JP2781270B2 - Hydraulic positive displacement machine - Google Patents

Description

The present invention comprises a chamber in a housing with a rotor and a liquid inlet tube and a liquid outlet tube, the chamber being sealed to the chamber wall. And a hydraulic positive displacement machine (pump or motor) separated by at least one partition which can move relative to the chamber wall.

[Conventional technology]

Liquid pumps or liquid motors that operate on the volume exclusion principle, collectively referred to herein as hydraulic displacement machines, are configured in various forms, for example, as vane pumps or vane motors. These are common in that liquid is introduced into or discharged from a space separated by a partition in a chamber of a housing, and the volume of the separated space changes. This requires additional moving parts besides the rotor moving relative to the chamber. For example, in the case of a vane pump, the vane forming the partition must move relative to the rotor in order to be able to change the chamber volume. In the case of a rotary piston pump, two rotary pistons are required which mesh with each other in a gas-tight manner.

In order to make the known positive displacement machines controllable, for example to make the volumetric flow of the pump controllable or to control the rotational speed of the motor, additional additional moving parts are required. .

Structural components need to move in and out of the chamber with respect to the pure rotational movement of the rotor, which increases construction costs and results in wear. In that case, it must be taken into account that such positive displacement machines in hydrostatic installations are often designed for very high pressures which produce high surface pressures in the sealing area.

Another problem with known controllable hydraulic displacement machines is that the control process cannot be performed quickly and sufficiently for many use situations. Often in the range of servo devices of various constructions, for example, hydraulic cylinders are operated at high speed, i.e.
Very precise control over distance, force, speed and acceleration at frequencies as low as Hz requires very short control times.

[Problems to be solved by the invention]

It is an object of the present invention to provide a hydraulic positive displacement machine of the type described at the outset in which there is no moving parts other than the relative movement of the rotor and the chamber with a simple structure and the pump and the motor can be controlled at high speed. It is in.

[Means for solving the problem]

According to the invention, it is an object of the present invention to provide a hydraulic positive displacement machine of the type mentioned at the outset in which a plurality of mutually opposing end walls of the chamber can be energized in pairs by an electric control device. This is achieved by having a condenser plate segment, wherein the chamber is filled with an electrorheological liquid, and the liquid inlet tube and the liquid outlet tube each open on opposite sides of the partition.

By using an electro-rheological liquid as the operating liquid of the hydraulic positive displacement machine, a part of the chamber can be partially formed only by applying a voltage to a predetermined capacitor plate segment when the rotor and the chamber move relative to each other. It can be separated in the form of a partition against the remaining chamber volume. This separation can be changed very quickly electrically, so that the volume of the space before and after the partition can be changed continuously during the relative movement of the rotor and the chamber. In this way, a hydrostatic positive displacement machine (pump or motor) can be realized which operates with continuous rotation and is controlled with little delay, without additional moving parts.

The use of electrorheological liquids for control and regulation is already known (DE-A-360986).
No. 1). The working principle used at that time is
A voltage is applied to the capacitor plate in the flow path containing the electrorheological liquid, thereby changing the viscosity of the electrorheological liquid between the capacitor plates until solidification.

An electrorheological liquid is a dispersion of fine hydrophilic solid particles in a hydrophobic, non-conductive oil. Under the influence of an electric field, the viscosity of this liquid changes very quickly to solidification. By using an electrorheological liquid, a hydraulic device having no moving parts can be made or the number of moving parts can be significantly reduced. It is known to be used for a hydraulic valve, a hydraulic cylinder, a vibrator, a viscous joint, an impact damper, or an engine mount (US Pat. Nos. 2,661,596, 3,840,086, and 2417).
No. 850, No. 3207269, German Patent Application No. 3128959, European Patent Application No. 1
No. 37112).

In an advantageous embodiment of the hydraulic displacement machine (pump or motor) according to the invention, the partition is a vane connected to the rotor, which vane rotates with the rotor between the two end walls fixed to the housing of the chamber. It is proposed that the liquid inlet pipe and the liquid outlet pipe are each led through the rotor to the opposite side of the vane, as possible and airtightly housed. Before and after the vanes rotating in the chamber, the space connected to the liquid inlet or liquid outlet tube, respectively, is spaced apart from the vanes, for example when the vane is one, for example on the side opposite to the vanes, By applying a voltage between the capacitor plate segments, a separation is made by creating a shield which acts as a wall for the liquid present in the space. As the vanes rotate, the walls created electrically in the liquid also move in the direction of rotation of the rotor.

According to another advantageous embodiment according to the invention, the rotor has at least two rotor disks forming end walls with capacitor plate segments of the chamber, the partition being fixed to the housing between the two end walls. Placed
It is proposed that the liquid inlet tube and the liquid outlet tube are each led in the housing to the opposite side of the partition.

In this case, unlike the structure described above, there is an advantage that the liquid pipe can be guided through the fixed housing, and nevertheless, it is only necessary to lead the electric wire to the capacitor plate segment via the rotating rotor in a structurally simple manner. Have.

Since the control of the positive displacement machine is performed solely electrically without moving parts, it is possible to switch very quickly, for example between pump operation and motor operation. In the same way, the pressure, the flow rate or the rotational speed can be controlled very quickly.
The main advantages of the positive displacement machine according to the invention are its high dynamics and its simple and almost wear-free construction. Positive displacement machines that can be controlled in this way combine, for example, the functions of a pump and a servo valve. This makes it possible to realize a very simple rotation and swing drive that can be controlled with high precision. Such drives are of great value for the automation and robotics industries.

Further advantageous embodiments of the invention are described in the other claims.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The positive displacement machine shown in FIGS. 1 and 2 will be described, for example, in the case of pump operation. In the housing 1,
A rotor 2 driven by a schematically illustrated motor 3 is supported. The housing 1 is formed with two chambers (chambers) 4 that are spaced apart in the axial direction.

End walls 5 located opposite each other in each chamber 4 are provided with capacitor plate segments 6. In the embodiment shown, the end walls 5 are mutually connected and the housing 1
Supports the capacitor plate segment 6 which is electrically insulated from the capacitor plate segment 6. This capacitor plate segment 6 is connected to an electric control device 8 via an electric wire 7.

In each chamber 4, a vane (blade) 9 connected to the rotor 2 rotates. This vane 9 is sealed against the wall of the chamber 4. A suction pipe or liquid inlet pipe 10 leads from the liquid storage tank 11 through the housing 1 to an annular groove 23 from which the passage 12 in the rotor 2 is located on the back of the vane 9 (in the direction of rotation). It leads to an opening 13.

A passage 14 extends from the front of the vane 9 through the rotor 2 to form an annular groove.
From this annular groove 15 a liquid outlet tube 16 leads through the housing 1 to a load 17 shown schematically in FIG. The introduction and discharge of liquid into the second chamber 4 takes place in the same way.

An electrorheological liquid is present in the chamber 4 forming the annular gap. When a voltage is applied to the pair of oppositely located capacitor plate segments 6 via the electric control device 8, the electrorheological liquid between the capacitor plate segments 6 on both sides solidifies, and the chamber 4 The circumferential area is sealed. In the illustrated embodiment,
When the vane 9 rotates in the direction of arrow 18 in FIG. 2, for example, a voltage is applied to a pair of oppositely located capacitor plate segments 6 ', whereby the chamber 4 is sealed in this area. The moving vane 9 sucks the liquid from the liquid inlet pipe 10 on the rear side and compresses the liquid on the front side. The liquid is thus pushed out to the load 17 through the passage 14, the annular groove 15 and the liquid outlet tube 16. During the continuous rotation of the vane 9, the voltage application to the capacitor plate segment 6 is controlled so that the voltage is applied to the pair of capacitor plate segments 6 ″ on both sides.

The liquid pressure in the space in front of the vane 9 is determined by the electro-rheological liquid between the capacitor plate segments 6 on both sides being electrically held. When the pressure increases, the blockage created between the energized capacitor plate segments 6 is more compressed by the solidified liquid. This results in an automatic pressure limitation.
In order to maintain the pumping action and the suction action, the voltage application on the capacitor plate segment 6 is turned in accordance with the rotational movement of the vanes 9. The pump pressure is controlled in accordance with the applied voltage. When trying to control the flow, this is done by pulsating modulation of the applied voltage. The resulting average flow rate is adjusted with respect to the pulse time and / or pulse frequency.

The control device 8 receives a signal from the rotor position detector 21 in order to ensure that the correct capacitor plate segment 6 is energized in each case according to the position of the vanes 9.

The vane 9 has a hydrostatic support 19 on the surface of the chamber 4 on the side of the end wall 5. The support pocket is a hydraulic throttle 20
Is connected to the pressure side of the vane 9. The hydrostatic support 19 is provided between the side walls 5 on both sides of the chamber 4 so that the vanes 9
Is hydraulically centered.

As in the embodiment in FIGS. 1 and 2, a plurality of vanes 9 can be arranged in their own chamber 4 on one common roller 2. Alternatively, it is also possible to construct a positive displacement machine with only one chamber 4 or to provide a plurality of vanes 9 in each chamber 4.

In the illustrated embodiment of the pump with two chambers 4, both chambers 4 can be operated as independent pumps as shown. Alternatively, both chambers 4 (or a plurality of chambers) can be connected in series as a pump stage, in which case the flow can be conveyed continuously by controlling in a pulsed manner.

A particularly suitable embodiment is that the pump is operated as a double pump. In other words, the double pump can simultaneously operate a differential cylinder or a same-speed cylinder by operating each pump stage (or a pump group connected in parallel) on one cylinder chamber of a double-acting hydraulic cylinder (not shown). It is also used as a servo pump for controlling Depending on the desired movement of the hydraulic cylinder, one pump stage is adjusted to inlet and the other pump stage is adjusted to return. Since no voltage is applied to the capacitor plate segments in the chamber 4 to adjust the return, the liquid flows freely through the chamber 4 from the inlet 13 to the outlet 14 and there is no obstruction inside the chamber 4.

3 and 4 show an embodiment different from the above-described embodiment. In that case, the same parts as those of the previous embodiment are denoted by the same reference numerals.

In this case, the rotor 2 has three rotor disks 22 which are connected to the capacitor plate segments 6.
Is formed on the end face wall 5 of the chamber 4 provided with. The partition 9 'functions in a manner corresponding to the vane 9 in the embodiment of FIGS. The partition wall 9 ′ is fixed to the housing 1, and protrudes airtightly between the end face walls 5 to the rotor 2. In this case, the liquid inlet pipe 10 and the liquid outlet pipe 16
Are guided through the housing 1 to the opposite side of the partition wall 9 '. The electric wire 7 is led to the capacitor plate segment 6 via, for example, a slip ring 24 or by inductive transmission by the rotor 2.

During the rotation of the rotor 2, the separation takes place in the chamber 4 by applying a voltage between the rotor disks 22 on the side remote from the partition wall 9 ′ to the capacitor plate segments 6 arranged there. In each such separated space of the chamber 4 a pressure is created by the rotation of the rotor 2.

The positive displacement machine described above can also operate as a motor in the same mechanical construction. For this purpose, liquid is introduced under pressure into the vane 9 or one side of the partition 9 ′, whereby a torque is applied to the rotor 2.

[Brief description of the drawings]

1 is a sectional view of a hydraulic displacement machine formed as a vane pump, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a hydraulic displacement machine formed as a pump. FIG. 4 is a sectional view taken along line IV-IV in FIG. DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Rotor, 3 ... Motor, 4 ... Chamber, 5 ... End wall, 6 ... Condenser plate segment, 8 ... Control device, 9 ... Vane, 9 '... Partition wall, 10 ... Liquid inlet pipe, 16
... liquid outlet tube, 19 ... support, 20 ... throttle, 22 ... rotor disk.

Claims (6)

(57) [Claims] 1. A chamber having a rotor and a housing in a housing having a liquid inlet tube and a liquid outlet tube, the chamber being sealed to the chamber wall and at least one being movable relative to the chamber wall. In a hydraulic positive displacement machine (pump or motor), such as partitioned by a partition, opposing end walls (5) constituting a chamber wall of the chamber (4) are each controlled by an electric control unit (8). It has a plurality of capacitor plate segments (6) each capable of applying a voltage in pairs, wherein the chamber (4) is filled with an electrorheological liquid, and the liquid inlet tube (10) and the liquid outlet tube (16) each have a partition wall. A hydraulic positive displacement machine characterized by having an opening on the opposite side of (9, 9 '). 2. The partition wall is a vane (9) coupled to a rotor (2), said vane (9) being located between two side walls (5) fixed to the housing of the chamber (4).
Liquid inlet pipe (10) that can be rotated and stored in an airtight manner
2. The vacuum positive displacement machine according to claim 1, wherein the liquid outlet pipes (16) are respectively guided through the rotor (2) to the opposite side of the vanes (9). 3. The rotor (2) has at least two rotor disks (22) forming an end wall (5) with a capacitor plate segment (6) of a chamber (4), and a partition (9 ') is provided. The liquid is fixedly arranged on the housing between the two end walls (5), and the liquid is supplied to the inlet pipe (10) and the liquid outlet pipe (1).
2. A hydraulic displacement machine according to claim 1, wherein each of the housings is guided in the housing on the opposite side of the partition wall. 4. A plurality of chambers (4) are arranged side by side in the axial direction, and at least one chamber is provided in each chamber (4).
4. The hydraulic positive displacement machine according to claim 2, wherein there are two vanes (9) or partition walls (9 '). 5. The partition (9, 9 ') has at least one hydrostatic support (19) on the side of the chamber (4) on the side of the end wall (5), the support pocket having a hydraulic pocket. Compression drawing (2
2. The hydraulic positive displacement machine according to claim 1, wherein said hydraulic positive displacement machine is connected to the pressure side of said partition wall via an outer wall. 6. A hydraulic positive displacement machine according to claim 1, wherein each end wall (5) of the chamber (4) is divided into four capacitor plate segments (6).