A Hydraulic Retarder Attached with Parking Brake

Europaisches Patentamt © J European Patent Office © Publication number: 0 287 099 Office europeen des brevets A2

EUROPEAN PATENT APPLICATION

@ Date of filing: 14.04.88

® Priority: 15.04.87 JP 92854/87 © Applicant: AKEBONO BRAKE INDUSTRY CO., 21.04.87 JP 98148/87 LTD. 19-5, Koami-cho, Nihonbashi @ Date of publication of application: Chuo-ku Tokyo(JP) 19.10.88 Bulletin 88/42 © Inventor: Fujinami, Hideyuki © Designated Contracting States: No. 703-3, Shimoishitoshimo DE FR GB IT Kitamoto-shi Saitama-ken(JP)

A hydraulic retarder attached with parking brake.

© Hydraulic retarder attached with parking brake is disclosed, which is characterized by comprising a brake drum (11); (53) which rotates unitedly with drive shaft or propeller shaft (2); (52) rotatable relative to a fixed member (1); (51) of behicle, member- (s) (5); (59), (75) which is(are) constructed unitedly with said fixed member (1); (51) and which has- (have) a plurality of stator vanes (8); (65), a drum brake (B) to brake said brake drum (1 1 ); (53) which is provided inside said brake drum (11); (53) and which works by operating a parking lever (20); (76) pivotally supported by said member(s) (5); (59), (75), a rotor (9); (57) which is opposite to said stator vanes (8); (65) and which has a plurality of rotor vanes (10); (56), said member(s) (5); (59), (75) which 2Shas(have) a supplying port (6); (78) to introduce the ^cooling liquid to a space between opposed faces of 05 said stator vanes (8); (65) and said rotor vanes (10); O> (56) and a discharging port (7); (79) to discharge the cooling liquid, a clutch piston (16); (70) which is ^ fitted insertedly to said member(s) (5); (59), (75), and 00 clutch mechanisms CM (26), (25a), (25), (24); (66), (64), (63a), (63), (55) to transmit the rotation of said drive O shaft or propeller shaft (2); (52) to said rotor (9); (57) Q,,by working of said clutch piston (16); (70). LU

Xerox Copy Centre 0 287 099

A HYDRAULIC RETARDER ATTACHED WITH PARKING BRAKE

cooling oil (A) is supplied to a portion between the BACKGROUND AND SUMMARY OF THE INVEN- rotor vanes (102) and the stator vanes (105) pro- TION vided oppositely in the vane chamber (104) to transmit the energy of rotating rotor vanes (102) to The present invention relates to a device in 5 the circulating cooling oil as a heat resulting in the which a hydraulic retarder used for large scale deceleration. vehicles such as buses, trucks, etc. and a parking Besides, in the drawing, numeral (106) is a brake are united, and the performance of the fluid tank of cooling oil and numeral (107) shows an oil type retarder is improved. pump feeding the cooling oil to the retarder. Usually, there are three kinds of braking de- m The control of the working of retarder afore- vices for motor cars, depending on the purposes mentioned is conducted by means of the flow rate for use routine brake, parking brake and reduction of cooling oil to be supplied into the vane chamber, device. Among them, the routine brake is a treadle that is, the level of oil surface. Therefore, in particu- type brake which brakes whole wheels and is used lar, when stopping the working, this is carried out for deceleration and stopping of vehicle. The park- 75 by discharging the cooling oil. As a result, in this ing brake is a manual brake and there are a type to case, the deceleration effect of retarder due to the work the same device as the routine brake for rear remaining cooling oil, that is, the drag torque re- wheels through a different transmission mechanism mains. Further, there have been such. problems and a center brake used exclusively for parking by that the device for controlling the level of oil sur- attaching to the transmission or the propeller shaft. 20 face is expensive and heavy in weight. It can be used for assistance at the time of the Moreover, the uniting of retarder with parking breakdown of the routine brake and for stopping brake has been desired strongly for lightening in vehicle at the time of emergency. weight and making compact. As such parking brake, duo-servo type drum The purpose of the invention is to provide a brake is used generally, in which two brake shoes 25 fluid type retarder attached with parking brake each laminated with brake lining on a semicircular eliminated the generation of said drag torque and member are connected through a link inside a capable of being manufactured in low cost.' brake drum rotatable unitedly with a wheel axle, and the rotation of the wheel axle is stopped by pressing these shoes against the brake drum 30 BRIEF DESCRIPTION OF THE DRAWINGS through the operation of a parking lever. The deceleration device is used for large scale Fig. 1 is a cross section in side view showing trucks or buses from a reason of being in danger the first example of the invention, Fig. 2 is a cross that, when descending a long slope, the perfor- section in side view showing the second example mance of brake is lowered with the routine brake 35 of the invention, and Fig. 3 is a cross section in alone due to the heat generation at the friction side view showing the conventional example. portion of the brake, and there exist exhaustion brake, hydyaulic retarder, electromagnetic retarder, etc. Among them, the hydraulic retarder DETAILED DESCRIPTION OF THE INVENTION (hereinafter referred to as retarder simply) exhibits 40 a preferable characteristic as the deceleration de- The first example of the invention will be illus- vice in that the absorbing horse power increases trated in detail using Fig. 1 . abruptly with an increase in the number of revolu- In this example, a side plate (1a) of a transmis- tions and is assembled most frequently into the sion case (1), through which a drive shaft (2) transmission or the driving device of rear wheels. 45 - passes, is made as one side plate of a vane As shown in Fig. 3, the body of the retarder chamber (3) of a retarder. The vane chamber (3) is aforementioned is fixed radially making the wheel covered fluid-tightly by measn of a backing plate axle (101) as a center, a vane chamber (104) is (5) attached to the transmission case (1) with a provided around the wheel axle (101) by means of plurality of bolts (4). A supplying port (6) for sup- a plurality of rotor vanes (102) which rotate unitedly 50 plying the cooling oil to said vane chamber (3) with the wheel axle (101) and a vane chamber case from lower portion and a discharging port (7) for di- (103) surrounded by said vanes (102), and stator scharging the cooling oil from upper portion are vanes (105) fixed to the vane chamber case (103) provided. And, on the side of vane chamber (3) of are formed in said vane chamber (104) oppositely said backing plate (5), a plurality of semicircular to the rotor vanes (102). For working the retarder, stator vanes (8) are formed radially of curvedly 0 287 099

making the drive shaft (2) as a center and further, the rotation of the drive shaft (2) can immediately oppositely to said stator vanes (8), a plurality of be braked. Also, when turning off the retarder, by semicircular rotor vanes (10) are provided radially working the clutch piston (16) to turn off the clutch, or curvedly in a similar manner to a rotor (9) the rotation of the drive shaft (2) vecomes instanta- rotatable around the drive shaft (2). 5 neously not subject to the braking of the retarder In the inner circumference of said rotor (9), and thus the drag torque also becomes unrelated. there exists a cylindrical member (25) which is in The response at the time of re-acceleration be- spline engagement (24) to said rotor. This cylin- comes good. Moreover, when parking, teh brake drical member (25) is extended from a space be- lining (17) is pressed against the outer circumferen- tween the backing plate (5) and the drive shaft (2) 10 tial plate (13) of the brake drum (11) by operating to outside the vane chamber (3) keeping the clo- the manual type parking lever (20) to allow the sure of vane chamber (3). With a flange (25a) rising drive shaft (2) to stop. at right angles to the drive shaft (2) from the end of The second example of the invention will be said extension, a disk-like clutch plate (26) is sup- illustrated in detail using Fig. 2. ported. Further, outside said plade (26), a circular 75 In this example, a plurality of planetary gears side plate (12) of a brake drum (11) being rotatable (55) are provided at a protrusion (61a) protruded and united with the drive shaft (2), is provided from a step portion (61) of a circular side plate oppositely and the outer circumferential portion of (54) of a brake drum (53) which rotates unitedly said side plate (12) is extended outward toward the with a drive shaft (52) provided protrusively form a transmission case (1) to form an outer circumferen- 20 transmission case (51). And, to a rotor (57) being tial plate (13) of the brake drum (11). Moreover, the an outer sun gear inscribing said gears (55), a outer circumference of a disk-like pressure plate plurality of rotor vanes (56) are provided radially (14) is fitted to said outer circumferential plate (13) making the drive shaft (52) as a center. A vane so that siad clutch plate (26) is put between the chamber case (59) is formed unitedly with the circular side plate (12) and the pressure plate (14) 25 transmission case (51) so that a vane chamber shile the inner circumference of the latter is fixed to (58) of the retarder is formed around the drive shaft the circular outer ring of a clutch release bearing (52) surrounding said rotor (57). One side plate (15). (60) of said vane chamber case (59) is allowed to Furthermore, one end of the circular inner ring slide fluid-tightly on the step portion (61) of the of the clutch release bearing (15) is fixed to a ring- 30 brake drum (53). Other side plate (62) is allowed to shaped clutch piston (16) axially displaceable in a slide fluid-tightly on a cylindrical member (64) fixed cylinder (5a) of said backing plate (5) so that said unitedly to an extended end (63a) at which an inner pressure plate (14) is pushed by working siad sun gear (63) circumscribing said planetary gears piston (16) and by allowing said clutch plate (26) to (55) and being rotatable around the drive shaft be held insertedly between the circular side plate 35 (52) is provided extendedly on the opposite side to (12) of the brake drum (11) and the pressure plate the brake drum (53). Moyeover, in the vane cham- (14), the rotation of the drive shaft (2) is transmitted ber (58) of this other side plate (62), a plurality of to the rotor vanes (1 0) of the retarder through said stator vanes (65) are provided radially making the clutch plate (26) and cylindrical member (25). dirve shaft (52) as a center so that they face Moreover, inside the outer circumferential plate 40 opposedly to a plurality of rotor vanes (56) afore- (13) of said brake drum (11), two semicircular mentioned. brake shoes (18) laminated with a brake lining (17) Further, a clutch plate (66) is provided unitedly are provided, said brake shoes (18) are allowed to with said sylindrical member (64) to allow the be pressed against the outer circumferential plate clutch plate (66) to face opposedly to a clutch (13) to construct a duo-servo type drum brake(B) 45 cover (67) formed unitedly inside the side plate for stopping the rotation of the brake drum (11), (62) of said vane chamber case (59). On the op- and a support shaft (21) of a parking lever (20) posite side to the clutch cover (67) of the clutch having a brake cam (19) to expand the brake shoes plate (66), a disk-like pressure plate (68) is pro- (18) outwardly is pivotally supported by the back- vided as facing opposedly. And, by pushing the ing plate (5). so pressure plate (68) and by holding the clutch plate With the hydraulic retarder attached with the (66) insertedly between said plate (68) and clutch parking brake as above, when decelerating the cover 967), the movement of turning on the clutch motor car, clutch is turned on by working the clutch is realized, and thus, a ring-shaped clutch piston piston (16), the rotation of the drive shaft (2) is (70) playing a role of switch of the retarder which transmitted to the rotor vanes (10) of the retarder 55 transmits the rotation of drive shaft (52) to the rotor and, by the self-pumping action of the rotor vanes vanes (56) of the retarder is inserted in a cylinder (10) or by supplying the cooling oil into the vane (71a) of a backing plate (71) fixed to the vane chamber (3), the rotation of rotor vanes (10), that is, camber case (59). 0 287 099

Furthermore, to the inside of an outer circum- said member(s) (5); (59), (75), a rotor (9); (57) ferential plate (72) provided by extending the outer which is opposite to said stator vanes (8); (65) and circumference of the circular side plate (54) of said which has a plurality of rotor vanes (10); (56), said brake drum (53) toward the transmission case, one member(s) (5); (59), (75) which has (have) a sup- of the butted portions of two semicircular brake 5 plying port (6); (78) to introduce the cooling liquid shoes (73) is connected through a link and, be- to a space between opposed faces of said stator tween the other butted portion of them, a brake vanes (8); (65) and said rotor vanes (10); (56) and a cam (74) is provided for actuating a duo-servo type discharging port (7); (79) to discharge the cooling drum brake (B). And a support shaft (77) transmit- liquid, a clutch piston (16); (70) which is fitted and ting the rotation force due to the operation of the w insertedly to said member(s) (5); (59), (75), parking lever (76) to said brake cam (74) is pivot- clutch mechanisms (26), (25a), (25), (24); (66), (64), ally supported by a support plate (75) formed un- (63a), (63), (55) to transmit the rotation of said drive itedly with the transmission case (51). shaft or propeller shaft (2); (52) to said rotor (9); At a lower portion of the vane chamber (58) of (57) by working of said clutch piston (16); (70). such fluid type retarder attached with the parking 15 (2) The hydraulic retarder attached with parking brake, a supplying port (78) of the cooling oil is brake according to Claim 1, wherein said clutch provided and, at an upper portion, a discharging mechanisms comprise a cylindrical member (25) in port (79) of the cooling oil is provided. When the a spline engagement (24) between it and siad rotor retarder was worked by working the clutch piston (9) and a clutch plate (26) supported by a flange (70) and turning on the clutch after allowing the 20 (25a) at an end of this cylindrical member. drive shaft (52) to rotate and supplying the cooling (3) The hydraulic retarder attached with parking oil, and then the clutch was turned off, the drag brake according to Claim 2, wherein said clutch torque was not generated to the drive shaft (52) at mechanisms work by being held between a pres- all. Further, these controls can also serve as a sure plate (14) against which said clutch plate (26) control lever for the exhaustion brake and can be 25 is pressed by said clutch piston through a clutch- conducted easily only by on-off of the clutch. release bearing (15) and a side plate (12) of said Therefore, the control of the level of oil surface etc. brake drum (11) whereby transmit the rotation of being expensive are unnecessary. said drive shaft or said propeller shaft (2) to said As described, in accordance with the invention, rotor (9). since the fluid type retarder and tye parking brake 30 (4) The hydraulic retarder attached with parking are united, lightening in weight and making com- brake according to Cliam 1, wherein said clutch pact are realized and the decrease in cost is mechanisms comprise a plurality of palnetary aimed. Further, according to the invention, the hy- gears (55) supported with said brake drum, an draulic retarder with simple and sure controlling inner side sun gear (63) circumscribing these plan- device can be realized and, in addition, the main- 35 etary gears and rotating greely around said drive tenances such as the exchanges of clutch facings shaft or propeller shaft (52) and a clutch plate (66) and brake linings etc. are easy and the perfor- united with cylindrical member (64) fixed to an mance of hydraulic retarder is improved. For these extended end (63a) of this inner sun gear (63), and reasons and others, the invention exerts a remark- said rotor (57) is constructed as an outer sun gear able effect industrially. 40 inscribing said planetary gears (55). (5) The hydraulic retarder attached with parking brake according to Claim 1, wherein said fixed Claims member (1) is a transmission case through which said drive shaft (2) passes, said member (5) is a (1) A hydraulic retarder attached with parking 45 backing plate fixed to said transmission case (1), a brake is the fluid type retarder assembled in the vane chamber (3) is which said rotor (9) is accom- transmission or the driving device of rear wheels modated is formed between this backing plate (5) and used for the deceleration of vehicles, char- and siad transmission case (1), and, with said acterized by comprising a brake drum (11); (53) backing plate (5), a parking lever for wirking said which rotates unitedly with drive shaft or propeller so drum brake (B) is pivotally supported and said shaft (2); (52) rotatable relative to a fixed member clutch piston (16) for working said clutch mecha- (1); (51) of vehicle, member(s) (5); (59), (75) which nisms (26), (25a), (25), (24) is engaged. is(are) constructed unitedly with said fixed member (6) The hydraulic retarder attached with parking (1); (51) and which has(have) a plurality of stator brake according to Claim 1, wherein said fixed vanes (8); (65), a drum brake (B) to brake said 55 member (51) is a transmission case, said members brake durm (11); (53) which is provide inside said (59), (75) comprise a support plate (75) formed brake drum (11); (53) and which works by operat- unitedly with said transmission case (51) and a ing a parking lever (20); (76) pivotally supported by vane chamber case (59) and, with this support 0 287 099 plate (75), a parking lever (76) for working said drum brake (B) is pivotally supported and, in said vane chamber case (59), a vane chamber (58) in which said rotor (57) is accommodated is formed. (7) The hydraulic retarder attached with parking 5 brake according to Claim 6, wherein, in a cylinder (71a) of a backing plate (71) fixed to said vane chamber case (59), a clutch piston (70) for working said clutch mechanisms (66), (64), (63a), (63), (55) is inserted. m (8) The hydraulic retarder attached sith parking brake according to Claim 7, wherein said clutch mechanisms work by being held between a pressure plate (68) against which said clutch plate (66) is pressed by said clutch piston (70) and a clutch 75 cover (67) formed unitedly inside a side plate (62) of said vane chamber case (59) whereby transmit the rotation of said drive shaft of propeller shaft (52) to said rotor (57). (9) The hydraulic retarder attached with parking 20 brake according to Claim 1, wherein said clutch piston (16); (70)is of a ring-shaped.

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Akebono Brake A-1 694-02

Fig. I

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Akebano Brake... A-1 694-02

Fig. 2

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Akebano Brake. A-1 694-02

Fig. 3

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