Data received from angularjs to MVC controller is null

Dears, I have two classes Master and detail named by Raterequest and Raterequestdetails. I have created a viewmodel contains both of them. in Angularjs i have an object contains rate and a list contains orderdetails. when i debug the controller the data received is null for both here is the code

Rate request class

 public class RateRequests
{
    public int RateRequestsID { get; set; }
    public DateTime RateRequestsDate { get; set; }
    public string RateRequestName { get; set; }
    public string RateRequestType { get; set; }
    public string RateRequestMode { get; set; }


}

Rate request details class

public class RateRequestsLines
{
    public int RateRequestsLinesID { get; set; }
    public int RateRequestsID { get; set; }
    [ForeignKey("RateRequestsID")]
    public virtual RateRequests RateRequestsFK { get; set; }
    public short FCLCNTRS { get; set; }
    public short FCLCNTRSSIZE { get; set; }
    public string FCLCNTRSTYPE { get; set; }

}

Rate request view model

public class RateRequestViewModel
{
    public RateRequests rate { get; set; }
    public IEnumerable<RateRequestsLines> ratelines { get; set; }
}

Angularjs

var linkers = angular.module("linkers", [])
.service("linkersSrv", function ($http) {

    var urlBase = "/LinkersEgypt/";

    this.save = function (url, ratee) {
        return $http({
            method: "POST",
            url: urlBase + "/" + url,
            data: ratee,
            ̶a̶s̶y̶n̶c̶:̶ ̶f̶a̶l̶s̶e̶,̶
        })

    };

})

.controller("linkersCon", function ($scope, linkersSrv) {

    $scope.fcl = [];

    $scope.addFCL = function () {
        $scope.fcl.push({ FCLCNTRS: $scope.ncntrs, FCLCNTRSSIZE: $scope.csize, FCLCNTRSTYPE: $scope.ctype });
        console.log($scope.fcl);
    }

    $scope.save = function () {

        var ratee = {
            rate: {
                RateRequestsDate: $scope.rdate,
                RateRequestName: $scope.rname,
                RateRequestType: $scope.rtype,
                RateRequestMode: $scope.smode
            },
            RateRequestsLines: $scope.fcl
        };

        console.log(ratee);
        var promisepost = linkersSrv.save("RateRequest/AddAllRate", ratee);
        promisepost.then(function () {
            toastr.success("Successfully saved");

        })

    }
})

Rate controller

[HttpPost]
    public JsonResult AddAllRate (RateRequestViewModel rate)
    {
        return new JsonResult();
    }

Any help Thanks in advance