Abstract:
A security device for a thermostat (1) for securing the thermostat (1) against theft and against damage and for securing a rotary knob (7) on the thermostat housing (6), which knob serves for adjustment of the desired value, against a predefined rotation, contains a security sleeve (4) which on the one hand engages over the coupling between the thermostat housing (6) and the adjusting valve and on the other hand engages over the rotary knob (7) and is arranged to be non-rotatably connected to the thermostat housing (6) and the rotary knob (7). So that the rotary knob (7) can be locked not only at a predetermined desired value, but can also be adjustable over a selectable range of desired values which is smaller than the normal adjustment range, provision is made for a coupling element (5) to be arranged between the rotary knob (7) and the security sleeve (4); in different rotated angular positions in relation to the rotary knob (7) the coupling element is either arranged to be non-rotatably coupled to the knob and to the security sleeve (4), or allows a limited rotation of the rotary knob (7) relative to the thermostat housing (6) for an adjustment of the desired value between two desired value limits, of which at least one limit is selectable by the non-rotatable coupling of the coupling element (5) in a rotated angular position, corresponding to this desired value limit, relative to the rotary knob (7).
Abstract:
A hydraulic machine (1) is disclosed, with an annular gear (3) with internal teeth (6, 7) and, eccentrically mounted in the annular gear, a gearwheel (2) with external teeth (4, 5) which engage with the internal teeth, the external teeth comprising one more tooth than the internal teeth and the contour of the external teeth being formed by an envelope of a system of generating circles (14), the midpoints of which lie on a trochoid (9) which, as a rolling circle (10) rolls without slipping on a base circle (11), can be generated by the movement of a point lying on a radial ray of the rolling circle co-rotating with the rolling circle. A method of producing the contour of a gear wheel of such a machine is also disclosed. In such a machine it is desirable to realise a satisfactory inner seal and low Hertzian stresses. To that end, the spacing of the point from the midpoint of the rolling circle (10) is larger than the radius of the rolling circle (10). The tooth form can then be formed by the end points of a system of line segments which are located at right angles to the trochoid (9) and are the same length as the radii of the generating circles (14), wherein the trochoid (9) encloses a closed inner face and separates it from an outer face and several intermediate faces, and the line segments are arranged only in the inner face.
Abstract:
A hydraulic axial piston machine is disclosed, having an inclined plate (7), on which a slider shoe (9) of at least one piston slides on relative movement between a cylinder body (2) receiving the piston and the inclined plate (7), and a pressure plate (10) articulated on the cylinder body (2) and holding the slider shoe (9) in engagement with the inclined plate. It is desirable for such a machine also to be operable with a hydraulic fluid that has no lubricating properties. For that purpose, between the pressure plate (10) and the cylinder body (2) there is arranged a bearing element (18) with a bearing surface (19) of plastics material, which slides with low friction on a counterpart (15) made of metal lying against the bearing surface (19).
Abstract:
A hydraulic piston machine is proposed, with a cylinder body (1), which comprises at least one cylinder (2) with a piston (3) movable therein, and a control counter-plate (7) which engages the cylinder body (1) by way of a contact surface (6) and, on relative movement between the cylinder body and the control counter-plate parallel to the contact surface, connects the cylinder in dependence upon its position with inlet and outlet channels (11, 12) respectively, the control counter-plate (7) and/or the cylinder body (1) being provided, at least in the region of the contact surface (6, 9), with a friction-reducing layer (13). A machine of that kind should be inexpensive to manufacture yet should operate reliably even when the hydraulic fluid has no or only slight lubricating properties. For that purpose the friction-reducing layer (13) is in the form of an injection-moulded part.
Abstract:
A method for mounting a cylinder sleeve (3) in a base member (1) is disclosed, in which the cylinder sleeve (3) is inserted in the base member (1) and the outer diameter of the inserted cylinder sleeve is enlarged at one end, and a hydraulic machine with a base member (1) in which at least one cylinder sleeve (3) is arranged in a cylinder bore (2). In this connection, it is desirable to be able to use materials for the cylinder sleeve that could not previously be satisfactorily fixed in the base member (1). For that purpose, the cylinder sleeve (3) is heated before the outer diameter is enlarged. The cylinder bore (2) has at at least one end a gradual enlargement (12) of diameter and the cylinder sleeve (3) has an enlargement (7) of its outer diameter matched to this enlargement (12) of diameter.
Abstract:
A hydraulic system with a pump (1) of fixed positive displacement, a tank (42) and a valve group connected via a tank line (118) to the tank (22) is disclosed, which has at least one load valve (105 to 107) and a control section (103) comprising a pilot overflow valve (16) for control of the hydraulic fluid supplied to the load valve in accordance with demand. In a system of that kind, it is desirable to be able to arrange an auxiliary valve arrangement in the tank line without the function of the system being adversely affected. For that purpose, besides the auxiliary valve arrangement (31) provided in the tank line (118) for controlling a further hydraulic load, provision is made for the discharge side of the pilot overflow valve (16) to be connected to a point of constant pressure.
Abstract:
A hydraulic steering arrangement for vehicles is proposed, with a steering motor (5), a flow amplifier (4) in fluid connection therewith, which amplifies a fluid flow measured by a steering measuring device (1), at least one sensor (10, 11, 13), which determines a performance characteristic of the vehicle, and a control device (9), which changes the amount of fluid supplied to the steering motor in dependence on an output signal of the sensor. In a steering arrangement of that kind, it is intended to correct or adapt the steering behaviour to the operational state of the vehicle using simple means. For that purpose, the control device (9) changes the amplification factor of the flow amplifier (4).
Abstract:
The invention concerns a motor power supply with a DC intermediary circuit (7) arranged between an inverter (8) connected to the motor (3) and a DC voltage source (6), the motor power supply having a control unit (10) with an input connected to the DC intermediary circuit (7). With a motor power supply of this kind it is possible to further improve the efficiency of a motor-compressor unit (2), driven by the motor (3). For this purpose the DC voltage source (6) is controlled by the control unit (10), and the control unit (10) sets the product of intermediary circuit current and intermediary circuit voltage at a value close to or at the lowest possible value.
Abstract:
The invention concerns a gear pump comprising a housing (12) provided with an inlet (17) and an outlet (19), an internally toothed ring (3) and an externally toothed gear wheel (2) which is arranged inside and meshing with the toothed ring. A cylindrical bore (7) is provided in the gear wheel, and a bearing unit (6) is arranged in the cylindrical bore for rotatable bedding of the gear wheel with respect to a rotation axis (A) arranged eccentrically in relation to the ring axis (C) and with the bearing unit being pivotable around the gear wheel axis. The gear ring is fixed to the housing, and means is provided for driving the gear wheel into an orbiting movement within and in relation to the gear ring to create a number of expanding chambers (16) and a number of contracting chambers (18) between the gear wheel and the gear ring. A commutator plate (20) is arranged next to the gear wheel and the gear ring in a space in the housing, and connected to the driving means in a way to rotate at the speed of the orbiting motion around the gear ring axis. The commutator plate has channels (32, 33) connecting the expanding channels and the contracting channels with the inlet and outlet respectively.
Abstract:
The invention concerns a sealing element for the establishment of a sealing in a pump, in which a rotatable shaft (2) extends through a shaft hole (11) and through an internal tooth wheel (9) arranged in a pump chamber (7). The sealing element (19) comprises a first fixed sealing ring (20) having a breast (22) bearing against a side wall (5, 6) of the pump chamber, and a second flexible sealing ring (21) arranged between the rotatable shaft (2) and the first sealing ring (20). Preferably, the first sealing ring has a collar (24), the second sealing ring being arranged between the rotatable shaft and said collar. The invention is characterised in that the mounting height of the sealing element in the pump is very small. This is caused by the fact that the second sealing ring is arranged between the first sealing ring and the rotatable shaft, and that the breast of the first sealing ring is bearing direct against the first side wall.