The two last mentioned or proposed arrangements may com- prise a hydraulically or pneumatically influenced pendulum piston motor or annular piston motor consisting of a cylin- der housing and a toroid shaped cylinder bore, in which a pendulum piston means is pivotable in two opposite direc- tions over an angle of up to approx. 350-356°, and where the cylinder bore at one location is divided by a piston chamber wall, and where the pendulum piston means is asso- ciated with a flywheel mass, which is connected to a cen- tral output shaft.

Thus, the invention is applicable to motors having constant rotation in one direction only to effect a reversal of the rotation direction of the output shaft, or applicable to motors of pendulum piston type as disclosed and described in the two last mentioned publications, said motors being designed in such a manner, that the output shaft always rotates in one direction only although the pendulum has a reciprocating sequence of operation.

Problem A problem related to such types of motors has been to ef- fect a reversal of the direction of rotation of the output shaft without using a specific reverse gear mechanism. With

such a motor it is desirable to provide a rotation revers- ing means, which is specially designed and connected within the pendulum piston motor itself.

According to the present invention this is achieved in such a manner, that between the output shaft and the drive cen- tre in the gear mechanism there are two sets each of which including two freewheels, one of the freewheels for driving clockwise and the other for driving anticlockwise. Inside the rotation centre the output shaft has a displaceable sleeve, which is displaceable to a limited extent on a part of the output shaft, and which can occupy two different end positions (c. f. figure 1 and 2, respectively), which are defined by two slots, through which radial pins are extend- ing, and these pins in co-operation with the slots provide a drive force transmission between the sleeve and the out- put shaft.

Attached drawings In the attached drawings the new invention is illustrated, which is applied to a constantly rotating motor as well as to a pendulum piston motor of the above-mentioned type known per se. In the drawings figure 1 shows a rotation reverser in accordance with the invention, which is applied in a motor of constantly rotation type, in a position for rotation in a first direction, and figure 2 shows the same rotation reverser for rotating the output shaft in a direc- tion opposite to the first direction. Figure 3 shows the rotation reverser of figure 1 being installed as a drive centre in a pendulum piston motor. Figures 4,5 and 6 show a somewhat modified type of rotation reverser, which is designed for driving in a first direction, e. g. clockwise as shown in figure 4, and also provided with a neutral function position, as shown in figure 5, as well as for driving in a direction opposite to the first direction, e. g. anticlockwise as shown in figure 6.

Detailed description Figures 1 and 2 show a gear mechanism with an input shaft 1, which constantly rotates in a certain direction, clock- wise in the illustrated case, and which is intended for driving an output shaft 2 by way of a differential gear mechanism 3 having input bevel gears 4, against one of which the input shaft 1 is connected in a non rotary fash- ion, and output bevel gears 5, which are provided to trans- mit a torque force from the input shaft 1 to the output shaft 2.

Between the output shaft 2 and each of the output bevel gears 5 the gear mechanism is provided with one set of two freewheels 6,7 and 6a, 7a respectively, e. g. of so called INA type, where one of the freewheels is arranged for driv- ing in a certain direction, e. g. in anticlockwise direc- tion, and the other freewheel is arranged for driving in clockwise direction. From a driving point of view the free- wheels are arranged as +/-and-/+ respectively.

The freewheels 6,7 and 6a, 7a, respectively, are installed in such a manner, that one of the freewheels in each pair of freewheels co-operates, in that one of the freewheels 6, 7a is a clockwise freewheel and the other freewheel 6a, 7 is a anticlockwise freewheel, this accordingly being the requirement of driving the output shaft constantly in one direction only, forwards or backwards respectively.

For driving influence by the freewheels 6 and 7 there is provided a sleeve 8, which is displaceable on a diametri- cally reduced part 9 of the output shaft 2, and which is provided with one or preferably two axial slots 10, through which extends a fixed pin 11, which is secured to the out- put shaft 2. In that way the pin 11 forms a rotational connection between the output shaft 2 and the sleeve 8. For each pair of freewheels 6,7 and 6a, 7a, respectively, there is a catch surface 12 and 12a, respectively, on the sleeve 8, e. g. an eccentric circular surface provided for

drivingly co-operating with one or other of the freewheels 6 (6a) or 7 (7a) thereby transmitting the driving movement from the input shaft 1 to the output shaft 2 by means of the sleeve 8 and the radial pins 11.

The freewheels 6-7 and 6a-7a are designed for opposite driving directions, and the pair of freewheels in the two sets of freewheels are mutually opposite, i. e. the free- wheel 6 of one set is driving at the same time as the free- wheel 6a of the other set is running freely, imposing clockwise drive direction on the output shaft 2, as shown in figure 1, whereas the freewheel 7a is driving and the freewheel 7 is running in free position in the axially displaced position of the sleeve 8 with the catch surfaces 12, imposing a reversed drive direction on the output shaft 2 which accordingly rotates in anticlockwise direction, as shown in figure 2. One of the directions is designated forwards and the other direction backwards.

The mechanism functions as follows: In figure 1 there is shown how the input shaft 1 rotates an input bevel gear 4, which causes a corresponding drive of the remaining bevel gears 4 and 5 in the differential gear mechanism. By means of the catch surface 12 one of the freewheels 6 transfers the driving movement forwards from the output gear 5 to the sleeve 8, which in turn transfers the rotational movement forwards to the output shaft 2. The other catch surface 12a co-operates simultaneously with the freewheel 6a of the other freewheel set, which freewheel runs freely in this position.

To effect driving of the output shaft 2 backwards, in anti- clockwise direction the case shown, the sleeve 8 is pulled out in such a manner that the catch surfaces 12 and 12a engage the freewheels 7 and 7a. The freewheel 7 runs freely, whereas the freewheel 7a is driving, in this case in a direction opposite to the direction mentioned above,

thus in anticlockwise direction as shown in figure 2, thus in the backward direction.

In figure 3 there is shown a pendulum piston motor of a type known per se, in which a piston 13, which is recipro- catingly pivotable in a toroid shaped working chamber 14, and which is fastened in a part 15 of a rotation centre 16 designed essentially as a differential with four co- operating bevel gears, in the case shown two pairs of co- operating gears 4 and 5. Between the output shaft 2 of the pendulum piston motor and the rotation centre 16 the motor is-in the same manner as described above with reference to figures 1 and 2-provided with two pairs of freewheels 6,7 and 6a, 7a respectively, e. g. of INA wheel type, which are mutually opposed; thus the reciprocating movement of the piston causes that the freewheels alternately drive and alternately run freely, i. e. one of the freewheels, e. g. 6, drives the output shaft 2 when the pendulum piston 1 pivots clockwise, and the other freewheel 7a drives the shaft 2 when the pendulum piston pivots anticlockwise, whereby the output shaft 2 constantly rotates in one direction only, forwards or backwards, in spite of the fact that the pendu- lum piston pivots to and fro in the toroid shaped working chamber 14.

The pendulum piston motor functions as follows.

The pendulum piston 13 performs a reciprocating movement in the working chamber. In the position shown in figure 3 the freewheel 6, which co-operates with a first catch surface 12, causes a driving in a certain direction, e. g. forwards, whereas the other freewheel 6a, which co-operates with the other catch surface 12a, is running freely. When the pendu- lum piston reverses direction after almost 360° rotation, the freewheel 6a of the other set of freewheels will engage and continue the rotation of the output shaft 2 in the same direction as before, that is to say forwards, whereas the

freewheel 6 is running freely. In this manner the output shaft 2 will be driven constantly forwards.

Then, when the sleeve 8 is displaced downwards as shown in figure 3, the freewheel 7a will-during the first oscil- lating movement of the pendulum piston 13-drive the out- put shaft 2 in a direction opposite to the first-mentioned direction, i. e. backwards, whereas the freewheel 7 runs freely, and during the opposite oscillating movement of the piston the freewheel 7 will continue to drive the output shaft in the same movement backwards as before, and simul- taneously the freewheel 7a runs freely.

Reversal from the forward direction to the backward direc- tion and vice versa is effected very simply by pulling out the sleeve 8 to its outer end position, which is defined by the ends of the slots 10, or by pushing it in to its inner end position, respectively, which also is defined by the ends of the slots 10.

In many cases it may be desirable that the gear mechanism has a neutral position, in which the motor with the input shaft 1 can rotate freely without driving the output shaft 2. This may be achieved in the manner shown in figures 4-6.

In this case the freewheels 6-7 and 6a-7a, respectively are separated by means of a neutral position sleeve 17 and 17a, respectively, which is slightly longer than the catch sur- faces 12,12a. In figure 4 the sleeve 8 is shown in a fully inserted position corresponding to driving forwards, in fig 5 the sleeve is shown in an intermediate position corre- sponding to the neutral position sleeve 17,17a, whereby the output shaft 2 is fully disconnected and the input shaft can rotate freely in either direction. Figure 6 shows the sleeve 8 in a fully extended position, whereby the rotational movement from the input shaft 1 is transmitted to a rotation backwards of the output shaft 2.

Reference designations 1 input shaft 2 output shaft 3 differential gear mechanism 4 input bevel gear 5 output bevel gear 6 freewheel 6a freewheel 7 freewheel 7a freewheel 8 sleeve 9 part (of the output shaft 2) <BR> <BR> 10 slot<BR> 11 pin 12 catch surface 13 pendulum piston 14 working chamber 15 fixed part 16 rotation centre 17 neutral position sleeve