JPH05157043A - Radial piston machine - Google Patents

Abstract

PURPOSE: To increase a torque without changing the size of structural space by forming a guide pin having a diameter smaller than that of a piston, and loading a bore space with the same operating medium pressure as an annular bore space. CONSTITUTION: The machine comprises pistons 12 slideably supported in a plurality of bores 11. Each piston 12 is provided with a guide pin 16 in the rotary axial direction. The diameter of the guide pin 16 is smaller than that of the piston 12. Bore spaces 19 each limited by a guide pin 16 cooperate with the guide pin 16 to receive the same operating medium pressure as an annular bore space 15 limited by the piston 12. In this way, a pressurized area as large as about 44% of the piston 12 having the guide pin 16 can be obtained with the same structure size, hence, a torque increased correspondingly can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial piston machine, which is constructed as an annular stroke plate fixed to a casing and a rotating body rotatably supported on the stroke plate about an axis. Cylinder block, a large number of holes radially arranged with respect to the rotation axis of the cylinder block, a piston slidably supported in the holes, and a cylinder for supporting the piston on the stroke plate. Roller is provided, the roller having an axis extending parallel to the axis of rotation of the cylinder block.

[0002]

Radial piston machines of this type are known from DE-A 32 16 007 and DE-A 35 31 632. This known machine is distinguished by its compact and inexpensive construction and high pressure resistance. In such radial piston machines, the piston takes on the displacement and sealing functions, and the rollers transmit the emerging forces from the stroke plate to the piston for the purpose of torque formation. In the known radial piston machine, the maximum diameter of the piston is defined by the number of pistons, the piston stroke and the radius of the rotor, which also defines the machine torque.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to improve a radial piston machine of the type mentioned at the outset such that a radial piston machine can be increased in torque under the same construction space. Is to provide.

[0004]

In order to solve this problem, in the structure of the present invention, the piston has one guide pin in the direction of the rotation axis, and the diameter of the guide pin is the piston. Smaller than the diameter of
Each of the hole chambers limited by the guide pin is loaded with the same working medium pressure as that of the hole annular chamber limited by the piston together with the guide pin in the cylinder block.

[0005]

According to the present invention, the arrangement of the guide pins allows the length of the piston to be shortened and thus the diameter to be increased, without having to reduce the distance to adjacent piston holes. Therefore, the strength of the cylinder block is not impaired. The guide pin and the piston together form a kind of stepped piston, and the annular chamber and the piston chamber of such a stepped piston are supplied with equal working medium pressure through the notches. .. Compared with the known art, the radial piston machine configuration according to the invention provides a pressure-bearing area which is about 44% greater than that of a piston with a guide pin under the same constructional dimensions, and thus a correspondingly increased torque. Be done. At the same time, due to the relatively large diameter of the piston and the guide pin which is connected to this piston in the direction of the axis of rotation, a good guide of the piston is obtained, so that when the torque is transmitted from the stroke plate to the rotor, The snags are effectively blocked, which guarantees a virtually lossless transfer of torque.

German Patent Application Publication No. 2004
In the radial piston machine known from U.S. Pat. No. 350, the working piston has a relatively large-diameter extension for accommodating a support sphere, this extension being exclusively for good guidance of the working piston. Only works. The annular chamber bounded by this extension is connected to the casing chamber via a lubrication gap between the guide hole and the piston-shaped extension. The application of working medium pressure to the annular chamber for the purpose of increasing the torque is not specified.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 indicates one casing half portion, and reference numeral 2 indicates the other casing half portion. A stroke plate 3 is arranged between the two casing halves. The two casing halves are combined with the travel plate by means of fixing screws 4 to form a fixed unit. A shaft 5 is supported on the casing half 1 by means of ball bearings 6, 7. End 8 of this shaft on the casing chamber side
Are configured as spline shafts and support the rotor 10 via corresponding notches 9. The rotor 10 is designed as a cylinder block and has holes 11, 18 (FIG. 2) uniformly distributed over its entire circumference. These holes are pistons 12 with guide pins 16
Help to accommodate. The piston 12 has, in its radially outer region, a bearing plate 13 for a cylindrical roller 14.
Is provided with a notch 12d for accommodating the. The cylindrical roller 14 is supported by a cam track 17 provided on the stroke plate 3. The area inside the radial direction of the piston has a piston ring 20 as a sealing element in an annular groove 12c. The length of the hole 18 is set so that the guide pin can still reliably guide the ejected piston. The guide pin is formed slightly longer than the piston stroke. The diameters of the holes 11 and 18 are set so that the hole walls left between the holes 11 and 18 adjacent to each other when viewed in the rotation direction of the rotor withstand the working pressure that appears.

Piston chamber 19 formed by hole 18
Communicates with the annular chamber 15 formed by the hole 11 and the guide pin 16 via a radial notch 27 formed in the rotor 10. The piston chamber 19 and the annular chamber 15 are likewise provided with an axially extending hole 21 provided in the rotor 10.
Is operatively connected to the control holes 22 and 23 which also extend in the axial direction. The control holes 22, 23 are provided in a stationary control sleeve 24 housed in the casing half 2. The control sleeve 24 limits the annular control chambers 25, 26, which are connection parts (not shown),
It is connected to a pressure medium source or a tank via a control valve. Depending on the relative position of the piston chamber 19 or the annular chamber 15 with respect to the control holes 22, 23, said piston chamber or the annular chamber is connected to a source of pressure medium or to a tank, whereby the torque on the rotor 10 is increased. Is formed. The rotor transmits the torque to the drive shaft or the driven shaft 5 via the spline coupling portion and further guides it to the outside.

FIG. 3 shows a different communication mode between the piston chamber 19 and the annular chamber 15 as compared with the embodiment shown in FIG. The piston chamber 19 is provided with a notch 28 extending in the axial direction provided in the center of the guide pin 16, a notch 29 extending in the radial direction, and an annular groove 30 provided at the end of the guide pin on the piston side. It is connected to the annular chamber 15.

When the supply of the working medium to the piston chamber and the annular chamber is performed separately through the separate control passage and the control chamber, the predetermined control valve is used to separately control the piston chamber and the annular chamber. It is possible to obtain a torque step. In this case, only the annular chamber is supplied with pressure medium, only the piston chamber is supplied with pressure medium, or both the annular chamber and the piston chamber are supplied with pressure medium at the same time.

[Brief description of drawings]

FIG. 1 is an axial longitudinal sectional view showing an embodiment of a radial piston machine according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an axial longitudinal sectional view showing another embodiment of the radial piston machine according to the present invention.

[Explanation of symbols]

1, 2 casing half, 3 stroke plate, 4 fixing screw, 5 shaft, 6, 7 ball bearing, 8 end part, 9
Notch, 10 rotor, 11 hole, 12 piston, 12c groove, 12d notch, 13 bearing plate, 14 roller, 15 annular chamber, 16 guide pin, 17 cam track, 18 hole, 19 piston chamber, 20 piston ring, 21 Hole, 22, 2
3 control holes, 24 control sleeves, 25, 26 control chambers, 27, 28, 29 notches, 30 annular grooves

Claims (9)

[Claims] 1. A radial piston machine, comprising an annular stroke plate (3) fixed to a casing, and a rotating body rotatably supported on the stroke plate (3) about an axis. A cylinder block (10), a large number of holes (11) arranged in the radial direction with respect to the rotation axis of the cylinder block, a piston (12) slidably supported inside the holes, and the piston. A cylindrical roller (14) for supporting the stroke plate (3), the roller having an axis extending parallel to the axis of rotation of the cylinder block. In, the piston (12) has one guide pin (16) each in the direction of the rotation axis, and the diameter of the guide pin is formed smaller than the diameter of the piston.
The hole chambers (1
Radial piston machine according to claim 9), characterized in that the cylinder block is coupled with the guide pin to be loaded with the same working medium pressure as the bore annular chamber (15) limited by the piston. 2. A sealing element (20) is provided on the piston (12) near the roller (14), the sealing element exposing the cylinder chamber formed by the annular chamber (15) to the outside. The radial piston machine of claim 1, wherein the radial piston machine is sealed against. 3. A radial piston machine according to claim 1, wherein the longitudinal extension of the piston ends immediately behind the sealing element (20) in the direction of the axis of rotation. 4. A radial piston machine according to claim 1, wherein the longitudinal extension of the guide pin is slightly longer than the working process of the piston. 5. The radial piston machine according to claim 4, wherein the longitudinal extension of the guide pin is larger than that of the working step of the piston by about 17 to 22%. 6. The radial piston machine according to claim 1, wherein the ratio of the diameter of the guide pin to the diameter of the piston is 0.5 to 0.8. 7. A hole chamber (1) limited by a guide pin.
9) is a notch (27) provided in the cylinder block
Radial piston machine according to any one of claims 1 to 6, which is connected via a piston to a bore annular chamber (15) defined by a guide pin. 8. A hole chamber (1) limited by a guide pin.
9) is a notch (28, 29) provided in the guide pin
Via an annular groove (30) and to a hole annular chamber (15) defined by a piston and a guide pin,
The radial piston machine according to any one of claims 1 to 6. 9. The working medium can be supplied to the bore chamber (19) limited by the guide pin and the annular chamber (15) limited by the piston and the guide pin together or separately via a valve. The radial piston machine according to any one of claims 1 to 6, which is