off valves 70a1, 70a3, 70a5, 70a7, 70a9 and 70a11 are controlled at the same time and the flow path to cylinders P1, P3, P5, P7, P9 and P11 is closed for the pressurised medium at its operating pressure. Correspondingly, through the other channel Y2 control pressure can be conducted into the other ring space 61 and further, as illustrated in the figure, to three different shut-off valves 70a2, 70a6, 70a10 , which are located in the cylinder body in connection with the oil channel leading to cylinders P2, P6, P10.

[0020] Correspondingly, to some cylinders P4, P8, P12 pressurised oil is conducted directly from distributor 13 in such a way that there is no shut-off valve in connection with the channels of the concerned cylinder spaces.

[0021] In this way, by using control into channels Y1 and/or Y2 shut-off valves 70a1, 70a2 . . . can be controlled and an operating pressure is obtained for the desired cylinders P1, P2 . . . When there are 12 pistons, the following volume flow combinations of ¼, ½, ¾and 1 revolution volume are obtained.

[0022] FIGS. 3A and 3B show ½revolution regulation. FIG. 3B is a section I-I of FIG. 3A. The cylinder block includes 12 cylinders, cylinders P1, P2 , P3 . . . P12. FIG. 3 shows darkened cylinders P1, P3, P5, P7, P9 and P11, which are in connection with channel Y1, whereby a control pressure is conducted to channel Y1. Cylinders P1, P3, P5, P7, P9 and P11 are divided equally by 600 in relation to one another in the cylinder block.

[0023] Cylinders P2, P6, P10 in connection with channel Y2 are divided by 120° in relation to one another. Those cylinders which do not in connection with themselves include any shut-off valve in the cylinder body are also divided by 120° in relation to each other in the cylinder block R1, and the cylinders in question are indicated by reference numbers P4, P5 and P12 in FIG. 3.

[0024] The figure indicates a so-called ½revolution volume regulation, wherein a pressure is supplied into channel Y1. Cylinders P1, P3, P5, P7, P9 and P11, are closed and an operating pressure can be conducted to all other cylinders of the cylinder block, that is, to cylinders P4, P8 and P12 and to cylinders P2, P6, P10. Thus, six cylinders are operating and the other six are closed.

[0025] FIG. 4 shows so-called ¼revolution volume regulation. Hereby the control pressure is supplied both through channel Y1 and through channel Y2, whereby the cylinders P1, P3, P5, P7, P9 and P11 connected to channel Y1 are closed and, correspondingly, cylinders P2, P6, P10 connected to channel Y2 are closed. Instead, cylinders P4, P8 and P12, which have no shut-off valve 70 connected to them, are operating.

[0026] FIG. 5A shows so-called ¾revolution volume regulation. In the regulation position concerned, a control pressure is supplied into channel Y2 and thus to cylinders P2, P6, P10. Hereby the said cylinders are in the closed state, whereas cylinders P1, P3, P5, P7, P9 and P11 as well as cylinders P4, P8 and P12 are operated.

[0027] When no control pressure is conducted into channel Y1 or into channel Y2, all cylinders P1, P2 . . . P12 are connected to operate and a so-called full revolution volume regulation position is obtained. The said regulation position is shown in FIG. 5B.

[0028] FIG. 6A shows an embodiment of the control according to the invention. In accordance with the invention, a distribution valve 100 is used, which includes control pins 101a1, 101a2. The pins can be affected with a control oil pressure or, for example, electrically by using a solenoid. By affecting the pins, a pressure connection with channels Y1 and Y2 is opened and closed. Distribution valve 100 may be located in a fixed position on the end of shaft 14 or it may be a part of shaft 14.

[0029] In the solution shown in FIG. 6A, an operating pressure is conducted to valve 10 through its channel 102. By affecting control pins 101a1 and 101a2 at their ends N1, N2 on the pressure side, the pins are moved towards the end of pin space 104a1, 104a2 and a connection for the pressurised medium is opened through channel 102 to channels Y2 and/or Y1. When no control is supplied electrically or hydraulically into pressure spaces N1, N2 at the pin ends, the pins will remain in such a position with the aid of springs Ja, Jb located around the pins, which allows a passage for the pressurised medium from control channels Y2, Y1 through outlet lines 103a1, 103a2 to the engine's outlet line.

[0030] FIG. 6B shows the structure of shut-off valve 70 on a larger scale.

[0031] As is shown in FIGS. 6A and 6B, control pressure is thus conducted into channels Y1 and/or Y2 . As is further illustrated in the figures, the said pressure is conducted to shut-off valve 70 in such a way that it will affect the end face of pin 80 of the shut-off valve. In the normal state, the end face of pin 80 is affected by spring 3, which holds the said shut-off valve 70 in the closed position, when no operating pressure has been conducted to the other side of the pin, and allows oil to flow to outlet F10, for example, to the box section through the central channel F of pin 80. When the pressurised oil affects on the side of spring J of pin 80, the operating pressure is not either able to move the pin 80, and pin 80 will close the passage for the operating pressure to the cylinder P1 or P3 or P5 . . . , which is in connection with shut-off valve 70. When no control pressure is supplied, for example, to channel Y1 as is shown in FIG. 6B, and operating pressure affects the end face of pin 80, the operating pressure moves pin 80, as is indicated by arrow S1 in the figure, to the right and the operating pressure can affect piston 16a1, 16a3 . . . Hereby the connection to outlet F10 through the central channel F of pin 80 is closed at the same time. When the operating pressure is effective, it moves pin 80 to the left (arrow S2) as shown in the figure, and the piston space of the cylinder opens to outlet channel F10 through the central channel F of pin 80. The spring J is intended to move pin 80 into such a position that the oil space located below the piston will be connected to the outlet at a time when the engine is not under pressure.

[0032] When no control pressure is supplied through channels Y1 and/or Y2 to pin 80 of shut-off valve 70 and when the operating pressure has moved pin 80 in the direction indicated by arrow S1 and has opened a passage for the operating pressure to the space below the piston, the pressure existing in the work cycle in question in the space below the piston with shut-off valve 70 in the said position will keep pin 80 pressed in direction S1. This is the case also when the rotated distributor 13 distributes oil to the different work steps and in between connects the oil space below piston 16a1, 16a2 . . . with outlet channel e2B, e2 through distributor 13.

Claims

1. Radial piston hydraulic engine (10), which includes a rotated box section (11), with which box section (11) a cam ring (12) is connected, and which radial piston hydraulic engine (10) includes a fixed non-rotary shaft (14), with which a cylinder body (15) is connected in a fixed position, whereby the radial piston hydraulic engine includes a distributor (13), which is connected with the box section (11) and rotates together with it, whereby through channels located in the distributor a pressurised medium is conducted to the pistons (16a1, 16a2 . . . ) of the cylinders (P1, P2 . . . ) under the distributing valve's, that is, the distributor's (13) control, and that at least some cylinders (P1, P2) include a shut-off valve (70a1, 70a2 . . . ) in connection with themselves, which is used for making some pistons (16a1, 16a2 . . . ) inoperative, characterised in that the shaft (14) includes in the same cylinder block (I) at least two control pressure channels (Y1, Y2) for the shut-off valves (70a1, 70a2) of the cylinder body (15), whereby by supplying a pressure selectively into the channel (Y1 or Y2; Y1 and Y2) certain cylinders (P1, P2 . . . ) can be made inoperative by supplying control pressure to the shut-off valves (70a1, 70a2, 70a3 . . . ).

2. Radial piston hydraulic engine as defined in claim 1, characterised in that channels (Y1, Y2) are in connection with a distributing valve (100), which includes control pins (101a1, 101a2), which are used to regulate the supply of pressurised medium selectively into channels (Y1 or Y2; Y1 and Y2) in order to control the shut-off valves (70a1, 70a2 . . . ) of the cylinder body (15) in connection with them.

3. Radial piston hydraulic engine as defined in claim 1 or 2, characterised in that the channel (Y1, Y2) is a boring in shaft (14) in connection with such a ring channel (51, 61) in the outer periphery of shaft (14), which is in connection with certain shut-off valves (70a1, 70a2, 70a3 . . . ) of the cylinder body (15).

4. Radial piston hydraulic engine as defined in any one of the preceding claims, characterised in that the shut-off valve (70a1, 70a2, 70a3 . . . ) includes a spring (3), which is used to press the shut-off valve towards one extreme position of a pin (80) (in direction S2), in which extreme position an oil space located below piston (16a1, 16a2 . . . ) is connected with an outlet channel (F10) through a central channel (F) in pin (80).

5. Radial piston hydraulic engine as defined in any one of the preceding claims, characterised in that control pressure of hydraulic oil from channel (Y1, Y2) is conducted to that end face of pin (80), which includes a spring (3).

6. Radial piston hydraulic engine as defined in any one of the preceding claims, characterised in that the control pressure distributing valve (100) located in connection with channels (Y1, Y2) is connected with shaft (14).

7. Radial piston hydraulic engine as defined in the preceding claim, 15 characterised in that the distributing valve (100) is connected with one end of shaft (14).

8. Radial piston hydraulic engine as defined in claim 1, characterised in that the radial piston hydraulic engine includes 12 cylinders (P1, P2 . . . P12).

9. Radial piston hydraulic engine as defined in claim 1, characterised in that the radial piston hydraulic engine includes N×12 cylinders (P1, P2 . . . PN), that is, a multiple of 12.

10. Radial piston hydraulic engine as defined in claim 8, characterised in that channel (Y1) conducts the hydraulic oil to those shut-off valves (70a1, 70a3, 70a5, 70a7, 70a9 and 70a11), which are connected with cylinders (P1, P3, P5, P7, P9 and P11).

11. Radial piston hydraulic engine as defined in claim 8, characterised in that channel (Y2) conducts the hydraulic oil to those shut-off valves (70a2, 70a6, 70a10), which are connected with cylinders (P2, P6, P10) of the cylinder body (15).

12. Radial piston hydraulic engine as defined in claim 8, characterised in that cylinders (P4, P8 and P12 ) do not in connection with themselves include any shut-off valve (70), whereby pressurised oil is supplied from distributor (13) to the concerned cylinders (P4, P8 and P12) at all times.