EP1907699A1

EP1907699A1 - Pump device, for instance for front and rear wheel driven motorcycle

Info

Publication number: EP1907699A1
Application number: EP06747934A
Authority: EP
Inventors: Leif Gustafsson
Original assignee: Ohlins Racing AB
Current assignee: Ohlins Racing AB
Priority date: 2005-06-20
Filing date: 2006-06-19
Publication date: 2008-04-09
Also published as: SE0501415L; US20090311117A1; WO2006137783A1; SE531362C2

Abstract

A pump arrangement (6) for generating outgoing hydraulic flow can be utilized in a front and rear wheel driven motorcycle (1). The pump arrangement is arranged to be driven by means of a rotating shaft (15) and comprises a piston arrangement that generates a flow pulse, which piston arrangement has pistons (16, 17) that move forward and backward in its longitudinal directions. An actuating device (14) connected to the rotating shaft drives the said piston arrangement. The actuating device has a cross section of constant width with at least three corners and is arranged to interact, via the periphery of the cross section, with the carrier devices (18) associated with the pistons, during its rotation caused by the rotating shaft. An improved and more durable pump arrangement with small external dimensions can thereby be obtained.

Description

Pump device, for instance for front and rear wheel driven motorcycle

The present invention relates to a pump arrangement for, among other things, front and rear wheel driven motorcycles, intended to generate outgoing hydraulic flow

(medium) that can also be at high pressure. By high pressure can, for example, be meant 350 bar. The pump arrangement is arranged to be driven by means of a rotating shaft and comprises a piston arrangement that generates a flow pulse or pulse of medium, which piston arrangement has pistons that move forward and backward in its longitudinal directions, and an actuating device for the said pistons arranged in association with the shaft.

For, among other things, the said type of motorcycle, the use of a hydraulically operating pump for supplying a propulsion arrangement for the front wheel is already known. Reference can be made, for example, to application PCT/SE2004/001782 submitted by the same applicant as the present patent application.

With this type of pump, there is a need for a pump that works efficiently but that has small external dimensions. The space for the pump is often limited and there is a need to be able to reduce the external dimensions by, for example, 40-60% compared with the external dimensions of currently known corresponding pumps. In spite of this, the pump must be able to operate with a very large output (for example 20 kW) and have a reliable and functional construction that can work with long service intervals. There is also a desire to be able to arrange for parts of the pump arrangement, for example oil supply, oil cooler, oil filter, etc, to be common to more than one hydraulic system and also to arrange the pump in such a way that this serves the hydraulic systems without there being any interaction between these, in other words achieving a modular construction.

The object of the present invention is, among other things, to solve this problem. The principal characteristic of a pump arrangement according to the present invention is that the actuating device described in the introduction has a cross section of constant width, a so-called Reuleaux cross section, with at least three corners. In a Reuleaux cross section, the distance between each corner and the opposite part of the peripheral surface perpendicular to this corner is essentially the same, irrespective of the rotational position of the cross section around the rotating shaft. The actuating device is also arranged to interact, via the peripheral surface of the cross section, with the carrier devices associated with the piston, during its rotation caused by the shaft.

In a preferred embodiment, the carrier devices are in the form of yokes that cannot rotate, but that are able to move in the longitudinal directions of the pistons. The actuating device rotates in relation to the flanges of the yokes in response to the rotation of the shaft and gives the pistons their forward and backward movements in the spaces for the pistons in a housing/body or in the cylinders. The pistons with their associated carrier devices are preferably two or more in number. In an additional embodiment, the actuating device is provided with an additional layer on the said peripheral surface, with the layer being rounded off at the corners of the actuating device in order to allow less damaging interaction with the inner surfaces of the flanges during the rotation. The number of corners is odd and can be three, five, seven, etc, in number.

In an embodiment of the invention, the pump comprises a housing with a first partial space for the actuating device and second partial spaces for the said cylinders, in which the pistons are arranged to carry out their forward and backward movements. The said rotating shaft extends into the first partial space, by means of which the actuating device is connected to the shaft. The carrier devices with the said yokes are arranged in the said first partial space, in which they are arranged to carry out forward and backward movements in the longitudinal directions of the pistons in response to the rotation of the actuating device effected by means of the shaft. In addition, in association with the said second partial spaces, the housing is provided with outlets for the generated flow of medium and inlets for a low pressure side in a particular hydraulic system. Each piston can be provided with an internal passage for medium that is open when the piston is in a first longitudinally displaced position in the relevant second partial space. The passage is closed when the piston is in a second position at least partially protruding from the relevant second partial space. A specific opening and closing arrangement is utilized for each piston. The pump can, in addition, comprise a valve arrangement that takes the flow pulses or pulses of medium generated by the pistons to a hydraulic motor for driving the drive unit for the motorcycle's front wheel. The valve arrangement can comprise spring-loaded devices, for example shims, arranged to be able to be opened and closed to pass parts or all of the flow pulses to the front wheel's drive unit. Additional further developments are apparent from the following subsidiary claims.

By means of what is proposed in the above, the pump can be assembled from reliable components. The pump can work with flow pulses or pulses of medium that are close together and that have reduced amplitude, for example considerably reduced amplitude, in comparison to pumps that operate at one pulse per revolution. The new pump can therefore easily be constructed to be very resistant to wear and it is in general less damaging to components comprised in the system. The effects on the system can thus be reduced considerably and many advantages are obtained as far as volume is concerned. No special measures need to be taken as far as space is concerned, in connection with the location of the pump. In the case, for example, of motorcycles of the type mentioned, the pump can be arranged in hitherto unutilized spaces, in spite of the fact that these have minimal volumes.

A currently proposed embodiment of an arrangement that has the significant characteristics of the invention will be described below, with reference to the attached drawings, in which

Figure 1 shows, from the side, a motorcycle with front and rear wheel drive, with the pump located in a hitherto unutilized space, Figure 2 shows, in horizontal view and in outline, parts of the motorcycle according to Figure 1 ,

Figure 3 shows, in the form of a diagram, pulse generation with one pulse per revolution according to a known pump,

Figure 4 shows, in the form of a diagram, pulse or medium generation with several pulses per revolution,

Figure 5 shows, in cross section and in outline, a carrier device with a cross section in the form of a Reuleaux triangle that can interact with a first piston arrangement,

Figure 6 shows, in cross section and in outline, the carrier device interacting with a second piston arrangement,

Figures 7-8 show, in cross section and in outline, the carrier device interacting with a piston,

Figure 9 shows, in longitudinal section, the construction of the pump with actuating device, piston and carrier device in relation to a rotating shaft,

Figure 10 shows, in horizontal section, a piston arrangement and duct system in the housing of the pump,

Figure 11 shows, in vertical section, a valve arrangement for taking pulses of medium or flow pulses generated by the piston arrangement to an outlet duct to the hydraulic unit of the front wheel, and

Figures 12-13 show, in horizontal view, constructions of the Reuleaux triangle. Figures 1 and 2 show, in outline, a motorcycle indicated by 1. The motorcycle can be of the type that comprises rear wheel drive combined with a front wheel drive that is not shown specially, cf. the abovementioned PCT-document. The rear wheel is driven in a conventional way by a motor 2 and a chain arrangement, see 3. The motorcycle's rear wheel is indicated by 4 and the front wheel is indicated by 5. The rear wheel is arranged to drive a hydraulic pump 6 via the shown chain 3, which hydraulic pump 6 is arranged in a space behind the motor 2 and an attachment point 7 for the rear wheel's pivot arm 8. The said space is indicated by 9 and is located on the left side of the motorcycle where the pump has a natural position from a functional point of view due to its small external dimensions and, in addition, does not obstruct the use of the motorcycle. Other parts of the motorcycle consist of previously well known components and will therefore not be described here in greater detail.

Figure 3 shows a diagram for pulse generation from previously known pumps. According to the diagram, one pulse 10 is generated per revolution, see the horizontal axis where the number of revolutions V is shown. The amplitude of each pulse is shown on the vertical axis. For the majority of the revolution time, there is no pulse generation by the pump in question.

Figure 4 shows the case according to the invention, from which it can be seen that the pump delivers three pulses of medium or flow pulses 11, 11' and 12 and 13. It can be seen from the diagrams according to Figures 3 and 4 that the amplitudes of the pulses differ considerably and that the amplitude of the pulse 10 is approximately three times as large as the amplitude of the pulses 11, 11' and 12 and 13. By means of the arrangement according to the invention, there is a less damaging effect on the pump and on the system in which the pump operates.

Figure 5 shows in outline the construction of an actuating device 14 comprised in the pump, which actuating device can be rotated by means of a rotating shaft 15. In the case illustrated, the actuating device consists of a Reuleaux triangle that has three corners 14a, 14b and 14c. The number of corners can vary and can be greater than three, provided that the number is odd, that is five, seven, etc. The Reuleaux-shaped cross section of the actuating device 14 acts upon a piston arrangement that has two pistons in the case illustrated according to Figure 1. Each piston is shown in outline and is indicated by 16 and 17 respectively. Each piston has a carrier device 18 that, in the embodiment, is in the form of a yoke, the flanges of which are indicated in Figure 5 by 18a and 18b. The triangular cross section 14, that thus consists of a cross section that has a constant width irrespective of the rotational position, determines the different positions of the pistons in the cylinders 19 and 20 respectively that are associated with the pistons. The pump housing can be said to comprise a first partial space 21, in which the actuating device and the said carrier device are arranged and operate. The pump housing can also be said to comprise a number of second partial spaces 22 in front of the cylinders 19, 20, in which the pistons operate. The pistons can assume first inserted positions in the partial spaces, cf. the position of the piston 16. The pistons can also assume partially projecting second displaced positions in the cylinders, cf. the position of the piston 17. The carrier devices are provided with elongated holes 23 in association with the rotating shaft 15 in order to enable each piston to assume the said longitudinally displaced positions.

Figure 6 is intended to show a case where the actuating device 14 interacts with four pistons 24, 25, 26 and 27 that are arranged in pairs on the carrier devices 28 and 29. The cylinder-shaped parts 30, 31 and 32, 33 with the second partial spaces are arranged opposite to each other in the housing 34. In other respects, the design and function correspond to what is shown in Figure 5.

Figures 7 and 8 are intended to show the case with a piston 35 and an associated carrier device 36. The actuating device with its cross section of constant width and its peripheral surface 37 acts upon the flanges 38 and 39 of the carrier device in a corresponding way to that described below, so that the piston 35 can assume its inserted position according to Figure 7 and its completely or partially projecting position according to Figure 8. In Figure 9, a piston is indicated by 39 and the actuating device by 40. A yoke on the carrier device is indicated by 41 and the housing that encloses the arrangement has the reference numeral 42. The rotating shaft is indicated by 49 and its bearings in the housing 42 are indicated by 44 and 45. A seal for the outer bearing 45 is indicated by 46. The motorcycle's motor drives an outgoing shaft 43 from the gearbox. The shaft 43 drives the rear wheel of the motorcycle via a drive 48 and chain drives the motorcycle's rear wheel via a drive 48 and chain 3 and drives a rotating shaft 49 via a carrier device 47. The bearings of the rotating shaft in the motorcycle are not shown specially, but are assumed to be constructed in a known way. The same applies for the driving of a chain wheel 48 by the drive chain 47, which chain wheel is arranged, in turn, to transfer the drive movement from the chain to the rotating shaft 43 by means of a transmission device 49. The first partial space in the housing has the reference numeral 50.

Figure 10 shows an example of the construction of the piston 51 arranged in a corresponding way as in the above, with a carrier device, one flange of which has been indicated by 52. Ducts 54 and 55 from the respective second partial spaces 56, 57 are arranged in the housing 53. The actuating device is indicated by 58. An inlet for medium that is to be pressurized is indicated by 59. The inlet leads into the first partial space 60 and the incoming flow of medium is given a certain overpressure in order to ensure the delivery of medium to the first partial space 60. Each piston consists of an outer cylinder 51a and a central part 51b that extends in the longitudinal direction of the piston. The central part has, at its upper part, a part 51c and the piston is also arranged with a part or cover 5 Id that can move in relation to the cylinder 51a. The displacement of the cover can take place upwards against the action of a spring, for example a spiral spring 5 Ie. In addition, the piston is provided with longitudinal holes, for example five longitudinal holes, one of which is indicated by 5 If, that thus extend in the longitudinal direction of the piston. The arrangement with the piston is such that when the piston assumes its fully inserted position in the partial space 56, the cover 51d closes the passage 5 If. When the piston moves towards the position in which it is partially projecting out of the second partial space 56, the overpressure on the medium in the space 60 is able to lift the cover and, during this movement of the piston, medium can flow from the space 60 to the upper side of the piston. During the movement caused by the actuating device 58 towards the fully inserted position of the piston, the medium transferred to the space 61 can, in this way, be forced via the duct 54 to the outlet 61 in the cylinder housing 53. A pulse of medium is obtained in this way.

A valve or a valve arrangement is arranged at the said outlet according to Figure 11. The valve arrangement is connected to the said ducts 54 and 55 that, in turn, according to the above, are connected to the partial spaces 56 and 576. The valve comprises a non-return valve arrangement for each internal duct 54, 55. The nonreturn valve arrangement can comprise a cover or shims 62, 63 that operate against the effect of a spring function, for example in the form of a spiral spring 64. The valve has a central part 65 arranged with openings 66. The duct 54 can be connected to the said openings 66 via a duct part 67, against the opening of which the device 62 makes contact by the action of the spring 64. In a corresponding way, the duct 55 can be connected to the said openings 66 via a duct part 68 against the opening of which the device 63 makes contact by the action of the spring 64 that can be common to the covers 62, 63. When the piston that operates in the space 56 generates a pulse of medium that enters the duct 54, the device 62 is pressed downwards in the figure and opens the duct 67, with the result that the pulse of medium can flow in through the openings 66 and out in the direction of the arrow 69 through the outlet 70 of the valve or the housing towards the unit that drives the front wheel. When the pulse of medium is forced out via the outlet, the spring 64 thereafter returns the device 62 and closes the duct 67. In a corresponding way, the device 63 is acted upon and opens the duct 68 when the piston 51 generates its impulse via the duct 55. The device 63 returns in a corresponding way to the position shown in Figure 11 when the pulse is achieved. 55a in Figure 10 represents the opening between the partial space 57 and the duct 55.

Figure 12 is intended to show that the Reuleaux triangle has a constant width, where the distance between each corner (14a, 14b, 14c) and the opposite part of the peripheral surface (37, 71) perpendicular to this corner is essentially the same size irrespective of its rotational position. The periphery 71 of the cross section (see also 37 in Figures 7 and 8) is composed of partial peripheries 71a, 71b and 71c that have essentially the same radius R. Irrespective of the rotational position of the actuating device or of the curve of constant width around the rotating shaft, the distance indicated by R will always be the same.

Figure 13 shows the case when the cross section or the periphery 71 is provided with an additional layer 72 that has a nose radius r. The total width for the curve of constant width will thus have the value of 2r+R. By the introduction of the layer 72, this can be rounded off and a less damaging interaction can be obtained with the flanges of the carrier device, cf. 18a and 18b in Figure 5. It is recognized that the pump principle has a more general application than being utilized for motorcycles, for example motorcycles of the said type. In an embodiment, the new pump arrangement can be arranged to supply medium to more than one hydraulic system, for example two, three, four, etc, hydraulic systems, that do not interact with each other in association with the provision of medium. Examples of hydraulic systems for, for example, motorcycles, include hydraulic systems for driving the front wheel, for controlling anti-locking brakes, for active control of steering dampers, etc. The arrangement can be divided between oil supply, oil cooler, oil filter, etc, without there being any interaction between the different hydraulic systems 73, 74 and 75 that are connected to second partial spaces as described above via ducts (see the broken lines in Figure 6).

The invention is not limited to the embodiments described above as examples, but can be modified within the framework of the following claims and concept of the invention.

Claims

1. A pump arrangement for, among other things, front and rear wheel driven motorcycles (1), intended to generate outgoing hydraulic flow (11, 11', 12, 13) that can also be at high pressure, which pump arrangement is arranged to be driven by means of a rotating shaft (15) and comprises a piston arrangement that generates a flow pulse, which piston arrangement has pistons (16, 17) that move forward and backward in its longitudinal directions, and an actuating device (14) for the said pistons arranged in association with the shaft, characterized in that the actuating device has a cross section of constant width (Reuleaux cross section) with at least three corners, (14a, 14b, 14c) where the distance between each corner (14a, 14b, 14c) and the opposite part of the peripheral surface (37) perpendicular to this corner is essentially the same, irrespective of the rotational position of the cross section around the rotating shaft and the actuating device is arranged to interact, via the peripheral surface (71) of the cross section, with the carrier devices (18) associated with the piston, during its rotation caused by the rotating shaft (15).

2. The arrangement as claimed in claim 1, characterized in that the carrier devices (18) are in the form of yokes (18a, 18b) that cannot rotate, but that are able to move in the longitudinal directions of the pistons, and the actuating device rotates in relation to the flanges of the yokes in response to the rotation of the shaft and gives the pistons their forward and backward movements in the spaces for the pistons in the housing/body or in the cylinders (19, 20).

3. The arrangement as claimed in claim 1 or 2, characterized in that the pistons (16, 17), and also their associated carrier devices, are preferably two or more in number.

4. The arrangement as claimed in claim 2 or 3, characterized in that the actuating device (14) in the form of the cross section (71) of constant width is provided with an additional layer (72) on the peripheral surface, and in that the layer is rounded off at the corners of the actuating device in order to allow less damaging interaction with the inner surfaces of the flanges during the rotation.

5. The arrangement as claimed in claim 2, 3 or 4, characterized in that it comprises a housing (53) with a first partial space (21) for the actuating device and second partial spaces (22) for the cylinders, in which the pistons are arranged to carry out their forward and backward movements, in that the said shaft is arranged to extend into the first partial space, by means of which the actuating device is connected to the shaft (15), in that the carrier devices (18) with the said yokes (18a, 18b) are arranged in the said first partial space, in which they are arranged to carry out forward and backward movements in the longitudinal directions of the pistons in response to the rotation of the actuating device effected by means of the shaft, and in that, in association with the second partial spaces (22), the housing is provided with outlets for the generated flow of medium and inlets for a low pressure side in a particular hydraulic system.

6. The arrangement as claimed in any one of the preceding claims, characterized in that each piston (51) is provided with an internal passage (5If) for medium between the underside and upper side of the piston and in that the passage is open when the piston is in a first longitudinally displaced position in the relevant second partial space, and is closed when the piston is in a second position at least partially protruding from the relevant second partial space (22).

7. The arrangement as claimed in claim 6, characterized in that each piston comprises a part (5Id) that is acted upon by a spring, which part, in the first longitudinally displaced position, closes the passage against the action of a spring (5Ie) and, in the second longitudinally displaced position, enables the passage to open.

8. The arrangement as claimed in claim 5, 6 or 7, characterized in that the housing (53) comprises an outer circular part that comprises the first partial space and an outer additional part connected to the circular part, which additional part extends from the circular part, and in that the said outlets and inlets (59, 76) are arranged in the said part and in that the cylinders of the pistons can be accessed from the outside of the said part.

9. The arrangement as claimed in any one of claims 5-8, characterized in that the second partial spaces (22) at the upper sides of the pistons are connected to a valve arrangement (65) that is arranged to take the flow pulses generated by the pistons to a pump, for driving the motorcycle's front wheel (5).

10. The arrangement as claimed in claim 9, characterized in that the valve arrangement comprises spring-loaded devices (shims) (62, 63) arranged to be able to be opened and closed to pass parts or all of the flow pulses (11, 11', 12, 13) to the front wheel's drive unit.

11. The arrangement as claimed in any one of the preceding claims, characterized in that, in the event of the number of corners exceeding three, the cross section of constant width has an odd number of corners (14a, 14b, 14c).

12. The arrangement as claimed in any one of the preceding claims, characterized in that the pump arrangement (6) is reduced in volume and is positioned on the motorcycle (1) in a space (9) located on one side and between the attachment point for the rear wheel's pivot arm (8) and the motor (2).

13. The arrangement as claimed in any one of claims 5-12, characterized in that one or more first second partial spaces (22) are connected to a first hydraulic system

(73, 74 and/or 75) and one or more second second partial spaces are connected to a second hydraulic system, etc, and in that the pump arrangement serves the hydraulic systems without there being any interaction between these.

14. The arrangement as claimed in claim 13, characterized in that the different hydraulic systems (73, 74, 75) utilize the basic components of the pump arrangement, for example oil supply, oil filter, oil cooler, etc.

15. A pump arrangement for, among other things, front and rear wheel driven motorcycles (1), intended to generate outgoing hydraulic flow (11, 11', 12, 13) that can also be at high pressure, which pump arrangement is arranged to be driven by means of a rotating shaft (15) and comprises an actuating device (14, 37, 40, 58) for the said pistons (16, 17, 24, 25, 26, 27, 35, 39, 51) which actuating device is arranged in association with the shaft and rotates in response to the rotation of the shaft and is arranged in a first partial space (21, 60) in a housing (34, 53), and a piston arrangement that generates a flow pulse with pistons (16, 17, 24, 25, 26, 27, 35, 39, 51) that move forward and backward in its longitudinal directions, which pistons each work in a separate cylindrical second partial space (22, 56, 57) in the same housing (34, 53) as the pistons (16, 17, 24, 25, 26, 27, 35, 39, 51), which second partial space is provided with outlets (61) for the generated flow of medium and inlets (59) for a low pressure side in a particular hydraulic system, in association with the second partial spaces (22, 56, 57), where the actuating device (14, 37, 40, 58) has a cross section of constant width (Reuleaux cross section) with at least three corners (14a, 14b, 14c), where the distance between each corner (14a, 14b, 14c) and the opposite part of the peripheral surface (71) perpendicular to this corner is essentially the same size, irrespective of the rotational position of the cross section around the rotating shaft (15) and where the peripheral surface (71) of the actuating device (14, 37, 40, 58) is arranged to interact with carrier devices (18, 28, 29, 36) connected to the pistons (16, 17, 24, 25, 26, 27, 35, 39, 51), characterized in that each outlet (61) from one or more of the partial spaces (22, 56, 57) at the upper sides of the pistons (16, 17, 24, 25, 26, 27, 35, 39, 51) is connected to a valve arrangement (65) arranged to pass the flow pulses generated by the pistons (16, 17) to a hydraulic system (73, 74 or 75) for driving the front wheel (5) of the motorcycle (1).

16. The arrangement as claimed in claim 15, characterized in that one or more second partial spaces (22, 56, 57) are connected to a first hydraulic system (73, 74, and/or 75) and one or more second partial spaces (22, 56, 57) are connected to a second hydraulic system, etc, and in that the pump arrangement serves the hydraulic systems (73, 74, and/or 75) without there being any interaction between these.

17. The arrangement as claimed in claim 15, characterized in that the first, second, etc, hydraulic systems (73, 74, and/or 75) are, for example, hydraulic systems for controlling anti-locking brakes and/or for active control of steering dampers.

18. The arrangement as claimed in claim 16 or 17, characterized in that the different hydraulic systems (73, 74, 75) utilize the basic components of the pump arrangement, for example oil supply, oil filter, oil cooler, etc.

19. The arrangement as claimed in claim 16, characterized in that the valve arrangement (65) comprises spring-loaded devices (shims) (62, 63) arranged to be able to be opened and closed to pass parts or all of the flow pulses (11, 11, 12, 13) to the front wheel's (5) drive unit.