Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
  • F04B1/2014—Details or component parts
  • F04B1/2078—Swash plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
  • F04B1/2014—Details or component parts
  • F04B1/2064—Housings
  • F04B1/2071—Bearings for cylinder barrels

Definitions

• axial piston machines In the technical field of hydraulic piston pumps and engines there are two basic types: axial piston machines and radial piston machines. As the designations indicate, the piston movements are substantially axial or radial relative to the axes of symmetry of the machines. According to the function of the machine, there are variations of these basic types, such as bent axis machines, where the cylinder body is pivoted up at a maximum of ⁇ 40°, and radial piston machines which operate with pivoting pistons. Moreover, in a number of axial piston machines, both of the bent axis type and the in-line type, the cylinder bores are orientated at a slight angle to the axis of the cylinder casing. The angles of inclination which occur are normally up to a maximum of approximately 5°.
• a considerably greater angle of inclination is used for the cylinder bore relative to the axis of the cylinder casing, to allow greater stroke length for the pistons and to make more room for the homokinetic Cardan joint which is used to transmit the piston power developed to the machine shaft as usable torque, and vice versa.
• Figure 1 shows the basic design of the machine
• Figure 2 shows a section of the contact surface between a valve plate and the cylinder casing
• Figure 3 shows a version of the machine which is very similar to the machine shown in Figure 1 but has the valve plate plan-parallel, and therefore has its hydrostatic bearings acting at a specific angle
• Figure 4 shows a complete machine constructed with 26 pistons and a very large-dimension shaft passing through it.
• Figure 1 also shows that spherical pistons 4 are used in the invention, although these are not essential to the invention.
• Conventional cylindrical pistons with a movable piston rod can be used, but spherical pistons 4 give the smallest dimensions for the cylinder casing 2 and thus for the whole machine.
• the cylinder casing 2 with its cylinder bores 5 extending at a considerable angle of inclination ⁇ to the axis of symmetry 1 of the machine can be produced with an arbitrary number of such cylinder bores.
• diagonal piston engines with up to 26 cylinder bores 5 have been envisaged, which means that a very large through-shaft 3 can be obtained.
• the cylinder bores 5 are also formed with the full diameter right through. They therefore have no constriction at the aperture 6 where they adjoin the valve plate 7.
• the valve plate 7 is shown here with its surface 8 which comes in contact against the cylinder casing 2 formed with conical or spherical shaping.
• the corresponding surface on the cylinder casing 2 is also conical or spherical.
• the hydrostatic bearing 9 is shown here in the special linear sealed embodiment which is described in Swedish Patent application No. 8102435-8, but other types of hydrostatic bearings are also possible, such as sliding shoe bearings or the so-called "Thin Land bearings" and the like.
• the number of hydrostatic bearing pockets 9 is the same as the number of cylinder bores 5 in the cylinder casing 2. Each bearing pocket 9 nas its own working medium supply via a bore 12 from the respective cylinder bore 5 via an aperture 13 in the cylinder wall near the end 6 of the cylinder bore at the contact surface 8.
• the hydrostatic bearing 9 slides up against the stationary force-absorbing part 14 which is rigidly connected to the housing 15 of the diagonal piston machine.
• the cylinder casing 2 is rotated with the drive shaft 3 by means of the entrainment component 16.
• the other ends 17 of the working pistons 4 are mounted in a drive plate (see Figure 4), which in turn transmits torque to the drive shaft 3 of the diagonal piston machine, via a homokinetic drive coupling such as a Rzeppa coupling 18, for example.
• Figure 2 shows part of the contact surface 8 between the valve plate 7 and the cylinder casing 2.
• the circle indicated in a broken line is the opening 6 of the cylinder bore against the valve plate 7. This opening lies above the plane of the paper in Figure 2. Only the part of the valve plate surface 8 which co-acts with one single cylinder opening 22 is shown, i.e. ⁇ 20° in a 9-piston machine.
• FIG. 1 shows a version of the diagonal piston machine where the valve plate 37 is made plan-parallel, and the surface 36 adjoining the cylinder casing 32 is at right-angles to the axis of symmetry 31 of the machine.
• the hydrostatic bearings 39 are posi- tioned with their centre axes 40 at an angle ⁇ counter to the angle ⁇ so that the piston forces developed from the pistons 34 and the bearing forces from the hydrostatic bearings 39 together correspond approximately with regard to direction and magnitude, and overcome the hydrostatic forces which are developed at the contact surfaces 36, 38 between the valve plate 37 and the cylinder casing 32.
• the hydrostatic bearings 39 (one for eachcylinder bore 35) obtain their working medium supply through a bore 42 from the respective cylinder bore 35 via an opening 43 in the cylinder wall near the end of the cylinder bore at the contact surfaces 36, 38.
• the sliding surface 46 on the part 44 is shaped spherically with a radius and centre positioning such that the direction of the forces developed by the hydrostatic bearings 39 is as intended, i.e. the normal to the plane which passes through the contact line between the sealing ring of the respective bearing 39 and the spherical surface 46 forms the angle ⁇ with the axis of symmetry 31 of the diagonal piston machine.
• Figure 4 shows an actual embodiment of a complete diagonal piston machine in section, with a very large through-shaft 52 with a diameter of 130 mm.
• the machine is constructed with 26 cylinder bores 55 with a diameter of 24 mm, and pistons 54 with a stroke length of 176 mm.
• the displacement of the machine amounts to 2070 cm 3 / revolution.
• Figure 4 also shows an example of how the mounting for the drive plate 56 can be designed.
• the drive plate 56 is rigidly connected to the outer ring 64 of the homokinetic drive coupling 58, the Rzeppa coupling, the inner ring 65 of which is mounted on splines 66 on the hollow shaft 53.
• the drive ends 57 of the pistons are fixed to the drive plate 56.
• the pistons 54 with piston rods have a bore through them and conduct working medium to hydrostatic bearing pockets 59, one for each piston 54, 57, on the lower face of the drive plate, which develop bearing forces directed counter to the piston forces.
• the hydrostatic bearings 59 slide against a bearing surface 60 on the part 61 which is the force-absorbing part, and are suspended by bearing pins in a bearing (not shown in the Figure) in the housing 63 of the machine and can thus rotate through an angle of - ⁇ around an axis 51 at right-angles to the plane of the paper.
• the forces at an angle to the hollow shaft 53 which are produced by the slanting pistons 54, 57 acting against the drive plate 56 are transmitted from this to the force-absorbing part 61 by means of roller elements 62 (roller bearings).
• the object of the invention is to make possible in a hydraulic machine, by means of hydrostatic bearings, the use of cylinder through-bores with the full area, and the orientation of these bores with their axes at a considerable angle of inclination relative to the cylinder casing and the axis of symmetry of the hydraulic machine.
• firstly improved flow behaviour is obtained for the working medium used, but also significantly longer stroke length for the working pistons of the hydraulic machine compared with that of all known types of hydraulic piston machine.
• the invention is not limited to the embodiment example shown on the drawings and described above, but may be modified within the frame work of the following Patent Claims.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)
• Hydraulic Motors (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20354525

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (6)

Citations (1)

Family Cites Families (12)

• 1984
  • 1984-01-31 SE SE8400473A patent/SE444839B/sv not_active IP Right Cessation
• 1985
  • 1985-01-29 DE DE8585900815T patent/DE3569275D1/de not_active Expired
  • 1985-01-29 JP JP85500621A patent/JPS61501408A/ja active Pending
  • 1985-01-29 WO PCT/SE1985/000039 patent/WO1985003554A1/en active IP Right Grant
  • 1985-01-29 AU AU38843/85A patent/AU3884385A/en not_active Abandoned
  • 1985-01-29 EP EP85900815A patent/EP0203071B1/en not_active Expired
  • 1985-01-29 US US06/783,929 patent/US4622885A/en not_active Expired - Fee Related

Patent Citations (1)

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