Hydraulic transmission device suitable for constituting a compact hydraulic starter motor

Abstract

A hydraulic transmission device for a machine, including a declutchable hydraulic motor having radial pistons, and including a cam that is secured to a casing, and a cylinder block and an internal fluid distributor that are disposed in the casing; a hydraulic pump including a drive member; and fluid exchange couplings; in which device the casing and the distributor are mounted to rotate relative to a stationary support about an axis of rotation, whereas the cylinder block is fastened to said support. In some embodiments, the drive member of the pump is constrained to rotate with the casing of the motor, and in that a delivery orifice of the pump is connected to one of said couplings.

1 . A hydraulic transmission device for a machine, which device comprises:
 a hydraulic motor declutchable by dog clutch, having radial pistons, and including a cam that is secured to a casing, and a cylinder block and an internal fluid distributor that are disposed in the casing;   a hydraulic pump including a drive member; and   a plurality of fluid exchange couplings;   in which device the casing and the distributor are mounted to rotate relative to a stationary support about an axis of rotation, whereas the cylinder block is fastened to said support;   wherein the drive member of the pump is constrained to rotate with the casing of the motor, and in that a delivery orifice of the pump is connected to one of said fluid exchange couplings.   
     
     
         2 . A device according to  claim 1 , wherein the pump and the fluid exchange couplings are situated on the same side of the cylinder block of the motor, relative to the axis of rotation. 
     
     
         3 . A device according to  claim 1 , wherein, relative to the axis of rotation, the distributor is interposed between the exchange couplings and the cylinder block, and/or between the pump and the cylinder block. 
     
     
         4 . A device according to  claim 1 , wherein the pump is disposed at least in part inside said support. 
     
     
         5 . A device according to  claim 1 , including a drive shaft constrained to rotate with the cam and suitable for actuating the pump, which shaft passes through the inside of the cylinder block. 
     
     
         6 . A device according to  claim 1 , including a drive shaft constrained to rotate with the cam and suitable for actuating the pump, which shaft is fastened to the casing and/or is disposed at least in part inside the support. 
     
     
         7 . A device according to  claim 5 , wherein a feed passage of the pump, via which passage a fluid feeding the pump passes is formed between the drive shaft and the support. 
     
     
         8 . A device according to  claim 7 , wherein a feed duct of the pump is formed in the support and connects an internal space of the casing to said feed passage. 
     
     
         9 . A device according to  claim 8 , including a fluid supply duct making it possible to inject a feed fluid for feeding the pump into said internal space; said internal space being, in addition, connected to said feed passage via a feed duct making it possible to feed the feed passage with fluid; in which device an orifice of the feed duct in the internal space of the casing and an orifice of the supply duct in the internal space are disposed axially on either side of the cylinder block. 
     
     
         10 . A device according to  claim 1 , wherein at least an admission duct or a delivery duct of the pump and/or at least a feed duct or a discharge duct of the motor passes through the support. 
     
     
         11 . A device according to  claim 1 , wherein the support is provided with an axial bore formed along the axis of rotation of the motor, and in which the distributor is disposed. 
     
     
         12 . A device according to  claim 1 , wherein the fluid discharge of the cylinder block takes place into an internal space of the casing. 
     
     
         13 . A device according to  claim 1 , wherein the support has a portion in the form of an arm through which at least one duct passes and which extends in a direction that is substantially perpendicular to the axis of rotation. 
     
     
         14 . A device according to  claim 1 , wherein, in order to enable the casing to be coupled to a member to be driven, said casing has a flange, an external groove suitable for receiving a belt, or else a set of teeth for receiving a chain or gearing. 
     
     
         15 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 1  and said rotary drive member, the casing being constrained to rotate with said drive member. 
     
     
         16 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 1  and said rotary drive member, the casing being constrained to rotate with said drive member. 
     
     
         17 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 2  and said rotary drive member, the casing being constrained to rotate with said drive member. 
     
     
         18 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 3  and said rotary drive member, the casing being constrained to rotate with said drive member. 
     
     
         19 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 4  and said rotary drive member, the casing being constrained to rotate with said drive member. 
     
     
         20 . A starter system for a machine having a rotary drive member, in particular for an internal combustion engine, which starter system includes a device according to  claim 5  and said rotary drive member, the casing being constrained to rotate with said drive member.